"**•

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Alex. Agassiz.

^ibraru of tbe Ulusciun

OF

I COMPARATIVE ZOOLOGY,

AT HARVARD COlLEliE, CAMBRIDGE, JIASS.
JFoimtirti bu priBatc subsntption, in 1S61.

Deposited by ALEX. AGASSIZ.

No.

I j-^T

ir v^.

^^^

ILLUSTRATED CATALOGUE^^^^"^^ ^^^^

^M^<jLi,/

MUSEUM OF COMPARATIVE ZOOLOGY,

AT HARVARD COLLEGE.

Published by order of the Legislature of Massachtisetts.

No. 11.

NOETH AMERICAN ACALEPHtE.

ALEXANDER AGASSIZ.

CAMBRIDGE:

FOR SALE BY SEVER AND FRANCIS.

1865.

ILLUSTRATED CATALOGUE

MUSEUM OF COMPAKATIVE ZOOLOGY,

AT HARVARD COLLEGE.

Published by order of the Legislature of Massachusetts.

No. II.

NORTH AMERICAN ACALEPHJE,

ALEXANDER AGASSIZ.

CAMBRIDGE:
FOR SALE BY SEVER AND FRANCIS.

1865.

University Press : Welch, Bigelow, & Co.,
Cambridge.

THE publication of the Illustrated Catalogue of the Museum of
Comjjarative Zoology has been undertaken with a threefold
object. In the first place, like the catalogues of most institutions of
a similar character, it is intended to make the contents of our Museum
generally known, and to flicilitate our exchanges. In the second place,
to be the medium of publication of the novelties received at the
Museum, which require to be described and illustrated by diagrams
or wood-cuts, or more elaborate plates. Finally, it is hoped that it
may be the basis of a systematic revision of such natural groups of
the animal kmgdom as are most fully represented in our collections,
and that it may, as far as possil^le, present to the scientific world
the results of the investigations carried on in the Museum with a
view of ascertaining the natural limits of the Faunte at the present
time and in past ages, and the genetic relations which may exist
between the order of succession of organized beings upon the earth,
their mode of growth, and their metamorphoses during their embry-
onic life, and the plan and compUcation of their structure in their
adult condition.

The means for publishing this work have been most liberally granted
by the Legislature, at a time when, in a less enlightened assembly,
the material cares of the community would have engaged their
exclusive attention.

L. AGASSIZ.

Cambridge, March 28, 1865.

PREFACE.

THE progress of our knowledge of the Class of Aeale2:»hs is at
present so closely linked with every new observation which may
be brought up in the history of the development of these animals,
that it has been thought advisable to extend this Catalogue some-
what, and not make it simply an enumeration of the Acalephs in the
collection of the Museum of Comparative Zoology at Cambridge. It
has, however, been limited to the North American species ; and even
many of the Sertularians, Campanularians, and Tubularians in the col-
lection are not described or mentioned here, because our information
with regard to them is too scanty to be available. The mere enu-
meration, with short descriptions, of Hydroids, the development of
which has not been fully traced, would probably only add, in the
course of a few years, synonymes to some of the Medusie, the adult
stages of which may be well known, and would not advance in the
least degree our acquaintance with the North American Acalephs.
To make this Catalogue useful to American students, a few species
described by other authors, of which there are no sjsecimens in the
Museum collection, are added, to facilitate further investigations. This
is done with the less hesitation, as it is hoped that in a short time
most of the species thus enumerated will have been figured in the
diagrams of the Museum.

In the descriptions of the species, constant reference has been made
to the bearing of the facts discussed, on the classification of Acalephs,
and consequently much has been introduced which would be out of
place in a descriptive catalogue. The wood-cuts, with the exception
of a few borrowed from the Contributions to the Natural History of
the United States by Professor Agassiz, have all been drawn on wood
from nature by myself, and, though not highly finished, will yet
generally give a better idea of the Acalephs, in this simple outline,
than could have been done by a more finished wood-cut. Such an
elaborate catalogue of Acalephs may seem somewhat out of place

vi PREFACE.

here, but as special attention has been paid to them in the Museum
at Cambridge, and as Professor Agassiz has introduced there a large
number of diagrams, all copied from original drawings, to illustrate
the structure and colors of animals which were too small or too
perishable to be preserved in the ordinary way, these valuable mate-
rials have been extensively used in the prepai'ation of this Catalogue,
as forming actually a jiart of the collections exhibited in the show-
cases. The diagrams, as well as the authorities from which they are
taken, are carefully enumerated below, after the specimens preserved
in the collection.

For the facilities I have enjoyed' in collecting the materials for this
Catalogue I am mainly indebted to Mr. and Mrs. J. M. Forbes, to Pro-
fessor A. D. Bache, Superintendent of the Coast Survey, to Mr. T. G.
Gary, and to Professor Agassiz. I have also to thank, for specimens and
valuable information. Professor Joseph Leidy, Dr. Fritz MUller of De-
sterro. Dr. W. Stimpson, and Professor H. J. Clark, who had already
arranged the greater part of the Hydroids before the collection of Aca-
lephs was placed in my charge. The Museum is also indebted for
specimens to many other persons, whose names will be referred to in

connection with the different species.

A. AGASSIZ.

Cambkidge, Mass., February, 1865.

CONTENTS.

PAGE

List of the Wood-cuts viii

Bibliography 3

Ctenophor^ 7

DiscoPHOR^ 40

HTDROIDiE 64

Geographical Distribution 221

Systematic Table of the Orders and Families 227

Index of Genera and Species 229

Zf

LIST OF THE WOOD-CUTS.

[Note. — Unless otherwise credited, the Figures are drawn from nature by Alex. Agassiz.]

Fig. 1

U

2

U

3

'<■

4

a

5

11

6

u

7

a

8

i.

9

u

10

il

11

a

12

it

13

((

14

t(

15

"

16

^'

17

((

18.

t(

19

"

20

((

21

'■

22

41

23

''

24

((

25

(4

26

il

27

11

28

U

29

u

30

u

31

"

32

u

33

((

34

u

35

4i

36

'■

37

u

38

u

39

a

40

(1

41

open

Young BoLiNA ALATA, Seen from the nan'ow side ....

Bolina in state of Fig. 1, seen from the broad side ....

Somewhat younger than Fig. 1, seen from the abactinal pole

Young Bolina, seen from the abactinal pole, older than previous figures

Formation of lateral tubes in young Bolina .....

Bolina in which lobes begin to appear, seen from the narrow .side, same state as Fig. 4

Somewhat more advanced than Fig. 0, seen from the actinal side

The tentacular ambulacra have united, and the lobes project well beyond the

ing of the mouth . . . . . . . . .

About in the condition of Fig. 1, seen from the broad side ., .

Somewhat younger than Fig. 8, seen from the broad side .

Fig. 8, seen from the broad side ........

Bolina showing first appearance of the auricles, seen from the broad side
Bolina in stage of Fig. 12, seen from the narrow side ....

Fig. 13, seen from the actinal pole . . . ' .

Adult Bolina, seen from the bi'oad side. (L. Agassiz.) ....

Fig. 15, seen from the narrow side. (L. Agassiz.) ....

Bolina, seen from the actinal pole. (L. Agassiz.) .....

Bolina, seen from the abactinal pole. (L. Agassiz.) ....

BoLix.\ viTREA, seen from the broad side. (L. Agassiz.) .

Mnemiopsis Gardeni, seen from the broad side. (L. Agassiz.)

Fig. 20, seen from the actinal pole. (L. Agassiz.) ....

Mnemiop.sis Leidyi, seen from the broad side

Same as Fig. 22, seen from the narrow side ......

A part of the tentacular apparatus near the opening of the actinostomo
Lesueuria hyboi'TERA, seen from the broad side ....

Fig. 25, seen from the naiTow side ......

The same, seen from the abactinal pole .....

Seen from the actinal pole ........

Adult Mertensia ovum, seen from the broad side

Young Mertensia, seen from the broad side ....

Fig. 30, seen from the abactinal pole

Somewhat more advanced Mertensia, seen from the narrow side

Same as Fig. 32, seen from the actinal pole ....

Still more advanced Mertensia, seen from the narrow side .

Fig. 34, seen from the actinal pole .....

Still further advanced Mertensia, seen from the broad side

Young Mertensia, about in the same condition as that of the precedinj

from the narrow side

Young Pleurobrachia rhodod.\ctyla, seen from the broad side
Same as Fig. 38, seen from the narrow side ...
Same as Fig. 38, sei'U from below ......

Somewliat more advanced, seen from the broad side .

figure,

PAGE

15
16
16
16
16
16
16

17
17
17
17
17
17
18
18
18
18
18
19
20
20
21
21
22
24
24
25
25
27
27
27
28
28
28
28
29

29
30
30
30
30

LIST OF THE WOOD-CUTS. ix

Fig. 42. Fig. 43, seen from above 30

" 43. Fig. 42, seen from the broad side 30

" 44. Pleurobraeliia, inimediati-lv before tlic escape from the egg ..... 31

" 45. Fig. 44, somewhat less magiiilied, to show the relative size of the egg-case and the

embryo . 31

" 46. Fig. 44, seen from the actinal pule .......... 32

" 47. Pleurobrachia swimming freelv about, seen from the broad side .... 32

" 48. Somewhat less advanced than Fig. 47, showing the lateral tubes from the narrow

side, as a prolongation of the ambulacral cavity 33

" 49. Pleurobrachia about in state of Fig. 47, seen from the actinal pole . . . .33

" 50. Adult Pleurobrachia, natural size, from broad and narrow side .... 33

" 51. Adult Pleurobrachia in a natural attitude, natural size ...... 33

" 52. Young Idyia roseola, seen from the narrow side ...... 36

" 53. Fig. 52, seen from the abaetinal pole ......... 36

" 54. Young Idyia, with distinct ambulacral tubes, seen from the narrow side . . 36

" 55. Fig. 54, seen from the abaetinal pole 37

" 56. Somewhat more advanced than Fig. 54, seen from the broad side . . . 37

" 57. The long chyraiferous tubes extend to the level of the actinostome . . . .37

" 58. The long chymiferous tubes have united with the lateral tubes ; first trace of the

ramifications of the long tubes . . . . . . . . .37

" 59. The short ambulacra have nearly united with the circular tube . . . . 37

" 60. The circuit is now complete between the short and long ambulacra ; the spurs or

ramifications of the chymiferous tubes are numerous, resembling somewhat

those of the adult 37

" 61. Fig. 57, seen from the abaetinal pole ......... 38

" 62. Adult Idyia, reduced in size one half (L. Agassiz.) 38

" 63. Idyopsis Clarkii, seen from the broad side. (L. Agassiz.) 39

" 64. Fig. 63, seen from the abaetinal pole. (L. Agassiz.) 39

" 65. Profile view of Aurei.ia flavidula, much reduced. (L. Agassiz.) . . .42

" 66. Abaetinal view of Aurelia flavidula. (L. Agassiz.) 42

" G7. Cyaxea arctica, very much reduced. (L. Agassiz.) 45

" 68. Pelagia cyanella. (L. Agassiz.) 47

" 69. Dactylometra quixquecirra, reduced about one fourth 48

" 70. Profile view of Campaxella p.^ciiyderma 53

" 71. Actinal view of Fig. 70 53

" 72. A somewhat more magnified view of Fig. 71 ....... 53

" 73. View of part of the actinal surface 53

" 74. Magnified profile view of portion of the base of a tentacle 53

" 75. View of basal portion of tentacle, seen from above 53

" 76. Profile view of Trachyxema camtsciiaticum 56

" 77. One of the genital organs . ........... 56

" 78. Section of Trachynema 56

" 79. Chymiferous cavity at the end of the gelatinous proboscis 56

" 80. View of Trachynema from above 56

" 81. Adult female Trachyxema digitale, seen in profile 57

" 82. Actinal view of the veil and circular tube of a very young Trachynema . . 57

" 83. Profile view of a part of the circular tube 57

" 84. Profile view of a young Trachynema, about one eighth of an inch in height . 58

" 85. Somewhat more advanced than Fig. 84 58

" 86. Young Trachynema, measuring over one third of an inch in height ... 59

" 87. ? Liriope scutigera. (L. Agassiz.) GO

" 88. IIaliclystus auricula, seen from the actinal pole 63

" 89. Different attitudes of Haliclystus auricula, attached to eel-grass . . . .63

" 90. Young IIaliclystus auricula, magnified 63

" 91. TiAROPSis DiADEMAT,\, natural size. (L. Agassiz.) 69

" 92. Young Tiaropsis, having twenty-four tentacles 69

" 93. Young Tiaropsis, having forty tentacles. (L. Agassiz.) ...... 69

" 94. Two marginal tentacles of Oceania laxguida, with a portion of the circular tube 70

" 95. Magnified view of the actinostome . . . . . . . . . .71

LIST OF THE WOOD-CUTS.

Fis. 96.

ii

97.

'^

98.

((

99.

((

100.

u

101.

u

10-2.

((

103.

11

104.

"

105.

((

lOG.

ti

107.

((

107«

it

108.

ii

109.

(I

110.

(I

111.

tt

112.

((

113.

((

114.

ti

115.

It

116.

ii

117.

11

118.

((

119.

((

120.

11

121.

ll

122.

1(

123.

11

124.

11

125.

11

126.

11

127.

11

128.

11

129.

11

130.

11

131.

11

132.

11

133.

11

134.

11

135.

11

136.

"

137.

"

138.

11

139.

11

140.

11

141.

11

142.

11

143.

11

144.

11

145.

11

146.

11

147.

11

148.

11

149.

11

150.

Young Medusa of Oceania languida, immediately after escaping from the re-
productive calycle ...........

Tlie same, seen from the actinal pole .........

Somewhat more advanced Medusa ..........

Quarter of the disk of a still more advanced Oceania

Adult Oceania languida, natural size .........

Magnified view of an ovary ..........

Peculiar attitude sometimes assumed by the Medusae

One of the four lips of the actinostome of Ockania gregahia

EUCHEILOTA VENTRICULARIS

More magnified view of a quarter of the disk .......

EUCHEILOTA DUODECIMALI8

Junction of one of the chymiferous tubes with the circular tube

Female Medusa of Eucheilota duodecimalis ........

Clytia bicophora, immediately after its escape from the reproductive calycle
A somewhat older ISIedusa ...........

An adult Medusa, measuring a quarter of an inch ......

Sterile Hydra and reproductive calycle, seen from the broad side . . . .

Reproductive calycle of Platypyxis cylindrica, seen from the broad side .
The same, seen from the narrow side .........

Sterile Hydra of Platypyxis cylindrica. (L. Agassiz.)

A EucoPE diapiiana, seen in profile, just after its escape from the reproductive

calycle

Quarter of the disk of the same, seen from above

A more advanced Eucope, with the second set of tentacles

An adult Eucope, seen in profile ........

Quarter of Fig. 118, more magnified .......

Magnified view of the circular tube of a young Eucope ....

Spermaries of Eucope .........

Female genital organs ..........

Proboscis of an adult jMcdusa . . . . ' .

Hydrarium of Eucope diaphana, natural size ......

^Magnified view of a sterile Hydra and reproductive calycle
Magnified view of part of main stem of Eucope polygena .

Eucope pyriformis, seen in profile

Quarternlisk of same Medusa .........

Portion of a Hydrarium of Fig. 127 .......

Quarter-disk of Eucope articulata

Portion of a Hydrarium of Eucope articulata .....

Hydrarium of Eucope fusiformis

Quarter-disk of the ISIedusa of Fig. 132

Portion of stem of Hydrarium of Obelia commissuralis .
Quarter-disk of the Medusa of Fig. 134 ......

Profile view, natural size, of Riiegm.^todes tenuis ....

Quarter-disk of Fig. 136, seen from the actinal side ....

Magnified portion of the circular canal .......

RnEGM.4.T0DES FLORIDANUS, natural size. (L. Agassiz.)
Actinostome of Stomobrachium tentaculatum, magnified
Stomobrachium tentaculatum, seen from the abactinal pole, natural size
Same as Fig. 141, seen in profile .....

Portion of the disk of Halopsis ocellata, seen from the
what reduced .......

Cavity from which the chymiferous tubes radiate

Profile, natural size, of Halopsis ocellata

Magnified part of circular tube ......

Magnified view of one of the eyes . • . . .
Young Halopsis ocellata, natural size .....

Young Haloiisis ocellata, one fifth of an inch in height .
Magnified portion of circular tube of Fig. 149 .

abactinal pole,

72

72
72

72
73
73
73
74
74
75
75
76
76
78
78
78
79
80
80
80

83
83
83
84
84
84
84
84
86
85
85
87
88
88
88
89
89
90
90
91
92
95
96
96
97
98
98
99

100
100
1 00
101
101

lui
nil

101

LIST OF THE WOOD-CUTS.

XI

;. 151.
152.
153.
154.
155.
156.
157.
158.
159.
159'.
160.
161.
162.
163.
164.
165.
166.
167.
168.
169.
170.
171.
172.
173.
174.
175.
176.
177.
178.
179.
180.
181.
182.
183.
184.
185.
186.
187.
188.
189.
190.
191.
192.
193.
194.
195.
196.
197.
198.
199.
200.
201.
202.
203.
204.
205.
206.
207.
208.

Pi-ofilo view, somcwliat magnified, of IIalopsis cuuciata .
Natural attitude of tliG same JItidusa (Fig. 151)
Abactinal view of ZY(ioDACTYLA gkoexlandica

Profile view of Fig. 153, lialf natural size

Portion of the circular tube

Young Zygodactyla, greatly magnified

Profile view of Zygodactyla crassa, somewhat reduced in size
Quarter-disk of Zygodactyla crassa ......

Portion of the disk of Zygodactyla cyanea, from the abactinal

Crem.\tosto.ma flav.\, in profile

Portion of the disk of ^Equorea albida, from the abactinal pole

A natural attitude of yEtjuorea albida

Magnified view of the marginal tube

EiRENE CCERULEA. (L. Agassiz.)

TiMA FORMOSA, half natural size

Quarter of the disk, from the abactinal pole, natural size
Digestive cavity and actinostome ......

Portion of the ovary

Magnified portion of the circular tube .....
Young Tima formosa, natural size .......

Digestive cavity of Fig. 169

Young Planulie of Tima ........

Single Hydra of the tuft of a Tima Hydrarium, greatly magnified
Profile of EuTiMA limi-ida, reduced iu size ....

Quarter-disk of Fig. 1 73

IMagnified view of proboscis and genital organs ....
Magnified portion of a part of the circular canal

Magnified marginal capsule .

Magnified view of the rudimentary tentacles ....
Profile view, somewhat magnified, of Polyorchis penioillata

0\-arics of one of the chymiferous tubes

Section of bell ..........

Part of disk of Fig. 1 79, seen from the abactinal pole
Two of the marginal tentacles in a contracted state

Adult Medusa of Lafcea calcarata

One of the ovaries and the actinostome

Actinostome, actinal view

Magnified view of a portion of the circular tube ....
Actinostome and rudimentary ovaries, seen in profile

Different attitude of ]\Icdusa of Fig. 184

Hydrarium of Lafoea calcarata. ......

Keproductive calycle .........

Medusa immediately after its escape from the reproductive calycle
Medusa somewhat more advanced, from tlie abactinal pole .
Young Medusa still further advanced than Fig. 193 .

Laodicea cellularia

One of the lips of the actinostome

G0N10NEMU.S vertexs, attached by its tentacles

The same in motion, natural size

Base of a contracted tentacle

A portion of the genital organs ......

One of the chymiferous tubes and half the digestive cavity .

Profile of Melicertum campanula, natural size .

Profile view of a very young Melicertum campanula .

Half the disk of the same, seen from the actinal pole

Young Melicertum, having only four completely Ibrnied chj-miferous

Same, seen from the abactinal pole ......

Magnified view of the two chymiferous tubes and genital glands
Mode of carrying the lips of actinostome

pole

(L.

As:

tubes

102
102
104
104
104
105
106
107
107
109
110

no
111

112
113
113
113
114
114
114
114
115
115
116
116
117
117
117
117
119
119
120
120
120
122
123
123
123
123
124
124
125
125
125
126
127
127
129
129
130
130
130
131
132
132
132
133
133
133

xii LIST OF THE WOOD-CUTS.

Magnified view of marginal tentacles . . . . . . . • .133

Spherical embryo ............ 134

The same, somewhat more advanced ......... 134

The same before it becomes attached ........ 134

Group of embryos attached, in difl'erent stages of development . . . .134

Different stages of growth beyond those of Fig. 213. . . . . . 134

Profile of Mklicertum GEORGICUM, natural size 135

Digestive cavity and point of junction of the chymiferous tubes . . . 135

Staurophora laciniata, having eight tentacles ...... 13G

Quarter of the disk of a young Staurophora, with sixteen large tentacles . 136

Young Medusa somewhat more advanced than Fig. 216' . . . . .136

Different stages of actinostome intermediate between that of Figs. 215* and 219 136
Young Staurophora, having the aspect of the adult . . . . . .137

Profile view of Ptychogena LACTEA, somewhat reduced .... 138

Magnified view of tlie genital organs, seen from the abactinal pole . . .138
Same as Fig. 221, seen in profile ......... 138

Actinostome .............. 138

Magnified base of tentacles and club-shaped appendages . . . . . 138

Cluster of Dyxamexa pumila. (L. Agassiz.) 141

Magnified portion of stem of Fig. 225. (L. Agassiz.) ..... 141

Young Nemopsis B.\CHEi, with four tentacles 149

Somewhat more advanced Nemopsis . ........ 150

Magnified view of the sensitive bulb 150

Nemopsis in whicli the genital organs extend a considerable distance along the

chymiferous tubes . . . . . . . . . . .150

Magnified view of the genital organs, the actinostome, and the oral tentacles . 151

Magnified profile view of adult BouGAiNViLLiA SCPERCILI.\R1S . . . .153

Ilydromedusarium of Bougainvillia 154

Young elongated Medusa . . . . . . . . . . .154

Somewhat more advanced than Fig. 234 . ... . . . . . 154

Appearance a short time before sejjarating from the stem . . . . .154

Same as Fig. 236, expanded .......... 154

Young Bougainvillia, iuunediately after its liberation from the Ilydromedusarium 154
Magnified view of sensitive bulb ......... 155

Tentacular bulb, with young tentacles . . . . . . . . .155

Adult M.\RGELis CAROLiNENSis, Seen in profile, magnified . . . . 156

Digestive cavity, genital pouches, oral tentacles, and actinostome . . . .156

Sensitive bulb at base of one of the chymiferous tubes ..... 156

Young Margclis, liaving only two mai-ginal tentacles at the base of each chymif-
erous tube . . . . . . . . . . . . 157

Young Margelis, seen from the abactinal pole, in condition of Fig. 244 . . . 157
Proboscis of a Margelis, having already six tentacles at each sensitive bulb . 158

Ilydrarium, greatly reduced in size ......... 158

Magnified heads and Medusas buds of Margelis carolinensis . . . . 158

Female Medusse buds of Eudendrium dispar, in different stages of development 159
Part of a male colony of EUDENDKIUM TENUE, magnified .... 160

Adult male of LizziA grat.\, seen in profile, magnified
Quarter-disk of a young Lizzia .....

Magnified view of sensitive bulb .....

Proboscis of male Lizzia, magnified .....

One of the four lobes of the actinostome, seen from above

Actinal view of proboscis of young Lizzia

Actinal view of proboscis of an older specimen

Abactinal view of Fig. 257, somewliat less magnified

Adult Dysmorpiiosa fulgurans, magnified

Magnified proboscis, showing young INIedusa; of the second and third generations 163

TuRRis VESICAUIA, natural size, seen in profile IGj

The same, with the bell contracted 1''"^

A portion of the disk, seen from the abactinal pole 165

Fig

209.

(I

210.

U

211.

u

212.

u

213.

tl

214.

li

215.

il,

216.

((

215'.

(t

216'.

li

217.

u

218.

u

219.

ti

220.

((

221.

((

222.

ti

223.

((

224.

(1

225.

((

226.

(i

227.

u

228.

((

229.

ti

230.

a

231.

a

232.

u

233.

it

234.

u

235.

a

236.

((

237.

11

238.

ii.

239.

a

240.

i(

241.

(I

242.

u

243.

n

244.

u

245.

n

246.

"

247.

((

248.

u

249.

a

250.

ti

251.

((

252.

u

253.

u

254.

u

255.

u

256.

(I

257.

u

258.

u

259.

u

260.

((

261.

4(

262.

((

263.

161
161
161
162
162
162
162
162
163

LIST OF THE WOOD-CUTS.

XlU

Fig

264.

(t

265.

c(

266.

t(

267.

tl

268.

li

269.

((

270.

((

271.

tl

272.

t(

273.

a

274.

((

274"

u

27.5.

((

276.

IL

277.

((

278.

u

279.

it

280.

u

281.

(1

282.

<c

283.

<t

284.

((

285.

<(

286.

t(

287.

ti

288.

11

289.

it

290.

a

291.

ti

292.

a

293.

((

294.

((

295.

li

296.

a

297.

a

298.

(t

299.

((

300.

(I

301.

((

302.

11

303.

a

304.

IL

305.

((

306.

ii

307.

a

308.

tt

309.

a

310.

a

311.

a

312.

a

313.

ii

314.

It

315.

11

316.

li

317.

11

318.

Magnified profile view of genital organs and actinostome 165

Ma;;ni(ied view of a part of a (Jiymiferous tube 166

Base of one of the ehymiferous tubes, and part of the circular tube . . .166

One of the tentacles, in a profile view 166

One of the tentacles, seen from the abactinal pole 166

Young TuRRiTOPSis NUTRicuLA, with four marginal tentacles . . . 167

Somewhat more advanced, having sixteen tentacles 167

Stomotoc.\ atr.4, somewhat magnified, seen in profile ..... 169

Magnified view of genital organs 169

Stomotoca atra 169

Clava leptostyla. (L. Agassiz.) 170

Young AVillia orxata, having only the second set of tentacles developed . 1 71

Young Willia, nearly in the stage of Fig. 270, seen from the abactinal pole . .171
Profile view of a young Willia . ......... 172

Part of the circular tube 172

View of ovary of Fig. 276 .......... 172

Same as Fig. 278, seen from the abactinal pole 172

Proboscidactyla flavicirrata 173

Actinostome and digestive cavity . . . . . . . . . .173

Portion of disk to show mode of branching of chymiferous tubes, and tubes con-
taining lasso-cells, as in Willia 174

Adult CoRYXE mirabilis, seen in profile. (L. Agassiz.) . . . . 175

Coryne, with proboscis contracted. (L. Agassiz.) 1 75

Coryne, with expanded proboscis. (L. Agassiz.) 175

Cluster of Hydraria of Coryne mirabilis. (L. Agassiz.) 170

Young Hj'drarium of Coryne. (L. Agassiz.) ....... 170

Magnified view of head, with Medusae buds attached. (L. Agassiz.) . . .176

CouYNE ROSARIA, natural size 177

Ilydromedusarium of Syndictyon reticulatum, greatly magnified . . .178
Syndictyon reticulatum, immediately after it has become freed from the Ilydro-
medusarium, in profile . . . . - • . • • .178

One of the tentacles of Fig. 291, magnified 178

Sensitive bulb of Fig. 291 178

Digestive cavity of Fig. 291 .......... 178

Fig. 291, from actinal pole . . . . . . . . . . .178

Fig. 291, from abactinal pole 179

Part of net-work of lasso-cells of surface of sphcrosome 179

Adult Medusa in a natural attitude 180

Same Medusa (Fig. 298) with the tentacles contracted 180

Actinostome of adult Medusa .......... 180

Young DiPURENA CONICA 181

Digestive cavity of a young Dipurena conica . . . . . . . 181

Tentacle of Dipurena conica .......... 182

Digestive cavity of a Medusa in which the constriction has already separated the

upper and lower halves . . . . . . . . . .182

Adult Dipurena conica, in which the two digestive cavities are widely separated 182

Profile view of half a young Gemmaria gemmo-sa 184

Profile view of Gemmaria cladopiiora, magnified 184

Quarter-disk of same, seen from the abactinal pole . . . . . .185

Actinostome of Gemmaria, enlarged . . . . . . . . 185

Cluster of lasso-cells of the marginal tentacles . . . . . . .185

Fertile Hydra of Pennaria tiarella 187

Medusa distended by eggs . . . . . • . . . . .187

Profile view of Medusa of Pennaria tiarella 187

Different attitude of the Medusa, seen from the actinal pole 188

Fig. 313, seen from the abactinal pole ........ 188

EupiiYSA viRGL'LATA, seen in profile . ........ 190

Magnified proboscis of Fig. 316 190

Actinal view of Euphysa virgulata 190

BIBLIOGRAPHY.

No memoirs published previous to 18 GO bave been included in this list, as they oan
be found in Agassiz's Bibliogruphia Zoologia et Geologiae, and in Carcs and Engel-
maxn's Bibliotheca Zooluyica.

Agassiz, a. The Acalcphian Fauna of the Southern Coast of Massachusetts, Buzzard's Bay ; in

Proc. Best. Soc. Nat. Hist., VIII. p. 224. 1861.
— " " Mode of Development of the Marginal Tentacles of the Free Medusaj of some Hy-

droids; iu Proc. Bost. Soc. Nat. Hist., IX. p. 81. 1802.
_ " " Nanomia eara ; in Proc. Bost. Soc. Nat. IIi.st., IX. p. 181. 1863.

Ilalopsis ocellata; in Proc. Bost. Soc. Nat. IIi.st., IX. p. 219. 1863.
__ Ag.^ssiz, L. Contributions to the Natural History of the United States (Acalephae). Vols. IU.
and IV. Boston. 1S60-18G2.
^ " " Methods of Study in Natural History. Boston. 1SC3.

Alder, J. Supplement to a Catalogue of Zoophytes of Northumberland and Durham ; in Trans.
Tyneside Nat. Chd), V. p. 22.5.
" " Description of some New an<l Rare Zoophytes found on the Coast of Northumberland ;

in Ann. & Mag. N. II., IX. p. 311. 1862.
" " Observations on British Zoophytes; in Edinb. New Phil. Journ., p. 144. 1862.
" " Descriptions of a Zoophyte and two Sjiecies of Echinodermata new to Britain ; in
Ann. & Mag. N. II., V. p. 73. 1860.
Allmax, J. G. On Laomedea tenuis; in Rep. Br. Ass. Adv. Sc. for 18,")9, p. 143. Trans. Sec.
On the Generative Zooid of Clavatella ; in Br. Ass. Adv. Sc. for 1862, p. 100.
" " Note on the Structure and Terminology of the Reproductive System in the

Corynida; and Sertularidaj ; in Ann. & ^lag. N. II., VI. p. I. 1860.
" " On the Reproductive System in the Ilydroidea; in Rep. Br. Ass. Adv. Sc. 1863.

London. 1864. p. 351.
" " Note on Carduella cyathiformis ; in Ann. & JIag. N. II., Yl. p. 40. 1860.

" " On the Structure of Carduella cyathiformis, a Contribution to our Knowledge of

the LucernariadiB ; in Trans. Mic. Soc, p. 12.5. London. 1860.
" " Notes on the Ilydroid Zoophytes; in Ann. & Mag. N. H., VIH. p. 168. 1861.

" " Notes on the Pliosphorescence of Beroe ; in Proc. Roy. Soc. Edinb., IV. p. 528,

Jan. 1862. Same in Edinb. New Phil. Journ., 1862, XV. p. 284.
" " Contributions to our Knowledge of the Structure and Development of the Bero-

idas ; in Proc. Roy. Soc. Edinb., IV. p. 519, Jan. 1862. Same in Edinb.
New Phd. Journ., 18C2, XV. p. 287.
" " On the Structure of Lucernariada; ; in Rep. Brit. Ass. Adv. Sc. for 1859, p. 143.

London. 1860. Trans. Sec.
" " On Dicoryne strieta, a new Genus and Species of the Tubularida; ; in Rep. Br.

Ass. Adv. Sc. for 1859, p. 142. London. 1860.
" " Notes on the Ilydroidea. I. On the Structure of Coryniorpha nutans. II. Diag-

nosis of new Species of Tubularidaa obtained, during the Autumn of 1862,
on the Coasts of Shetland and Devonshire ; in Ann. & Mag. N. II., Jan.
1863, XL p. 1.
" " Notes on the Ilydroidea ; in Ann. & Mag. N. II., July, 1864.

" " On the Structure of Corymorpha nutans j in Rep. Br. Ass. Adv. Sc. for 1862,

p. 101. Trans. Sec.

4 BIBLIOGRAPHY.

Allman, J. G. On the Construction and Limitation of Genera amonrj the Hydroidea ; in Ann.
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" " On some new British Tulmlaridie ; in Rep. Br. Ass. Adv. So. for 18G2, p. 101.

" " Kep. on the Reprod. Syst. in tlie Hydroidea ; in Rep. Br. A. A. S. f. 1863, p. 351.

" " On the Oeeurrenee of Ama?biform Protoplasm, and the Emission of Pseudopodia

among the Hydroidea; in Ann. & Mag. N. II. March, 18G4.
Beneden, J. P. VAN. On the Strobilation of the Scyphistomata ; in Ann. & Mag. N. II., 18G0,

V. p. .504. From Acad. Belg.
BoECK, CriR. Beslcrivelse over en Tubularie fra Belsund paa Spitzliergen, Tubularia regalis, in

Forhandl. Vid. Selsli. (.Var 18.J9.) Christiania. 1860. pp. 50, 6C, 151.
Bronx, II. G. Die Klassen u. Ordnungen des Thier-Reiehs (Actinozoa). Leipzig u. Heidel-
berg. 1860.
Busk, G. On a new Ilydroid Polype belonging to the Genus Cordylophora .1//., discovered by

Senator Kirchenpauer of Ritzebiittel ; in Mic. Jour., p. 283. 1861.
Clapar'ede, a. R. E. Beitriige zur Fauna der Schottischen Kiiste ; in Zeits. f. Wiss. Zool., X.
p. 401. 1860.
" " Bcobachtungen liber Anatomic u. Entwickelungsgeschichte Wirbelloser

Thiere. Leipzig. 1863.
" " in Bibliog. Univ. de Geneve, XV. p. 150. 1862.

Clark, II. J. Lucernaria, the Ca?notype of Acalepha;; in Proc. Bost. Soc. N. H., p. 47. 1862.
" " Prodromus of the History, Structure, and Physiology of the order of Lucernaria; ;

in Journ. Bost. Soc. Xat. Hist., VII. 1803.
" " Lucernaria, . . . . ; in Am. Journ. Arts and Sciences, May, 1863.

" " " . . . . ; in Ann. & Mag. N. II., XII. p. 19. 1863.

" " in Agassiz's Contrib. Nat. Hist. U. S., Vols. HI. and IV. passim.

" " Tubularia not Parthenogenous ; in Am. Journ. Arts and .Sciences. Jan. 1864.

Claus, C. Neue Beoljachtungen iiber die Structur u. Entwickelung der Siphonophorcn ; in Zeit.
- f. AViss. Zool., XII. p. 536. Jan. 1863.
" " Ueber Physophora hydrostatica, nebst Bemerkungen iiber andcre Siphonophorcn ; in
Zeit. "f. Wiss. Zool., X. p. 8. 1860.
Dawson, J. W. Zoological Classification, or Coelenterata and Protozoa rersus Radiata ; in Can.
Nat. & Geol., VII. p. 438.
" " Elementary Views of the Classification of Animals ; in Can. Nat. & Geol.,

Aug. 1864.
Edwards, H. Milne et Haime, J. Ilistoire Naturelle des Coralliaires, T. lU. Paris. 1860.
Fuller, C. B. In Journ. Portland Soc. N. H., L pp. 64, 91. 1862.

" " Report on Marine Zoology ; in Second Annual Report Nat. Hist. & Geol. of the

State of Maine, p. 129. 1863.
Gegenbaur, C. Neue Beitrage zur Naheren Kenntniss der Siphonophorcn ; in Nova Acta Acad.

Nat. Cur. 1860.
GossE, P. II. Evenings -with the Microscope. New York. 1864.
" " The Blue Cyanea ; in Intellectual Observer, Oct. 1863.

" " On the Lucernaria cyathiformis of Sars ; in Ann. & Mag. N. II., V. p. 480. 1860.

Greene, J. R. Manual of the Sub-kingdom Coelenterata. London. 1861.

" " Recent Contributions to the Literature of the Sub-kingdom Ccelenterata ; in Nat.

Ili.st. Rev., I. 18C1.
" " Review of Agassiz's Contrib. to Nat. Hist. U. S. ; in Nat. Hist. Rev. HI. 1863.

" " On Sertularia tricuspidata, and on the Genus Iluxleya ; in Ann. & Mag. N. II.,

V. p. 431. 1860.
" " A Word on Embryology, with Reference to the Mutual Relations of the Sub-

kingdoms of Animals ; in Rep. Br. Ass. Adv. Sc, p. 132. 1860. Trans. Sec.
Grube, E. Ausflug nach Triest u. dem (juarnero. Berlin. 1861.
Hi.vc'KS, Tiios. On New Australian Ilydrozoa ; in Ann. & Mag. N. IL, VH. p. 279. 1861.

" " On the Production of similar jNIedusoids by certain Ilydroid Polypes belonging to

ditl'erent Genera; in Rep. Br. Ass. Adv. Sc. f 1862, p. 107. Trans. Sec.
« " On Clavatclla, a new Genus of Corynoid Polyps, and its Reproduction ; in Ann.

& Mag. N. II., VIII. p. 73. 1861.
" " A Catalogue of Zoophytes of South Devon and South Cornwall ; in Ann. &

Mag. N. II., VIII. pp. 172, 251, 290, 360. 1861.

BIBLIOGRAPHY. 5

JIiNCKS, Tuos. Catalogue of Zoophytes of Soiitli Devon and Soutli Cornwall ; in Ann. & Ma"-.
N. 11., IX. pp. S-J, 200, 303, 4G7. 18(i2.
" " On the Production of Similar Gonozooids by Ilydroid Polyp.s belon'rin" to dif-

ferent Genera; in Ann. & Mag. N. II., X. p. 459. 18(J2.
" " Cataloj^ue of the Zoophytes of South Devon and South Cornwall ; in Ann. &

Mag. N. H., X. p. SCO. 18(32.
" " On some new British Ilydroids ; in Ann. & Mag. N. II., XI. p. 4"). 18G3.

" " On the Development of the Ilydroid Polyps, Clavatella and Stauridia, with

Remarks on the Relation between the Polyp and the Medusoid, and between
the Polyp and the Medusa; in Rep. Brit. .tVss. Adv. Science, p. 145. 1861.
Trans. Sec.
Hodge, Geo. Contributions to the ^Marine Zoology of Seaham Harbor. Occurrence of Cory-
morpha nutans at Seaham ; in Trans. Tyneside !Nat. Field Club, V. Pt. II.
p. 78. 18G1.
" " On a new Ilydroid Zoophyte (Podocoryne Alderi) ; in Ti-ans. Tyneside Xat. Field

Clul), v. Pt. II. p. 82. 1861.
HouGnTOX, W. On the Hydra rubra of Mi-. Lewes ; in Ann. & Mag. N. H., V. p. 228. 18G0.
Huxley, Thos. H. Elements of Comparative Anatomy. London. 1862.
Jager, G. LTeber das spontane Zerfallen der SUsswasserjiolypcn nebst einigen Bemerkunfcn

iiber Generationswechsel ; in Sitzb. d. Akad. Wien., XXXIX. p. 321. 1860.
JouRD.Aiix. Kote sur les organes genitaux de la Cyanea aurita Cue. : in Comptes Rendus, Vol.

LV. p. 834. 1862.

Kefersteln, W. L'ntei-suchungen ueber niedere Seethiere ; in Zeits. f TViss. Zool., XII. p. 1.

June, 18G2. I. L'eber die Gattung Luecrnaria O. F. Midler : in Zeits. f.

Wiss. Zool., Xn. p. 1. U. Ueber einige Quallen ; in Zeits. f. Wiss. Zool.,

XII. p. 26.

" " u. EiiLERS, E. Auszug aus den Untersuchungen vom Mittebneer ; in Wieg-

mann's Archiv, 1860. I. p. 324.
" " Same in Xachrieht. der Univ. u. Ges. d. Wiss. Gdttlngen, No. 23, p. 25. 1860.

KiRciiEXP.irER. Die Seetonnen der Elbmiindung. Ein Beitrag zur Thier u. Pflanzen Topo-
graphic ; in Abhandl. d. Xaturh. Vereins, IV3. Hamburg. 18G2.
Krohx, a. Beobachtungen iiber den Bau u. die Fortpflanzung der Eleutheria Quatref. ; in
Wieg. Archiv, 1861. L p. 157.
" Observations on the Structure and Reproduction of Eleutheria Quatref. ; in Ann. &

Mag. N. II., IX. p. 1. 1862.
Lac.^ze-DuThiees, H. Embryogenie des Rayonnes, Reproduction geneagenitique des Porpites ;

in Comptcs-Rendus, LV. p. 851. Nov. 1861.
" " On the Reproduction of Porpita ; in Ann. & Mag. N. H., p. 186. 1862.

Leuckart, R. Bericht ueljer die Leistungen in der Naturgeschiehte der niederen Thiere ; in

Arehiv fur Nat. 1860-1863.
Lewes, G. H. New British Species of Hydra; in Ann. & Mag. N. H., V. p. 71. 1860.
Ll'TKex, Cur. F. Forvandlingerne i Dyreriget ; in Tids. for pop. Frem. af Nat. 1861 -G2.
McA>DREW, R. List of the British Marine Invertebrate Fauna ; in Rep. Br. Ass. Adv. Sc,

p. 217. 1860.
Mettexheijier, C. I'ebcr die Gesichtsorgane des violetten Seesterns, nebst Beobachtungen
iiber die Ohrenquallc u. Versuchen iiber die Jlotilitiit derselben ; in Archiv f Anat. u.
Phys., p. 214. 1862.
Meyer, A. u. Mobius, K. Kurzer Ueberblick der in der Kieler Bueht von uns beobaehteten wir-

bellosen Thiere, als Vorliiufer einer Fauna derselben ; in Archiv f. Nat., 1862. I. p. 229.
MiJLLER, Fr. Cunina Kollikeri F. liliill. ; Beitrag zur Natui-geschichte der iEginiden ; in Archiv
f. Nat., L p. 42. 18G1.
" " Polypen ii. Quallen v. Santa Catharina, Olindias sambaquiensls ; in Archiv f Nat.,

1861. Lp. 312.
" " Ueber die Angebliehe Bilateralsymmetrie der RippenquaUen ; in Ardiiv f Nat.,

1861. L p. 320.
" " Ueber die System. Stellung der Charibdeiden ; in Archiv f. Nat., 1861. L p. 302.

" " OntheSystematiePositionoftheCharibdeida!;in Ann.&Mag. N. H., X.p. 6. 1862.

" " Ueber die L'rsache der Strdmungen in der Leibeshdle der Sertularien ; in Archiv

f. Nat., L p. 34. 1863.

6 BIBLIOGRAPHY.

Murray, A. Descriptions of New Sertularitla; from tlie Californian Coast ; in Ann. & Mag.
N. IL, V. p. 250. l.SGO.
" " On Sertularia tricuspidata ; in Ann. & Jlatr. N. II., V. p. .504. 18G0.

NORMAX, A. M. On Unilcsoribed British Ilydrozoa, Actinozoa, and Polyzoa; in Ann. & Mag. N.
II., XIII. p. 82. Jan. 18G4.
" " On the Crustacea, Echinodennata, and Zoophytes obtained in a Deep-Sea

Dredging, off the Shetland Islands in 1861 ; in Rep. Br. Ass. Adv. Se.,
p. 151. 18G1. Trans. Sec.
Packark, a. S. Jr. A List of Animals dredged near Caribou Island, Southern Labrador ; in

Canadian Nat. & Geolog. Dec. 18G3.
Pagensteciieu, H. Untersuchungen iiber niedcre Seetliicre aus Cette ; VIII. Zur niiheren
Kenntniss der Vellelidenforin Rataria, nebst Betraehtungen iiber die Velleliden im Allge-
mcinen ; in Zeits. f. Wiss. Zool., XII. p. 49G. Jan. 1863.
Peach, C. W. On the Zoojjhytes of Caithness; in Rep. Br. Ass. Adv. Se., p. 155. 1859.

Trans. Sec.
Peters, W. C. H., Carus, J. V., & Gerstaecker, C. E. A. Ilandbuch der Zoologie. Leip-
zig. 1863.
Price, John. On the Genus Cydippo ; in Rep. Br. Ass. Adv. S. 1859, p. 155. London. 18G0.

Trans. Sec.
Quatreeages, a. de. Metamorijhoses de riiomme ct dcs animaux. Paris. 1862.
Sars, M. Ueber das Ammengeschlecht Corymorpha und seine Arten, nebst den von dicsen aufge
ammten Medusen ; in Archiv f. Nat., 1860. I. p. 341.
" " Bemaerkninger over noi-ske Coelcnterater ; in Vidensk. Selks. Forh., p. 140. Chris-

tiania. 1860.
" " Tegningcr af og Oplysninger om nogle Coelcnterater fra Norges Kyster ; in Skand.

Naturf Mode i Kjoljenhavn. 18G0. p. 690.
" " On the Nurse Genus Corymorpha and its S])eeies, together with the Medusa; produced

from them ; in Ann. & Mag. N. II., VIII. p. 353. 18G1.
" " Bemaerkninger over d. norske Hydroidcr ; in Videns. Selks. Forhand. 1862.
T " " Geologiske og zoologiske Jagttagelser anstillede paa en Reise i en Deel af Trondhjems
Stift. Christiania. 1863.
SiEiiOLD, K. Th. v. Ueber Parthenogenesis. Miinchcn. 1862.
Se.mper, K. Reisebericht von Dr. Karl Semper, Briefliche Mitthcilung, an A. Kolliker; in Zeits.

f. Wiss. Zool., X. p. 558.
Steenstrup, J. B. Om de ved Norges Kyst forekommcnde Artcr af Slaegten Lucernaria ; in
Forhand. Vid. Selsk. i Christiania, Aar 1860. Christiania. 1861. p. 145.
« " Bidrag til Kundsab om de nordiske Lucernarier ; in Vidensk. Med. 1859,

p. 106. Kjobenhavn. 1860.
Troschel, F. H. Ilandbuch der Zoologie. Beriin. 1864. 6'" Auflage.

Verrill, a. E. List of Polyps and Corals sent by the Museum of Comparative Zoology to other

Institutions in Exchange, with Annotations ; in Bulletin INIuseum Comparative Zoology,

No. 3. Cambridge. 1864.

"Wright, T. S. On the Reproduction of Thaumantias inconspicua ; in Quart. Journ. !Mic. Scien.,

p. 221. 1862.

" " Observations on British Zoophytes and Protozoa ; in Edinb. New Phil. Journ.,

XVI. p. 154. 1862.
" " Observations on British Zoophytes ; in Quart. Journ. Mic. Scien., p. 45. 1863.

" " On the Reproduction of ^E(piorea vitrea ; in Edinb. New Phil. Journ., XV. p.

144. 1862.
" " Observations on British Protozoa and Zoophytes ; in Ann. & Jlag. N. 11., VIII.

p. 120. 1861.
« " On Hermaphrodite Reproduction in Chrysaora hyoscella; in Ann. & Mag. N. II.,

VII. p. 357. 1861.
" " Observations on British Zoophytes and Protozoa; on Atractjlis coccinea ; in

Edinb. New Phil. .Tourn., XIV. p. 150. 1861.
Wood, W. In Journ. Portland Soc. Nat. Hist., I. p. 63. 186 2.

NOETH AMERICAN ACALEPH^.

Oedee CTENOPnORyE Esch.

Ctennplioriv Esch. Syst. der Acalcplion, p. 20. 1820.
Cleiwplwrie Gegenbauk. Archiv. f. Naturg., 185G. I. p. 1()3.
Ctenophone Agass. 1860. Cont. Nat. Hist. U. S., III. p. 289. 18G0.
Ciliofjrades Blain'V. Man. d'Actin., p. U.'J. 1830.
Bdrokles Less. Zooph. Aoal., p. Gl. 1843.

The affinities of the Ctenophoraj have l^ecome one of the most fertile
topics of discussion among recent investigators. Vogt, following Quoy,
removes them from the Acalephs altogether. Huxley places them in
clo.se proximity to Polyps. Clark has made a special class of them,
equivalent to Echinoderms, while Milne Edwards and Agassiz, after a
careful revision of the whole subject, have followed Cuvier and Esch-
scholtz, and retained them as an order of Acalepha?. These various views
of the true relations of the Ctenophorae are based upon very different
grounds, and are urged with more or less force in accordance with the
degree of impoi'tance attached by investigators to the details of struc-
ture upon which they separate the Ctenophorae from the Acaleph*, and
refer them to other classes of the Animal Kingdom ; the apparent bilatr
erality so strongly developed in some of the families (as Cestum, Bolina,
and Mertensia) being urged by Yogt as the principal ground for re-
moving them from Acalephs, and associating them with the Mollusks ;
Avhile Huxley places them with Polyps on the ground of the special
structure of their digestive cavity ; and Clark simply states his belief
in their separation a.s a class, without furnishing us any proofs. We
are able to throw new light on this question by a series of facts derived
from their embryological development, hitherto unnoticed. As the ol)-
servations of Dujardin on the development of Coryne gave us the key
which led to the ultimate separation of the Hydroids from the Polyps,
so 1 hope to be able to show that the development of the Ctenophora3
gives us a true insight into the disputed affinities of these animals.

Before the publication of the valuable observations of McCrady on the
development of a species of Bolina, little was known of their embryology
except the mere fact, derived from the few casual observations of Miiller,
Wright, Boeck, and Price, that the Ctenophoras were probably all repro-

8 CTEXOPHOR^.

duced from eggs, and that at an early age they gave unmistakable
signs of their parentage. McCrady's observations showed us how great
were the changes of iigure their young undergo before they assume
the aspect of the joarent. It has been my good fortune to trace these
changes in several of our species of Ctenojihoraj somewhat in detail,
and I shall make use of the material thus afforded in discussing the
position of these animals, as well as theu- pretended bilaterality, and,
by comparing their mode of development with that of Polj^ps, Acalephs,
and Echmoderms, endeavor to ascertain whether their association with
them into one great branch of the Animal Kingdom is true to nature,
or whether the affinities between the mode of execution in the plan of
the members of the Coelenterata are really of such a character as to
justify their separation from the other Radiates as one great bi^anch
of the Animal Kingdom.

Let us first examine the character of the Coelenterata and of the
Radiata as they are understood. What is common to Polyps, Acalephs,
and Echinoderms is a vertical axis, or rather an axis through which
we can pass a plane at right angles, and in this plane draw two axes
at right angles to each other. These axes, of course, are not equally
prominent in Polyps, Acalephs, and Echinodeniis ; taking, for instance,
the three axes as we find them in some of the Sjjatangoids, we have a
vertical axis, a coeliac axis, and a diacoeliac axis, the mouth and anus
being placed in such a position with reference to the coeliac axis as to
give us a right and left, an anterior and a posterior extremity. In the
Acalephs, it is only among the Ctenophora3 that we can distinguish
between the coeliac and diacoeliac ; but we have neither right nor left
— no anterior or posterior — side ; while in Polyps -we can distinguish
their axes with greater exactness than in the Ilydroids and Discophora?.
We are so accustomed to impose our notions of symmetry on every-
thing we meet, that it is difficult to divest ourselves of the idea that
every animal has not necessarily a right and a left side, an anterior and
a posterior extremity ; we start with the idea that such relations must
exist in all animals, however disguised, and under this impression we
try to reconcile plans which are totally distinct. If, however, we admit
the idea of different plans as the foundation of animal life, we must
give u]} all attempt to find some passage from one to the other. Ani-
mals the equation of which could be represented by that of a sphere,
or by that of two parallel planes, or of a series of cylinders, or of two '
parallel cylinders, can never pass from one to the other ; the equation
of a sphere cannot be transformed into that of a jilane, nor into a
cylinder ; the equations representing each of these figures include, it
is true, all the jiossible spheres or all the possible cylinders which may
be constructed by changing the values of the variables, but can never
be transformed one into the other. The infinite variety of forms, and

CTENOPIIOR^E. 9

apparently aberrant types, constantly met with among animals, has
been the main cause of om' dithciilty in referring them to their proper
jjlan. It is not always an easy matter to reduce an equation to its
simplest form, and find out what it is ; it may be concealed by coef-
ficients which will disappear only after repeated operations, and then
only enable us to determine of what degree the equation is. These
coefficients in an equation may be compared to the modifications of
those parts which appear to affect the mode of execution in animals ;
and it may not always be an easy matter nor a possible one, in the
present state of our knowledge, to solve these organic equations. The
history of Science is full of exam2:)les of this kind ; and we may have
to discover new methods in Natural History, as well as in Mathematics,
before we can proceed with our eliminations, or arrive at a solution.
Thus the plan of radiation may be so carried out, by a modification
of some of the parts, as to appear at first sight to be bilateral ; but
analyze these modifications carefully, and beneath them all can be
traced the plan of radiation, hidden only by external featui'es of bilater-
ality. Such is eminently the case in the larvtc of Echinoderms, and to
a less degree in the imitations of Echinoderm larva?, the CtenophorjB.
Bilaterality seems at first sight to be the plan upon which these animals
are built; but an elimination of the decejitive coefficients will show the
plan of radiation underlying this apparent bilaterality.

The figures here given of vei-y young Ctenophora) show no indica-
tion of this bilaterality, at least no more than can be traced in any
four-rayed jelly-fish. The tubes are as yet all of equal size, no jiromi-
nence is given to one side over the other, and the only hint of bilater-
ality is the early distinction of the longitudinal and of the transverse
axis by the position of the tentacles. No lateral a^Ji^endages develop-
ing into immense lobes, as m the adults, can as yet be detected. The
characteristic feature of the eggs of the Ctenophorae is the great diam-
eter of the envelope compared to the yolk, which is hardly more than
one third the diameter of the egg. The whole yolk is transformed hy
segmentation into the embryo ; this at an early j^eriod assumes a very
slightly pear-shaped form, and is moved by means of a few pairs of
large locomotive combs, equalling in length the diameter of the em-
bryos. This is the first indication we have that the embryo is a Cteno-
phore ; and the early stages are marked by the constant and violent
flapping of the combs, arranged in four bunches near the abactinal
jjole, immediately at the base of the large eye, also disproportionately
large in the young, containing but few granules, and seeming almost
like a glass ball fastened to the top of this active embryo. During this
stage the young Ctenophore is moving about somewhat slowly within
the envelope of the egg. With increasing age the locomotive flajipers
descend somewhat along the spheromeres, and we find at the opposite

10 CTENOPHOK^.

extremity from the eye the first trace of a small cavity (the digestive
cavity of the adult), Avhich increases in size till it becomes spherical. At
about this time there is founds between the four clusters of the locomo-
tive flappers, a second cavity, which has at first no connection whatever
Avith the digestive cavity, and develops independently of it. This sec-
ond formed cavity, now a large rectangular bag, slightly lobed between
each of the four clusters of locomotive flappers^ is the chymiferous
cavity, from which the funnel and the chymiferous tubes take their
origin in somewhat older stages. With advancing age the walls of the
two cavities become more circumscribed, and at the same time more
clearly defined, approaching each other constantly, until finally they
open into each other. The digestive cavity and the chymiferous tubes
diminish in diameter, becoming more circumscribed, and losing little by
little the character of broad pouches for that of narrow tubes, extending
through the gelatinous mass. The locomotive flappers extend with the
chymiferous tubes along each one of the four pouches, which have
given rise to two chymiferous tubes, one long and one short one, devel-
oping independently. This difterence is barely perceptible in the adidt
Pleurobraehia ; it is well marked in Mertensia, still better in Idyia,
quite prominent in Lesueuria, and takes its greatest development in
Bolina, whei'e adjoining tubes anastomose after almost endless windings
through the large lobes formed by the lateral projections of the gelati-
nous mass. The cause of the predomineiice of some of the sphero-
meres over the others, is the unequal develoj^ment of these two sets of
tubes, Avhich may or may not extend into lobes, thus giving to the
Ctenophorte the appearance of Ijilateral animals. But examine this
same development in another class of Radiates, among the Echino-
derms, in the Spatangoids, for instance, where the odd ambulacrum is
the one which takes the least development, when the other four are
more equally developed, and no one will for that reason forget their
radiate character, and call them strictly bilateral animals.

We can thus distinguish, among Spatangoids, an anterior and a poste-
rior extremity, a right and a left side. In Ctenophoraj, owing to the
peculiar manner in which the difference between the chymiferous tuljes
is developed, we are enabled to distinguish simply two diameters, but
not an anterior and a posterior extremity, or a right and a left side ; it
seems, therefore, scarcely logical to call these animals bilateral, when in
reality they show less sign of bilaterality than the Spatangoids. which
no one, except Huxley, seems to doubt belong to Radiates.* The axes
we can thus distinguish among the Ctenophonv by the unequal devel-
opment of the chymiferous tubes, would not enable us to decide whether
the long tubes of the different genera were the same tubes developed
more fully in the different species. For instance, we should at first

* See analysis of this view in Agissiz's Contributions, Vol. V. p. GO, by A. .\gassiz.

CTENOPHOR.E. 11

sight suppose the long tubes of Pleurobrachia, of Mertonsia, of Idyia, of
Bolina, of Lesueuria, to be 'homologous, but such is not really the case ;
and the only means we have of determining this is the plane passing
through the tentacles, enabling us to ascertain whether the longitudinal
axis is in the trend, or at right angles to that plane. We shall soon see
that in Pleurobrachia and Mertensia the plane, including the tentacles,
passes through the long axis, while m Bolina and Lesueuria it passes
through the short axis ; that the long tubes are on each side of the ten-
tacles, and consequently that the long tubes of Mertensia and the long
tubes of Bolina are not homologous ; but what corresjsonds strictly to
the long tubes of Pleurobrachia and Mertensia are the short tubes
placed on each side of the tentacular system. The lateral tubes invari-
ably in the plane of the tentacular system give us the means of deter-
mining to which of these two classes Idyia belongs, and we find that
its longitudinal axis corresponds with that of Bolina, the lateral tubes
being in the shorter axis, as in the last-named genus, while in Pleuro-
brachia, as in Mertensia, they are in the longer axis. Such is the origin
of the characters Avhich give to some members of the Ctenophor* their
remarkable bilateral ajipearance. It is simply a modification of what is
l^erfectly familiar to us among Echinoderms, and especially among the
Spatangoids ; but owing to the bilateral character of their develop-
ment, the Ctenophoraj make us lose sight entirely of the original radi-
ate plan upon which these animals are built. Viewing, however, this
diflerentiation of the axis in all its stages, as we find it in Pleurobra-
chia, in Idyia, in Mertensia, in Lesueiu-ia, ia Bolina, we constantly keep
before our eyes the original formula from which the other members are
derived.

Examined in the light of prophetic beings, the bilaterality of the
Acalephs is but another of those Avonderful links which unite in one
great whole the different members of the Animal Kingdom. As the
Polyps are the prophetic representatives of the Acalephs in their em-
bryonic condition, the Hydroid state, so must we look at the Ctenophora^
as the jirophetic type of those still more wondei'ful bemgs, the Echino-
derm larvas, in which bilateral symmetry is carried to such an extent
that even the great mind of a Miiller is led to consider them as exhibit-
ing a direct passage from a bilateral to a radiate plan of structure. In
the bilateral symmetry of the Ctenophorte we are constantly reminded
of the general appearance of Echinoderm larvae, in which the radiate
structure should still be so far apparent as not to be concealed by the
bilateral symmetry.

Looking at the Ctenophorae as prophetic animals, we are able to
understand the separation of the digestive cavity into two distinct
parts. It is only what we find more fully developed m the Echino-
derm larvas ; the separation of a sort of alimentary'canal, in Ctenophorae,

12 CTENOPHOR^.

from the rest of the digestive apparatus, exactly corresponding to what
exists in Echinoderm larvte. The connection between the water system
and the digestive system is hkewise precisely similar to that of Echino-
derms in their larval state ; for although in the adult Star-fish, or Sea-
nrchin, or Ophiuran, there is no apparent connection between the am-
bulacral and the digestive system, yet in the young larvas we can see
that this connection exists, the water system being formed by diver-
ticula from the digestive cavity ; while the injections of Professor Agas-
siz have proved the existence, in the adult, of a similar connection in
Echinarachnius, in Mellita, and in Clypeaster.

It was only after the embryos of Echinoderms had been compared
with Ctenophora3 that undoubted evidence of their identity of plan was
obtained. The embryological development of Ctenophora? leaves no
doubt as to the Acalephian character of the order. It remains only for
us to see whether the Ctenophorje form a group of equal value with the
rest of the Acalephs, or stand simply as an equivalent of the other two
orders, the Discophoraj and the Hydroids. The careful examination
lately made of many genera of which we had no definite knowledge
before, as well as their embryology, has now left it difficult to decide
Avhether the Discophoraj and Hydroids are independent orders, or wheth-
er the distinction established between the Discojjhorai and Hydroids is
merely a subordinal division in a great order, including these two. If
so, this order might be called the Medusidaj, in opposition to the Cteno-
phora^, which are an order jjerfectly and accurately circumscribed ; the
presence of locomotive flappers being as characteristic for the Cteno-
phorre, and as constant a feature of Ctenophora3 among Acalepha*, as
feathers are for the class of Birds among Vertebrates. These flappers
exist almost from the earliest embryonic stages, and thus far not a
single exception is known to the rule. Fritz Miiller and Agassiz have
shown that it is hardly natural to associate the Charibdeidai and ^gi-
nidfB with the Hydroids, and the latter has proposed to imite them Avitli
Discophorjp, Avhile the former would make a separate order of them.
This seems hardly justifialjle, as there are as many reasons — their mar-
ginal appendages, genital organs, &c. — for uniting them with Disco-
phortB, as for leaving them with the Hydroids, — the shajoe of the bell,
the great development of the veil. If, in addition, we take into account
what we have observed in the Trachynemid*, it will be seen that wo
can no longer draw the line between the Discophorse and Hydroids as
distinctly as before ; while the creation of a third group equivalent
to these two, to contain the families in dispute, does not bring ns any
nearer to the solution of the problem. A more accurate knowledge of
the tropical forms will go far to settle this point ; and in the mean
while, with this explanation, I will place temporarily (until further
information -can be gained) the yEginida) and the Trachynemidoe among

CTEiVOPIIOR^. 13

the Discophora?, with the full expectation that future researches will
give us better reasons than we-have at present for abandoning, as con-
trary to nature, two orders which have thus far been almost universally
acknowledged by all investigators of Medusae. If the Discophoraj ai-e
to be united with the Hydroids, we shall have to divide the Acalephs
into two orders, Ctenophoraj and Medusida3 ; the different suborders of
the latter division including all the suborders of the Discophoraj of
Eschscholtz, and those of the Hydroids as limited by Professor Agassiz.

The remarkaljle changes of form the CtenophorJB undergo until they
attain their adult state, will necessitate at no very distant time a com-
plete revision of the Otenophorse, as soon as the embryology of a suffi-
cient number of families has become well known. What is now espe-
cially wanting is an embryology of Cestum, which would give us, with
what has been shown here of the embryology of the three other sub-
orders of Ctenophoraj, a standard for an embryological classification of
the Ctenophora?. We can already see that many of the genera of
Eschscholtz {Medea and Pandora), as has already been suggested by
Professor Agassiz and by McCrady, are only embryonic stages ; all such
species as the Cydippe quadricostata of Sars {Boliiia norvegica), the
Cydijype brevicostata of Will {Chiaja midticornis M. Edw.), and the
Slcyosoma rutilum of Gegenbaur, are undoubtedly undeveloped stages
of some of the well-known CtenophortB of the Northern Ocean, the
Adriatic, and the Mediterranean. From what has been shown of the
transfonnations of BoUna alata, I should even be inclined to consider
the Cyd'q^i^e horm'iphora of Gegenbaur as one of the stages of growth
of Euramphcea vexilligera Gegenb. It seems to me that there is be-
tween these two species the same relation which exists between some
of the stages here figured of BoUna alata. The material at my com-
mand is too imperfect to attempt anything more definite than the few
hints here thi'own out for more fortunate observers.

Professor Agassiz, in his third volume of the Contributions, intended
to give an embryology of some of our species of Ctenophorte. He
made many observations previous to 1856, which, however, were never
noted down ; only a couple of sketches of a young Pleurobrachia were
drawn by Mr. Sonrel ; and during the subsequent summers other and
more pressing work compelled him to forego his intentions. The ob-
servations here presented, in the descriptions of our common species,
were made independently during the summers of 1860 - 63.

14 LOBAT^.

SUBOEDER LOBAT^ ESCH.

Lobala. EscH. Isis., p. 741. 1825.

Lohalce Agass. Cont. Nat. Hist. U. S., III. p. 289. 1860.

Mnemiidm Esch. Syst. d. Acalephen, p. 29. 1829.

In the LobatoB we find that the diameter passing through the ten-
tacular apparatus is invariably the smaller, while the compression of
the spherosome is in the plane at right angles to it. This is reversed
in the Saccata?. The spheromeres at the extremity of the longer trans-
verse axis, the coeliac axis, develop into lobes.

Family BOLINID^ Agassiz.

Bolin'ulie Agass. Cont. Nat. Hist. U. S., HI. pp. 200, 289. 18G0.

The fiimily of Bolinidae has here a somewhat different circumscrip-
tion from that ascribed to it by Professor Agassiz in his " Contribu-
tions." The genus Lesueuria, of which no species was known on our
coast in 1860, has been removed from the Mnemiidte to the Bolinidje.
It is evident from the description hereafter given of Lesueuria, that
this genus is only a Bolina with diminutive lateral lobes. The genus
Mnemiopsis also is shown to belong to the Boliuidas, and not the
Mnemidoe.

BOLINA Meet.

Bolina Meet. Mem. Acad. St. Petersb., H. p. 513. 1833.
Bolina Agass. Mem. Am. Acad., IV. p. 349. 1849.
Bolina Agass. Cont. Nat. Hist. U. S., HI. p. 249. 1860.
Mnemia Saus (non Esch.). Boskriv., p. 32. 1835.
Alcinoe Less, (non Rang). Zooph. Acal., p. 88. 1843.
Anais Less. Zooph. Acal., p. 101. 1843.

Bolina septentrionalis Mert.

Bolina septentrionalis Meut. (HO^Agass.). Acad. St. Petersb., p. 515, PI. VH. 1833.
Bolina seplenlriunalis Less... .-Zooph. Acal., p. 83. 1843. _,"

Off Matthoei Island, Behring's Straits (Mertens).

BOLINA ALATA. 15

Bolina alata Agass.

Bolina alata Agass. Mem. Am. Acad., Vol. IV. Vt. 2, p. 349, Pis. 6, 7, 8. 1849.

Boltna ithtla AoASS. Contrib. Nat. Hist. U. S., Vol. III. pp. 249, 289.

Alriinik vcniiu-ulari.i Goia.D {non Rang). Inverteb. of Ma.ss., p. 349. 1841.

Bolina alata Stimps. Mar. Inv. Grand Manan, p. 11. 1853.

Bolina alata Packd. A List of Animals dredged near Caribou Island, Can. Nat. & Geol. 18G3.

It is quite remarkable that there .should Ije no mention made by
Fabricius of a single Ctenophore which may be identified with any
species of the genus Bolina. There is hardly a more common Medusa
than the Bolina alata of our coast ; and the occurrence of so many of
our species of Gtenophora3 on the coast of Greenland makes the ab-
sence of Bolina the more striking, and quite interesting in a geograph-
ical point of view, as we should thus have among Acalephs a case of
geographical distribution analogous to that of Echinarachnius, which
does not extend tiirther north than Labrador.

To the description of the adult given by Professor Agassiz I have
nothing of importance to add, with the exception that the chymiferous
tubes which run along the edge of the lateral lobes, when seen from
the narrow side, should unite, and thus complete the circuit (Fig. 16),
instead of stopping short at a little distance apart, as they have been
represented by him. This connection takes place at an early period of
the development. (See Fig. 8.)

The compression of the spherosome of Bolina and of Pleurobrachia
is in diflerent planes, otherwise it would be exceedingly difficult to
distinguish a very young Pleurobrachia from a young Bolina. In the
young Bolina, as has been shown already by McCra-
dy, we find long tentacles ; so that the j^ounger stages
of this Medusa are so unlike the adult, that it would
]je the most natural error to commit, to consider it
the young of Pleurobrachia. The accompanying fig-
ures (1-3) are taken immediately after the escape of
the young from the egg. It will be noticed, when coinjjared to Pleuro-
brachia, that besides the position of the tentacular organ, the outline of
the spherosome is somewhat different, and that the ambulacra are quite
narrow. The digestive cavity also fills a comparatively small space.
(Fig. 2.) The extreme tenuity of the tubes soon becomes a character
by which the young Bolina is at once distinguished from the young
Pleurobrachia, as well as its ellipsoid shape, which greatly increases

In all the young Ctenopliorsc tlie follnwing lettering lias been adopted : rf, digestive cavity ;
n, anal rosette ; /, tentaele ; c, long ambulacral tube (longitudinal ambidacra) ; r\ short ambulacral
tube (lateral ambulacra) ; e, eye speck ; /, funnel ; o, ambulacral cavity ; /, lateral tubes, c' is the
longest tube at fii-st, and c the shorter ; n, lobes of spherosome ; the names are taken fi-om the adult.

Fig. 1. Young Bolina, seen from the narrow side.

16

BOLINA A LATA.

with age

(Fig. 4, which is Fig. 6 seen from abactinal side.) We soon
l)erceive in the young of this species changes of shape simihxr to those
to be described m Idyia and Pleurobrachia : the outhne becomes more
elongated ; tlie lateral tubes, at first simple diverticula from the main

Fiff. 2.

Fig. 3.

Fig. 4.

Fin 5.

ambulacral tubes (I, Fig. 5), extend to the level of the opening of the
mouth (Fig. 6). We can also trace a difference in the rapidity of
growth of the ambulacral tubes, but, contrary to what we find in
other genera, we observe the tentacular ambulacra are the most rapid

in their growth. When
^■«' ^'^•'- they reach the bottom of

the spherosome, they bend
towards each other (Fig.
7), and finally join (Fig. 8),
but have at present no
connection with the lat-
eral tubes near the mouth.
It will be noticed by the
figure (n, Fig. 8) that that
part of the spherosome
which contains tlie junc-
tion of the two lateral am-
bulacra (Figs. 9, 71, 10), has a tendency to expand beyond the level
of the mouth ; this is the first appearance of the lobes of the adult
Bolina. This part of the spherosome increases rapidl}^ in dimensions,
and we have a minute Ctenophore with well-marked lobes, like a
Bolina, and highly developed tentacles, like a Pleurobrachia (Fig. 11).
Still greater changes are yet to take place ; we soon perceive that

Fig. 2. Bolina in state of Fig. 1, seen from tlie broad side.

Fig. 3. Soiiiewhat younger than Fig. 1, scon from the abactinal pole.

Fig. 4. Young Bolina, seen from the abactinal side, somewhat older than previous figures.

Fig. 5. Formation of lateral tubes in young Bolina.

Fig. G. Bolina in which lolies l)cgin to a])|)car, seen from narrow side, same state as Fig. 4.

Fig. 7. Somewhat more advanced than Fig. C, the tube c' not yet having formed the circuit ;
seen from the actinal side.

BOLINA ALATA.

17

Fig. 8.

the lono; ambulacra do not remain regularly arched, but bend towards
the vertical axis (Figs. 12,
13) ; this bend is soon
changed into a loop, which
passes through a corre-
sponding protuberance of
the spherosome. This be-
comes the auricle, from
the angle of which (Fig.
14) we also perceive a
branch of the chymiferous
tube, which soon pushes
its way through the gela-
tinous mass, and forms a

junction with the lateral tubes, exactly as we shall find it to be the
case with Idyia. In the mean time the other ambulacra have been

increasing in length, and we

Fi". 10.

Fig. 11.

find that they reach almost to
the lower end of the lobe ;
when there, they make a sharp
angle, turn upwaixl, and form
thus the beginning (Figs. 12,
13) of the complicated system
of Avindings which we find in
the lobes of the adult Bohna.
During the later stages of
growth the tentacular appara-
tus has been shifting its posi-
tion, the opening coming nearer

and nearer to the level of the mouth ; the tentacular bulb leng-thenino;

in proportion, and finally appearing like a long, narrow rod, with a

slight swelling at the extremity, from

which the remnants of the threads

of the tentacles are suspended. The

only changes necessary to make this

young an adult Bolina, are changes

of quantity. The apparent differ-
ence in the mode of growth of the

Fig. 8. The tentacular ambulacra have united, and the lobes (h) project well beyond the

opening of the mouth.

Fig. 9. About in the condition of Fig. 2, seen from the broad side.

Fig. 10. Somewhat younger than Fig. 8, seen from the broad side.

Fig. 11. Fig. 8, seen from the broad side.

Fig. 12. Bolina with first appearance of the auricles, seen from the broad side.

Fig. 13. Bolina of stage of Fig. 12, seen from the narrow side.

NO. II. 3

Fig. 13.

18

BOLINA ALATA.

lateral and longitudinal tubes is entirely done away with in subsequent
^.^ ^^ changes, as we find that the

short ambulacra are the lateral
ambulacra, though at tirst they
are more rapid in their growth,
but are afterwards outstripjjed
by the rapid increase in length
of the longitudinal tubes ; but
it must be remembered that,
in this genus, the flattening of
the spherosome takes place in
different planes from Idyia and Pleurobrachia. The young Bolina has
now attained a condition in which it will be very easy to recognize
the different parts of the adult, if compared in homologous jiositions.
Fig. 15 is an adult seen from the broad side, corresponding to Fig. 12 ;
Fig. 16 is an adult seen from the narrow side, corresponding to Fig.

Fig. 17.

Fig. 18.

Fig. 16.

h r o e

13 ; Fig. 17 is an adult Bolina, seen from the actinal side, corre-
sponding to Fig. 14 ; and in Fig. 18 'we have the adult seen from the
abactinal pole.

Coast of New England, and northward to the Bay of Fundy (Agassiz).

Museum diagrams Nos. 1, 2, after L. Agassiz.

Kg. 14. Fig. 13 seen from the actinal pole, and more magnified. ?•, circular tube ; m, auri-
cles.

Fig. 1.5. Adult Bolina seen from the broad side. n,f, longitudinal ambulacra; y, h, lateral
ambidacra; o, eye-speck ; i — in, digestive cavity; i-o, funnel; v, lateral tulie leading to tentacular
a])paratus just on level of mouth, in ; r, r, auricles ; I, t, prolongation of the longitudinal ambulacra ;
«, », same tubes turning upwards, bending down at i; x : z, z. point of junction of tubes from op])o-
site sides ; u\ prolongation of tubes from the lateral ambulacra. About half natural size.

Fig. IG. Fig. 15 seen from the narrow side, a, h, longitudinal ambulacra ; c, !i, lateral ambu-
lacra ; other letters, as in Fig. 15.

Fig. 1 7. Bolina seen from the actinal pole ; lettering as above.

Fig. 18. Bolina seen from the abactinal pole, o, h, e, f, longitudinal ambulacra; c, d, g, h,
lateral ambulacra ; s, s, circumscribed area ; other letters, as above.

MNEMIOPSIS. 19

Bolina vitrea Agass.

BoJina vilrca Agass. Contrib. Nat. Hist. U. S., Vol. III. pp. 2Gn, 2S9, Fig. 93. 18C0.
f Bolina littoralis McCr. On the Development of two Sjjecies of Ctenophoras, 1857 ; Proc. Elliot
Soc. N. II., p. 1. 1858.

The BoUna UttoraUs McCr. is probably either this ^'«- "•

species, or one of our species of Mnemiojjsis ; but ^.'i'^i'm\. J'

not having the means to detenniiie this point, a I

figure (Fig. 10) of the BoVina vitrea Agass. is added f

here, to serve as a basis for its identification here- /f"]^

after. J. (^

Eeef of Florida (Agassiz) ; Charleston (McCrady). \X\/

Bolina microptera A. Agass.

Bolina septentrionalis Agass. {non Mortens). Cont. Nat. Hist. U. S., HI. p. 289. 18G0.

The discovery of several sjDecies of Bolinidae on the eastern coast of
North America, belonging to different genera, which had all been con-
founded together, has induced me to examme anew the descriptions
and drawings of the species of Bolina observed on the northwest coast.
I have become satisfied that the species of Bolina here noticed is not
the B. sejifenfrionalis of Mertens, but differs specifically from it. It
is quite elongated ; the lateral lobes are very short, with complicated
windings of the long ambulacral tubes. This species resembles in out-
line more the Bolina vitrea Agass. than any other. It has, like it,
a long digestive cavity, but differs from it in the proportions of the
lateral lobes, and the complexity of the windings of the long amliulacra.
It is, like the B. vitrea, perfectly transparent and nearly colorless, of a
slight bluish tinge ; the polar diameter measures about two inches.
Found in June, in the Straits of Kosario, Washington Territory.

Gulf of Georgia, W. T. (A. Agassiz).

MNEMIOPSIS Agass.

Mnemiopsis Agass. Cont. Nat. Hist. U. S., III. pp. 2C9, 290. 18G0.

The genus Mnemiopsis is remarkable among the Bolinidae for the
peculiar structure of the tentacular apparatus, which sends a branch
along a deep furrow, protected by a lappet, to the base of the auricles.

Fig. 19. Bolina vitrea seen from the broad side. /-, T, long ambulacra; /', /'. short amb*
lacra; /, ftinnel ; rl, digestive cavity ; I, tentacular tube ; x\ x'' auricles ; /, /, anterior and poste-
rior lobes ; /(', tentacle.

20

MNEMIOPSIS LEIDYI.

Mnemiopsis Gardeni Agass.

Mnemiopsis Gardeni Agass. Cont. Nat. Hist. U. S., III. pp. 269, 290, Figs. 95, 96. 18G0.

^'^■^''' The accompanying figures (Figs. 20, 21) of

Ilnemiopsis Gardeni Agass. are here introduced
to show how striking are the differences in the
proportions of the two MedustE of this genus
found upon our coast. The great length of the
digestive cavity, together with the size of the
auricles and loljes, enable us at once to distin-
guish this species from its ally, the 3fnemiopsis
Leicli/i A. Agass. The genus Mnemiopsis had
been placed by Professor Agassiz among the
Mnemiida?, on account of the deep furrow sepa-
rating the anterior and posterior lobes from the
lateral spheromeres. The differences of form
based upon this structural feature, which are in
such striking contrast in Bolina and Mnemiojjsis Gardeni, are far from
being marked when we compare Bolina alata and Mneinio2)sis Leidyi.
Charleston, S. C. (L. Agassiz).

Mnemiopsis Leidyi A. Agass.

This Medusa would readily be mistaken for a true Bolina, at first
glance ; a closer examination, however, will show that, notwithstanding
the short digestive cavity which reminds us of Bolina, we have the
deep furrow sej^arating the anterior and posterior lobes from the lateral
spheromeres. The long ambulacra are covered with locomotive flap-
pers to the actinal margin, and we have long auricles, showing that
this is a Mnemiopsis, with longer anterior and posterior lobes than we
have in the 3£nemio2)sis Gardeni Agass.

This species grows very large, specimens measuring six and even
eight inches in length are frequently found. Like the other Cteno-
pliora? of our coast, it is gregarious ; thousands being collected to-
gether basking in the sun. It is exceedingly phosphorescent ; and
when passing through shoals of these Medusa?, varying in size from
a pin's head to several inches in length, the whole water becomes
so brilliantly luminous that an oar dipped in the water uji to the

Fig. 20. Mnemiopsis Gardeni seen from the broad side, a, folds of digestive cavity. Letter-
ing of Figs. 20 and 21 same as Fig. 19.

Fig. 21. Fig. 20 seen from the actinal pole, o, mouth; I*, P, lateral ambulacra; x'l X^ •"'"■
cles ; t'jl'jPjr, anterior and posterior ambulacra.

MNEMIOPSIS LEIDYI.

21

handle can plainly be seen, on dark nights, by the light produced
by this illumination. The seat of the phosphorescence is confined to
the rows of locomotive flappers, and so exceedingly sensitive are they
that the slightest shock to the jar in which these Meduste are kept
is sufficient to make them plainly visible by the light emitted from
the eight phosphorescent ambulacra. This species is long, almost ellip-
soidal, when at rest. (Fig. 22.) The auricles extend about one third
their length beyond the oral aperture (o, Fig. 22), taking their origin
on a level with the eye-speck (a, Fig. 22). The prolongation of the
chymiferoiis tubes, and their manner of anastomosing, is exceedingly
simple ; we find nothing of the complicated bends and turns (Fig. 23)

Fig. 22. Fig. 23.

of the same tubes which we have in Bol'ma alata (Fig. 16). BoUna
cdata ranks among the most perishable of all our MedusJB ; but this
species seems to be very hardy, as I kept one large specimen alive
for three weeks, during the whole of my stay at Naushon. This speci-
men also laid eggs, which were developed into small MnemiopsidiB,
after passing through stages in which it was almost impossible to say
whether the Medusa was a young Pleurobrachia or not. As is the
case in Bolina, the long tentacles, the globular outline of the young,
resem))led so closely the young of Pleurobrachia, which were develop-
mg at the same time in another Jjottle, that frequently I would be
unable, after leaving them for some time, to decide at once to which

Fig. 22. Mnemiopsis Leidyi seen from the broad side, o, starting-point of branch of tentacu-
lar apparatus extending along the furrow,/, to n, the base of the auricles.
Fig. 23. The same as Fig. 22, seen from the narrow side.

22 JMNEMIOPSIS LEIDYI.

species the young belonged, as the difference between the diameters is
far less marked than in Bolina. As they advance in size, the lobes
become developed, the tentacles disappear, and they can be readily
distinguished. The development goes on in the envelope for a week
or ten days after the eggs are laid, the young Medusa not breaking
through the outer membrane before it is well advanced, and capable
of guiding its motions through the water. The difference between the
two transverse diameters of the spherosome is not as great as in Bolina,
as will readily be seen by comparing the broad and narrow views of
this Ctenophore (Figs. 22, 23). What is very peculiar in the genus
Mnemiojisis is the peculiar development of the tentacular apparatus.
It is not, as in Bolina, reduced to a simple bulb, with a few tentacles
clustered at the base ; but is more like what we find in Lesueuria,
where the threads of the tentacular bulb are quite long, and have a
decided, tendency to spread fon-shaped on both sides of the bulb. We

have a rather small tentacular bulb placed
^^^^^^^^^^^ 'it the end of a long, slender tube, a short
distance above the opening of the actino-
stome (o. Fig. 22). This tentacular bulb
is protected by a kind of two-lapped hood
(Fig. 24), the folds of which extend on
each side aloiig a groove towards the abac-
tinal pole, to the very origin of the auri-
cles, at o. Fig. 22, taking their origin at
o. Fig. 22 ; their origin from the bulb is
better seen in Fig. 24, where a portion of the two branches of the
tentacular apparatus, extending along this groove, is represented.
It is exactly as if we had the tentacles of a Pleurobrachia, instead of
swimming and floating freely about, 2:)rotected by a kind of cover, and
thus pressed towards the spherosome, and prevented from moving
freely about. The whole spherosome is covered with minute spots,
clusters of lasso cells scattered iiTegularly over the surface. (See
Fig. 23.)

From what we know of the amount of water which enters into the
composition of Acalephs, and when we I'ememJjer that not more than one
half of one per cent, is animal matter, it seems strange that anything
like a parasite should be found upon these Acalephs, and stranger still
that this parasite should be able to find enough to live upon in such
a delicate animal. As early as 1835 Sars had observed a species of
intestinal worm {Scolex acalepharum) upon a large species of Mnemia
(31. norvegica Sars), ten and even twelve specimens being found at-

Flg. 24. A ]iart of tlii; tfntacular a]ii)aratiis, near the opening of the aetinostome, to show the
mode in wljieli tlie branches of tlie tentacle extend, under cover of a lappet, towards the abactinal
extremity.

LESUEURIA. 23

tachcd to the inner wall, near the upper part of the furrow, separating
the lobes from the spherosoine. Foster, in 1841, found a species of
Filaria, which he called 2'etrasfoma PlayfalrU, upon a sj^ecies of Cy-
dippe ; Greene and others have also seen parasites upon Hydroid
Medusa? ; and finally, in this species, five to eight worms, which re-
semble more a leech than anything else, though I cannot refer them
to any of the genera which are described, attaining a length of an
inch, and even an inch and a half, are frequently found attached to
the inner wall, in the upper part of the long furrow, near the eye-
speck. Hardly a specimen of this Medusa is found which has not one
or two of these parasites. It is a long, flesh-colored, cylindrical worm,
with five longitudinal white lines extending the whole length ; the
mouth, by which it is fastened to the jelly-fish, occupying the whole
of the anterior part. This mouth can be closed, extended to a point,
end, when inserted in the substance of the jelly-fish, it is expanded
again like the mouth of a trumpet, and the worm is firmly fastened.
These Avorms are sluggish in their movements, and when detached and
disturbed hardly show signs of life by the slow contractions of their
body. The worms live several days after they have been sej^arated
from the Medusa?.

Naushon, Buzzard's Bay (A. Agassiz).

LESUEURIA Milne Edw.

Lesxteuria Milne Edw. Ann. Sc. Nat., XVI., 1841, p. 199.

Lesuewia Less. Zooph. Atal., p. 90. 1843.

Lesueuria Agass. Cont. Nat. Hist. U. S., HI. p. 290. 1860.

Lesueuria hyboptera A. Agass.

In Lesueuria the tentacular ambulacra are by far the most developed ;
the locomotive flappers of the short ambulacra extend but to the be-
ginning of the auricle ; the immense size of this apparatus, projecting
beyond the level of the mouth, and the winding of the tube running
through the auricle, before it joins the lateral chymiferous tube, gives
this tube a great length when compared to the longitudinal ambulacra,
Avhich run in an almost straight course from the abactinal pole till they
meet the horizontal part of the tentacular branch which connects near
the mouth with the opposite tentacular apparatus. The tentacular ap-
paratus is similar to that of Bolina, and is also situated in the short
transverse axis. The lobes of a Lesueuria can hardly be called by that
name, as what corresponds to the loljes of Bolina are small projections
scarcely reaching below"the level of the mouthy, and in which all we

24

LESUEURIA.

find corresponding to the complicated windings of the longitudinal
aml:)iilacra are a few short, straight jDrojections of the anibulacral tuljes,
running like spurs into the thickness of the spherosome.

The outline of our Lesueuria (Fig. 25) is entirely different from that
of the Mediterranean ; the latter is quite ellipsoidal, while the North
American species shows a strong tendency to bulging out near the
actinostome, and to imitate in its outhue that of Bolina, mutilated
specimens of which, when seen swimming in the water, can easily be
mistaken for this species. It is only on noticing the position of the
mouth, the great length of the auricles, that the mistake becomes
apparent. Lesueui'ia is as transparent as Bolina, and even more slug-
gish ; it grows to a large size, four inches in polar diameter, and is
exceedingly abundant during September, large numbers being visible
on almost any clear, hot day. Its phosphorescence is a very pecuhar
bluish hght, of an exceedmgly pale steel color, but veiy intense.

What is peculiar to our species is the almost rectangular outhne
which it has when seen from the broad side (Fig. 25). The shortness

Fig. 25.

of the funnel ; the extreme tenuity of the chymiferous tubes ; the deep
depression, or rather cut, in which the eye-speck is situated, for the
abactinal part of the gelatinous spheromeres joins so closely above this
that the eye-speck literally seems imbedded in the solidity of the

Fig. 25. Lesueuria seen from the broad side, natural size.
Fi". 26. Fiii. 20 sc'cu from the uaiTOW side.

OCYROE^.

25

gpherosome. The lateral tubes are also very attenuated, and bulge
well out from the digestiV^e cavity, as is ^,^ ^

seen in a profile view from the narrow
side (Fig. 26). The view from the narrow
side shows this species to be compressed
to a far greater extent than anything we
know in Bolina ; approaching almost to
Mertensia. When in motion the auricles
are often held out extended from the body
(Fig. 26), one pair bending one way, and
the other in the opposite direction, as is
shown in Fig. 27 ; the outline of the body
when seen from the abactinal pole is nearly
elliptical (Fig. 27), and we have not the
strongly-ribbed appearance so characteris-
tic of the other Ctenophorae. The connec-
tion between the lateral and longitudinal
ambulacra, forming a circular tube round
the actinostome, can be traced in Fig. 28,
and it differs in no essential way in its
mode of formation from what we observe
in Bolina.

Massachusetts Bay, and Newport, R. I. (A. Agassiz).

Museum diagram No. 2 after A. Agassiz.

Family OCYROEiE Less.

Ocyroece Less. Zooph. Acal., p. 98. 1843.

Ocyroece Agass. Cont. Nat. Hist. U. S., IH. p. 292. 1860.

OCYROE R.iNG.

Ociiroe Raxg {non Per. et Les.). Mem. de la Soc. d'Hist. Nat., IV. p. 1"0. 1829.

Ocjiroe Less. Zooph. Acal., p. 98. 1843.

Ocijrue Agass. Cont. Nat. Hist. U. S., IH. p. 292. 1860.

Ocyroe maculata Rang.

Ocyroe maculata Rang. Mem. Soc. d'Hist. Nat. de Paris, IV. 1829, PI. 20, Fig. 1.

Ocyroe maculata Less. Zooph. Acal., p. 99. 1843.

Orymc maculata Agass. Cont. Nat. Hist. U. S., HL p. 292. 1860.

Antilles (Rang).

Fig. 27. Lesueuria seen from tlie abactinal pole.

Fig. 28. Seen from the actinal pole, to show tlie connection of the lateral and longitudinal
ambulacra.

NO. II. 4

26 SACCATE.

Suborder SACCATJE Agassiz.

Saccake Agass. Cont. Nat. Hist. U. S., HI. p. 293. 1860.
Callianiridm Esch. Syst. der Acal., p. 21. 1829.

Family MERTENSID^ Agass.

Mertensida Agass. Cont. Nat. Hist. U. S., HI. pp. 19C, 293. 1860.

MERTENSIA Less.

Mertensia Less, (non Gegenb.). Zooph. Acal., p. 100. 1843.

Mertensia ovum Morch.

Cylippe {Meriensiri) ovum Mokcii. In Nat. Bitl. til en Besk. af Grbnland, p. 97. 1857.

Berne ovum Fau. Faini. Groonl. 1 780. No. 3.5.5.

Beroe cucuUus Mod. Svensk. Vet. Ak. Nya Handl., XI. 1790.

Beroepileus ScoR. (nee Fab. nee Mull). Ar.t. Reg., II. PI. XVI. Fig. 4. 1820.

Cj/dippe ovum EscH. Syst. d. Acal., p. 25. 1829.

Cydippe cucullus Esch. Syst. d. Acal., p. 25. 1829.

Mertensia Scoreshji Less. Zooph. Acal., p. 100. 1843.

Ci/dlppe cuciwiis Less. (syn. not correct). Zoo])li. Acal., p. 105. 1843.

Mertensia cucullus Agass. Cont. Nat. Hist. U. S., III. p. 293. 18G0.

The compression of Mertensia coincides with that of Pleurobrachia.
The axis passing through the tentacular apparatus is more than twice
as long as the coeliac diameter. What is very characteristic of this
genus is the great distance at Avhich the lateral chyiniferous tubes aie
placed from the digestive cavity, and the close connection which is
shown there to exist between the tentacular apparatus and the lateral
tubes, the base of the tentacular apjiaratus seeming to give rise to
this long, slender tube, enclosing the digestive cavity in its two wide
arches, when seen from the broad side. (Fig. 29.) The spherosome
rises so much above the opening for the passage of the tentacular api)a-
ratus, that it seems, in 3,dult specimens, as if the tentacular ambulacra
were the longest.

Only one large adult specimen of this jelly-fish has been taken in
our Bay. It was at first mistaken for a large Pleurobrachia ; but the
great flattening of the spherosome, and the peculiar spiral motion
which they keep up while active, soon enal)les one to distinguish them
readily from that genus, while swimming in the water. The color, also,
is of a light-pink hue ; the spermaries are of a very brilliant crimson,
the ovaries being more dull. It has the rosette of an Idyia, with the

MERTENSIA OVUM.

27

edges smooth ; the circumscribed area is quite small ; the tentacles are
but moderately long, apparently not capable of as
great expansion as Pleurqbrachia. Our species of ^'° ^^'

Mertensia is exceedingly delicate ; the specimens
taken at Nahant and Eastport, though treated
with the greatest care, not living more than a
couple of hours when brought into confinement.
I suppose this to be the Beroe ovum of Fabricius.
The difference between the tentacular chy-
miferous tuljes and the median pairs is very
marked in young specimens. In the youngest
Mertensia observed, we find the same pear-shaped
form noticed in young Pleurobrachia. (See Fig. 41.)
The ambulacx'a, however, are far more advanced
in comparison to the tentacles, and occupy nearly
the whole of the spherosome (Fig. 30) ; the
pouches of the ambulacra concealing almost en-
tirely the digestive cavity. There are also very
prominent orange pigment-cells, which are not
found in the 3'oung of Pleurobrachia, along the

rows of locomotive flappers ; the tentacles remain simple much longer
than in Pleurobrachia. The young Mertensia is not as much com-
pressed as the young Pleurobrachia (compare Figs. 31 and 46, repre-
senting almost corresponding stages of Mertensia and of Pleurobrachia).

Fig. 30.

The compression goes on increasing with age, and in the adult it has
become one of the striking characteristics of the genus. With advan-
cing age the actinal part of the young Medusa becomes more promi-
nent, while the ambulacra have remained nearly unchanged, the long
and short ambulacra not retaining quite the same proportions they had
before they wei'e almost equally developed ; the fuimel has become

rig. 29. Adult Mertensia seen from the broail side.

Fig. 30. Young Mertensia seen from the broad side, with a simple tentacle.

Fig. ai. The same as Fig. 30, seen from the abaetinal poie.

28

MERTENSIA OVUM.

Fig. 32.

formed, the digestive cavity (d) and the lateral tubes (7) are well de-
fined. (Fig. 32.) In a view from below of this same individual (Fig. 33)
we notice the narrowing of the large ambulacral pouch into somewhat

more circumscribed
tubes. In the next
stage which is here
represented ( Fig.3 4 ),
the ambulacra have
assumed still more
the aspect of tubes,
the funnel has elon-
gated, the tentacles
have begun to send
out lateral j^rocesses,
the lateral tubes ex-
tend nearly to the
level of the mouth,
the actinal part of the young Medusa having
taken a still greater development, and having
become as long as the ambulacral part. The
tubes, both ambulacral and lateral, when seen
from below (Fig. 35), are also more narrowed
and Ijctter circumscribed. In the next stage the develojjment of the acti-
nal part of the spherosome (Figs. 36, 37) has become so striking, that we
Fig. 35. cannot fail to recognize in the young Acaleph a

Mertensia. The difference between the coeliac and
diacoeliac axis is quite prominent, giving to the
animal, when viewed from the broad (Fig. 36) or
narrow side (Fig. 37), a totally different aspect.
The tentacular apparatus differs from that of Pleu-
roljrachia in being limited to the abactinal part of
the spherosome, and not extending towards the
actinostome, as in Pleurobrachia. In the young
stages the lateral tubes are still quite close to the
digestive cavity, and do not yet flare out, as in the
adult. (See Figs. 29, 36.) The ambulacra are very nearlj' equally
developed, the tentacular pairs and the median tubes differing but
slightly in length. The tentacles are lashed and covered with large
orange jiigment-spots, similar to those of the rows of locomotive

Fig. 32.
are present.
Fig. 33.
Fig. 34.
Fisr. 35.

Somewhat more advanced IMertcnsia, seen from the narrow side ; the lateral tubes, /,

The same as Fig. 32, seen from the actinal pole.

Still more advanced Mertensia, seen from the narrow side.

The same as Fig. 34, seen from the actinal pole ; the tulies are circumscribed, and

the tentacular apparatus isolated.

CYDIPPID^.

29

flapjjers. The jMgment-spots become smaller and less conspicuous with
advancing age.

This species is exceedingly common in Eastport harbor, during the "
month of September.

Arctic Ocean (Mertens, Scoresby) ; Baffin's Bay (Fabricius) ; Massa-
chusetts Bay, and Eastjjort, Me. (A. Agassiz).

Museum diagram No. 3 after Alex. Agassiz.

Family CYDIPPID^ Gegenb. {nst. Ag.)

Cydippidce Gegenb. Archiv f. Nat., 1856, I. p. 196.
CallianirklcE EscH. (/). p.) Syst. d. Acal., p. 21. 1829.
Cydippidce Agass. Cont. Nat. Ilist. U. S., m. p. 293. 1860.

PLEUROBRACHIA Flem.

Pleurobrachia Fi.EM. Phil. Zool., 11. p. 612.
Ctjdippe EsCH. Syst. der Acal., p. 29. 1829.
Cydippe Less. Zooph. Acal., p. 104. 1843.
Pleurohrachia Agass. Mem. Am. Acad., IV. 1849, p. 314.
Pleurohraclda Agass. Cout. Nat. Ilist. U. S., III. p. 203. 1860.

Fig. 36. Still furtber advanced Mertensia, seen from the broad side.

Fig. 37. Young Mertensia about in the same condition as that of the preceding figure, seen
from the narrow side. The main branches of the ambulacral system have lost the character of
pouches.

PLEUROBRACHIA RIIODODACTYLA.

Pleurobrachia rhododactyla Agass.

rkurobraclna rTiododactyla Agass. Mem. Am. Acad., IV. p. 314, Pis. 1, 2, 3, 4, 5.
Pleurohi-achia rhododactyla Agass. Coiit. Nat. Hist. U. S., III. pp. 203, 294, PI. 2*. 18G0.
Beroe pileus Fab. (non Flem., Miill., and Eseh.). Faun. Grcinl. 1 780. No. 354.
Ci/di/ipc pileu.t GoVLV. Rep. Inv. Mass., p. 349. 1841.
Pleurohrachia rhododactijla Stimps. Mar. Inv. Grand Manan, p. 11. 1853.
Ci/dippe pileus Morch. In Naturhist. Bid. til on Bosk, af Grcinland, p. 97. 1857.
Pleurohrachia Scoresbyi Morch. In Naturli. Bid. til on Bosk, af Gronland, p. 98. 1857.
J'leurobrachia rhododactyla Packard. List of Animals dredged near Caribou Island. 1863.

The young Pleurobrachia early assumes an outline resembling the
adult ; it is slightly pear-shaped, with two very small protuberances,
like buttons, indicating the first appearance of the tentacles (Figs.
38-40, t), and has a very large transparent sphere (e) with two or

Fig. 38.

Fig. 39.

Fig. 40.

three granules, as an eye-speck. The first cavity formed in this em-
bryo is a small spherical space (Figs. 38-40, d) near the pole opposite
the eye-speck. As this grows larger it becomes elliptical, reaching to

Fig. 43.

the base of the tentacular (Fig. 41, t) knob, which now extends, like
the handle of a jar, beyond the outline ; this cavity is the digestive
cavity, and there is up to this time no sign of ambulacral tubes or cavi-

Fig. 38. Young Pleurobrachia scon from tlie broad side.

Fig. 39. Same as Fig. 38, seen from the narrow sule.

Fig. 40. Same as Fig. 38, seen from below.

Fig. 41. Pleurobrachia somewhat more advanced, seen from the broad side.

Fig. 42. Same as Fig. 43, seen from above.

Fig. 43. Same as Fig. 42, seen from the broad side, older than Fig. 41.

PLEUROBEACHIA RHODODACTYLA.

31

ties of any kind. The position of the ambulacral system is early well
defined l\v four short double rows of combs, each row not having more
than three or four combs ^( Figs. 38-41). The spherosome early shows
the great difference in the size of the longitudinal and coeliac diameters,
the tentacular diameter being nearly twice as long as the other (Figs.
40, 42). The locomotive rows extend i-apidly to the level of the upper
part of the digestive cavity. At this time the ambulacral cavity makes
its ai)pearance as a small spherical cavity, in the same way as the diges-
tive cavity. The ambulacral cavity increases rap-
idly, soon attains the size of the digestive cavity,
and occupies the whole of the abactinal extrem-
ity of the animal (Fig. 43, o). At this time the
young Pleurobrachia is quite pear-shaped, with
solid tentacles about as long as the polar diam-
eter. The ocular sphere is large, very promi-
nent (Fig. 43, e). There are two large elliptical
cavities, of nearly equal size (Fig. 43, o, d). In
the next stage the two cavities differ in their
outline, the ambulacral cavity Ijecoming more
and more rectangular, and the digestive cavity
triangular, the two being separated by a wall which grows thinner and
thinner. The combs of the amljulacral rows increase in size, and the
flappers are quite long, equalling in length half the transverse diameter
of the spherosome. The ambulacral cavity extends towards the abac-
tinal region on both sides of the thickening of the wall, supporting the
sensitive bulb. This is the first sign of the for-
mation of the funnel (Fig. 44,/), and its division
into the two branches, opening outwards. The
compression of the digestive cavity is plainly
seen at this stage, as when seen facing the ten-
tacles the cavity comes close to the outer wall
(Fig. 44), while when seen at right angles to
the tentacular diameter it occupies but a much
smaller space (Fig. 45). The tentacular bulli becomes more isolated,
the tentacle is about three times as long as the polar dia::neter. During
all this time, and from the first appearance of the locomotive flappers,
the young Medusa moves about with the greatest rapidity, turning over
in every possible direction, running round and round, with the diges-
tive cavity forward, in the envelope of the egg, as if trying to make
its escape from it ; while at other times the young Medusa remains

Fig. 44. Pleurobrachia in wliicli the digestive cavity and the ambulacral cavity are already
connected, immediately before the escape of the Medusa from the egg.

Fig. 45. Same as Fig. 44, somewhat less magnified, to show the relative size of egg envelope
and embrvo.

32

PLEUROBRACHIA RHODODACTYLA.

poised in the centre of the egg, rotating slowly on its axis, imitating,
while still in the egg, all the movements which are so characteristic of
the adult. The young Medusa, before it escapes from the egg, occupies
a comparatively small space, having thus ample room for its manifold
movements. In Fig. 44 the outline of a part of the egg is seen ; Fig. 45
is the same as Fig. 44 from the opposite side, showing the whole egg.

Before the young leaves the egg, we
^'^' *'^^ find that the ambulacral cavity and

digestive cavity connect by means of
a small opening in the centre of the
dividino- wall, and at the same time a
depression at the actinal pole soon
increases sufficiently to pierce through
the wall, and make an opening,
the mouth (Fig. 46). The young
Pleurobrachia now makes its escape
from the egg, and the changes it undergoes are very rapid ; the funnel
becomes well isolated, and the digestive cavity quite compressed, and
we see the first sign of the separation of the double row of locomotive
fiappers into tAvo very distinct rows. At the same time, when flicing

the tentacular bulb, we see a small triangular
jiouch extending along the digestive cavity,
which, when seen in profile, plainly appears
to be nothing but a coecum of the ambiUacral
cavity, formed exactly as in Bolina (Fig. 5).
These pouches are the rudimentary lateral
chymiferous tubes so characteristic of Cteno-
phoraj. At this stage the ambulacral flappers
are not as near the abactinal pole as in
former stages, on account of the elongation
of portions of the spherosome. The lateral
tubes increase rapidly in length, and soon
extend to the level of the mouth (Fig. 47, I),
while the forking of the amljulacral tubes becomes more deep. We
notice also at this time a marked difference in the size of the ambu-
lacral tubes. The tentacular ambulacra (those on each side of the
tentacular apparatus) are much shorter than the longitudinal ambulacra
(Fig. 48, c). The tentacle, also, is no longer a simple solid thread ;
long, slender offshoots, similar to the tentacle, have developed near the

Fig. 46. Same as Fifj. 44, seen from actinal side.

In all the jireeedini; fitjin-cs the cnilirvo has been drawn without the egg envelope ; but it must
be remembered that the little Medusa does not escape from the egg till it reaches the condition of
Fig. 44.

Fig. 47. Pleurobrachia swimming freely about, in which the lateral tubes, the funnel, have
become highly developed ; seen from the broad side.

PLEUROBRACHIA RHODODACTYLA.

33

point of attachment, and the peculiar abactinal system (Fig. 48) has
also made its appearance. The young Pleurobrachia has now aU the

Fig. *3.

Fig. 60.

Fig. 51.

appearance of the adult, only it is more pear-shaped, and it is about one
half of an inch in polar diameter. The ambulacra are yellowish, with large
orange pigment-cells on the svu'face of the ambulacral tubes (Fig. 49).

The difierence between the
axes, the coeliac and the dia-
coeliac, grows less and less with
advancing age, till they assume
the almost identical outlines of
the adult, as seen in Fig. 50,
which represents the coeliac
and diacoeliac views of an adult.
In Figs. 47 and 48 we have
also the first trace of the cirri
which assume such graceful
shape in the tentacles of the
adult Medusa (Fig. 51) ; the
cirri begin nearest the tentac-
ular Ijiilb, and there are at
first but two or three at the base of each tentacle.

Greenland (Fabricius) ; New England (Agassiz).

Cat. No. 3G6, Nova Scotia, Anticosti Expedition, 18G1.

Museum diagrams Nos. 4, 5, after L. Agassiz and Alex. Agassiz.

Fig. 48. Somewhat less advanced than Fig. 47, showing the lateral tubes from the nan-ow
side, as a prolongation of the ambulacral cavity.

Fig. 49. Plcui-obrachia about in condition of Fig. 47, seen from actinal pole.
Fig. 50. Adult Pleurobrachia, from the head and narrow side, natural size.
Fig. .51. A<lidt Pleurobrachia in a natural attitude, natvu-al size.
NO. II. 5

34 DRYODORA.

Pleurobrachia Bachei A. Agass.

Plcurohrachia Bachei A. Agass. ; in Agassiz's Cout. Nat. Hist. U. S., III. p. 294. 1860.

Pleiirobraclua Bachei A. Agass. resembles Pleurobrachia rhododac-
tyla in its general appearance, having about the same size ; the color
of the spherosome and of the tentacles being nearly the same. The
opening of the tentacular sac, however, is at a greater distance from
the pole, and the tentacles come out more from the side of the sphero-
some than in Pleurobrachia rhododactyla. The coeliac cavity is also
shorter, the funnel is longer, and the actinal portion of the sac shorter.
The branches leading from the digestive cavity to the chymiferous
tubes are much longer and more slender, the junction being above the
opening of the tentacular sac, while in Pleurobrachia rhododactyla
it is below, nearer the actinal pole. The greatest swelling of the
spherosome is nearer the actinal pole, not in the middle of the actinal
axis.

Found in the Gulf of Georgia, and entrance of Admiralty Inlet, W. T.,
durhig the whole Summer of 1859, from May to September.

Washington Territory (A. Agassiz).

Cat. No. 288, Gulf of Georgia, W. T., 1859, A. Agassiz.

JANIRA Oken.

Janira Oken. Lclirb. d. Naturj?., HI. 1815.

■e-'

Janira cucumis Less.

JamVn c»/c«mw Less. Zooph. Acal., p. 104. 1843.

Beroe cucumk Mert. (non Fab. n. Esch.). Mem. Ac. St. Pet., p. 522, PI. VIII. 1843.

Janira cucumis Agass. Cont. Nat. Hist. U. S., III. p. 294. 18G0.

Between Sitka and Unalaschka (Mertens).

DEYODORA Agass.

Dnjodnra Agass. Cont. Nat. Hist. U. S., III. p. 196. 18C0.

EM'hscholtzia Less. (ex. p.). Zooph. Acal., p. 102. 1843.

Merlensia Gegenbaur {tion Less.). Archiv f. Nat., 185C. I. p. 198.

Dryodora glandiformis Agass.

Dnjodnra cjUmdiformis Agass. Cont. Nat. Hist. U. S., IH. p. 294. 1860.
Beroe (/laiiijiformis Mert. Mem. AcaJ. St. Pet., p. 530, PI. XL 1833.
Eschscholtzia f/landiformis Less. Zoopli. Acal., p. 102. 1843.
Mertensia (jlaruliformis Gegexb. Archiv f. Nat., 1856, I. p. 198.

Beliring's Strait (Mertens).

EURYSTOM.E. 35

Suborder EURYSTOMJE Leuck.

Eur>/sto7ncE Leuck. ; in Van d. Hoeven HancHjuch d. Zool. German Transl. 1850.
Euryslomm Agass. Cont, Nat. Hist. U. S., III. p. 295. 1860.

Family BEROID^ Esch.

Beroiila: Escn. Syst. d. Acal., p. .38. 1829.

Beroidcc Agass. Cont. Nat. llist. U. S., III. p. 295. 1860.

BEROE Brown.

Beroe Browts. Nat. Hist. Jam., p. 384. 1756.
Medea Esch. (ex p.). Syst. d. Acal., p. 38. 1829.
Cijdalisia Less. Zool. du la Coq., p. 101. 1829.
Cijdalisia Less. Zooph. Aoal., p. 138. 1843.
Bene Agass. Cont. Nat. Hist. U. S., IH. p. 295. 1860.

Beroe punctata Cham. & Eysen.

Beroe punctata Cham. & Eys. Nov. Act., X. p. 361, PI. 31, Fig. 1.

Beroe punctata Esch. Syst. d. Acal., p. 37. 1829.

Beroe punctata Blainv. Man. d'Actin., PI. 7, Fig. 2. 1830.

Cydalisia punctata Less. Zooph. Acal., p. 139. 1843.

Beroe punctata McCr. Proc. Elliot Soc. N. H., p. 1. 1858.

Beroe punctata Agass. Cont. Nat. Hist. U. S., IH. p. 295. 1860.

McCracly has identified a species of Beroe found at Charleston with
the B. punctata Esch. I am inclined to think that it may jjrove to be
one of the species of Idyopsis found on the coast of Florida.
. Charleston, S. C. (McCrady).

IDYIA Frem.

Idi/ia Frem. Nouv. Bull. Soc. Phil., 1809, p. 329.
Medea EscH. (ex. p.). Syst. d. Acal., p. 38. 1829.
/(/,(/'■" Less. Zooph. Acal., p. 132. 1843.
Idtiia Mert. Mem. Acad. St. Pctersb., IL p. 532. 1833.
hiyia Agass. Cont. Nat. Hist. U. S., HL p. 295. 1860.

Idyia ovata Less.

Idyia omta Less. Zooph. Acal., p. 134. 1843.

Beroe Brovts. Nat. Hist. Jam., p. 384. 1 756.

Medusa Beroe LiNX. Syst. Nat. ed. X. p. 660.

Beroe ovata Escn. Syst. d. Acal., p. 36. 1829.

Idi/ia orafa Agass. Cont. Nat. Hist. U. S., HL p. 295. 1860.

Is this not one of our species of Idyopsis ?
Jamaica (Patrick Brown).

36

IDYIA ROSEOLA.

Idyia cucumis Less.

Idyia cucumis Less. Zoopli. Acal., p. 133. 1843.
Beroe cucumis Fab. Fauna Groul., 1 780, No. 353.
Beroe cucumis EscH. Syst. d. Acal., p. 36. 1829.
Medea fulgens Less. Zooph. Acal., p. 136. 1843.
Beroe cucumis Morch ; in Natiirh. Bid. af Grdnland, p. 98. 18.57.
Idyia cucumis Agass. Cont. Nat. Hist. U. S., III. p. 296. 1860.
? Idi/ia borealis Less. Zooph. Acal., p. 134. 1843.

The many species of Idyia which are described from the arctic parts
of the Atlantic Ocean, and which have been identified with Idyia
cucumis and Idyia horecdis Less, by Professor Agassiz, are probably
all identical with the Beroe cucumis of Fabricius.

Baffin's Bay (Fabricius).

Idyia roseola Agass.

Jdyia roseola Agass. Cont. Nat. Hist. U. S., HI. pp. 270, 296, Pis. 1, 2. 1860.
Idyia roseola Vack. List of Animals dredged near Caribou Island. 1863.

In the youngest Idyia which I have had the opjoortunity to observe
the digestive cavity, the eight ambulacral rows, the lateral chymiferous
tubes were already developed. When seen from above, the ambulacral
cavity has the shape of an eight-lobed rosette, with loops of different size.

Fig. 52.

Fig. 54.

Fig. 53.

^-'W^

occupying half the space of the spherosome, seen in profile (Fig. 52), and
the whole when seen from the abactinal pole (Fig. 53). We are struck
by the immense size of the lateral tubes (1), and find that the inequahty
in the lobes of the ambulacral cavity is caused by the greater size of

In Idyia, owing to a mistake in the lettering of the figures, c' is the long tube, and c the short
ambulacral tube, so that the lettering of Idyia does not exactly correspond to that of the other
young CtenophorEB.

Fig. 52. Young Idyia, seen from the narrow side.

Fig. 53. Fig. 52, seen from abactinal pole.

Young Idyia, in which the ambulacral tubes are distinct, seen from the narrow side.

Fig. 54.

IDYIA ROSEOLA.

37

the longitudinal ambulacra, the rows of locomotive flappers extending
but little way from the abactinal pole, as is the case in Pleuroln-achia.
We find also the whole spherosome covered with large pigment cells.

Fig. 66.

Fig. 57.

Fig. 65.

In specimens slightly older, the difference in size between these two
sets of tubes becomes more marked in proportion as they become sepa-
rated and distinct, as is seen in the two figures, in profile (Fig. 56) and

Fig. 59.

Fig. 5S.

from above (Fig. 55). Tlie manner in which the ambulacra! tubes are
formed, hy the drawing up into loops of the original chymiferous cavity,
is very easily followed in Idyia. It is the same in all the CtenophorEe

Fig. 55. Fig. 54, seen from the abactinal pole.

Fig. 5G. Somewhat more advanceil than Fig. 54, seen from the lii-oad side.

Fig. 57. The chymiferous tubes, c', have extended to level of actinostome ; narrow side.

Fig. 58. Tlie chymiferous tubes, c', have united with the lateral tubes, and formed a circular
tube, towards which the short ambulacra, c, are fast pashing their way. Fii-st trace of the ramifi-
cations on the long tubes, c'. Figs. 58 - 60 are seen from the broad side.

Fig. 59. Tlie short ambulacra, c, have nearly united with the circular tube ; the spurs of the
ambulacra have become more numerous and quite prominent.

Fig. GO. The circuit is now complete between the short and long ambulacra. The spure or
ramifications of the cliymiferous tubes are numerous, resembling somewhat those of the adult.

38

IDYIA CYATHINA.

Fig. 61.

Fig 62.

I have observed ; but as the tubes of the other genera are so soon
hidden by the rows of locomotive flappers, it becomes more difficult to
follow this separation than in Idyia, where the ambulacra retain always
a great size, and develop faster than the rows of flappers which cover
them. The longitudinal ambulacra increase rapidly in length, pushing
their way through the gelatinous mass (Fig. 56, c') till they reach the
level of the mouth (Fig. 57) ; they then bend inwards (Fig. 58) till
they meet the lateral chymiferous tube. The lateral ambulacra go
through the same process (Figs. 58, 59) ; and thus we have formed, by

the junction of the aml^ulacra
with the lateral chymiferous
tuljes, a circular tube round the
mouth. (Fig. 60.) The distinc-
tion between the longitudinal
and lateral ambulacra is always
maintained by the length of the
rows of locomotive flappers which
cover the ambulacral tubes. The
fringed abactinal apparatus is in
the young a circular ring ; afterwards it has four folds developed at
the extremity nearest the sensitive bulb (Figs. 59, 61), which soon
become fringes similar to those of the adult. Shortly before the circuit
is thus completed (Figs. 58, 59), the ambulacra of the young Idyia give
out a few lateral processes, the first traces of the ramifications of the
ambulacra of the adult (Fig. 62), which become more and more numer-
ous until the processes branch as in Fig. 60.

The short chymiferous tubes are, as in Pleurobrachia, on each side of
the lateral tubes, while in Bolina this is not the case, the long tubes
being near the short transverse axis.

Coast of New England, and northward to Bay of Fundy (Agassiz).
Catalogue No. 368, Nova Scotia, Anticosti Expedition, 1861.
Museum diagrams Nos. 6, 7, after Alex. Agassiz and L. Agassiz.

Idyia cyathina a. Agass.

Idyia ci/nthina A. Agas.s. ; in Agassiz 's Contrib. Nat. Hist. U. S., Vol. III. p. 296. 18C0.

This species differs from the Idyia roseola Agass. of the coast of New
England, by the sudden widening of the spherosome from the abactinal
pole. It is widest at two thirds the distance from the mouth ; it then
tapers as suddenly for another third of the distance to the mouth, and

Fig. 61. Fig. 57, seen from the abactinal pole.

Fig. 62. Adult Idyia, reduced in size one half, a, ami opening ; /), lateral radiating tube ;
c, circular tube ; d, e, f, g, h, vertical rows of dappers. Seen from the broad side.

IDYIOPSIS.

39

then very gradually. The actinal extremity of the spherosome is
slender and exceedingly movable, and the edges of the actinostome
can be extended so that it presents the appearance of two distinct
lobes. The ovaries and sperniaries are much longer sacs than in /.
roseola, and not so numerous. The locomotive flappers do not extend
as far down the chymiferous tubes as they do in our species, though
this difference may only be one of age. Found in the Gulf of Georgia,
W. T., and in the eastern part of the Straits of Fuca, during the sum-
mer of 1859. The habits of this Idyia are somewhat different from
those of our species. Instead of the sluggish movements which charac-
terize Idyia roseola, Idyia cyathina is very active, and seems to retain
the embryonic features of the genus, — short rows of flappers, and
great activity in its adult condition.

Noi'thwest coast of North America (A. Agassiz).

Cat. No. 287, Gulf of Georgia, W. T., A. Agassiz, 1859.

IDYIOPSIS Agass.

Idyiopsis Agass. Gont, Nat. Hist. U. S., III. pp. 288, 29G. 18C0.

Short vertical axis ; ambulacra very prominent ; interambulacra con-
cave ; fringes of circumscribed area arranged in two prolonged circles ;
numerous branching tubes arising from circular tube ; compression of
the body veiy strilving. (Agassiz.)

Idyiopsis Clarkii Agass.

Idyiopsis Clarkii Agass. Cont. Nat. Hist. U. S., HI. pp. 288, 296, Figs. 101, 102. 18G0.

It remains yet to be sho^vn
whether the two species of Idyi-
opsis here mentioned may not be
identical with species of Idyia de-
scribed by Eschscholtz as found on
the Brazilian coast and in the Gulf
of Mexico. The figures of Idyiop-
sis given by Professor Agassiz are
here reproduced. (Figs. 63, 64.)

South Carolina (L. Agassiz).

Fig. 63.

Fig. 64.

Fig. 63. Idyiopsis Clarkii seen from the broad side. /, funnel ; 1°, P, anterior and posterior

ambulacra ; /', I', lateral ambulacra ; d, digestive cavity ; o, moutli ; c, the lateral tube.

Fig. 64. Fig. C3, seen from the abaetinal pole, c, circumscribed area; /', I', I*, P, lateral

ambulacra ; 1°, i\ l^, l\ anterior and posterior ambulacra.

40 DISCOPIIOR^E.

Idyiopsis affinis Agass.

Idyiopsis affinis Agass. Cont. Nat. Hist. U. S., III. pp. 288, 296. 1860.

Gulf of Mexico, Tortugas, and Florida (L. Agassiz).

Oedee DISCOPnORiE Esch.

MedusaricB 'LplMK. (l^- p)- 1816.

Me'duses Per. et Les. (p. p.). 1809.

DiscophorcB planerocarpce Escir. Syst. d. Acal. 1829.

Discophorce crijptocarpce Esch. Syst. d. Acal. 1829.

Pulmograda Bl. (p. p.). Manuel d'Actinologie. 1830.

MedusidcB Br. {p. p.). Mem. Acad. St. Petci-sb. 1833.

Medusce Less. (p. p.) Zooph. Acal. 1843.

Steganophthalma Forbes. Brit. Nak. Medusae. 1848.

Acraspeda Gegenb. Syst. d. Med. ; in Z. f. W. Zool. 1856.

Craspedola Gegenb. (;j. ;;.). Syst. d. Med. ; in Z. f. AV. Zool. 1856.

Lucernariada HuxL. (non Johnst.). Lectures on Genl. Nat. Hist. . . . 1856.

Dkcophoroe Agass. Cont. Nat. Hist. U. S., IV. 1862.

Suborder HHIZOSTOME^ Agass.

Rhizoslomea; Agass. Cont. Nat. Hist. U. S., Vol. IV. pp. 9, 131. 1862.
RhizostomidcE Esch. Syst. der Acal., p. 42. 1829.
Polysiomce Br. Mem. Acad. St. Petersb. 1835, Prod., p. 228.
Rhizostomide'es Less. Zooph. Acal., p. 404. 1843.

Family RHIZOSTOMIDiE Esch.

Rhizostomidce Esch. Syst. der Acal., p. 42. 1829.

Rhizostomidm Agass. Cont. Nat. Hist. U. S., Vol. IV. p. 149. 1862.

STOMOLOPHUS Agass.

Stomolophus Agass. Cont. Nat. Hist. U. S., Vol. IV. pp. 138, 151. 1862.

Stomolophus meleagris Agass.

Stomolophus meleagris Agass. Cont. Nat. Hist. U. S., Vol. IV. pp. 138, 151 ; HI. PL 14.
Cephea rhizosloma Gibbes (jion Lamk.). Fauna of South Carolina. 1847.

Atlantic Ocean, coast of Georgia.

Catalogue No. 335, Warsaw Shoals, Georgia, L. Agassiz.

Museum diagram No. 8 after L. Agassiz.

SEMuEOSTOME.E. 41.

Family POLYCLONID^ Agass.

PolyclonidcE Agass. Cont. Nat. Hist. U. S., Vol. IV. pp. 140, 159. 1862.

POLYCLONIA Br.

roh/cloma Bn. Mem. Acad. St. Petersburg, p. 396, Pis. 21-23. 1838.
Poli/clonia Agass. Cont. Nat. Hist. U. S., IV. p. 139. 1862.

Polyclonia frondosa Agass.

Pohjdonia frondosa Agass. Cont. Nat. Hist. U. S., Vol. IV. pp. 139, 159, HI. Pis. 13, 13*.

Medusa frondosa Pall. Spicil. Zool., p. 30, PL 2, Figs. 1-3.

Cassiopea frondosa Lamk. (non Til.). Anim. s. Vert., II. p. 512.

Cassiopea frondosa EscH. Syst. (1. Acal., p. 43. 1829.

Cassiopea Pallas Per. et Les. Hist. Gen. d. Med. ; in An. Mus., XIV. p. 45.

Medusa frondosa Bosc. Hist. Nat. d. Vers., II. p. 1 70.

Cassiopea frondosa Less. Zooph. Acal., p. 405. 1843.

West Indies (Pallas) ; Florida, Key "West, and Key Largo (L. Agassiz).

Cat. No. 332, Tortugas, Fla., March, 1858, L. Agassiz.

Cat. No. 333, Key West, Fla., March, 1858, L. Agassiz and J. E. Mills.

Cat. No. 334, Key West, Fla., March, 1858, L. Agassiz and J. E. Mills.

Cat. No. 346, Florida, L. Agassiz.

Cat. No. 383, Havana, Professor F. Poey.

Museum diagram No. 8, after L. Agassiz.

Suborder SEM^OSTOME^ Agass.

SemceostomecE Agass. Cont. Nat. Hist. U. S., Vol. IV. pp. 9, 159. 1862.

Family AURELIAD^ Agass.

AureliadcE Agass. Cont. Nat. Hist. U. S., Vol. IV. pp. 80, 159. 1862,

AURELIA Per. et Les.

Amelia P:6r. et Les. Ann. du Mus., XIV. p. 45. 1809.
Aurelia Less. Zooph. Acal., p. 348. 1843.
Amelia Agass. Cont. Nat. Hist. U. S., IV. p. 159. 1862.
Medusa Linn. Faun. Suae., p. 511.
Medusa EscH. Syst. der Acal., p. 61. 1829.
Ephijra Pek. et Les. Hist. Gen. des Med., p. 42.
Ocyroe Per. et Les. Hist. Gen. des Med., p. 43.
Evayora Per. et Les. Hist. Gen. des Med., p. 31.
Scyp/ihtoma Sars. Bidrag til Socdyrenes Nat. 1829.
Rhizostoma EsCH. Syst. d. Acal., p. 45. 1829.
Strohila Sars. Beskriv. . . . over Polyp, ... p. 16. 1835.
Diplocraspedon Br. Prod. ]Mem. Acad. St. Petersburg, p. 226. 1835.
Monocraspedon Br. Prod. Jlem. Acad. St. Petersburg, p. 225. 1835.
Claustra Less. Zoopli. Acal., p. 378. 1843.
Biblis Less. Zooph. Acal., p. 339. 1843.
NO. II. 6

42

AURELIA FLAVIDULA.

I h

Aurelia flavidvila Pee. et Les.

vl ure/ia /?oivV/H/a Per. et Les. Ann. Mus., XIV. p. 47. 1809.

Aurelia Jlai-iiliiJa Less. Zoopli. Aeal., p. 376. 1843.

Medusa aurila Fab. Faun. Gron., No. 356. 1780.

Aurelia aurila Gould. Rep. Inv. Mass., p. 348. 1841.

Aurelia flaridula GoviX). Rep. Inv. Mass., p. 348. 1841.

Ephyra octohbala Gould. Rep. Inv. Mass., p. 348. 1841.

Aurelia aurila Stimps. Mar. Inv. Grand Manan, p. 11. 1853.

Aurelia aurila Morch ; in Nat. Bid. til en Besk. af Grbnl., p. 95. 1857.

Aurelia sex-orariis MoRcn ; in Nat. Bid. til en Besk. af Gronl., p 95. 1857.

Aurelia faridula Agass. Cont. Nat. Hist. U. S., III. Pis. 6, 7, 8, 9, 11, 11% IP; PI. 10, Figs. 18,

22, 31, 32, 36 ; PI. 10% Figs. 4\ 13, 15', 16-41 ; PI. IP, Figs. 1-13 ; IV. pp. 10, IGO.
Aurelia Jiavidula Packard. A List of Animals . . . 18G3.

^J?L**- Occurs from March to the

end of October ; they collect
together, and form large
banks at the spawning sea-
son. Professor Agassiz has
already spoken of the possi-
bility of this species proving
identical with the Northern
Eurojiean Aurelia aurita.
But this, as well as the
identity of Cyanea arctica
with the European representr
atiye, can only be decided
after renewed examination
of these species.

Figs. 65, 66 are copied
from Professor Agassiz's Con-
tributions ; they give a pro-
file, and a view from the ab-
actinal pole, of our Aurelia.
Greenland (Fabricius) ;
New England (Gould, Ag-
assiz).

Cat. No. 3.37, Nahant, 1861, L. Agassiz.

Cat. No. 338, Nahant, 1861, A. Agassiz.

Cat. No. 339, Nahant, 1858, L. Agassiz.

Cat. No. 340, Boston, 1862, H. J. Clark.

Cat. No. 341, Trenton, Me., 1860, Verrill and Shaler.

Cat. No. 347, Boston, 1862, H. J. Clark.

Cat. No. 367, Gulf of St. Lawrence, 1861, Anticosti Expedition.

Museum diagrams Nos. 9, 10, 11, after L. Agassiz.

Fig. 65 is a profile view of Aurelia flavidula, much reduced.

Fig. 66 an abactinal view of Aurelia flavidula. I, II, III, IV, arc the ambulacral zones ; A, B,
c, D, the interainbulacral zones ; 1, 2, 3, 4, a, b, the respective halves of these systems.

STHENONI^. 43

Aurelia labiata Cham, et Etsen.

Aurelia labiata Cham, et Eysenh. N. Acta, X. p. 3a8, PI. 38, Fig. 1.

Medusa labiata EscH. Syst. d. Acal., p. 64. 1829.

Oci/roe labiata Bl. Man. d'Actinol., PI. 42, Figs. 1, 2. 1834.

Aurelia labiata Less. Zooph. Acal., p. 377. 1843.

Aurelia labiata Ag.\ss. Cont. Nat. Hist. U. S., IV. p. 160. 1862.

Many of the Discophora? of the southern part of the Northwest Coast
must breed during the whole year, as I have found the adult with the
ovaries fully developed during nearly every month of the year, in the
harbor of San Francisco. This is at least the case with Phacellophora
and Aurelia, which are the two most common genera of the harljor of
San Francisco. Further north, however, in the Gulf of Georgia, the
Discophorre pass the winter in their hydra state.

North California (Cham, and Eysen.) ; California (Eschscholtz) ; San
Francisco Bay (A. Agassiz).

Aurelia marginalis Aoxass.

Aurelia marginalis Agass. Cont. Nat. Hist. U. S., IV. pp. 86, 160. 1862.

Florida, Key West (L. Agassiz).

Cat. No. 352, Key West, Fla., L. Agassiz.

Family STHENONIiE Agass.

Sthenonice Agass. Cont. Nat. Hist. U. S., Vol. IV. jjp. 115, 161. 1862.

HECCiEDECOMMA Br.

Hecca-decomma Brandt. Mem. Acad. St. Pctei-sb., p. 300. 1838.
Hecccedecomma Agass. Cont. Nat. Hist. U. S., IV. p. IGl. 1862.

Heccaedecorama ambiguum Br.

Hecccedecomma amhir/uum Be. Mem. Acad. St. Petersb., p. 300, Pis. 27, 28. 1838.
Hecccedecomma ambiguum Agass. Cont. Nat. Hist. U. S., IV. p. 161. 1862.
Cijanca amhicjua Less. Zooph. Acal., p. 388. 1843.

A species of this genus was observed in the Straits of Fuca, agreeing
with the description and figures of Mertens so closely, that it is prob-
able he observed this same species on the coast of Russian North
America.

Port Townshend, W. T. (A. Agassiz).

44 CYANEID^.

PHACELLOPHORA Br.

Phacellophora Br. {non Hiixl.). Prod. Mem. Acad. St. Pet., p. 223. 1835.
Phacellophora Less. Zoopli. Acal., p. 343. 1843.
Phacellophora Agass. Cont. Nat. Hist. U. S., IV. p. 161. 1862.

Phacellophora camtschatica Br.

Phacellophora camtschatica Br. Mem. Acad. St. Pctcrsb., p. 366, PI. 8. 1838.
Phacellophora camtschatica Less. Zooph. Acal., p. 344. 1843.
Phacellophora camtschatica Ag.\ss. Cont. Nat. Hist. U. S., IV". p. 161. 1862.

The number of species of large Discophorous Medusae found on the
western coast of North America gives to the Acalephian Fauna of
California a very characteristic stamp, when compared with that of
the eastern coast.

Petropaulowsk (Mertens) ; San Francisco Bay (A. Agassiz).

Family CYANEID^ Agass.

Cyaneidce Agass. Cont. Nat. Hist. U. S., Vol. IV. pp. 114, 161. 1862.

CYANEA Per. et Les.

Cyanea Per. et Les. Ann. du Mus., XIV. p. 51. 1809.

Cyonea EscH. Syst. der Acal., p. 67. 1829.

Ci/anea Cuv. Reg. An. 1818.

Cyanea Less. Zooph. Acal., p. 379. 1843.

Cyanea Agass. Cont. Nat. Hist. U. S., Vol. IV. p. 161. 1862.

Cyanea arctica Per. et Les.

Cyanea arctica Pin. et Les. Ann. Mus., XIV. p. 51. 1809.

Cyanea arctica Agass. Cont. Nat. Hist. U. S., IV. pp. 87, 162; Vol. HI., Pis. 3, 4, 5, 5'; PI. 10,

Figs. 1-17, 19-21, 23-30, 33-35, 37-38; PI. 10", Figs. 1-4% 5-12", 14, 15, 17-40.
Medusa capillata Fab. (non Lin.) Faun. Groenl. No. 358. 1 780.
Cyanea Postelsii Gould (non Br.). Rep. Inv. Mass., p. 347.
Cyanea Postelsii Stimps. Mar. Inv. Grand Manan, p. 11. 1853.
Cyanea arctica MoRCH. In Naturh. Bid. til en Besk. af Grijnl., p. 95. 1857.
Cyanea arctica Packard. Canad. Nat. Dec. 1863.

This species attains an enormous size. I measured myself a speci-
men at Nahant, the disk of which had attained a diameter of seven and
a half feet, the tentacles extending to a length of more than one
hundred and twenty feet. Our total ignorance of the young of these
large Discophora? is due to their peculiar habits. As has already been
suggested, they probably remain a great part of the time groping about

CYANEA ARCTICA.

45

the bottom of the sea, apparently coming to the surface only in their
adult condition. Havmg accidentally visited the wharves of Province-

town harbor early one morning, between four and five, I was aston-
ished to perceive what a large number of young Cyaneas were floating

Fig. 67. Cyanea arctica very much reduced. The tentacles are cut off for want of room.

46 CYANEA VERSICOLOR.

about, measuring all the way from a quarter of an inch to three inches
in diameter. On my return to the same place at seven o'clock, al-
though not a breath of air had ruffled the surflice, they had all re-
turned to deeper water. The early habits of the young Cyanea may
be only one of many similar instances of early rising among Acalephs.
Fig. 67 is copied from the Contributions of Professor Agassiz.

Greenland (Fabricius) ; Northeastern Coast of America, from Bay of
Fundy to Boston Harbor (Gould, Agassiz) ; Long Island Somid, Vine-
yard Sound (A. Agassiz).

Cat. No. 326, Chelsea Beach, Oct. 1851, L. Agassiz.

Cat. No. 327, Nahant, Aug. 1858, L. Agassiz.

Cat. No. 328, Nahant, Aug. 1858, L. Agassiz.

Cat. No. 369, Gulf of St. Lawrence, 1861, Anticosti Expedition.

Museum diagrams Nos. 12, 13, after L. Agassiz.

f

Cyanea fulva Agass.

Cyanea fuh-a Ag ASS. Cont. Nat. Hist. U. S., IV. pp. 119, 1G2. 1862.

The youngest specimerf of Cyanea which has been observed meas-
ured about one third of an inch in diameter. Its peculiar habit of
always remaining at the bottom of the vessel in which it was kept,
seemed to explain — until the observations, above mentioned, of the
early habits of Cyanea arctlca — the periodic appearance of adult
Medusae at certain times of the year, simply for the purpose of spawn-
ing, while for the remainder of their life they remain groping near
the bottom. In general appearance the young Cyanea resembles the
Cyaneidaj. It has but few marginal tentacles, the centre one being
developed far above the others ; the separate lobes of the actinostome
are, howevci-, distinct, and do not form the inextricable mass of curtains
surrounding the actinostome of a Cyanea. The digitate appendages
are developed in pairs on each side of a median line, indicating, the
position of the future genital organs. This gives us at once the rela-
tive position of the Cyaneidte and Pelagidie, the latter being only per-
manent forms resembling somewhat embryonic CyaneidtB.

Long Island Sound (L. Agassiz) ; Vineyard Sound (A. Agassiz).

Cat. No. 331, Naushon, A. Agassiz, Sept. 1861. Young.

Cyanea versicolor Agass.

Cyanea versicolor Agass. Cont. Nat. Hist. U. S., IV. pp. 119, 162. 1862.

South Carolina (L. Agassiz). ,^^

Cat. No. 329, Charleston, S. C, 1852, L. Agassiz.

PELAGIDiE. 47

Cyanea Postelsii Br.

Cyanea Postdnii Br. J>16m. Ac. St. R-t., p. 375, PI. 12, 1,3, 13». 1838.
Cyanea Postelsii Ag.\ss. Cont. Nat. Ili.st. U. S., IV. p. 162. 1862.
CyaneO]>sis heJirinc/iann Br. Mem. Ac. St. Pot., PI. 11, Fig. 1. 1838. Young?
f Cyanea ferrwjinea EscH. Svst. d. Acal., p. 70. 1829.
Cyanea Postelsii Less. Zooph. Acal., p. 387. 1843.

This species is extremely abundant diu'ing the Fall, in the Gulf of
Georgia and the Straits of Fuca, and rivals in size its representative on
the eastern shores of North America.

Kamtschatka, Aleutian Islands, and Western Coast of North America
(Eschscholtz) ; North Pacific, Norfolk Sound, between Sitka and Una-
laschka (Mertens) ; Port Townsend, W. T. (A. Agassiz).

Family PELAGID^ Geg.

PelayiclcB Gegenb. Zeitsch. f. Wiss. Zool., YIII. p. 210. 1856.
PekKjidce Agass. Cont. Nat. Hist. U. S., IV. pp. 121, 163. 1862.

PELAGIA Per. et Les.

Pelagia Per. ct Les. Ann. du Mus., XIV. p. 37. 1809.

Pelagia Escii. Syst. dcr Acal., p. 72. 1829.

Pelagia Less. Zooph. Acal., p. 388. 1843.

Pekujia Agass. Cont. Nat. Hist. U. S., IV. p. 163. 1862.

Diancea Lam. Syst. An. s. Vert., II. p. 507.

Pelagia cyanella Ter. et Les.

Pelagia cyanella Per. et Les. Ann. du ]\Ins., XIV. p. 37. 1809.

Pehtrjia cyanella EsCH. Syst. der Acal., p. 75. 1829.

Pelayia cyanella Bosc. Hist. Nat. des Vers., II. p. 140, PI. 17, Fig. 3.

Pelayia cyanella Agass. Cont. Nat. Hist. U. S., IV. jip. 128, 164, HI. Pis. 13, 13% PI. 12.

Medusa pelagia Sw.\RTZ. Konig. Vetensk. Akad. 1 788.

Medusa pelagia Li6FFl.n^G. Reise, p. 105.

Medusa pelagia Li>f. Syst. Nat.

Pelagia americana Per. et Les. Ann. du Mus., XIV. p. 39. 1809.

Pelagia noctiluca Chaji. ; in Choris' Voyage Pittoresque, p. 3. Fig. 68.

Pelagia denticnlata Per. et Les. Ann. du Mus., XIV. p. 38.

Dianwa cyanella Lamk. An. s. Vertcb., II. p. 507.

Dianma denticulata Lamk. An. s. Verteb., II. p. 507.

This species (Fig. 68) is found along the Florida
Reef In this genus the eggs develop directly into
the young MedusEe, and the embryos are never at-
tached to the ground.

Caribbean Sea (Swartz, Lciffling) ; Coast of Florida,
Tortngas (L. Agassiz).

Fig. 68. Pelagia cyanella Per. et Les. (copied from Agassiz's Contributions), a, umbrella ;
m, actinal appendages ; t, marginal tentacles.

48

DACTYLOMETRA.

Pelagia Brandtii Ag

ASS.

Pdagia Brandtii Agass. Cont. Nat. Hist. U. S., IV^. p. 164. 1862.

Pelayia denliculata Br. {non Per. et Les.). Mem. Acad. St. Pet., p. 383, PI. 14, Fig. 2. 1838.

Aleutian Islands (Mertens).

DACTYLOMETRA Agass.

Dactylometra Agass. Cont. Nat. Hist. U. S., IV. pp. 125, 166.
Chrysaora EsCH. (p.p.). Syst. d. Acal., p. 78. 1829.

1863.

Fig 69.

Dactylometra quinquecirra Agass.

Dactylometra gidnquecirra Agass. Cont. Nat. Hist. U. S., IV. pp. 125, 166. 1862.
Pelagia quinquecirra Bes. Proc. Bost. Soc. N. H., p. 76. 1848.

Mr. Desor has described, in the Proceedings of the Boston Society of
Natural History, a Pelagia under the name of P. quinquecirra ; as his
description is hardly sufficient to enable one to recognize it, I add

the following particulars, on the
supposition that the Pelagia which
I found at Naushon is identical
with the one described by Mr.
Desor.

Several specimens of this Pela-
gia were taken at Naushon, the
disk measuring from four to eight
inches in transverse diameter, and
one and a quarter to two inches in
height. The general color of the
disk is yellowish blue, the surface
being covered with reddish-brown
spots (Fig. 69), crowded more
thickly towards the abactinal pole.
The spotted surface does not reach
the margin of the disk ; only dot-
ted lines extend from the lobes un-
til they are lost in the more numer-
ous spots of the central part. The
marginal tentacles have the same
color as the spots of the disk.
There are five between each of the eight eyes, arranged, one, the
largest, in the middle of the broader central lobe, and one on each side

Fig. 69. Dactylometra quinquecirra Agass. one fourth the natural size.

DACTYLOMETRA QUINQUECIRRA. 49

of the smaller lobe, the shorter tentacles being placed nearest the eyes.
There are eight marginal lobes in which the eyes are placed, eight
large lobes in the middle of the space between the eyes, from which tlie
large tentacles arise, and the space between this large lobe and tlie
lobe of the eye is occupied by the small lobes on the sides of which
the smaller marginal tentacles are placed, — making in all thirty-two
marginal lol^es. The fringes of the actinostome extend in four simple
thick lobes, with frilled edges, about twice the length of the transverse
diameter ; they are flesh color. The ovaries are seen from above as
four large yellow bunches. These Medusse are nocturnal in their hal>
its ; they are only occasionally found floating at the surface during the
day, while at night, in the same localities, the bottom swarms with
these large masses of dull phosphorescence, moving about with the
greatest rapidity. When kept in tanks, they remain torj^id during the
day at the bottom of the jars, and when night comes on begin to
become more animated, and soon move briskly about, emitting a dull
phosphorescent light. This Pelagia is always accompanied by a spe-
cies of Clupeoid, found in the folds of the frmges of the actinostome,
moving along with the jelly-fish, which, when they are pushed off
accidentally, I'ush back to their place of shelter. From twenty to thirty
specimens have been found swimming in the fringes of the actinostome.
It is strange that the fish should go there for shelter, for every once in
a while one of them pays the penalty Ijy being swallowed, Avithout this
disturbing the others in the least ; they in their turn find food in the
lobes of the actinostome, and even eat the folds themselves, until their
turn comes to be used as food. I have seen in this way three fishes
eaten during the course of as many days. The s^DCcimens measured
about an inch in length. Sars, Leuckart, and Peach have observed this
same kind of parasitism of certain species of fishes upon other Dis^
cophora3. Nor is this limited to Acalephs ; some species of Holothu-
rians, and even a Culcita, are said to give refuge to fishes.

It is somewhat strange that almost all the Medusa3 which have been
observed are found in the brighest sunshine only, or in very dark
nights. Early in the morning, and till about ten o'clock, even on clear
days. Medusa) do not make their appearance, while frdiii eleven till one
or two o'clocji they can be caught in abundance. After that time they
disappear gradually, and late in the afternoon, towards sunset, it is rare
to see a single jelly-fish. Between nine and twelve o'clock at night,
they come to the surface again; and that hour, in fiict, is one of the
most favorable for collecting, in spite of the darkness.

Nantucket Bay (Desor) ; Naushon (A. Agassiz) ; between Bermudas
and Azores (J. Di'ayton).

Cat. No. 343, Naushon, Mass., Sept. 18G1, A. Agassiz.

Cat. No. 388, Bermudas, A. S. Bickmore.

NO. II.

^M/tf-^M^,

50 MELANASTER.

POLYBOSTRICHA Br.

Polybostricha Br. Mem. Acad. St. Petersb., p. 384. 1838.
Polybostricha Agass. Cont. Nat. Hist. U. S., IV. pp. 126, 166. 1862.

The species of Polybostricha and Melanaster which are here enumer-
ated were observed during a calm oflf the bar of San Francisco ; and
although tolerably accurate notes were taken at the time, yet they are
not sufficient to warrant the description of these species under new
names. They are therefore mentioned here more for the sake of the
geographical distribution of these genera; and as some of the marine
animals of Kamtschatka are found on the coast of California, it is by
no means improbable that the species I have referred to the figures of
Brandt wiU prove, on closer examination, to be identical with them.

Polybostricha helvola Br.

Polybostricha helvola Br. Mem. Acad. St. Petersb., PI. 15, p. 384. 1838.
Polybostricha helvola Agass. Cont. Nat. Hist. U. S., IV. p. 166. 1862.
Chrysaora helvola Less. Zooph. Acal., p. 402. 1843.
Polybostricha sp. A. Agass. ; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 166.

Aleutian Islands, Sitka (Mertens) ; Punta de los Reyes, California
(A. Agassiz).

MELANASTER Agass.

Melanaster Agass. Cont. Nat. Hist. U. S., IV. pp. 126, 166. 1862.
Chrysaora Br. (^p- p-). Mem. Acad. St. Petersb., p. 385. 1838.

Melanaster Mertensii Agass.

Melanaster Mertensii Agass. Cont. Nat. Hist. U. S., IV. p. 166. 1862.
Chrysaora melanaster Br. Mem. Acad. St. Petersb., Pis. 16, 17, p. 385. 1838.
Chrysaora melanaster Less. Zooph. Acal., p. 403. 1843.
Melanaster sp. A. Agass.; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 166. 1862.

Kamtschatka and Avatska Bay (Mertens) ; off San Francisco Bar

(A. Agassiz). ^

haplostome.e. 51

Suborder HAPLOSTOME.E Agass.

Haplostomece Agass. (cxcl. Lucernarim A. Ac). C'out. Nat. Hist. U. S., IV. p. 1G7. 18G2.

Family THALASSANTHE^E Less.

ThalasMnthcce Less. Zoopli. Acal., p. 298. 1843.
Thalaifmnlheoe Agass. Cont. Nat. Hist. U. S., IV. p. 167. 1862.
yE(linul(K Gegenb. Zeits.. f. W. Zool., VIII. p. 258. 18.5G.
jEijinidije McCk. Gymn. Charl. Harb., p. 107.

FOVEOLIA Per. et Les.

Fovcolla Per. et Les. Ann. dn Mus., XIV. p. 27. 1809.
Foveolia Agass. Cont. Nat. Hist. U. S., IV. p. 168. 1862.
Cunina EscH. Syst. d. Acal., p. 116. 1829.
Cunina Bl. Man. d'Actinol., p. 279. 1834.
Cunina Less. Zoojib. Acal., p. 301. 1843.
Cunina Lamk. Syst. Anim. s. Vert., III. p. 142.
Cunina Gegexb. Zeit. f. Wiss. Zool., p. 259. 1856,
Cunina McCr. Proc. Elliot Soe., p. 108. 1857.

Foveolia octonaria A. Agass.

Cunina octonaria McCr. Proc. Elliot Soc, PI. XIL Figs. 4, 5, p. 109.

Cunina octonaria Agass. Cont. Nat. Hist. U. S., IV. p. 168. 1862.

Cmnna octonaria McCr. Pis. 4, 5, 6, 7, for Embryolog. Hist.; Elliot Soc, pp. 1-36. 1856.

Charleston, S. C. (McCrady).

Museum diagram No. 15, after McCrady.

CAMPANELLiV Bl.

CampancUa Bl. (non Less.). Man. d'Actin., p. 286. 1R34.
CampaneUa Agass. Cont. Nat. Hist. U. S., IV. p. 169. 1862.
yEyinopsis J. Mull, (non Br.). Archiv f. Anat., p. 272. 1851,

Fritz Miiller was the first to show (Wieg. Archiv., 1861) that the
position of the iEginidaj and Cliaryljdeidixj among the Hydroids was
not a natural one. He proposed for the reception of these groups a
new division equivalent to the Discophora3 and Hj'di-oids. But as he
considers the Ctenophora? and Hydromedusa^ as the two great divisions
of the Acalephs, his group of ^Egineas would hold very nearly the same
rank as that which we are induced to assign to it here, — that of a
suborder among Discophoras. From the examination of the only spe-
cies of CampaneUa thus far found on our coast, and a comparison

52 CAMPANELLA PACHYDERIVIA.

■\vitb the two species of Trachynema here enumerated, I am incHned to
add, near this suljorder, two other famihes, the j^osition of which in the
diflerent systems of classification has always been a great puzzle. I
mean the Trachynemidae and the GeryonidaB (Persa, Aglauridaj).* The
peculiar solid character of the bell of these foniilies, incapable of con-
traction to any extent, is in striking contrast with the transparent filmy
disk of the true Hydroids, reminding us of the solid mass of the larger
Discophoras. The character of the development, also, which takes
place directly from the egg, differs from that of the true Hydroids,
and we should thus remove from them those Jelly-fishes which do not
pass through an alternate generation. The peculiar character of the
marginal appendages of the Trachynemidae, so different from anything
found among the true Hydroids, and which resemble so closely those
of the Charybdeida?, is another character in fiivor of this division, as
well as the nature of the veil, which is a thick, solid, folded membrane,
approaching somewhat in character the actmal pouches formed by the
veil of Campanella.

Campanella pachyderma A. Agass.

This small Medusa is particularly interesting on account of the light
it throws on the systematic position of the ^Eginida?. Having the gen-
eral appearance of the ^ginidaj, it has, however, distinctly marked
radiating and circular tubes ; the genital organs are developed, as in
that family, in horseshoe-shaped j^ouches arranged round the base of
the proboscis, which projects through a small space left by the pendent
folds of the veil beyond the level of its actinal siu'face. The circular
tube is thus apparently placed at nearly one third of the height of the
bell, owing to the great expansion of the eight lobes of the lower floor.
The veil is attached at the inner extremity near the genital pouches,
and between every two of the chymiferous tubes it is drawn up, form-
ing a distinctly marked indentation. The position of the genital pouches
is very similar to what we find among other Discophorae, as the Lucer-
narise and Cuninidaj, for mstance, where they form an elongated lobed
rosette round the centre. The genital pouches extend in a continuous
line round the base of the proboscis. The shape of the bell is a some-
what depressed hemisphere, flaring slightly at the base ; the tentacles
are carried somewhat stiffly (Fig. 70), and are capable of but limited
contraction and expansion ; the proboscis equals in length the height
of tlie bell ; it is conical, and terminates in a smooth opening. The
veil is not very opaque, and when the medusa is seen from the actinal
side (Figs. 71, 72), tlie chymiferous tubes, as well as the circular tube,

* From the figure given by Gegcnbaur of tlio pfdunculated marginal bodies in Aglaura, the
affinity to Traeliynema (Ciree) is iinqiiestionaljle.

CAMPANELLA PACIIYDERMA.

53

can readily be seen tln-ough its thickness. The bell itself is of a dirty
yellowish color, with dark sorrel-colored spots scattered thickly over its

Fig- 71

Fig. 70.

surface ; these pigment spots are similar to the little bunches of lasso
cells found on the surface of Aurelia. The pouches are capable of

expansion and contraction, as it will often be seen that the proboscis
has considerable play when the pouches are thrown out beyond the

Fig. 70. Profile view of Campanella. 2»

Fig. 71. Actinal view of Fig. 70 ; the tentacles are cut off.

Fig. 72 is a somewhat more magnified view of Fig. 71, in which the pouches arc thrown out
beyond the circular tube, p is the outer wall of the proboscis ; g, the genital pouches ; /, the place
of attachment of the veil, as seen from the actinal side ; /', one of the pouches formed by the veil ;
/", the part of the veil intermediate between two pouches ; ^ the base of a tentacle.

Fig. 73 is a view of a part of the actinal surface in the condition of Fig. 71, when the pouches
are drawn closely round the proboscis ; lettering as in Fig. 72. p', interior of proboscis.

Fig. 74 is a magnified profile view of a portion of the base of a tentacle, c, the circular tube ;
t\ the chymiferous tube ; p", the pigment spot on lower surface of bulb ; m, the upper part of sen-
sitive bulb, in which pigment cells are loosely scattered.

Fig. 75. View of basal portion of tentacle, seen from above ; lettering as in Fig. 74. /, clus-
ters of lasso cells ; o, outer wall of bulb.

54 TRACHYNEMIDiE.

margin of the circular tube (Fig. 72), while at other times it is closely
hemmed in on all sides. (Fig. 73.) The base of the tentacles swells
out aljove and below the chyniiferous tube, forming a large bulb, in the
upper portion of which pigment-cells of a brownish-red color (Fig. 73, m)
are loosely scattered, while in the lower portion (Figs. 74, 75, jf) a
dark concentrated pigment-spot is found. The tentacles are hollow,
and are surrounded for their whole length by clusters of lasso cells
(Fig. 75, 1} similar to those of young Tubularian MedusEe, such as
Coryne and Syndiction.

The size of this Medusa is about one twentieth of an inch in diameter.

Found at Nahant, September, Alex. Agassiz.

Museum diagram No. 16, after Alex. Agassiz.

^GINOPSIS Br.

jEghiopsis Br. (7ion J. Miillor). Prod. Mem. Acad. St. Petersburg, p. 222. 1835.
JEfjinopsis Agass. Cont. Nat. Hist. U. S., IV. p. 170. 1862.
jEyinopsis Less. Zooph. Aeal., p. 304. 1843.

iEginopsis Laurentii Br.

JEginopiiis Laurentii Bii. Me'm. Ac. St. Petersb., PI. 6, p. 363. 1838.

JEginopsis Laurentii Lkss. Zooph. Acal., p. 304. 1843.

JEjinopsis Laurentii Agass. Cont. Nat. Hist. U. S., IV. p. 170. 1862.

Laurent Bay, Behring's Straits (Mertens).

Suborder TRACHYNEMID^ A. Agass.

Forbes, in his Natural History of the British Naked-eyed Medusae,
characterized as a family the Circeidte ; at that time only a few other
species of this group were kno\vii, but so imperfectly described that
even at the present day the natural affinities of these MedusiB are far
from being well ascertained. Gegenbaur, who has studied Medusa?
which I suppose to be only the young of closely allied forms, has also
separated his young Medusa? as a distinct family, under the name of
Trachynemida?. The Dicmcm conica of Lesson may even prove to be
the adult of his Trachyuema cUiatum, as it is evident from the draw-
ing of Lesson* that he has figured there a Medusa closely allied to
Circe Forbes, and perhaps identical with it. A comparison of D-achi/-
nema clliatmn (Geg. PI. IX. Fig. 6) with the young specimens of Circe
here figured, will show the close affinity of these two Medusa?. The
family name of Trachynemida^ ought therefore yield to that proposed

* Anu. Scion. Nat., Vol. X. PI. 6, Fig. 3.

TRACIIYNEMA CAMTSCIIATICUM. 55

bv Foi'bes ; vinfortunately, the name Circe had already been apphed to
a genus of Molhisks, before Brandt proposed it in 1838, and we have
therefore retained the name of Gegenbaur. Gegenbaur phiced these
Medusae m the vicinity of the Eucopidaj ; but a close examination of
their charactei's, to which I have already referred when speaking of
Canipanella, leads us to remove them — as well as the Aglaurida^,
Geryonidip, and Leuckartida3 — to the Discophora3 Haplostomea\ as a
separate suborder closely allied to the ^ginidte. Dr. Fritz Miiller,
to whom I had suggested the probability of Circe being the adult of
Trachynema, says, in one of his letters, that he has found Trachynema
near Desterro ; " in consequence of this, it is- highly probable that they
are the young of Tamoia, never having met with Circe on our coast."
If this should prove to be the case, we have a very strong argument
in favor of joining the Trachynemidge (Cu'ceans) with the Discophorie.

Family TRACHYNEMIDiE Gegenb.

TracJii/nimii/a- Gegenb. Zeit. f. Wlss. Zool., VIII. p. 249. 1856.
CIrccidm Foube.s. Brit. Naked-eyed Medusie, p. 34. 1848.
CirceidxB Agass. Cont. Nat. Hist. IT. S., IV. p. 348. 1862.
Tracliynemidce. Agass. Cont. Nat. Hist. U. S., IV. p. 3G5. 1862.

TRACHYNEMA Gegenb.

Trachiinema Gegenh. Gcnerationsweclisci, p. 50. 1854.

Circe Mertens. Br. Mem. Acad. St. Petersb., p. 219. 1835. (Preoccupied in Moll.)

Circe Forbes. Brit. Nak. Medusse, p. 34. 1848.

Circe Less. Zooph. Acal., p. 285. 1843.

Circe Agass. Cont. Nat. Hist. U. S., IV. p. 348. 1862.

Trachynema camtschaticura A. Agass.

Circe camtschalica Br. Me'm. Acad. St. Pet., p. 354, PI. I. Figs. 1-5. 1838.
Circe camtschalica Agass. Cont. Nat. Hist. U. S., IV. p. 348. 1862.
Circe camtschatica Less. Zooph. Acal., p. 285. 1843.
Circe impaliens Agass. Cont. Nat. Hist. U. S., IV. p. 349. 18C2.

A few specimens of this beautiful little jelly-fish (Fig. 76) were
caught on the shores of Galiano Island, in the Gulf of Georgia, W. T.
The greatest diameter is situated on a level with the point of suspen-
sion of the ovaries. The ovaries are flat, triangular-shaped (Fig. 77),
the chymiferous tubes very slender. The solid prolongation of the
abactinal portion of the spherosome, which extends, in the Eastern
species, to a short distance of the actinostome, is much shorter (Fig.
78) ; the chymiferous cavity is especially long, and extends to the

56

TRACHYNEMA CAMTSCHATICUM.

actinal pole in tlie ordinary state of expansion (Figs. 76, 79) ; it is only
.slightly contractile, and terminates in four stout lappets. (Fig. 80.)
The outline of the abactinal portion of the spherosome is conical, with
two very slight curves, one immediately above the point where the

Fig. 76.

Fig. 78.

Fig

;. 79.

I^^H

Fig. 80.

chymiferous tubes turn towards the actinal pole, along the solid pro-
longation of the spheromere, and the other nearer the abactinal pole.
The outline of the spherosome bends very suddenly towards the abac-
tinal pole immediately above the point of attachment of the ovaries,
somewhat as we have it in younger specimens of Trachy-
nema. The number of spheromeres is eight, and that of
the oral appendages four. The ambulacral tentacles (40
to 48) are rather contractile, and when contracted apjjear
as if they had been knotted. The general color is very
pale pink ; the ovaries, ambulacral tentacles, and the ]5ro-
boscis bemg of a liglit-l:)rown color. Although generally
this medusa moves very slowly, when disturbed its movements are very
rapid; and instead of continuing in the same direction, the animal draws
all its tentacles inside of the actinal veil, and then suddenly throws them
out again, this contraction turning the medusa almost upside down, and
starts off in nearly the opposite direction from that which it had previ-
ously pursued. This species was only seen during a short time in July.
The drawing of Brandt seems to have misled Forbes ; he speaks of
the want of ocelli of the British species as distinguishing it from the
G. camtschatlca ; what Forbes has taken for ocelli are only sections of
the chymiferous tubes leading into the peripheric tube.

Kamtschatka (Mertens) ; Galiano Island, Gulf of Georgia, W. T.
(Alex. Agassiz).

Cat. No. 282, Gulf of Georgia, W. T., 1859, A. Agassiz.

Fig. 76. Profile view of Traehynema camtscliaticum, slightly magnified.

Fig. 77. One of the genital organs, g, point of attachment to chymiferous tube.

Fig. 78. Section of Traehynema to show the size of the gelatinous prolongation, p, ami the
mode of attachment of the genital organs, rj.

Fig. 79. Cliymifernns cavity of Traehynema at the end of the gelatinous proboscis.

Fig. 80. View of Traehynema from above, to show the shape of the lips of the actlnostome.
c, chymiferous cavity at base of proboscis into which the tubes lead ; p, gelatinous ])art of pro-
boscis ; I, lips of actinostome ; Oj^qpenin^ formed by contraction of part of the chymiferous cavity.

TRACIIYNEMA DIGITALE.

57

Trachynema digitale A. Agass.

Medusa cliffilalis Fah. Faun. Groenl. No. 361. 1780.

Turns (Circe) ilifjilalis MoRCH (non Forbes). Besk. af Gronl., p. 95. 1857.

Eirene diyitale EscH. Syst. tier Acal., p. 95. 1829.

There is considerable doubt as to the specific diiference of this spe-
cies of Trachynema from the Enghsh Circe of Forbes, and from tlie
Circe camtschatica of Brandt, the series of young observed at Nahant
being the only one which gives us any measure of the changes one
species undergoes during its growth. It is evident from the figure of
Forbes that the genital organs are but slightly develojied ; m the north-

western species the only specimens observed were all males, while the
only adults of this species obtained on our coast were females. This
question must be left undecided until we have a complete history of the
English species.

The adult medusa (Fig. 81) is characterized by the thinness of the
bell, the great size of the gelatinous proboscis, which extends nearly to

Fig. 81. Adult female Trachynema, seen in profile ; magnified.

Fig. 82. Actinal view of the veil and circular tube of a very young Trachynema. c, c, c, c,
tentacles opposite the chymifcrous tubes ; greatly magnified.

Fig. 8.?. Profile view of a part of the circular tube to show the fijhls of the veil, e, one of the
pedunculated marginal capsules; t, young tentacle ; v, folds of the veil; somewhat more magnified
than Fig. 82.

NO. II. 8

58

TRACHYNEMA DIGITALE.

the level of the circular tube, and the small size of the digestive cavity.
Tlie eight ch^aniferous tubes are broad, and their course can readily be
traced along the proboscis. Tlie summit of the bell is quite conical ;
the chymiferous tubes lead into a broad circular tube, opening into the
tentacles, whicli ai'e hollow ; the tentacles appear to be easily lost, as
it is rare to obtain adult specimens in which we find anything more
than mere stumps in the place of tentacles. I have been unable
on this account to ascertam the normal number of tentacles in the
adult ; they never seem to become very numerous. (See Fig. 81.) A
tentacle is placed opposite the base of each chymiferous tube, c, c, c, . .
Fig. 82, being a view from the actinal side of the youngest Circe
observed ; between the chymiferous tubes there are in these young
Meduste two other tentacles. We find also four marginal capsules in
the young as well as the adult ; their number does not increase with
age. The capsules are large, ellipsoidal, garnetrcolored bodies, enclosed
in a fold, standing out from tlie circular tube as if attached by a short
peduncle, (e, Fig. 83.) The veil is thick, snugly folded at the inner mar-
gin (Fig. 82), the larger folds extending to the circular tube. Owing to
the sUght contractility of the bell of these Medusae, they use the veil as

Fig. 84.

Fig. 85.

their principal means of propulsion, bending it into the cavity of the
bell, and then throwing it out with great force (see Fig. 86) ; we have
nothing of the graceful motions of the gelatinous disk, so characteristic
of the Hydroid Medusae. In an adult, when seen in profile, the folds
of the veil are so thick that they are easily mistaken for rudimentary
tentacles (w, v, Fig. 83) ; it is only when we see the veil turned in, or
expanded fully outside of the bell, that their true nature is under-
stood. In adult females, the cavity of the bell is almost filled by the
eight sausage-like ovaries wliich hang do^vn from near the upper jiart
of the chymiferous tubes, almost to the extremity of the gelatinous
proboscis. (Fig. 81.) They are of a milky color, the bell is of a slightly
pinkish tint ; far from being transparent, it has a horny look, and he-

Fig. 84. Profile view of a young Tracliynema, about one eightli of an inch in height.
Fig. 85. Trachvnenia somewhat more advanced than Fig. 84.

TRACHYNEMA DIGITALK 59

comes wrinkled between the chymiferous tubes ; the tentacles, when
contracted, become crimson at the extremity.

The young Medusi.\3 are veiy difierent in shape from the adults.
Small sjDeciniens, measuring not quite an eighth of an inch in height
(Fig. 84), are quite globular; they have but few tentacles (Fig. 82),
the ovaries are not developed, the gelatinous proboscis is a mere knob
at the bottom of the bell, from which hangs dowm quite a long digestive
cavity. The abactinal part of the bell projects but slightly beyond the
general outline. It is in this stage that it resembles so closely the
Trachynema ciUatum of Gegenbaur. When ^g gg

disturbed, they carry the lips of the actinos-
tome turned up, in a very characteristic
manner, as Gegenbaur has figured them.
In somewhat older specimens (Fig. 85) the
bell has become more elongated, the tenta-
cles more numerous, the ovaries make their
appearance as small pouches, as in Eucope,
and the gelatinous proboscis has extended
somewhat into the cavity of the bell. In
still older forms (Fig. 86) these parts have
all taken a more prominent develojjment,
and we readily recognize, in the somewhat elongated bell, with the
large proboscis and slightly pendent ovaries, the future adult Trachy-
nema (Fig. 81), in which the development of the gelatinous proboscis,
of the ovaries, of the tentacles, the lengthening of the bell, and its
increase in thickness at the abactinal extremity, have been carried
still furthei-. The adult medusas attam a height of an inch or an inch
and a half

I have identified this Medusa with the Medusa digitalis of Fabricius.
Forbes had, in his Naked-eyed Medusae, supposed a species of Turris to
be identical with it ; after a careful perusal of the description of Fa-
bricius, I am satisfied that it does not belong to the genus Turris, but
to Circe of Brandt, or Trachynema of Gegenbaur. Morch, in his List
of Medusa) of Greenland, retains the generic name of Forbes, and makes
it synonymous wdth Circe ; this is certainly a very different intei'preta-
tion of the genus Turris of Lesson from what it has received thus flir
by any writer on Acalephs.

Baffin's Bay (Fabricius) ; Massachusetts Bay, Nahant (Alex. Agassiz).

Cat. No. 376, Nahant, Mass., A. Agassiz. Meduste.

Cat. No. 377, Nahant, Mass., A. Agassiz. Medusa3.

Cat. No. 449, Nahant, Mass., A. Agassiz. Medusaj.

Museum diagram Nos. 16, after Alex. Agassiz.

Fig. 8G. Young Trachynema, measuring over one third of an inch in height; the veil is
thrown out beyond tlie level of the circular tube.

'^^^j^-^-V)^ oj^.

60

LEUCKARTID.E.

PERSA McCr.

Persa McCr. Gymn. Charl. Harb. 1857.

Persa Agass. Cont. Nat. Hist. U. S., IV. p. 349. 18G2.

Persa incolorata McCr.

Persa incolorata McCr. Gymn. Charl. Harb., p. 104, PI. 12, Fig. 3. 1857.
Persa incolorata Agass. Cont. Nat. Hist. U. S., IV. p. 349. 1862.

Charleston Harbor (McCrady).

Family LEUCKARTID^ Agass.

LeucTcartidce Agass. Cont. Nat. Hist. U. S., IV. p. 3G4. 1862.
Geryonidce EscB. (p. 2).'). Syst. d. Acal., p. 86. 1829.

LIRIOPE Gegenb.

Liriope Gegenb. (non Less.). Zeit. f. W. Zool., p. 256. 1856.

Geryonia Less. Zooph. Acal., p. 329. 1843.

Geryonia EsCH. (p.p.). Syst. d. Acal., 1829. (Non Per. et Les.)

Diana;a Q. and G. Voyage de I'Uranie, p. 566.

Eurybia EsCH. Syst. d. Acal., p. 118. 1829. Young?

Eurybiopsis Gegenb. Zeit. f. Wiss. Zool., p. 24 7. 1856.

Liriope Agass. Cont. Nat. Hist. U. S., IV. p. 365. 1862.

Liriope tenuirostris Agass.

Liriope temtirostris Agass. Cont. Nat. Hist. U. S., Vol. IV. p. 365. 18G2.

Florida, Key West (L. Agassiz).

Liriope scutigera McCr.

Liriope scutigera McCr. Gymn. Cliarl. Harb., p. 106.
Liriope scutigera Agass. Cont. Nat. Hist. U. S., IV. p. 365

1862.

In company with Liriope temdrosiris is found
another species of Liriope (Fig. 87), which may
prove identical with the Liriojje scutigera of
McCrady, although it differs in the shape of the
ovaries, which are more heart-shaped than he
describes. The description of McCrady agrees
better with the figure of Liriope catherinensis
of Fritz MiiUer, with which it may prove iden-
tical.

Charleston, S. C. (McCrady).

Fig. 87. Liriope scutigera McCr. ?

LUCERNARI^. 61

Suborder LUCERNARI^ Johxst.

Lucernariadm Johxst. {non IIiixl.). Brit. Zooi>h., p. 244, Second Edition.
Calyrozoa Leuck. IMoi-phol. u. Verwandtschat't der Wirljell. Thiuru, p. 20. 1848.
Podaclinarin Edw. and IIaijie. Brit. Foss. Corals. 1850.
Luctnmriadm Agass. Cont. Nat. Hist. U. S., IV. p. 175. 1862.
Lucernarim H. J. CL.A.nK. Proc. Best. Soc. Nat. Hist., p. 47. 1862.
Lucernarim H. J. C'L.iKK. Journ. Best. Soc. Nat. Hist., p. 531. 1863.

Clark licas made of the Luceriiaria^ an order equivalent to the Hy-
droids and the Discophoraj ; but it should be remembered at the same
time that his Acalephas correspond to the Hydroid and Discophorous
Medusae of other authors, and do not include the Ctenophora?. We
would reduce this group to the level of a suborder ; for, as Professor
Agassiz has very justly said, the Lucernarias are only pedunculated
Discophora?, and have no claim to be considered as a group of a higher
value than a suborder. They seem to bear the same relation to the
free Discophora? which the Pentacrinida? do to the Comatulidtw Their
mode of development may show that their separation as a distinct sub-
order is giving even too much Aveight to their embryonic character ;
and we may find, with future investigations, a somewhat similar rela-
tion between them and the Strobila, from which free Discophor^ are
produced, as that which we have between the free and sessile species
of Tubularians.

Family CLEISTOCARPID^ H. J. Clark.

Cleistocarpidce H. J. Clark. Journ. Bost. Soc. Nat. Hist., p. 535. 1863.

HALIMOCYATHUS H. J. Clark.

Halbnoojathus H. J. Clark. Journ. Bost. Soc. Nat. Hist., p. 536. 1863.

Halimocyatlius platypus H. J. Clark.

Halimocyathus platypus H. J. Clark. Journ. Bost. Soc. Nat. Hist., p. 537.

Chelsea Beach, Mass. (H. J. Clark).

MANANIA H. J. Clark.

Manama H. J. Clark. Journ. Bost. Soc. Nat. Hist., p. 541. 1863.

62 ELEUTHEROCARPID^'E.

Manama auricula H. J. Clark.

Manama auricula H. J. Clark. Journ. Bost. Soc. Nat. Hist., p. 542. 1862.
Lucernaria auricula Fab. (iwn Miill.). Fauna Groenl., 1780, No. 332.
Lucernaria t;/pica Greene. Nat. Hist. Rev., p. 132. 1858.
Lucernaria Fabricli Agass. Cont. Nat. Hist. U. S., IV. p. 176. 1862.

I give here only the principal synonymes. For the remaining syno-
nymes of this and other species of Lucernariaj, I would refer to the
papers of Professor Clark.

Swanipscott (Agassiz) ; Greenland (Fabricius) ; Eastport, Maine (W.
Stimpson).

Family ELEUTHEROCARPID^ H. J. Clark.

Eleutherocarpidm H. J. Clark. Journ. Bost. Soc. Nat. Hist., p. 536. 1863.

LUCERNARIA Mijll.

Zwcernarm Mull. Prod. Zool. Dan. 1776.

Lucernaria Agass. (p- p.). Cont. Nat. Hist. U. S., IV. p. 175. 1862.

Lucernaria II. J. Clark. Journ. Bost. Soc. Nat. Hist., p. 551. 1863.

Lucernaria quadricornis Moll.

Lucernaria quadricornis Mi'LL. Zool. Dan., I. p. 51, PI. 39, Figs. 1-6.
Lucernaria ipiadricornis Sars. Fauna Littor., p. 20, PI. 3, Figs. 1-7.
Lucernaria quadricornis: JoHNST. Br. Zoopli., p. 252, PI. 15, Figs. 3-7.
Lucernaria fascicularis Flem. Wern. Soc, II. p. 248.

Lucernaria quadricornis Agass. Cont. Nat. Hist. U. S., IV. p. 175. 1862.
Lucernaria quadricornis Stimps. Mar. Inv. Grand Manan, p. 8. 1853.
Lucernaria quadricornis H. J. Clark. Journ. Bost. Soc. Nat. Hist., p. 551. 1863.
Lucernaria quadricornis Edw. & Haime. Hist, des Cor., HI. p. 459.

Grand Manan (W. Stimpson) ; Massachusetts Bay, Chelsea Beach,
and Swanipscott (Dr. A. A. Gould and L. Agassiz) ; Greenland (Fa-
bricius).

Cat. No. 324, Owl's Head, Maine, W. Stimpson.

Museum diagram No. 14, after L. Agassiz.

HALICLYSTUS H. J. Clark.

Haliclysius H. J. Clark. Journ. Bost. Soc. Nat. Hist., p. 559. 1863.

HALICLYSTUS AURICULA.

63

Haliclystus auricula H. J. Clark.

Halicli/slus miriciila II.-J. Clark. Journ. Bost. Soc. Nat. Hist., p. 509. 1863.
Lucernaria auricula SIull. Zool. Dan., PI. 152.
Lucernaria auricula Mont. Lin. Trans., IX. PI. 7, Fig. 5.
Lucernaria auricula JoHXST. Br. Zoopli., p. 246, Second Edition.
Lucernaria auricula Sars. Bidr. Siic. dyr., PI. 4, Fig. 1-13.
Lucernaria ocioradiata Lamk. An. s. Vert., II. p. 414. 1816.
Lucernaria auricula Edw. & Haime. Hist. d. Coralli, HI. p. 458.
Lucernaria auricula Agass. Cont. Nat. Hist. U. S., IV. p. 176. 1862.
Haliclystus auricula Fack. List of Animals. 1863.

Without attempting a critical revision of the Lucernariae, which has
become necessary in consequence of the somewhat contradictory state-
ments of Sars, Edwards, Allman, Gosse, Keferstein, and Clark, and for
Avhich the materials in the Museum do not afford sufficient data, I have
adopted the generic names of Clark, as it is plain, from what was al-
ready suggested by M. Edwards, that the Lucernaridse do not belong
to a single genus, but that severfil genera can very justly be distin-
guished upon the single genus of Lucernaria of previous authors.

Fig. 88.

Fig 89.

i«%S^

The figures here introduced are of our common Lucernaria (Figs.
88, 89), and will give a tolerable idea of the varied attitudes they
assume. This species is quite common, found at- Fig.90.

tached to eel-grass. For a further knowledge of this
group of Acalephs, I would refer to the original
j^apers quoted above.

The young of our Lucernaria (Fig. 90) shows how
much still remains to be done respectuig the changes
Avhich it undergoes. In a small Lucernaria, of one

Fig. 88. Haliclystus auricula, seen from the actinal pole.

Fig. 89. Different attitudes of Lucernaria, of Fig. 88, attached to sea-weed, contracted, ex-
panded, or with the disk thrown back, and the actinostome projecting like a proboscis. These
figures are of natural size.

Fig. 90. Young Lucernaria, magnified, about one tenth of au inch in height, a, anchors still
retaining the shape of the tentacles, t.

64 HYDROID^.

tenth of an inch in height, the arrangement of the tentacles is totally
different from that of the adult. They are as yet not arranged in clus-
ters, but placed at regular intervals in one line on the edge of the disk.
No difference can at present be detected between the anchors (a, Fig.
90) and the tentacles [t, Fig. 90) of the disk, showing plainly that the
anchors, as Professor Clark has proved, are only nKxlilied tentacles ; the
jDcduncle is also quite short, and stout in proportion to the disk. The
young Lucemaria is in this state a close representative of the genus
Carduella of Allman, which may possibly prove to be only the young
of some European species.

Greenland (Steenstrup) ; Anticosti (Verrill, Shaler, and Hyatt) ;
Massachusetts Bay (H. J. Clark).

Cat. No. 320, Nahant, Mass., A. Agassiz, May, 1862.

Cat. No. .321, Chelsea Beach, L. Agassiz.

Cat. No. 322, Mount Desert Islands, Maine, W. Stimpson.

Cat. No. 323, Anticosti Island, Anticosti Expedition, August, 1861.

Cat. No. 380, Anticosti Island, Anticosti Expedition, August, 1861.

Haliclysttis salpinx il. J- Clark.

IlaUdystus salpinx IL J. Clark. Joiirn. Bost. Soc. Nat. Hist., p. 563. 1863.

Mount Desert Islands. Maine (Stimpson).

Oeder HTDROIDiE Johnst. o«orf. agass.).

Antliozoa Hjiilroida JonxsT. Brit. Zooph., Second Edition, p. 5.

(ri/iiinnphthalma Forbes. Brit. Naked-eyed Medusa;. 1848.

Comllkiria Tabulala, Rugosa, and Hydraria Milnk Edw. & Haime.

HijilromedusK et Siphonophorce Vogt. Sipli. de Nice.

Hi/droiJea, Mvdumla Craspedola, and Siphonophnra Gegenb. Zoit. f. W. Zool. 1856.

Ifi/droidce McCr. (p. p.). Proc. Elliot Soc. 1857.

Hijdrozon HuxL. Ray Soc. 1859.

HydroUlm Agass. Cont. Nat. Hist. U. S., HI. 18G0. IV. p. 337.

From want of materials, no writer on Acalephs has thus far attempted
to make use of the embryological characters noticed in the development
of }-oung Hydroid Medusaj and of the young Hydraria. From the ob-
servations of Wright on the development of Thaumantlas inconsjncua,
of JSquorea, and from what I have had occasion to observe myself on
the Hydroid of Melicertum and of Tima, we have acquired sufficient
information to satisfy ourselves that Tubularian-like Hydroids stand
lower than the Campanularians ; while such forms as the Hydroids of

HYDROID.E. 65

Melicertum, of Trichvra, and Lafoea, stand intermediate between them.
Resembling the yonngest stages of the Campanularian Hvdrariinn we
liave such forms as Chiva and Rhjzogeton ; while the more braachin')-
forms, Eudeudrium and Bougainvillia, remind us already of somewhat
older stages. Lower still we must place Hydractinia, where the poly-
morphism of the individuals is an evident sign of inferiority, remindino-
us of the free couununities formerly separated from the Hydroids as
Siphonophores. From the close resemblance of the animal of the
Tabulata to such forms as Halocharis and the fresh-water Hydra, we
must consider them as an order, or perhaps only a suborder standinfr in
close relation to the Tubularians. Unsatisfactory as this may seem,
these few facts throw much light on our knowledge of the relations of
the Hydroids. Somewhat more satisfactory and more general results
can be obtained by comparing the young Medusa? in their various
stages of growth. As I have already shown, in a short paper on the
order of appearance of the tentacles of Hydroid Medusiv, the young,
when liberated, undergo great changes before arriving at their mature
condition ; and it requires a thorough knowledge of all these changes
to be able to recognize one and the same species in its various stages
of growth, and not to divide, as has been done so far, difterent species
by the number of tentacles, of margmal bodies, or the size of the ova-
ries. The main characteristic of the greater number of Tubularians,
when first liberated, is the totally difterent shape of the bell from that
of the adult. The bell is very deep, the number of tentacles is small
(Turritopsis, Bougainvillia, and Nemopsis) ; in the adult the shape of the
bell has become quite globular, the tentacles have increased in number,
the ovaries, which are generally absent or but slightly developed in the
young Medustv, have taken a development corresponding to their age.
Applying this to the standing of the difterent Tubularians, we should place
genera such as Clava and Eudendrium, in which the Medus* are always
sessile, lowest in their families ; next, the old genus Tubularia, such as
Tubularia proper, next Corymorpha, Hybocodon, then Ectopleura, where
we find the Medusa? losing almost entirely their embryonic character.
From these we pass to Sarsia, Syndictyon, Dipurena, Saphenia, Turris,
and Turritopsis. We then have families where the localizii tion of the ten-
tacles, the position of the ovai-ies along the prolwscis, and partly along
the chymiferous tubes, is a character of superiority, such as Dysmorphosa,
Lizzia, Bougainvillia, and Nemopsis, having a limited number of tentacles
placed at stated points along the circular tube. Closely allied to these
are such more Campanularian-like forms, as Melicertum, Ptychogenia,
and Staurophora, where the number of tentacles is large, but which
want the peculiar marginal bodies so characteristic of Campanularian
MedusfB, and where the genital organs are intimately connected with
the digestive cavity. The young of these Medusse (MeUcertum and

NO. II. 9

66 HYDROID^.

Stauropliora) have, like the young Tuljularian Medusae, a deep bell and
few tentacles ; these characters they lose witli advancing age. The
young MedusfB of the greater part of the Campanularian Hydroids,
with the exception of the Eucopidge and some of the ^Equorid«, also
have, immediately after they are liberated, a form totally unlike that
which they eventually assume. A young Clytia or Oceania has a deep
bell, only a couple of long tentacles, and few marginal capsules, having
a totally diflerent arrangement from what we find in the adult. With
advancing age, the tentacles and marginal bodies increase in number,
the disk becomes flattened, and ovaries make their appearance along
the chymiferous tubes. In the Eucopida^ the numlaer of tentacles with
which the young Medusae are liberated is far greater, the marginal cap-
sules being constant in young and old. The same is the case with the
^quorid;i5 ; they are liberated with many tentacles, and the disk, like
that of the Eucopidai, is quite flat. We find also among the Campanu-
larians, in some genera, a tendency to localization of the tentacle.s, as in
Eucheilota ; or to great complexity of the marginal capsules, as in Tima
and Tiaropsis ; and finally a great development of the gelatinous pro-
boscis, as in Eutima, Geryonia, and Tima. The gelatinous prolongation
of the disk we must regard as an embryonic feature ; the great number
of chymiferous tubes is likewise a character of inferiority ; so that we
would place lowest among the Campanularians the Geryonopsida?, all
these having tolerably deep bells and few tentacles, more I'esembling the
Tubularians ; next the ^quoridie, some of which, in their young stages
(Halojjsis), resemble the Medusce of Tubularians, with their high bell and
few tentacles ; next would come the Eucopidte, having still a large num-
ber of tentacles, but where the marginal capsules are limited in number,
and in which the young Medusa) at no time resemble the young Me-
dusae of Tubvflarians ; finally, highest of all the Campanularians would
stand the OceanidiB, where the number of tentacles is not very great, and
the complication as well as localization of the marginal capsules is very
definite. The ovaries likewise guide us somewhat in this classification ;
they extend along the proboscis and chjaniferous tubes in Tima and
the Geryonopsida^ ; in the ^quorida) they take their origin from the
base of the digestive cavity ; in the Eucopida? they are limited, as well
as in the Oceanida?, to definite parts of the chymiferous tubes.

Were we to judge simply from the nature of the Medusai of the so-
called Siphonophorae, the swimming bells and the sexual Medusae, we
should be justified in uniting them with the same order as Hydroids,
making, of the different orders which had been proposed before, only
suborders of the great order of Hydroids, and thus not recognizing the
class of SijDhonophora?, as recently modified by some natui'alists. There
is perhaps no stronger case to be brought up in confirmation of this
view, than the fact that the free Medusas of Yelella are so closely allied

IIYDROID.E. 67

to the Medusa? of some of our Tubularians, that McCrady even proposed
to separate the VelelHdi^j from the Siphonophora?, and to place them
next the Tuhuhirians ; the sexual Medusa\ also, of several of these free
Hjdroids resemble very closely other Medusae, as those of Hybocodon,
Corymorpha, and the like. AVheu we add to this the strong argument
derived from the homology of the development of the Hydroids, whether
free or floating, as is shown hereafter from Nanomia, we can have but
little hesitation in acknowledging the value of the order of Hydroids as
first limited by Professor Agassiz, and the return, as proposed by him,
to the old sul)divisions of Eschscholtz, the great master in the classifica-
tion of the Acalephie, whose views seem to stand out brighter with
every fresh investigation. For certainly the subdivision by Leuckart
of the Siphonophorse into two suborders, and the uniting of Physalia
and Porpita and the like into one order with Agalma and its allies, is a
disregard of the true value of the ordinal characters which are to be
found m the combination of the float with the rest of the community,
such as we find developed in the three great phases of embryonic
growth of a Physophore. (See Nanomia.) As to the true position of
the difi'erent orders of the old group of Siphonophora) among the
Hydroids, we cannot fail to consider them as lowest in the series ; they
form communities, the diflerent individuals of which never attain the
high degree of complication and the individuality so characteristic of
the Campanularian Medusa?, and they must therefore rank lowest, next
to Hydractinia and the like, which form the connecting link between
them and the truly fixed Hydroids.

In the limitation of the families of Hydroids, it is very difficult to
draw any line of demarcation, whenever we attempt to separate, as dis-
tinct families, those Medusa? which are always sessile, from those which
lead an independent existence. The close affinity existing between the
Hydroids of genera in which we have free and sessile Medusae, seems to
preclude the idea of separating them as distinct fiimilies, notwithstand-
ing the great difference of form between the adult Medusa?. As our
knowledge of the embryology of Hydroids becomes more extended,
cases occur more frequently in which Hydroids, so closely allied that it
is difficult to distinguish them generically, unless it be-in the breeding
season, jiroduce Medusse which are either sessile, or lead an independent
existence ; for instance, the many species of Campanularians closely allied
to Laomedea, the Tubularians of the genus Tubularia, and the different
species formerly referred to Eudendrium. We must combine, as flir as
Ave are able from existing information, our knowledge of the Medusa and
of the Hydrarium ; this seems the only rational method, and one which
has already lead those who have adopted it to very important relations
of the true affinities of Acalepha?. This view of the proper method to
be followed in the classification of Hydroids has been frequently em-

68 SERTULARI^.

ployed by Agassiz, Leuckart, and Vogt. Sars, in his paper on Cory-
morpha, has developed it fully, quoting many instances in support of
this theory. Alhnan, in a i-ecent paper on the Classification of Hy-
droids, has carried the same method out for the Tubularians.

Suborder SERTULARI^ Agass.

Serhilarkc Agass. Cont. Nat. Hist. U. S., IV. p. 348. 18G2.
Sertularina Ehrenb. C'orall. des roth. Meeres.
Serlularina Johnst. Brit. Zooph., p. 56.

Family OCEANID^ Esch. {rest. Ag.).

Oceaiililfi; Escn. Syst. d. Acal., p. 96. 1S29.

Eucopkhv Gkoenb. (p.p.). Versueh eines Sj-st. fl. Med., p. 241. 1856.

Oceanidce Agass. Cont. Nat. Hist. U. S., IV. p. 352. 1862.

The free Medusa3 which belong to this family are characterized in
their adult condition by the flatness of the bell, and its thinness, long,
hollow tentacles, not very numerous, four chymiferous tulles, marginal
capsules, and a short proboscis. The Hydrarium is remarkable for its
ringed or pedunculated reproductive calycles.

The genus Thaumantias, until the time of Forbes, contained in it
Medusa3 belonging to several genera. Forbes first jjroposed to divide
it, and suggested the name Cosmetira for his lliaumantias pilosella.
Gegenbaur, in 1856, proposed another name, that of Eucope, which in-
cluded several species of the genus Thaumantias, belonging to a dif-
ferent family, the Eucopidte.

As long as the numerous species of Thaumantias, described by Forbes,
have not been investigated again with special reference to the marginal
capsules, it is impossible to assign many of them their true position in
the genera Eucope, Oceania, and Laodicea, which have been distin-
guished in these Acalephs. It seems to me doubtful whether the genus
Epenthesis of McCrady can be retained, and I think it will eventually
prove identical with Oceania, if we limit the genus to such species as
Thaumantias hemispharica of Forbes. The Hydra of Oceania is a
Wrightia ; that of tlie Eucojie dlaphana of our coast is a Laoraedea,
resembling the L. geniculata of England. The genus Eucope of Gegen-
baur would be limited to those species which have small ovaries, occu-
pying but a short space of the ch3an!ferous tubes ; and instead of
having the long, thin, and exceedingly contractile tentacles of Oceania,
have short, stout, knotty tentacles, which are carried straight from the
edge of the disk, are hardly contractile, and have a prolongation inside
of the circular tube.

TIAROPSIS.

69

TIAROPSIS Agass.

Tiaropsis AoASa. Mem. Am. Acad., IV. p. 289. 1849.
Tiaropsis Agass. Cont. Nat. Hist. U. S., IV. p. 355. 1862.

Tiaropsis diademata Agass.

Tiarnpah diademata Agass. Mem. Am. Aca<l., IV. p. 289, PI. 6.

Tlampsis diademata Agass. Cont. Nat. Hist. U. S., lU. p. 354, PI. 31, Figs. 9-15; IV. pp. 308

-311, Fi^s. 45-48. 1862.
T'i(7TO/).«/.« diademata A. Agass. Proc. Bost. Soc. Nat. Hist., IX. p. 93, Fig. 10.
Tiarops'ix iliademata MoKCH. ; in Beskriv. af Groenland. 1857.

This Medusa is one of the earliest visitants of our wharves in the
spring. In company with Sarsia and Syndictjon, it occurs in great
numbers during the spring months ; it attains its full size in a com-
paratively short period (Fig. 91), spawns during April and May, and
after that it is found but rarely, disappearing totally during the sum-
mer. Although so common, the Hydroid of this Medusa has not been
observed. Young Medusse (Fig. 92), which are fully described in Pro-
ng. 91. Fig. 93.

fessor Agassiz's Contributions, are exceedingly numerous. The tentacles
develop independently of the eyes, while the latter never mcrease in
number. (See Fig. 93.) For a more detailed description of their mode
of growth, see also my paper on the marginal tentacles of Hydroids.

The Thaumantias Pattersonii of Greene seems to me, as far as I can
make out from his description and figures, to belong to the genus Tia-
ropsis. There must be some error in his view from above, in which he
represents black ocelli at the base of the chymiferous tubes ; I doubt if

Fig. 91. Tiaropsis diademata, natural size.

Fig. 92. Young Tiaropsis, having twenty-four tentacles.

Fig. i)3. Young Tiaropsis, having forty tentacles, r, eye-speck;/, digestive ca\'ity ; 7, chy-
mifeniLis tube ; c, primary tentacles ; o, middle tentacle ; b, third set of tentacles in pairs ; a, fourth
and fifth sets of pairs of tentacles.

70

OCEANIA.

this is really the case, as -we have nothing of the sort among any of the
other Hyflroicl Medusa?.

Massachusetts Bay (Agassiz).

Cat. No. 266, Boston, April, 1862, A. Agassiz. Medusa.

Cat. No. 267, Boston, May, 1862, A. Agassiz. Medusa.

Cat. No. 358, Boston, May, 1862, H. J. Clark. Medusa.

OCEANIA Pes. et Les.

Oceania Per. et Les. Ann. du Mus., XIV. p. 32. 1809.

Tkammmtias Escn. S)-st. d. Aoal., p. 79. 1829.

Oceania Less. Zooph. Acal., p. 318. 1843.

Phialiiliiim Leuck. Arch. f. Nat., I. 1856.

Epenihcsis McCe. Gymn. Charl. Harb., p. 89.

Oceania AoASS. Cont. Nat. Hist. U. S., IV. p. 352. 1862.

Wrightia Agass. Cont. Nat. Hist. U. S., IV. p. 35-1. 1862. Hydrarium.

Oceania foUeata Agass.

Oceania folleata Agass. Cont. Nat. Hist. U. S., IV. p. 353. 1862.
Epenthenis folleata McCr. Gymn. Charl. Harb., p. 89.

Charleston Harbor (McCrady).

Oceania languida A. Agass.

Oceania languida A. Agass. ; in Agassiz's Cont. Nat. Hist. U. S.,-IV. p. 353. 1862.
Hydrarium. The American species of Wrightia mentioned in a note by Professor Agassiz, in

Cont. Nat. Hist. U. S., IV. p. 354. 1862.
1 Campanularia syringa Stimps. Mar. Inv. Grand Manan, p. 8. 1853.

It must remain doubtful whether this species is not the Epenthesis

folleata McCr. found in Charleston Harlsor. McCrady observed only a

single specimen, and his description is too short not to leave some doubt

Pig ^ on this point. His single specimen, moreover, was

not in a normal condition, as he says there were

five labial appendages. From the ftict that there

is but one marginal capsule between each tentacle

in the Charleston species, and rarely two, Avhile

there are always tAVO, and frequently three, in the

specimens taken on our coast, I would infer that

they are distinct species.

The capsules are small, and contain only one
large granule. The bulbs at the base of tlie ten-
tacles {h, Fig. 94) are large swellings, colored with dark pigment-cells ;
the tentacles are thread-like, very extensible, with lasso-cells scattered

Fig. 94. Two marginal tentacles, with a portion of the circular tube, c, one of the marginal
capsules in process of division ; h, sensitive bulb of tentacle.

OCEANIA LANGUIDA. 71

irregularly all over the surface ; the walls of the tentacles are thin,
leaving a wide tube running to their extremity ; the labial folds of the
short digestive cavity are simple, the edges not being fringed (/, Fig.
95) ; the bell is perfectly transparent and ex-
ceedingly thin, remaining of the same thick-
ness close to the edge ; the veil is of medium
size. The ovaries and the base of the diges-
tive cavity are light brown ; the base of the
tentacles is somewhat darker. The number of
tentacles is from thirty-two to forty ; the Me-
dusa measures from three fourths to seven
eighths of an inch in size. The marginal cap-
sules are formed by division, a small portion
of the capsule being separated by a constriction, and a granule devel-
oped in it (c, Fig. 94) forms the new capsule, which gradually becomes
more and more distinct in older specimens.

The observations of Wright on Laomedea acuminata, combined with
the development given here of a Medusa (Fig. 9G) similar to the one
he observed, give us the complete history of the genus Oceania. It is
particularly important on account of the light it throws on the jarobable
identity of many of the species described by Forbes under the name of
Thaumantias, and which are distinguished by the greater or smaller
number of tentacles, and the position and size of the ovaries. Differ-
ences, similar to those by which he has distinguished such a large
number of species, are readily traced in the different stages of our
Oceania. Professor Agassiz had separated the Hydroid figured by
Wright, as a distinct genus, from Clytia, on account of the peculiar
position of the marginal capsules, totally different fi'om what is observed
in that genus. The development of the Medusa shows this to be a
correct appreciation of the differences noticed in the young ; but as the
genus of the adult Medusa is one already weU known, Wrightia, the
name given to the Hydrarium by Professor Agassiz, must be rejected.
We have on our coast two species of Wrightia?, one of which produces
planulag, and resembles, in its general apj^earance and mode of branch-
ing, the Laomedea acuminata figured by Wright in the Edinljiirgh New
Philosophical Journal for 1856; the latter, however, produces Medusje,
while the second species is closely allied to the European Campanularia
syringa ; it has reproductive calycles similar to the calycles of the
Campamdaria fastigiata Alder ; it differs considerably from the figure
of the C. syringa given by Van Beneden, the stolon of our species
being as strongly ringed as the pedicel ; the calycle is likewise slightly
constricted in the middle. This species has not been found with

Fig. 95. Magnified view of the actinostome. T, chj-iniferous tube ; /, one of the four simple
lobes of the actinostome.

72

OCEANIA LANGUIDA.

reproductive calycles in March, April, or September ; I am therefore
unable to state whether it is the Hydrarium of our common Oce-
ania.

A very young Oceaiiia (Fig. 96), soon after its escape from the
reproductive calycle, has a very deep bell (Fig. 96), two long tentacles
and two rudimentary ones at the base of the chymiferous tubes. It
resembles in its general appearance and motion the Medusa of Clytia
hicoijhora ; the bell is covered with large lasso cells, scattered irregu-
larly over the surface ; it can at once be distinguished from the latter

Fig. 97.

Fig. 9H.

Fig. 98.

Fig. 99.

Medusa by the absence of ovaries, the two long tentacles [t, Fig. 97),
and by what characterizes at once this genus, the position of the mar-
ginal capsules (c. Fig. 97) on each side of the primary tentacles {t, t',
Fig. 97), at the base of the chymiferous tubes, while in Clytia they are
placed on each side of the secondary rudimentary tentacle, half-way be-
tween the chymiferous tubes. The young Medusa, in more advanced

stages, has become' quite conical (Fig. 98),
the ovaries are forming, and, besides the two
original long tentacles, we have the two ru-
dimentary primary tentacles fully formed, as
well as eight others half-way between the
chymiferous tuljes, and rudiments of eight
additional tentacles half-way between these
and the chymiferous tubes. The proboscis
has likewise somewhat lengthened. In still
older specimens, in which the fourth set of
rudimentary tentacles has developed ( t^, Fig.
99), and in which we can trace the position of
the remaining sixteen tentacles {t", Fig. 99),
the ovaries have also taken a greater development, and are now ellipti-

Fig. 96. Young Medusa of Oceania languida, immediately after escaping from the reproduc-
tive calycle.

Fig. 97. The same, seen from the actinal pole, to show the position of the marginal capsules,
c, on the sides of the tentacles, t, V.

Fig. 98. Somewhat more advanced Medusa, in which traces of the ovaries can be detected.

Fig. 99. Quarter of the disk of a still more advanced Oceania, wdicre the remaining tentacles
of the adult Q") are developing between the tentacles, t^, t\ i', «', (^ as well as additional mai-ginal
capsules, c.

OCEANIA LANGUIDA.

73

Fi;;, 100.

Fig. 101.

cal pouches, occupying about one fifth of the length of the chymiferous
tubes. With advancing age the bell of the Oceania grows more and
more flattened, until, in the adult (Fig. 100),
it has assumed the shape of a flat segment of
a sphere. New marginal capsules are devel-
oped at the same time with the rudimentary
tentacles, one between every two tentacles
in the younger stages ; afterwards there are
from two to three capsules between the ten-
tacles in the adult. The genital organs of
the adult Medusa occupy more than two
thii'ds the length of the chymiferous tubes ;
when distended with eggs, as in Fig. 101,
they hang in irregular lobes from the point

of attachment, a ; the eggs are quite large ; there is no difference in

the shape of the male and female genital
organs, those of the males are siraj^ly some-
what darker brownish-colored than the ova-
ries. These Medusa3 are among the most
common on our shores ; they attain their
full size during September, when they are
frequently met in immense shoals on warm,
still, sunny days, collected together for spawning. The young (Fig. 90)
make their appearance as early as the end of May. The adult MedusjB
assume the most extraordinary attitudes as they float along, carried
about by the current ; the disk is so Fig. 103.

extremely flexible that at times it
seems almost as if the Medusa had
rolled itself up, as in Figure 102,
the tentacles being the strings by
which the two edges have become fas-
tened together. They are exceedingly
lazy in all their movements, hard-
ly contracting their tentacles when
disturbed, contrasting strangely with their foi'mer activity in younger
stages (Fig. 96), when they move through the water with short,
raj^id jerks, stopping only to take a more vigorous start. The
young Medusfe of Campanularians are all very active, whatever may
be the habits of the adults, while in the Tubularians we have gen-
erally in the young Medusae the temperament of the adult. Young
Medusa; of Bougainvillia, Lizzia, and Zanclea are lazy, hke the adult ;

Fig. 100. Adult Oceania languiJa, natural size.

Fig. 101. Mafjnified view of an ovary, o, aljaetinal part of the genital organ.

Fig. 102. Peculiar attitude sometimes assumed by these MedusEe.

NO. II. 10

74

EUCHEILOTA.

while Sarsia, Nemopsis, and Margelis are as active when young as
Avhen full grown.

Eastport, Maine (L. Agassiz) ; Massachusetts Bay (A. Agassiz) ; Buz-
zard's Bay (A. Agassiz).

Cat. No. 280, Naushon, A. Agassiz, September, 1861. Medusa.

Cat. No. 450, Nahant, A. Agassiz, June, 1864. Medusa.

Oceania gregaria A. Agass.

Oceania gregaria A. Agass.; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 353. 1862.

This Medusa is somewhat smaller than its Eastern representative.

It differs from it strikingly by the great length of the slender lij^s

Fig. 103. of the actinostome (Fig. 10-3) ; the color of

the genital organs and of the sensitive Ijulb

of the tentacles is a beautiful pale yellow,

in strong contrast to tlie dark coloring , of

our species ; the marginal tentacles are only

moderately contractile. The whole surface

of the water for several miles Avas often tliickly covered with these

MedusjB. Found in the Gulf of Georgia, from June to October.

Gulf of Georgia, W. T. (A. Agassiz).

Cat. No. 124, Gulf of Georgia, W. T., June, 1859, A. Agassiz. Medusa.

EUCHEILOTA McCr.

EucTieilota McCr. Gymn. Charl. Harb., p. 84.
Eucheilota Agass. Cout. Nat. Hist. U. S., IV. p. 353.

1862.

Eucheilota ventricularis McCr.

Eucheilota ventricularis McCr. G\'mn. Charl. Harbor, p. 85, PI. 11, Figs. 1 -3 ; PI. 1, Figs. 1, 2.
Eucheilota ventricularis Agass. Cont. Nat. Hist. U. S., IV. p. 353. 18G2.
Eucheilota ventricularis A. Agass. Proc. Bost. Soc. Nat. Hist., IX. Figs. 16, 17.

Fig. 104.

The small Medusa represented in Fig. 104 is exceedingly
common at Naushon, and I suppose it to be a young of this
species, though I did not trace its development long enough
to satisfy myself fully on this point. It has the characters
of the genus as given by McCrady, with the exception of
the ovaries, which were not yet developed in the oldest
specimens observed. Young specimens, of a sixteenth of an
inch in diameter, have four tentacles, one opposite each of
the chymiferous tubes, of the length of the diameter of the

Fig. 103. One of the four lips of the actinostome of Oceania gregaria.
Fig. 104. Young of Eucheilota ventricularis McCr.

EUCHEILOTA DUODECIMALIS.

75

Fig. 105.

bell, with tentacular cirri well developed ; two marginal capsules be-
tween each tentacle, and rudiments of four additional tentacles half-
way between the capsulejs. (Fig. 105.) These tentacles have at first no
lateral cirri ; it is only when they have assumed the shape of the lower
basal part of a full-grown tentacle that the cirri appear like two round
knobs, which are rapidly developed into lateral cirri before the lash of
the tentacle has been formed. The form of the young Medusa, with
only four tentacles, is globular, but it soon becomes flattened as it ad-
vances in growth. The digestive cavity is a sunple long
tube, hanging stiffly in the interior of the bell, which has
a very small circular opening ; the chj'miferous tubes are
wide ; the basal swelling of the tentacle is large and coni-
cal, narrowing very rapidly into the thread of the tentacle
itself, which is exceedingly slender, with thin walls, and
lasso cells scattered irregularly over its surface. The
marginal capsules contain only one granule, while Mc-
Crady's species contains three or four. This may prove to be the
specific difference between these young specimens and the Charleston
species, as I have not, even in those specimens Avhicli had already eight
tentacles, found more than one granule, except in a single case two, in
one of the capsules.

Charleston, S. C. (McCrady) ; Buzzard's Bay, Naushon (A. Agassiz).

Eucheilota duodeciraalis A. Agass.

Eucheilota duodecimalii A. Ag.\ss. ; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 353. 1862.

This species differs from the above in having twelve marginal cap-
sules, one on each side of the four large tentacles (c, Fig. 107), and one
in the middle of the circular tube (Fig. 106) ; there are four long ten-
tacles, with lateral cirri (f, Fig. 107)
and long slender lashes, which are
covered with lasso cells ; the cliymif-
erous tubes are wide, and from their
point of junction with the circular tube
arise ribbon-shaped genital organs (o.
Fig. 107), which do not extend more
than one third of the length of the
chymiferous tube (Fig. 106) ; the
disk is of very uniform thickness, the
inner and outer surface of the bell being almost concentric to the very

Fig. 105. More magnified view of a quarter of the disk, to show the position of the capsules
and tentacular cirri. 2, the second set of tentacles in Fiffs. 104, 105.
rig. 106. Eucheilota duodecimalis A. Agass.; greatly magnified.

Fig. 106.

76

EUCHEILOTA DUODECIMALIS.

Fig. 107. edge ; in the cavity hangs a short urn-shaped digestive sac,
attached to the four chymiferous tubes by a circular base,
and not quadrangular, as in the E. ventriailaris ; there is
only a single granule in each of the marginal ca])sules.
This species seems to be full grown, as the sexual glands
were very much distended with spermaries, and I could
not see any traces of additional tentacles ; however, as
the presence of eggs and spermaries is far from being a
criterion of maturity among these animals, we must have
further materials to decide this point. Only three speci-
mens of this species were found, — a very young female,
the male here figured, and an older female (Fig. 107''), in
which the ovaries were filled with apparently mature eggs,
the genital pouches extending from the base of the chymif-
erous tubes to the base of the 2:)roboscis ; the thickness of the
bell and its shape is totally difierent from that of the male, if it belongs
to the same species ; the bell is of uniform thickness, quite squarish
in outline ; the trace of the connection with the Hydrarium is still
very distinct, and the tentacles are carried in the erect manner so
characteristic of young Hydroid Medusae, showing that, in spite of its
well-developed ovaries, it must have but recently been liberated from its
j,.^ jj^. Hydrarium. The character of the differ-

ence between the young of these two spe-
cies of Euclieilota makes it highly probable
that the E. duodecimaUs may form, when
its adult is known, the basis for a sejjarate
genus ; we find in the arrangement of the
capsules differences siniilar m character to
those observed between the young of Oce-
ania and of Clytia, the adult Medusie of which are generically distinct,
I cannot help surmising that we shall find differences of a like nature
when the adult of E. duodecimaUs becomes known. This is the more
probable now that we know the young of E. veiitricidarls, the adult
of which has so much the general appearance of an Oceania.
Buzzard's Bay, Naushon (A. Agassiz).
Cat. No. 453, Naushon, July, 1864, A. Agassiz. Medusa.

.//.■

Fig. 107. Junction of one of the chymiferous tubes with the circular tube,
marginal capsule ; t, one of the four primary tentacles ; t', tentacular cirri.
Fig. 107*. Female Medusa of Eucheilota duodecimalis ; greatly magnified.

0, spermary ; c,

CLYTIA. 77

CLYTIA Lamx.

Cbilia Lamx. Bull. Soc. Phil.

Ciiilia Agass. Cont. Nat. Hist. U. S., IV. pp. 297, 354. 1862.

CaUcdla HixcKS.

Trochopiii-is Agass. Cont. Nat. Hist, V. S., IV. pp. 297, 3.54. 1862.

? Platijpijxk Agass. Cont. Nat. Hist. U. S., IV. pp 306, 354. 18G2.

The adult Medusa of Platypyxh a/Jindrim of Professor Agassiz is
not known ; he has separated this genus from Clytia from the character
of the reproductive calycles only. The young Medusa3 are very much
alike, and we may have a case here, the reverse of what we find in
Sarsia and Syndictyon. of Medusre very similar in their yomiger stages,
but totally different in the adult forms.

Clytia intermedia Agass.

Clytia intermedia Agass. Cont. Nat. Hist. U. S., IV. p. 305, PI. 29, Figs. 10, 11. 1862.

Cat. No. 143, Nahaut, Mass., April, 1855, H. J. Clark. Hydrarium.

Clytia VOlubiliS A. Agass.
Campamdaria voluhilis Aider Qion Auct). Cat. Zoopb. Northumb. and Durham, p. 35.

Alder was the first to distinguish the several species which have
been confounded under the name C. volubiUs by different authors.
Specimens in no way to be distinguished from the European C. volu-
biUs have been found on our coast with their reproductive calycles,
seeming to leave little doubt that the specimens here catalogued
belong to this species.

Massachusetts Bay (L. Agassiz) ; Cape Cod (L. Agassiz).

Cat. No. 145, Norway, Sars. Hydro medusarium.

Cat. No. 146, Cape Cod, June, 1857, Captain N. E. Atwood. Hydro-
medusarium.

Cat. No. 432, Sea Coal Bay, N. S., 1861, Anticosti Expedition. Hy-
dromedusarium.

Cat. No. 435, Mingan Islands, 1861, Anticosti Expedition. Hydro-
medusarium.

78

CLYTIA BICOPHORA.

Clytia bicophora Agass.

Clytia bicnphora Agass. Cont. Nat. Hist. U. S., IV. pp. 304, 354, PI. 27, Figs. 8, 9 (as C. cylin-

drka) ; PI. 29, Figs. 6-9. 18G2.
Clytia hlcoi)hora A. Agass. Proc. Boston Soe. Xat. Hist., IX. Figs. 14, 15.
Clytia cylindrica Agass. (p.p.). Cout. Nat. Hist. U. S., IV. Fig. 14. 18G2.

Under the name of Hucope campanulata, Eucope Thamnantoides, and
JEucojJe affinls, Gegenbaur has described three species, which, to judge
from the development of a similar Medusa of our coast, Clytia hicojih-
Fig. los. ora, are probably only difierent ages of the same species.

The difference in shape of the ovaries in the different
stages of the males and females, as seen in our Oceania,
may account for the diflference of form which Gegenbaur
has foimd in the genital glands : I have been able to
observe the same differences in our Clytia. The differ-
ence in the shape of the bell of his species is similar to
what we find at different periods m our Clytia. When
hatched from the calycle, the bell is globular (Fig. 108) ;
the digestive cavity is a simple cylinder ; the ovaries are
hardly visible, as very short narrow lines on both sides
of part of the upper half of the radiating tubes ; there are only four
tentacles. As it grows older, the actinal portion of the bell bulges out ;
the second set of tentacles, which were small bulbs, have now grown
out, and there are traces of eight other tenta-
cles (Fig. 109) ; the ovaries are also larger. At
this stage the bell has the shape of a segment of
a sphere, and has entirely lost its gloljular out-
line, the marginal capsules have not increased
in number, there are only two between each
radiating tube, just as we have them in the young Medusa at the time
when they are freed from the reproductive calycle. In the next stage
of the Medusa the rudimentary tentacles of Fig. 109 have developed
Jig no into long flexible lashes, usually carried curled

up, as in Fig. 110. In the adult of this Medusa
there are no traces of any additional tentacles ;
though not measuring more than a quarter
of an inch in diameter, yet they are very con-
spicuous on account of the accumulations of
black pigmentrcells in the bulb of the tentacles ;
two additional marginal capsules have also been formed, one on each
side of the four primary tentacles ; the ovaries are brownish purse-like

Fig. 109.

Fig. 108. Clytia bioophora, immediately after its escape ft-om the reproductive calycle.

Fig. 109. A somewhat older Clytia bioophora.

Fig. 110. An adult Clytia bicophora, measuring one quarter of an inch.

CLYTIA BICOPIIORA. 79

glands, extending towards the base of the proboscis. The Ilydrarium
(see figure of Professor Agassiz in Vol. IV. PI. 29, Fig. 6) grows from
three quarters to an inch jn height, in small tufts attached to Fucus ; the
calycles are strongly compressed (Fig. Ill), and differ as much in their
proportions as those of C. cylhidrica, when seen from the broad or from
the narrow side. This species may yet prove identical with the Chjtia
Johmtoni of Alder. According to the figure of Wright of the Medusa
of Ckmipanularia Johnsfoni, it can hardly be distinguished from the
Medusa of our Cli/tia bicojihora ; the Medusa of C. volnbiUs figured by
Hincks resembles also closely our Clytia Medus*. The Medusa figured
by Dalyell as the young of 31. Jimbriafa, on PI. Fig. lu.

52, Fig. 4, Rare and Remarkable Animals of
Scotland, is undoubtedly a young Medusa of C.
Johnsfoni, to judge from its characteristic attitude.
If the figure which Gosse has given of the calycle
of this same species in his " Devonshire " is correct,
there can be liut little question as to their specific
difference ; the peculiar species figured by Gosse
has, however, not been noticed by other English
observers. The Medusae of Clytia cylindrica and
of Clytia bicojjhora are so alike, immediately after
their escape from the reproductive calycles, that
when the development of Clytia cylindrica was first discovered, the
Medusas which are here figured as Clytia bicojihora (Fig. 41, Agassiz s
Cont. Nat. Hist., p. 307) were mistaken for the adult of the Medusa? of
Clytia cylindrica. As the Clytia bicojihora is very common at Nahant,
the complete development of the Medusa has been traced, and the
error is here corrected.

Ejistport, Maine (W. Stimpson) ; Massachusetts Bay (Agassiz) ; Vine-
yard Sound and Naushon (L. and A. Agassiz).

Cat. No. 133, Eastport, Maine, July, 1852, W. Stimpson. Hydrome-
dusarium.

Cat. No. 134, Beverly, Mass., July, 18G1, A. Agassiz. Hydrarium.
Cat. No. 135, Vineyard Sound, July, 1849, L. Agassiz. Hydromedu-
sariura.

Cat. No. 136, Grand Manan, August, 1857, J. K Mills. Hydromedu-
sarium.

Cat. No. 137, Nahant, Dec. 1855, H. J. Clark. Hydromedusarium.

Cat. No. 154, Eastport, Maine, July, 1852, W. Stimpson.

Cat. No. 401, Nahant, June, 18G2, A. Agassiz. Hydromedusarium.

Cat. No. 443, Nahant, June, 1864, A. Agassiz. Medusa.

Museum diagram No. 17, after L. and A. Agassiz.

Fig. 111. Sterile Hydra and reproductive calycle, seen from the broad side.

80

PLATYPYXIS.

PLATYPYXIS Agass.

Platypyxis Agass. Cont. Nat. Hist. U. S., IV. pp. 306, 354. 1862.

Platypyxis cylindrica Agass.

Cliitia {riatypyxh) cylimhlca Agass. Cont. Nat. Hist. U. S., IV. pp. 306, 354 {non PI. 27, Figs.

8, !)) ; p. 307, Figs. 42-44 {nor, Fig. 41). 1862.
Cdinpanularia volubUis Leidy. ]\Iar. Iiiv. Faun. N. Y. and R. I., p. 6. 1855.
Cmnpanularia nolifoiinis McCr. Gymn. Cliarl. Ilarb., p. 92, PI. 11, Fig. 4. ?

The reproductive calycle is conical, smooth, strongly compressed in
one direction, with a slight constriction near the free end, which jBares
outwards (Fig. 112) ; there are from thi*ee to four young Medusje
develojjing simultaneously, though only one seems to escape at a
time, and not several in close succession, as is the case with Laomedea ;
the Medusa nearest the upper extremity occupies more than half of
the whole ^pace ; there is nothmg here like the corrugations which

Fig. 114.

Fig. 112.

Fig. 113.

Gosse has figured in his C. vohibUis, or of the spur which projects
beyond the point of attachment of the calycle ; when seen edgeways,
the calycle is strongly bent at the base (Fig. 113), and the upper edges
do not flare out, as when seen from the broad side. The Hydrarium
(Fig. 114) is found in shady places, near low-water-mark, and imme-
diately beyond it ; largest specimens about an eighth of an inch in
height.

Charleston, S. C. (McCrady) ; Point Judith (Leidy) ; Massachusetts
B.ay, Nahant (L. Agassiz) ; Buzzard's Bay, Naushon (A. Agassiz).

Cat. No. 141, Naushon, Sept. 1861, A. Agassiz. Hydromedusarium.

Cat. No. 142, Nahant, Mass., Sept. 1854, H. J. Clark. Hydrarium.

Fig. 112. Reproductive calycle of P. cylindrica, seen from the broad side.
Fig. 1 1 3. The same, seen from the narrow side.
Fig. 114. Sterile Hydra of P. cylindrica.

EUCOPID^E. 81

ORTHOPYXIS Agass.

Orthopyxis Agass. Cont. Nat. Hist. U. S., IV. pp. 297, 355. 1862.
Cli/tia Lamx (p.p.). Bull. Soc. Phil. 1812.
.* Silicularia Meyen. Nov. Act., XVI. 1834.

Orthop3rxis poterium Agass.

Orlhopyxh poterium Agass. Cont. Nat. Hist. U. S., IV. pp. 297, 302, Fig. 40 ; p. 355 ; Pis. 28, 29,
Figs. 1-5. 1862.

Massachu.setts Bay (Agassiz) ; Nova Scotia (Anticosti Expedition).
Cat. No. 125, Naliant, April, 1850, H. J. Clark. Hydromedusarium.
Cat. No. 126, Nahant, June, 1861, A. Agassiz. Hydrarium.
Cat. No. 127, Nahant, July, 1861, A. Agassiz. Hydrarium.
Cat. No. 128, Nahant, August, 1861, A. Agassiz. Hydrarium.
Cat. No. 129, Nahant, September, 1854, H. J. Clark. Hydrarium.
Cat. No. 1-30, Nahant, December, 1854, H. J. Clark. Hydrarium.
Cat. No. 131, Nahant, March, 1856, H. J. Clark. Hydrarium.
Cat. No. 400, Nahant, Mass., 1862, A. Agassiz.
Cat. No. 414, Mingan Islands, N. S., Anticosti Expedition, 1861.
Museum Diagram No. 18, after L. Agassiz.

Family EUCOPID^ Gegenb.

EucopidcE Geg. (emend Agass.). Zeit. f. Wiss. Zool., p. 241. 1856.
EucopidcE Agass. Cont. Nat. Hist. U. S., IV. p. 351. 1862.

Great confusion has always existed in the identifications made of the
different species of Campanularians, on account of the difficulty of dis-
tinguishing in certain stages closely allied species. If, however, we
are fortunate enough to examine them at the breeding season, when
the characteristic reproductive calycles of the different species are in
their full development, our task will be greatly facilitated ; and any
doubts we may still have of the identity or difference of closely allied
species will be entirely removed, should we succeed in tracing the
development of the young Medusa. Although we may find it impo.s-
sible to distinguish, at certain stages of growth, young Medusaj, it
by no means follows that these Medusae, which have developed from
Campanularians easily distinguished, are identical. (Comj^are the dif-
ferent Campanularians figured in the sequel.) Whenever we succeed
in tracing the comj^lete history of any one of our Jelly-fishes, we
always find that we are able to distinguish readily closely allied
species, which our previous ignorance had led us to consider as

NO. n. 11

82 EUCOPID^.

identica. ; as, for example, the Medusas of Euco-pe. pohjcjena, Eucoj^e
diaphana, Eucope p>iiriformis, and Eucope articulata. The strongest
case we can cite is perliaps that of Syndictyon and Coryne, the adult
Medusa3 of which had long been distinguished by the difference of
color of the sensitive bulb ; but whether this was anything more than
mere individual differences could not be ascertained till we became
acquainted with the comj^lete development of the former genus, which
will be found given in its place in this Catalogue. Hincks, after
some observations limited to two genera of Hydroids, came to the
conclusion that we could have Medusa^, generically identical, developed
from Hydroids generically distinct ; this is so entirely opposed to any-
thing known in the history of the development of these animals, and
so totally disproved by the examples of Campanularians here described,
that I believe that, when the complete history of the two Medusa?
described by Hincks is fully knowai, we shall find we have only a case
of very close affinity at one stage of their development, and that, as
we become acquainted with their more advanced stages, differences will
be perceptible.

The different species of Eucopida? found on our coast, of wdiich we
know the develojjuient, explain many of the contradictory statemeuts
of European writers concerning the ixiode of development of the dif-
ferent species of Eucope. It has been shown only more recently that
many of the species, so closely allied as to be readily mistaken at any
time, except the breeding season, were reproduced, on the one hand by
Planulse, and on the other by Medusje ; and now it is found that the
Medusae produced from Hydroids which have been considered identi-
cal species, develop into very different adult forms. See, for example,
the differences in the Medusa? of Laoinedea genicidata, figured by
Wright and Gosse ; one has ovaries and the other has none, imme-
diately after its escape from the reproductive calycle, as in our Eucope
diaphana and Eucope articidcda. The Laomedea gekd'mosa of Van
Beneden has twenty-four tentacles and ovaries, as in our Eucope 2)y)'i-
formis, to which it is closely allied, while the Medusa of Laomedea
gelafinosa of English writers has sixteen tentacles at first, and is an
Obelia. The European Campanularians require a thorough revision in
order to extricate them from the confusion existing in their synonymy,
and this can only be done after a thoi'ough acquaintance with the de-
velopment of their Medusae.

The Laomedea dichotoma of Dalyell is jirobably the same as the
CampHomlaria gelafinosa of Van Beneden. The same confusion oc-
curs in the fourth volume of Professor Agassiz's Contributions ; the
Eucope which is there figured as Eucope diaphana Agass., and the
Campanularian of that name (Plate 34), is not the Hydroid of En-
cope diap)hana, as will be seen in the description of the latter. The

EUCOPE. 83

Eucope diaphana of the fourth vohime (not that of the Memoirs of the
American Academy) is probably identical with the English Euco2ie
geniculata of Wright, not that of Gosse, and it may hereafter be desig-
nated as Eucope alternata.

EUCOPE Gegenb.

E»co/ie Gegenb. Yersueh eines System ; Zeit. f. Wiss. Zool., p. 241. 1856.
Eucope Agass. Cont. iSfat. Hist. U. S., IV. p. 351. 18G4.

Eucope diaphana Agass.

Eucnpe dinphana Agass. {ex p.). Cont. Nat. Hist. U. S., IV. PI. 33, Fig. 2. Ilydrariura. 18G2.
Thaumaulidf dUiphnnn Agass. Mem. Am. Acad., IV. p. 300, Figs. 1, 2.
Eucope ilia/iliaiKi A. Agass. Proc. Bost, Soc. Nat. Hist., IX. p. 92, Figs. 7-9.
Thaumanlias diaphana MtiRCH ; in Beskriv. af Grdnlaud, j). 96. 1857.

This is by far the most common of onr Jelly-fishes ; it does not grow
to a large size, adult specimens not measuring y,„ us.

more than a quarter of an inch across the disk.
On escaping from the reproductive calycle, the
little medusa has but twenty-four tentacles, and is
constantly swimming with the disk turned inside
out, as in Fig. 115 ; at the base of two of the ten-
tacles {t', t', Fig. 116), situated on both sides of the mid-
dle tentacle, between the chymiferous tubes, are found
large spherical capsules ; there are no traces of ovaries
to be found in this early stage, it is not till the second
set of tentacles begin to develop (2, Fig. 117) that they
make their appearance. Young tentacles do not pos-
sess the rootrlike projection at their jig n,.
base ; this is only developed in older tentacles
of more advanced Medusae. (See Fig. 120.) With
advancing age the Medusas lose the haliit of
swimming with the proboscis uppermost, and grad-
ually assume the usual mode of swimming of Jelly-
fishes. The young Eucope of Fig. 117 develops
rapidly additional tentacles, the ovaries increase in
size, and we soon have an adult Medusa, with large bag-like ovaries, a

Fig. 115. A Eucope diapliana just after its escape from the reproductive calycle, seen in
profile.

Fig. 116. One quarter of the disk of the same, seen li-oni above. 1, tentacle opposite chymif-
erous tube ; t', /', tentacles with capsules.

Fig. 117. A more advanced Eucope, in which the second set of tentacles (2) is developing
between the original tentacles (1).

84

EUCOPE DIAPHANA.

slioi't proboscis, and an extremely attenuated disk, as in Fig. 118. Fig.

119, which is a still more magnified view of a quarter of the disk, seen
Fig. lis. from above, shows the extraordinary increase of

the number of tentacles, and the position of the
genital organs near the circular tube. As the
Medusa? become older, a sort of sensitive bulb is

formed at the base of the tentacles, in which a little pigment matter

is accumulated (6, Fig. 120) ; this bulb is hardly perceptible in younger

tentacles, and is totally wanting in the young Medusa?. The original

number of the capsules between every two chymiferous tubes is not

changed as the tentacles become more numerous ; in adult specimens

(Fig. 119) there are only two to be found, as in the ^.^ ^^^

youngest Medusae, just escaped from the calycle. When

examining a part of the circular tube of a Eucope -"j

somewhat more advanced than the stage represented in

Fig. 117, we find only a great increase in the sensitive

bul])s and the root of the tentacles (r, Fig. 120), but

we can perceive nowhere, in any of the most advanced

tentacles, the least trace of additional capsules, such as

are found in the two tentacles, t', t', Fig. 116, and /',

Fig. 120. The capsules (c. Fig. 120) have the same

shape and position they had in younger Meduste. The

genital organs, at first mere swellings of the chymiferous
tubes (Fig. 117), soon develop into regular pouches,
which hang down on jjoth sides of the tube ; the tube
also forms a sort of pocket at the point of attachment
of the pouch, {a, a", a'", Fig. 121.) This pocket is read-
ily seen in the male (Fig. 121) ; its shape, when seen
from above, changes considerably according to the position of the
genital pouch, {a, a", Fig. .121.) The shape of the spermaries has

Fig. 118. An adult Eucoiio diaplian.i ■.^'r-.i in profile.

Fig. 119. A quarter of Fig. 118, mon uiagiiificil.

Fig. 120. Magnified view of the circular tube of a young Eucope. 6, sensitive bulb ; r, root

of tentacle ; c, capsule ; (', tentacle with capsule.

Fig. 121. Spermaries ; a', seen from above ; a", in profile ; a'", different attitude from above.

Fig. 122. Female genital organs.

Fig. 12

EUCOPE DIAPHANA..

85

Fig. 123.

a tendency to be somewhat rectangular or bottle-shaped (Fig. 121),
while the ovaries, when distended with eggs (Fig. 122), are more
generally spherical ; the aunnber of eggs in an adult female
are not numerous, not more than twelve to fifteen ; the eggs
are quite large, and have a very sharply defined germinative
vesicle. The proboscis (Fig. 123) lengthens but little in
older Medusa?, almost the only change being the greater
mobility of the lips of the actinostome ; the veil is totally
wanting in young Medusa?, and in the adult is a very nar-
row ribbon round the circular tube, hardly extending beyond
the root of the tentacles, so that it easily escapes notice.

This Medusa is exceedingly phosphorescent, having a very white
brilliant light, which is given out most strongly at the base of the
Fig. i2i, long tentacles. These Medusae appear as early as

March, and are found as late as November. The
Hydrarium (Fig. 121) grows to but little more than
an inch in height, and resembles Laomedea genicu-
lata ; but the absence of the knee at the base of the
sterile Hydra, and the long ringed branch support-
ing it, distinguish it at once from that species. The
calycle is elliptical, arching regularly towards the
centre, and tapering at the two ends (Fig. 125) ; from twelve to
fifteen Meduste develop in each calycle. Found at rig. 125.

near low-water-mark, attached to the base of Fums
vesiculosiis.

It may be that the Medusa of Laomedea genicxdata
of Gosse, figured on Plate IV. of his "Devonshire,"
may prove to be the young of Thaumantias hicida of
Forbes, which is the English representative of our
Eucope diaphana. Should this be the case, the two
species are evidently distinct, and representative spe-
cies in the Acadian and Lusitanian Fauna. Is not
the 3Iedusa fimbriata of Dalyell (PL 52, Figs. 6, 7)
the same as the Medusa of Laomedea genicidata, and is it not also
identical with the Thaumantias lucida of Forbes ?

Massachusetts Bay, Nahant (Agassiz) ; Buzzard's Bay, Naushon (A.
Agassiz).

Cat. No. 78, Nahant, July, 1861, A. Agassiz. Hydromedusarium.

Cat. No. 79, Naushon, Sept. 1861, A. Agassiz. Hydromedusarium.

Cat. No. 281, Naushon, Sept. 1861, A. Agassiz. Hydromedusarium.

Fig. 123. ' Proboscis of an adult Medusa.

Fig. 124. Hydrarium of Eucope diaphana, natural size.

Fig. 125. Magnified view of sterile Hydra and of a reproductive calycle.

86 EUCOPE POLYGENA.

Eucope alternata A. Agass.

Eucope diaphana Agass. (ex. p.). Cont. Nat. Hist. U. S., IV. pp. 322, 352, PL 34, Figs. 1-9.
1862. Non Th. diaphana Agass., Mem. Am. Ac.

This species was at first mistaken by Professor Agassiz for the young
of Thaitmantias diaphana, figured in the Memoirs of the American
Academy. The development of the Hydrarium of these two closely
allied forms shows that two species have been confounded.

Massachusetts Bay, Nahant (Agassiz).

Cat. No. 83, Nahant, Mass., Aug. 1861, A. Agassiz. Hydromedusarium.

Cat. No. 84, Nahant, September, 1854, H. J. Clark. Hydrarium.

Cat. No. 85, Nahant, May, 1862, A. Agassiz. Hydrarium.

Cat. No. 86, Nahant, July, 1861, A. Agassiz. Hydrarium.

Cat. No. 87, Nantasket, April, 1861, H. B. Rice. Hydrarium.

Cat. No. 88, Nahant, L. Agassiz.

Cat. No. 394, Nahant, July, 1862, A. Agassiz. Hydromedusarium.

Cat. No. 395, Nahant, Jimo, 1862, A. Agassiz. Hydromedusarium.

Eucope polygena A. Agass.

The only adult Medusa of the genus Eucope, of which we know
the complete development, being Eucope. diaphana, it is not possible
at present to decide whether we have not among these closely allied
Campanularians the Hydraria of several genera. There are certainly
differences among the young Medusa?, at the moment of escaping
from the calycles, which must give them totally distinct characters
when adult, to judge by what we know of the mode of development
of marginal tentacles, and the increase in size of the genital organs.
•There is a great similarity in the young Medusa? of Eucope articidata,
E. jjyriformls, E. alternata, and E. j^olygena, all these species having
twenty-four hollow tentacles, and ovaries close to the base of the jiro-
boscis, at the time they escape from the reproductive calycles ; while
in E. diaphana and E. genicidata Gosse we have twenty-four tentacles,
nearly solid, and no ovaries in the younger stages. Another type
occurs in Ohelia coimnisstircdis and Laomedea gelatinosa of English
authors, where the Medusa has sixteen tentacles and no ovaries ;
and finally there is a still different type in the Eucope fusiformis
and Laomedea divaricata of McCrady, in which we find forty-eight
tentacles at the time of hatching, and long spindle-shaped genital
organs along the chymiferous tubes. These are undoubtedly good
structural characters upon which genera can easily be distinguished,
but it would Ije premature to make all these divisions until we know.

EUCOPE PARASITICA.

87

from actual observations, in what manner these differences of the
young Medusa are carried out in the adult. The Hydrarium and the
Medusa of several specie^s are described here under the generic name
of Eucope, simply to call attention to the great structural differences
found among Campanularians apparently so closely related.

Eucope 2)ohjcjena is remarkable for the short stems of the sterile
Hydra, the stoutness of the main
stem, and the great number of Me-
dusae developed in a single reproduc-
tive calycle ; the bell is flaring, with a
smooth edge, and rather shallow ; the
reproductive calycles are elliptical,
slightly wavy (Fig. 126), and some-
what bottle-shaped at the extremity.
The Medusa resembles closely that
figured by Professor Agassiz as Eu-
cope dicqjhcma, in Vol. IV. PI. 34, Fig.
9, Contributions to the Natural His-
tory of the United States ; the tenta-
cles are larger in proportion to the
size of the disk. This species is found

growing on stems of Lammaria, in small branching tufts, of one to two
inches in height.

Cat. No. 39.3, Nahant, June, 1862, A. Agassiz. Hydromedusarium.

Cat. No. 399, Nahaut, Jmie, 1862, A. Agassiz. Hydromedusarium.

Eucope parasitica A. Agass.

This species is closely allied to the E. p)ohjrjena ; it has, like it, short
branches, composed of not more than thi-ee or four rings, supporting
the sterile Hydr* ; the inner w\alls of the stems are parallel to the
outer wall ; the sterile Hydra; go off nearly at right angles to the
stem ; the reproductive calycles are very graceful, terminating with a
peculiar mitre-shaped top. The Medusa has twenty-four tentacles ; it
has thus far only been found growing on a species of Penella, parasitic
on Orthagoriscus mola.

Massachusetts Bay, Nahant (A. Agassiz).

Cat. No. 80, Nahant, August, 1861, A. Agassiz. Hydromedusarium.

Cat. No. 81, Nahant, August, 1856, L. Agassiz. Hydromedusarium.

Fig. 126. Magnified view of part of main stem of E. polygena.

88

EUCOPE PYRIFORMIS.

Fig. 123.

Eucope pyriformis A. Agass.

Laomedea gelatinosa Leidy Qion Auct.). ]\Iar. Inv. New York ami Rhode Island, p. G. 1855.

""«•'''• This Medusa has, on its es-

cape from the reproductive caly-
cles, small pear-shaped ovaries
placed close to the digestive
cavity (Fig. 127), which is short
and almost globular ; there are
four chymiferous tubes ; the
tentacles are shorter than in
Ohelia commissuralis, and not
as slender ; at the moment of hatching there are twenty-four tenta-
cles, five between each of the chy-
miferous tubes (Fig. 128), and two
large marginal capsules, with one
granule in each, placed a little on
one side (towards the circular tube)
of the two tentacles adjoining the
middle one between the chymiferous
tubes ; the lasso cells are arranged in
broken rings round the tentacles. The
Hydrarium (Fig. 129) is found growing
in large quantities on the eel-grass ;
the walls of the tube run parallel to
the outer envelope ; there are no
knees or breaks in the continuity, nor are there any swellings where

the reproductive calycles are attached ; the
branches are wide apart, the whole tuft spread-
ing like a bush ; the bell of the hydra is short
and flaring, and is attached to the main stem by
a long branch, having from twelve to fifteen
rings. The reproductive calycles vary greatly
in shape during their growth ; when small, they
are almost rectangular, with rounded corners,
and a slight constriction in the middle ; as they
become larger, they grow more pear-shaped ;
and in still more advanced stages the cah'clos
assume the shape of an elongated ellipse, with
a pointed cap, and three or four deej) consti'ic-

Fig. 127. E. pyriformis, seen in profile ; greatly magnified.

Fig. 1 28. Quarter of disk of same Medusa.

Fig. 129. Portion of Hydrarium of E. jjyriformis ; magnified.

Fig. 129.

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EUCOPE ARTICULATA.

89

tions. There are from nine to twelve Medusae growing in eacli calycle
at once.

This species is closely ,allied to the Ckmqmmdarla gdatinosa of Van
Boneden, and to the Camjxuiularla dkhotoma of Dalyell. The details
of structure of the Hydrarium, especially the reproductive calycles and
the stem of the sterile Hydra, seem to prove that they are different
species. The mode of branching is the same in both. Compare Van
Beneden, PI. 1, Fig. 1, Campanulaires de la Cote d'Osteude, and the
figures of the Medusae here given.

Point Judith (Leidy) ; Beverly, Massachusetts Bay (Alex. Agassiz) ;
Grand Manan (Mills).

Cat. No. 74, Beverly, Mass., July, 1861, A. Agassiz. Hydromedusarium.

Cat. No. 75, Nahant, Mass., July, 1861, A. Agassiz. Hydromedusarium.

Cat. No. 76, Grand Manan, Aug. 1857, J. E. Mills. Hydrarium.

Cat. No. 77, Grand Manan, Aug. 1857, J. E. Mills. Hydrarium.

Eucope articulata A. Acxass.

This species is so closely allied to Eucope pyr'xform'is that the Me-
dusie can hardly be distinguished. The Medusa of Eucope articulata
(Fig. 130) has more slender marginal tentacles, and the lips of the
actinostome are deeply cleft and extremely movable, which is quite
the contrary of what we find in young Medusfe of Eucopidce. The

Fig. 130.

Hydrarium is at once recognized by the extraordinary length of the
ringed branch supporting the sterile Hydra?, the cups of which are quite
deep and narrow. The reproductive calycle (Fig. 131) resembles in
shape that of Ohelia commissuralis, but is in addition supported upon

Fig. 1 30. Quarter of the disk of Eucope articulata ; magnified.
Fig. 131. Portion of a Hydrarium of Eucope articulata.

NO. II. 12

90

EUCOPE FUSIFORMIS.

a larger pedicel, having from eight to ten rings. It is very common to
see the sterile Hydras, placed as in the figure (Fig. 131), in pairs at the
base of the reproductive calycle. The Hydrariuni grows to about the
size of the Eucope jji/riformls, from three to four and even five inches
high, and is readily mistaken for the Hydrarium of Ohella commissu-
ralis. It grows in pools on rocks at low-water-mark.

Cat. No. 39(3, Nahant, June, 1862, A. Agassiz. Hydromedusarium.

Cat. No. 397, Nahant, June, 1862, A. Agassiz. Hydromedusarium.

Eueope? fusiforrais A. Agass.

Eucope? A. Agass. ; in Proc. Bost. Soc. Nat. Hist., IX. p. 91, Fig. 6.

From a Hydrarium, in which the cavity of the main stem passes
from one side to the other {s, s, Fig. 132), similar in its mode of
branching to that of Eucope dlapluuia, but in which the
Hydra?, remarkable for their small bell, h, are attached
to the main stem by short branches, not having more
than three or four rings (Fig. 132), is produced a small
Medusa of a sixteenth of an inch in diameter, having,
when hatched, four long fusiform ovaries (Fig. 133), oc-
cupying nearly the whole length of the chymiferous
tubes, and forty-eight long, slender tentacles, having
well-developed rootlets, usually ci^rried quite stiffly, with
two marginal capsules between each pair of chymifer-
ous tubes, occupying the same position as in E. d'wpha-
na, when it has forty-eight tentacles. The digestive
cavity is quite long and movable, and differs from that
of the last species by the more marked lobes of the actinostome. The
different species of Eucoj^idoe, thus far described, can easily be distin-
guished by the number of tentacles, the presence
or absence of the ovaries, and their position
when they escape from the reproductive calycles.
Among the many specimens of E. dicqihana
which I had occasion to examine, I have only
found two in which there were not twenty-four
tentacles on hatching, and in the Ohella commls-
suralis and E. pyrlformis the same holds good ;
the number of tentacles at the time of escape
from the calycles being very constant.
Massachusetts Bay, Nahant (A. Agassiz).
Cat. No. 90, Nahant, July, 1861, A. Agassiz. Hydromedusarium.

Fig. 133.

Fig. 132. Hydrarium of Eucope fusiformis ; magnified.

Fig. 133. Quarter of the disk of the Medusa of Eueope fusiformis ; greatly magnified.

OBELIA. 91

Eucope ? divaricata A. Agass.

Laomedca diairicala McCr. Gymn. C'liarl. Ilarb., p. 93.

An examination, bj Professor Clarlv, of the reproductive cal^-cles of
specimens collected at Charleston by Professor Agassiz, shows that the
MedusfB have forty-eight tentacles. The Hydrarium is closely related
to that of the Eucope j)i/rifo7'mis, which, together with the present
species, will probably form the basis for a new genus.

Charleston, S. C. (L. Agassiz).

Cat. No. 82, Charleston, S. C, January, 1852, L. Agassiz.

OBELIA Per. et Les.

Obelia Per. et Les. ; in Ann. du M119., XIV. p. 43. 1809.
Obdia Agass. C'ont. Nat. Hist. U. S., IV. p. 351. 1862.
Obelia McCk. Gymn. Charl. Harb., p. 94.

Obelia commissuralis McCr.

OhcUa commissuralis McCr. Gymn. Charl. Ilaib., p. 95, PI. 11, Figs. 5-7.

Obelia commissuralis Agass. Cont. Nat. Hist. U. S., IV. pp. 315, 351, Pis. 33 (non Fig. 2), 34,

Figs. 10-21. 1862.
Obelia commissural i,<i A. Agass. Proc. Bost. Soc. Nat. Hist., IX. p. 91, Fig. 5.
Laomedea dichotoma Leidy Qwn Aiict.). Mar. Inv. N. J. and R. I., p. 6, PI. XI. Fig. 36. 1855.
Laomedea gelatinosa Stimps. (non Auct.). Mar. Inv. Grand Manan, j]. 8. 1853.
Laomedea gelatinosa Gould. Rep. Inv. Mass. Bay, p. 350. 1841.

The Obelia commissitrcdis of McCrady, which extends from Charleston
to the coast of New England, and even as far as Grand Manan, has an
exceedingly slender polypidou and Fig. 134.

branches very profusely ; the branches,
stretching in graceful cui'\'es on both
/ sides of the mam stem, reach their
greatest length a]:)out midway, and
then taper very gradually towards the
upper extremity. It can at once be
distinguished on account of its pecu-
liar mode of growth ; it attains from
five to six and even seven inches in
length. At the time when it bears
reproductive calycles, it is still more
easily distinguished from the allied
species by the shape of the calycles ;
they are slender, conical, the base of the cone with its rounded edges
being surmounted by a short neck (Fig. 134) ; they bear from ten to

Fig. 134. Portion of stem of Ihdrarium of Obelia commissuralis.

92 , OBELIA COMMISSUEALIS.

twelve and even sixteen Medusae. The young Medusa (Fig. 135), when
hatched, has sixteen tentacles, four chymiferous tubes, a rather long
cylindrical digestive cavity, with foiu' labial loljes ; there are no ovaries
yet developed. I have not found these Medusa3 in a more advanced
condition, though they become free in the first weeks of July, and are
Fig. 135. found during the whole summer, as late as September,

but in no case were there any ovaries developed. In
confinement they do not jirosper, and after a few days
die, without assuming a different sliape from that in
which they become free. The tentacles are slender, as
long as the diameter of the disk ; in two of the tentacles
there are large marginal cajjsules in a swelling on the under side ; the
re-entei'ing spur of the tentacles is small. There is considerable differ-
ence between the Hydrarium of the specimens found at Charleston and
those of our coast ; the Charleston specimens are uniformly thinner
and more slender ; it remains yet to be seen whether any further spe-
cific differences can be detected in the Medusae. If Van Beneden's
figure of the Campcumlaria geniculata is correct, the European and the
Amei'ican species of Obelia are distinct.

Absecom Beach (Leidy) ; Charleston (McCrady) ; Buzzard's Bay,
Naushon (A. Agassiz) ; Massachusetts Bay and Grand Manan (Agassiz).

Cat. No. 65, Charleston, S. C, January, 1852, L. Agassiz. Hydrome-
dusarium.

Cat. No. 66, Charleston, S. C, February, 1852, L. Agassiz. Hydrome-
dusarium.

Cat. No. 67, Nahant, July, 1861, A. Agassiz. Hydromedusarium.

Cat. No. 68, Nahant, July, 1861, A. Agassiz. Hydromedusarium.

Cat. No. 69, Nahant, July, 1861, A. Agassiz. Hydromedusarium.

Cat. No. 70, Nahant, Sept. 1861, A. Agassiz. Hydromedusarium.

Cat. No. 71, Grand Manan, Sept. 1857, J. E. Mills. Hydromedusarium.

Cat. No. 72, Nahant, July, 1857, L. Agassiz.

Cat. No. 73, Newport, R. I., Dr. Leidy. ScA^

Cat. No. 392, Nahant, July, 1862, A.' Agassiz. '

Fig. 135. Quarter-disk of the Medusa of Obelia eommissuralis.

LAOMEDEA. 93

LAOMEDEA Lamx.

Laomedea Lamx.; in Bull. Soc. Phil. 1812.

Laomerka Agass. Cont. Nat. Hist. U. S., IV. p. 352. 1862.

Campanulwia Lamk. {p- p-)- An. s. Vert, II. p. 129.

Laomedea rigida a. Agass.

This species is remarkable for its peculiar mode of growth. At first
glance it would readily be mistaken for a species of Djnamena, so
regular is the succession of the hydra? along the stem, and also on
account of the absence of branches. The sterile and reproductive hy-
drai are found on the sides of the main stem, attached by a very short
pedicel, and alternate so regularly on each side that its Campanularian
natm-e is noticed only after a careful examination. The sterile hydrJB
resemble those of Laomedea ami^liora, while the reproductive calycles
are identical m shape with those of Ohella commlssundis. The main
stems of a cluster are closely crowded together, and attain a height of
three to four inches.

Cat. No. 122, San Francisco, Cal., December, 1859, A. Agassiz. Hy-
dromedusarium.

Laomedea amipliora Agass.

Laomedea amphora Agass. Cont. Nat. Hist. U. S., IV. pp. 311, 314, Fig. 50 ; p. 352, Pis. 30, 31,
Figs. 1-8. 1862.

Massachusetts Bay (Agassiz) ; Grand Manan (Mills) ; Long Island
Sound (Leidy, A. Agassiz).

Cat. No. 91, Nahant, July, 1852, H. J. Clark. Hydromedusarium.

Cat. No. 92, Nahant, July, 1861, A. Agassiz. Hydromedusarium.

Cat. No. 93, Nahant, July, 1861, A. Agassiz. Hydromedusarium.

Cat. No. 94, Nahant, March, 1861, H. J. Clark. Hydromedusarium.

Cat. No. 95, Nahant, April, 1855, H. J. Clark. Hydrarium.

Cat. No. 96, Nahant, 1857, L. Agassiz. Hydrarium.

Cat. No. 97, Nahant, March, 1856, H. J. Clark. Hydromedusarium.

Cat. No. 98, Naushon, Sept. 1861, A. Agassiz. Hydromedusarium.

Cat. No. 99, Grand Manan, Aug. 1857, J. E. Mills. Hydromedusarium.

Cat. No. 100, Newport, K. I., S. Powell. Hydromedusarium.

Cat. No. 101, Newport, R I., Dr. J. Leidy. Hydromedusarium.

Cat. No. 102, Boston, March, 1856, H. J. Clark.

Cat. No. 114, Nahant, Sept. 1854, H. J. Clark. Young ?

Cat. No. 398, Nahant, July, 1862, A. Agassiz.

Museum Diagram No. 18, after L. Agassiz.

94' LAOMKDEA PACIFICA.

Laomedea gigantea A. Agass.

This species of Laomedea, found growing in the brackish water of
Charles River, grows to an enormous size, as much as fifteen to twenty
inches. It sends oif only short branches from the stout principal stem,
so that in its general ajjpearance it resemljles somewhat Sertularia
cupressina ; the branches, however, are very closely arranged round the
main stem ; near the extremity we often find, in very large sj^ecimens,
the branches spreading out somewdiat fan-shaped. It can readily be
distinguished from its congener, the L. amjihora, by the shape of the
calycles, which are totally different ; they are elliptical, flaring but
slightly towards the opening, and taper oif somewhat suddenly', with
a bottle-shaped extremity entirely unlike the calycles of L. cmqjliora.

Boston Harbor (H. J. Clark).

Cat. No. 103, Boston, July, 1861, H. J. Clark. Hydromedusarium.

Cat. No. 104, Boston, July, 1861, H. J. Clark. Hydromedusarium.

Cat. No. 105, Boston, July, 1861, H. J. Clark. Hydromedusarium.

Laomedea paciflca A. Agass.

This is another gigantic species closely allied to Laomedea amjyliora ;
the reproductive calycles are similar in both ; the main stem of this
sj)ecies is exceedingly stout ; the mode of branching resembles that of
L. cjelatinosa. Specimens of this species have been collected by Dr.
Stimpson, of the North Pacific Exploring Expedition under Commo-
dore Rodgers, in Behring's Straits, and in Avatska Bay, Kamtschatka.

Gulf of Georgia, W. T. (A. Agassiz) ; San Francisco, Cal. (A. Agassiz).

Cat. No. 117, Gulf of Georgia, W. T., June, 1859, A. Agassiz.

Cat. No. 118, San Francisco, Cal., December, 1859, A. Agassiz.

Cat. No. 120, San Francisco, Cal, December, 1859, A. Agassiz. Hy-
dromedusarium.

^QUORID^. 95

Family ^QUORID^ Esch. {rest. Ac.)

jEquoridm Esch. (emend. Agass.). Syst. d. Acal., p. 108. 1829.
JSquorklw Agass. Cont. Nat. Hist. U. S., IV. p. 3.59. 1862.

RHEGMATODES A. Agass.

Rhegmatodes A. Agass. ; in Agass. Cont. Nat. Hist. U. S., IV. p. 361. 1862.

Umbrella flat, chymiferous tubes numerous, digestive cavity short,
with small lips scarcely fimbriated ; the chymiferous tubes extend
along the prolongation of the umln-ella into the cavity of the bell ;
large tentacles, somewhat more numerous than the chymiferous tubes,
very contractile. To this genus I suppose that Gosse's ^quorea forhes-
iana belongs; it is closely allied to Stomobrachium Brandt {non Forbes),
and difiers from it in not having numerous long marginal tentacles, in
the greater number of radiating tubes, and the numerous short lips at
the extremity of the digestive cavity. Like ^quorea and Zygodactyla,
it has marginal capsules, and the peculiar spur at the base of the large
tentacles. Two species of this genus have been noticed on our coast ;
the one in Florida, bv Professor Agassiz, and the other at Naushon.

Rhegmatodes tenuis A. Agass.

Rhegmatodes tenuis A. Agass. ; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 361. 1862.

This is a large sj^ecies ; specimens measuring between three and four
inches have frequently been found. The spherosome is thick (Fig. 136)
along the polar axis, bulgmg, in the shape of a rounded obtuse cone,

Fig. 136. A profile view, natural size, of Rliegmatodes tenuis.

96

RHEGMATODES TENUIS.

Fig. 137.

into the interior cavity ; the chymiferous tubes extending nearly to the
apex, leaving but a short digestive cavity, the edges of which scarcely
meet (Fig. 137), so that, when the actinostome is closed, the lips resem-
ble a piece of catgut tied by a string close to the end ; the marginal

tentacles are long, gener-
ally carried extended, and
when contracted twist only
two or three times, and are
not carried tightly curled,
as in Zygodactyla ; the ova-
ries are very narrow, and
extend almost the whole
length of the chymiferous
tubes, from the upper mar-
gin of the digestive cav-
ity, to about one tenth the
length of tlue radiating tube
from the circular tube ; the
ovaries hang down in two
masses on each side of the
chymiferous tubes ; there is
no connection between the
two pouches, except near
their point of attachment,
where they unite again.

Younger specimens, meas-
uring about one and a half
to two inches, and not hav-
ing more than sixteen to twenty-four chymiferous tubes, resemble Sto-
mobrachium ; they differ, however, in the small number of tentacles.
The marginal capsules are large, elliptical ; the granules placed far
apart, two in each (c, Fig. 138) ; the tentacles taper rapidly from the
base (f, Fig. 138), the walls are thin, the lasso cells scattered irregularly

over the whole surface. At the base of the
large tentacles we find a very prominent pro-
jection (s. Fig. 138), in the shape of a small
tentacle opening into the circular tube ; it is not
exactly a spur, as in Lafoea ; it develops only
after the rudimentary tentacles, being a button
scarcely to be recognized when the tentacle is
already quite well formed ; there are usually only rudimentary tenta-

Fig. 133.

'-& -A

Fig. 137. Quarter of the disk of Fig. 1.36, seen from tlie actinal side.

Fig. 138. A magnifieil ])()rtii]ii of the einndar canal, showing the position of the spur of the
tentacles, s, .«, and of the marginal capsules, r. between the tentacles, (.

RHEGMATODES FLORIDANUS. 97

cles between the chymiferous tubes, except one large tentacle in the
middle of the space ; there is always one marginal capsule between the
adjoining tentacles. These Medusaj are slow in their movements, allow-
ing themselves to be carried along with the current, after one or two pul-
sations ; they swun near the surface. Found at Naushon in September.

Buzzard's Bay, Naushon (A. Agassiz).

Cat. No. 278, Naushon, September, 1861, A. Agassiz. Medusa.

Rhegmatodes floridanus Agass.

Rhegmatodes floridanus Agass. Cont. Nat. Hist. U. S., IV. p. 3G1. 18G2.

A second species of this genus (Fig. 139) is found along the Florida
Reefs. It resembles the young of the northern species at the time
when it has from sixteen to twenty-four chymiferous tubes ; the part of
the gelatinous disk which projects into the interior cavity of the bell is
larger, giving the spherosome a somewhat heavy look ; the fringes of
the actinostome are longer ; the ovaries are confined to a small part of
the chymiferous tubes, and do pig. 139.

not begin at the point of junc-
tion of their upper extremity,
but a short distance from it ; the
circular tube is large ; in speci-
mens having sixteen chymiferous
tubes, there were forty marginal
tentacles ; in specimens having
twenty, there were sixty. This
species is much smaller than its
northern representative, speci-
mens having already sixteen chy-
miferous tubes not being more
than an inch in diameter ; while
specimens of the northern species, which have attained the same de-
velopment, measure about two inches. The marginal capsules contain
two to three granules each.

Additional chymiferous tubes in the -^quoridaj are developed from
the digestive cavity, as has already been shown by Kdlliker, and
not from the vertical tube, as is the case in the branching tubes of
Willia. They are at first simple short sacs, which gradually extend ua
length till they become long tulies, opening into the circular tube ; the
chymiferous tubes and the marginal tentacles are not developed with
equal regularity, in the order of their cycles ; the chymiferous tubes
especially are veiy irregularly formed, and nothing is more common

Fig. 139. Rhegmatodes floridanus, natural size.

NO. II. 13

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V '\ r // '^ "^■''~'

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'^M^.

'\ S-^

lj:m'\:

98

STOMOBRACHIUM.

than to find specimens having twenty or twenty-two chymiferous tubes,
instead of the normal number. The same is the case in the order of
development of the chymiferous tubes of Zygodactyla, and the other
^quorida3 which I have had occasion to observe. The tubes are fre-
quently added all on one side of the spherosome, and will be nearly
fully formed before they begin to be developed in the other half The
specimens observed of this sjjecies are evidently not full-grown, as the
ovaries were but imperfectly developed.
Key West, Florida (L. Agassiz).

STOMOBRACHIUM Brandt.

StomobracMum Br. (non Forbes). Prod. ; in Mem. Acad. St. Petersb., p. 220. 1835.
Stomohradiium Less. Zooph. Acal., p. 315. 1843.
Stomobrachium Agass. Cont. Nat. Hist. U. S., IV. p. 361. 1862.

Storaobrachiura tentaculatum Agass.

Stomobrachium tentaculatum Agass. Cont. Nat. Hist. U. S., IV. p. 361. 1862.
Stomobrachium lenliculare Gould {non Br.). Rep. Inv. Mass., p. 349. 1841.
? Medusa bimorpha Fab. Fauna Groulandica, No. 35G. 1781.

This species is occasionally found at Nahant during July. It has
twelve chymiferous tubes, a small digestive cavity, the folds of the acti-
nostome hanging down in four lobes, placed at right angles to one
another ; these lobes are triangular (Fig. 140), the apex of the triangle

being placed nearer the origin of the chymiferous tubes ; the edges
are frilled ; the trend of the triangles is in the direction of four of
the chymiferous tubes. Between each two of the chymiferous tubes
(Fig. 141) there are from thirty to forty tentacles, in all stages of

Fig. 140. The actinostome of Stomobracliium tentaculatum, magnified to sliow the peculiar
mode of carrying the folds of the digestive cavity-
Fig. 141. Stomobrachium tentaculatum, seen from the abactinal pole; natural size.

HALOPSIS. 99

development ; they are not capaljle of great expansion, and when short-
ened, the extremities are clirled up. The ovaries, which are hnear,
extend along the chymiferous tuhes in such a way as to leave both the
actinal and abactinal extremities free (Fig. 142) ; the spherosome in-
creases very gradually in thickness from the circular tube towards the
abactinal pole. This species differs j.i„ j^,,

from the S. lenticulare of the Falk-
land Islands, in having a smaller
free area, longer chymiferous tubes,
and more numerous tentacles ; it
grows from one and a half to two
inches in diameter, and half an inch
in height, is sluggish in its movements, is colorless, and has a gelatinous
disk of considerable consistency. These Medusae are frequently found
thrown up on the sandy beaches, encased in sand in such a way as to
be preserved from decomposition and loss of shape for several days.
This may explain the mode in which the few fossil Medusae known
have been formed.

Massachusetts Bay, Nahant (L. Agassiz).

HALOPSIS A. Agass.

Halopsis A. Agass.; in Proc. Bost. Soc. Nat. Hist., IX. p. 219. 18G3.

The genera Berenix and Carisochroma have been placed by Professor
Agassiz among the Williadte on account of their forking chymiferous
tubes. The discovery of HalojDsis shows this association to be mi-
natural, and that most probal)ly, when the genera Berenix and Cariso-
chroma are better known, they will be associated with Halopsis into a
distinct family, the Berinicida3 of Eschscholtz. Whatever may be the
result, it is at least highly proljable that their closer relations are with
the yEquoridae, and not with the Tuljularian family of the Williadte.

Halopsis ocellata A. Agass.

Hahpsls ocellata A. Agass. ; in Proc. Bost. Soc. Nat. Hist., IX. p. 210. 18G3.

The genus Halopsis differs from the other iEquoridaB by the presence
of large compound eyes, as in Tiaropsis, from three to six between
every two of the chymiferous tubes. There are likewise long tentacu-
lar cirri ; tlie flatness of the disk, the large number of tentacles, the
nature of the digestive cavity and of the genital organs, place this
genus among the iEquorida3. Two species are found on our coast,

Fig. 142. The same as Fig. 141, seen in profile.

100

HALOPSIS OCELLATA.

Fig. U3.

which are so closely allied that, were, not the complete history of their

earlier stages known, they would readily have
been mistaken for different ages of the same
species.

The first species, Halojjsis ocellata, would
at first glance be taken for a Stomobra-
chium ; on examination we find that the chy-
miferous tubes take their origin in clusters
of three to five (in adults), radiating, like the
spokes of a fiin (Fig. 143), from a large cross-
shaped cavity (Fig. 144), from which hangs
down a short digestive cavity, terminating in
four lips. When seen in ^Jrofile, the disk is
quite flat, regularly arched, the genital organs
extend nearly to the circular tube (Fig. 145),
occupying almost the whole length of the
chymiferous tubes. The tentacles are very
numerous, and capable of great expansion and
contraction (Figs. 143, 145) ; there are as
many tentacular cirri as tentacles [c, Fig. 146) ; they are long, slender,
of uniform diameter ; the main tentacles {t, t, Fig.
146) bulge out prominently immediately at the
circular tube, tapering very rapidly. The com-
pound eyes are large {e, Fig. 146); the granules in.
them are arranged in two rows, from six to seven
in each row (Fig. 147) ; the structure of these
comjiound eyes is similar to those of Tiaropsis.
These Medusae are exceedingly sluggish in their
movements ; they are colorless, the genital organs
having a slight grayish tinge at the time of spawning,
from July to September, quite commonly. In young specimens, meas-
Fig, U5. uring not more than an

inch in diameter, there
are only four chymif-
erous tubes (Fig. 148),
uniting in the form of
a cross ; there are no
signs of genital organs ;
the shape of the disk is somewhat more hemispherical than in tlie

Fig. 143. Portion of the disk of Halopsis ocellata, seen from the abactinal pole, somewhat
reduced.

Fig. 144. Cavity from which the chymiferous tubes radiate, rf, opening of actinostome ; c,
chymiferous tube ; h, connecting fold between the point of attachment of two chymiferous tubes ;
I, lips of actinostome.

Fig. 145. Profile of Halopsis ocellata ; natural size.

Found at Nahant,

HALOPSIS OCELLATA.

101

Fig. 146.

adult. Si^ecimens measuring an inch and a half in diameter have
as man}' as twelve chymiforous
tubes, the cavity from which the
tubes originate being u'regularly
shaped ; it is not till the Medusa
measures from tAvo to two and a
half inches in diameter, that it
takes the regular stai'-shaped form
of Fig. 143 ; it is then also that the
genital organs first appear, like
threads on each side of the tubes.
Additional chymiferous tubes are
formed quite irregularly as diver-
ticula sent off from the digestive pouch, as in other ^quoridae. It is
quite a common thing in this species to have two actinostomes, in speci-
mens where the central cavity is very elongated and irregular m out-
line, a beginning, perhaps, of a transverse fission similar to that observed
by Kolliker in Stomobrachium, but which I have never noticed in our
species. In a still younger Medusa (Fig. 149), not measuring more than
a fifth of an inch in height, and which I suppose to be the young of this
species (it cannot be the young of Tiarojisis diademata ; see the draw-
ings of the young of that species), we find already four eyes between

Fig. 149.

Fig. 150.

Fig. 143.

r-^

two of the chymiferous tubes (Fig. 150), but having only two to three
granules in each, one large tentacle at the base of the chymiferous
tubes, one in the middle, and rudimentary tentacles of the third set in
the intermediate sjjaces ; on each side of these rudimentary tentacles
are long cirri ; there are no ovaries. It is interesting to see that among
the ^quoridfe, the flattest of our Medusae, the young iave a deep bell
(Fig. 149), which becomes gradually shallower, as in the other Campanu-
larians. The deep bell of the young Halopsis is totally different from
the other form of young iEquorea figured hereafter, which resembles

Fig. 146. Magnified part of circular tube, c, tentacular cirri ; e, compound eye ; t, main ten-
tacles.

Fig. 147. ^Magnified view of one of the eyes, to show arrangement of granules.

Fig 148. Young Halopsis ocellata, natural size.

Fig. 149. Young Halopsis ocellata, a fifth of an inch in height.

Fig. 150. Magnified portion of circular tube of Fig. 141). c, c, c, c, cliTi ; at base of each is
placed an eye.

102

HALOPSIS CRUCIATA.

more a Eucope. This may eventually show us two modes of develop-
ment among the ^quorida? into forms, forming groups corresponding to
those of the Oceanidaj and Eucopida? as here limited, in one of which
the young Medusa has a deep bell and few tentacles, as in Clytia and
Oceania, while in the other group they have, when hatched from the
reproductive calycles, a Hat disk and many tentacles, as in Eucope and
Obelia.

Massachusetts Bay, Nahant (A. Agassiz).

Cat. No. 364, Nahant, August, 1862, A. Agassiz. Medusa.

Cat. No. 375, Nahant, 1863, A. Agassiz. Medusa.

Halopsis cruciata A. Agass.

During the early part of the summer there is frequently found a
Medusa, at first supposed to be the young of Halo2)i<ls ocellata ; a com-
parison of the size, the character of the genital organs, and the number
lig 151. of tentacles, shows this to be im-

possible. H. cruciata never grows
to more than one and a half to two
inches in diameter. The tentacles
are much less numerous (Fig. 151),
the genital organs are lolled pouch-
es, hanging down in folds from the
chymiferous tubes ; there are only
three compound eyes between ev-
ery two of the chymiferous tubes ;
these three eyes are already pres-
ent in the youngest Meduste ob-
served, which measure hardly half an inch in diameter, and in which
the genital organs are already well developed, Avhile in the young of
H. ocellata, in specimens measuring nearly two inches, and having as
many as twelve chymiferous tubes, we find no trace of them. The bell
Fi„. 152. of these young Medusae is very high ; the eyes

differ from those of H. ocellata, having only four
or five gi'anules arranged in a single row ; the
tentacular cirri and the large tentacles are essen-
tially the same in both species ; the spermaries
of the males are quite slender and more linear,
compared to the heavily filled, convoluted genital
pouches of the females. The genital organs are
of a light pink color, as well as the beU.

Fia;. 151. A prnfik' view, somewhat niairnifinl, of Ilalopsis <'riR'ia
Fig. 152. A natural attitudf of the same species ; both females.

ZYGODACTYLA. 103

Maj' not the T. gibbosa of Forbes be a young Halopsis ? They re-
semble the young of this species ; also T. glohosa, and perhaps T. ji'do-
sella. We have here agam one of those ever-returning questions of the
generic identity or difference of species, showing great structural differ-
ences, such as we find between these two species ; the discovery of tlie
Hydrarium will settle the point. H. cruciata, with its high bell (Figs.
151, 152), its four chymiferous tubes, the nature of its compound eyes,
and its habits, would seem to be associated with Tiaropsis, among the
Oceanidoe ; while the tentacular cirri and the arrangement of the com-
pound eyes place it in the closest relationship to H. ocellata.

Massachusetts Bay, Nahant (A. Agassiz).

Cat. No. 374, Nahant, 186-3, A. Agassiz. Medusse.

Cat. No. 379, Nahant, June, 1862, A. Agassiz. MedusEB.

Cat. No. 445, Nahant, June, 1864, A. Agassiz. Meduste.

ZYGODACTYLA Br.vndt.

Zi/godacli/la Bk. Proil. ; in Mem. Acad. St. Petersburg, p. 221. 1835.
Rhacostoma Agass. ; in Proe. Bost. Soe. Nat. Hist., III. p. 342. 1850.

Zygodactyla groenlandica Agass.

Zijfjodaclijla groenlandica Agass. Cont. Nat. Hist. U. S., IV. p. 360. 1862.
^JEquorea groenlaivUca Per. et Les. ; in Ann. du JIiis., XIV. p. 27. 1809.
Medusa (equorea Fab. Fauna Groenlandica. No. 357. 1780.
Rhacostoma adanlicum Agass. ; in Proc. Bost. .Soe. Nat. Hist., IH. p. 342. 1862.
JEr/uorca gtubularit MoucH. ; in Besk. af Groiiland, p. 96. 1857.
yEquorea groenlandica Less. Zooph. Acal., p. 313. 1843.

This species, of which a short description was given by Professor
Agassiz in the Proceedings of the Boston Society of Natural History for
1850, who supposed it to be an undescribed species, is one of the largest
of our naked-eyed Medus*. It is not uncommon to find specimens meas-
uring as much as fifteen inches in diameter when fully extended. There
are in full-grown specimens from eighty to a hundred chymiferous tvibes
(Fig. 153), with three and even four long retractile marginal tentacles
between every two chymiferous tubes ; the pendent membrane, which
forms the digestive cavity, is very contractile, having a circular opening,
with short lips and fimbriated edges, corresponding to the chymiferous
tubes, which appear to be hardly long enough, when expanded (Fig. 153),
to close up the edges, while at other times the lips of the actinostome
hang down far below the level of the circular canal, like a sheaf (Fig.
154), and at other times the lips hang down loosely from what seems a
small opening, or flare out so as to measure five or six times the diam-
eter of their base. The chymiferous tubes extend a short distance down

104

ZYGODACTYLA GROENLANDICA.

Fig 153.

the bulging part of the spherosome, the free space left in the centre

having a radius of about
one third that of the
.spherosome itself The
lips of the actinostome
are formed by the folding
of the membrane of the
digestive cavity along the
direction of the radius ;
as the membrane becomes
more and more fimbri-
ated, the fold becomes
deeper and deeper, and
projects beyond the gen-
eral outline, like an ex-
ceedingly delicate frill.
The tentacles at the base
are swollen, tajDer very

suddenly, are hollow (Fig. 155), the walls of the tentacles are thin,

and the lasso cells are arranged irregularly over the whole surface m

small clusters. At the base

of each of the large tentacles

there is a small hollow spur

{s, Fig. 155) projecting inward,

the walls of which are thick,

and made up of large cells ;

the rudimentary tentacles are

swollen at the extremity, and

the spur is not developed until

the lash of the tentacle be-
comes apparent ; the marginal capsules are large, ellipsoid, with two

large granules in each. In young specimens of Zygodactyla, not hav-
ing more than forty large chymif-
erous tubes reaching to the mar-
gin, we find the other tubes but
slightly developed, two or three
sometimes between each of the
larger tubes extending from the
upper edge of the digestive cav-
ity to various distances from it ;

Fig. 154.

Fig. 15.3. Abactinal view of Zygodactyla prroenlandica.
Fia;. 154. Profile view of Fig. lUS, half natural size.

Fig. 155. Portion of the eircular tube, showing the mode of development of the marginal ten-
tacles, s, spur of marginal tentacles.

ZYGODACTYLA GROENLANDICA. 105

these rudimentary tubes are mere threads, running a short distance,
and then suddenly terminating, or tapering gradually to a point. In
the latter part of June, or^early in July, the Zygodactyly are all in this
condition, while later in the season, in August and the latter part of
September, they attain their full size, all the chymiferous tubes being
about equally developed. The lips of the actinostome are so read-
ily movable that the outline of its edge will assume the most varied
shapes, the opening being either concentric and perfectly circular,
or else thrown entirely to one side, or assuming a pear-shaped form,
closing at another time like the actinostome of an Actinia, and then
suddenly spreading into a pentagonal opening ; or the membrane of
the digestive cavity is expanded to its fullest capacity, extending far
below the circular tube, and leaving but a very small elliptical acti-
nostome, from which a sheaf of long, slender, highly fimbriated, lance-
olate lips are suspended.

Notwithstanding the facility with which this species is kept alive, I
have never succeeded in raising the eggs, as is so easily done with
Tima and Melicertum, and can therefore add nothing to the oljserva-
tions of Wi'ight on the Hydrarium oi yEquorea vltrina.

Among the numerous 3-oung Eucopidiv, daily examined, are fre-
quently found exceedingly small Medusae, not larger than the heatl
of a pin, which I suppose to be the young of Zygodactyla. They
resemble the Eucopidre, but differ in having Fig. ise.

rather more slender tentacles, and a very
peculiar gelatinous projection of the disk, at
the base of which are situated four round
genital organs (Fig. 156) ; there are four
chymiferous tubes opening into a large cav-
ity, leading into a slightly pendent stomach,
exactly as would be the case in a Zygodac-
tyla, if we were to reduce the chymiferous
tubes to four, and make the genital organs
round. The youngest Meduste have already twenty-four tentacles,
and the next size, scarcely larger, forty-eight ; from this large number
of tentacles, as well as the peculiar projection of the gelatinous disk,
and the large cavity from which the chymiferous tubes take their
origin, I have but little doubt that they are the young of iEquoridte,
probably of our Zygodactyla. The small size of these Medusae, coupled
with their habit of living at the bottom, till late in the f;ill, when
they make their appearance as full-grown Medusa?, will readily account
for their having escaped our notice thus far. These 3'oung ^Equorido)
are quite common early in June ; their further development could not
be traced, as they do not thrive in confinement.

Fig. 156. Young Zygodactyla, greatly magnified.
NO. ir. 14

lOG

ZYGODACTYLA CRASSA.

Greenland (Fabricius) ; Maine, and Massachusetts Bay (L. Agassiz) ;
Naushon (A. Agassiz).

Cat. No. 277, Naushon, September, 18G1, Alex. Agassiz. Medusa.

Zygodactyla crassa A. Agass.

This species, which grows to almost as large a size as Zygodactyla
groenlandica, can be recognized at first glance by the small number
and great size of the genital organs ; there are not more than thirty-
two chymiferous tubes (Fig. 158) in a Medusa measuring ten inches in
diameter, while in a specimen of Z. groenlandica of the same size we
should find at least eighty to ninety ; the ovaries have an extraor-
dinary development, and bulge out at the time of spawning fully as
much as the ovaries of Melicertum, hanging very much in the same

Fig. 157.

manner from the chymiferous tubes (Fig. 157) ; the radius of the
digestive cavity is larger ; the number of lips of the actinostome cor-
responds to that of the radiating tubes (Fig. 158) ; the digestive cavity
is far less capable of expansion and contraction than in Z. groenlan-
dica ; the marginal tentacles are much heavier and more massive ; the
color of the base is slightly greenish-blue, as well as the genital
organs ; the latter have a rather more yellowish hue. Found at

Fig. 1.57. Profile view of Zygodactyla crassa, somewliat reduced in size.

ZYGODACTYLA CYANEA.

FiR. 15S.

107

Nahant, in company with the Z. groenlandica. The color of the males
is somewhat more pinkish than that of the females.
Massachusetts Bay, Nahant (A. Agassiz).

Zygodactyla cyanea Agass.

Z ijgodactijla cyanea Agass. Cont. Nat. Hist. U. S., IV. p. 361. 1862.

This species is of a light-blue color ; can read-
ily be distinguished from Z. groenlandica by the
great thickness of the spherosome, and the large
digestive cavity ; the actinostome is bordered by
a number of very small and finely fimbriated
lips (Fig. 159) ; the chymiferous tubes do not
curve down and extend along the projection of
the spherosome in the inner cavity of the bell ;
at their highest point they empty into the diges-
tive cavity, the radius of which is more than one
half that of the spherosome itself, leaving but a
short space between the abactinal edge of the
digestive cavity and the circular tube ; the chy-
miferous tubes are numerous, ninety to a hun-
dred, usually placed opposite a long and exceed-
ingly contractile tentacle ; these are generally

Fig. 15S. Quarter of the disk of Z. crassa.

Fig. 159. rortion of the disk of Zygodact}'la cyanea, from the abactinal

Fig. 159.

pole.

108 CREMATOSTOMA.

carried curled tightly to the edge of the disk. Found in great nmn-
bers, from February to May, along the Florida Reef

Florida, Key West (L. Agassiz).

Cat. No. 349, Florida, L. Agassiz. Medusa.

Cat. No. 350, Tortugas, Fla., May, 1858, L. Agassiz. Medusa.

Zygodactyla ccerulescens Br.

Zygodactyla ccerulescens Br. ; in Mem. Acad. St. Petersb., p. 360, PI. 5. 1838.
Zygodactyla ccerulescens Agass. Cont. Nat. Hist. U. S., IV. p. 360. 1862.
Mesonema ccerulescens Br. ; in Mem. Acad. St. Petersb., p. 360. 1838.
Mesonema ccerulescens Less. Zooph. Acal., p. 307. 1843.

Eiitrance of Straits of Fuca (A. Agassiz).

CREMATOSTOMA A. Agass.

Crematostoma A. Agass. ; in Agassiz's Cont. Nat. Ilist. U. S., IV. p. 360. 1862.

The genera of ^quoridte found on the Pacific coast are either
identical with those of our coast, or have representatives which give
to the members of that family found on the two sides of the continent
a striking similarity. Stomobrachium, Zygodactyla, and jEquorea are
found both in the Atlantic and Pacific ; we have Rhegmatodes, which
has as yet no representative on the Pacific coast of North America,
while Crematostoma has not been found on the Atlantic side.

This genus recalls Zygodactyla, in having a large digestive cavity ; it
is, however, much less contractile than m that genus, and hangs always
fiir below the level of the cu-cular tube. The actinostome, as in Zygo-
dactyla, is surrounded by a number of narrow, lanceolate, fimbriated
lips, one for each chymiferous tube, which are from sixty to eighty in
number.

Crematostoma flava A. Agass.

Crematostoma flava A. Agass.; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 360. 1862.

The lower part of the digestive cavity, immediately above the acti-
nostome, is alone capable of considerable contraction, the digestive
cavity hanging down like a large cylindrical sac, with numerous longi-
tudinal folds extending from the origin of the chymiferous tubes along
the whole length of the sac to the actinostome. The chymiferous
tubes are broad, extending a short distance along the projection of the
spherosome into the cavity of the bell. The ovaries extend the whole

^QUOREA.

109

Fig. 159».

length of the chjmiferous tubes, they are linear (Fig. 159") ; opposite
each of the chj-niiferons tubes there is one large tentacle, veiy con-
tractile, with a slight swelling at the base ; between the chymifor-
ous tubes, one smaller tentacle and marginal capsules ; the chymiferous
tubes, near the base of the
digestive cavity, anasto-
mose frequently ; the sec-
tion of the spherosome re-
sembles that of Zygodac-
tyla more than any other
genus of the family. The
disk increases rapidly from
the circular tube, and re-
mains then of the same
thickness to the base of
the projection of the disk
in the inner cavity ; here
the outline of the inner
bell suddenly curves down,
and projects like a spheri-
cal segment, nearly hemi-
spherical, in the cavity of
the bell, the outline of the
outer bell having a slight
constriction at this point, and from there curving gradually to the
abactinal pole. From three to four inches in diameter ; specimens one
and a half inches high, measured three and a half inches in diameter.

Gulf of Georgia, W. T. (A. Agassiz).

Cat. No. 123, Gulf of Georgia, W. T., June, 1859, A. Agassiz. Medusa.

^QUOREA Per. et Les.

Jlquorea Per. et Les. ; in Ann. du Mus., p. 22. 1809.
uEquorea Less. (p. p.). Zooph. Acal., p. 305. 1843.
^quorea Xgass. Cont. Nat. Hist. U. S., IV. p. 359. 1862.

.ffiquorea ciUata Esch.

^qunrea cilinta 'Escii. Syst. der Acal., p. 109, PI. 9, Fig. 1. 1829.
yEquorea ciliata .-^gass. Cont. Nat. Hist. U. S., IV. p. 359. 1862.
jEquorea ciliata Less. Zooph. Acal., p. 306. 1843.

Northwest Coast of North America, Lat. 41° to 51° N. (Eschscholtz) ;
Straits of Fuca (A. Agassiz).

Fig. 159'. Crematostoma flava A. Agass.

110

^QUOREA ALBIDA.

rig 160.

^quorea albida A. Agass.

Mquorea albida A. Agass.; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 359. 18G2.

The genus ^quorea, as generally received, includes sj^ecies which
have been separated from it, under the name of Zygodactyla, by
Brandt, and to which the ^quorea vitrina of Gosse also belongs. The
long pendent membrane of the digestive cavity, with the actinostome
surrounded with numerous lanceolate and strongly
fimbriated folds, at once distinguishes this genus
from Rhegmatodes, which includes such species as
Rhegmatodes tenuis and Jioridamis, and the ^qiiorea
forbesiana of Gosse, in which the chymiferous tubes
are not numerous, the tentacles few in number, and
the digestive cavity not capable of extension as in
Zygodact^da, the Hps of the actinostome being short
and simple folds, j^quorea is distinguished from
both these genera by having a greater number of
chymiferous tubes, the ovaries extending for their
whole length, from the circular tube to the mem-
brane of the digestive cavity. The tentacles are numerous, the spurs
at the base of the large tentacles being more closely connected with
them than in the other genera of this family. The actinostome is a
simple ojiening, without appendages such as w.e find in Zygodactyla,
Stomobrachium, and others, having only slight indentations formed
along its margin, giving the opening a somewhat polygonal shape

(Fig. 160) ; and when entirely
closed, the edges of the acti-
nostome meet, forming a slight
button. The spherosome has a
slight indentation near the ab-
actinal pole, the bell diminish-
ing very gradually in thickness
towards the circular tube (Fig.
IIIIm^K^OkBSHS^^^^H 161) ; the gelatinous disk hardly

projects into the cavity of the
bell ; the chymiferous tubes run
into the digestive cavity at
their highest point, the radius
of the digestive cavity being about one third that of the spherosome ;
the chymiferous tubes are narrow, there are three or four marginal
tentacles between every two chymiferous tubes, and two or three

Fig. IGO. A portion of the disk of ^quorea albida, from the abactiual pole.
Fig. 161. A natural attitude of .Slquorea albida.

Fig. 161.

^QUOREA ALBIDA. HI

marginal capsules, two for every large tentacle, between the tubes, in
each of which there are from three to four granules arranged in a
cluster in the centre ; the capsules are perfectly spherical (c. Fig. 162) ;
the walls of the tentacles taper very gradually from the circular tube,
the swelling has but little j^rominence, and the pigment cells at their
base are not numerous, scarcely coloring it ; the lasso cells are arranged
in small knobs, scattered, at some distance from one another, all over
the surface of the tentacles; the spur of the tentacles (s, Fig. 162) is
placed directly opposite Fig. 162.

the large tentacle on the
other side of the circular
tube ; the walls of this spur
are thick, and its hollow
space appears like a small
elliptical opening when
seen from above ; the un-
developed tentacles are solid conical protuberances, from which the
cavity of the tentacle is little by little hollowed out ; the tentacles are
usually carried tightly twisted like a corkscrew ; when in motion, the
tentacles are fully exjianded, then bent at right angles and drawn
inside the veil and slowly thrown out, the tentacles almost closing the
opening of the cavity of the bell, giving these Medusae the appearance
of having numerous long tentacles (Fig. 161) arising from a small cir-
cular tul)e, the chymiferous tubes and the tentacles in their prolonga-
tion making almost a complete sphere. Specimens from one to two
and a half inches in diameter were taken at Naushon during Sep-
tember.

Buzzard's Bay, Naushon (A. Agassiz).

Cat. No. 279, Naushon, Mass., Sept. 1861, A. Agassiz. Medusa.

Fig. 162. ' Magnified view of part of the marginal tube, c, capsule ; .«, spur of the tentacles, L

112 GERYONOPSIU.E.

Family GERYONOPSIDiE Agass.

Geryonopsidw Agass. Cont. Nat. Hist. U. S., IV. p. 362. 1862.
Geryonida, EscH. (p- 1>-)- Syst. der Acal., p. 86. 1829.

EIKENE EscH.

Eirene Escn. Syst. der Acal., p. 94. 1829.
Geryonopsis Forbks. Naked-eyed Medusae, p. 39. 1848.
Phortis McCr. Gymn. Charl. Harb., p. 90.
Eirene Agass. Cont. Nat. Hist. U. S., IV. p. 362. 1862.

Eirene gibbosa Agass.

Eirene gibbosa Agass. Cont. Nat. Hist. U. S., IV. p. 362. 1862.
Phortis gibbosa McCr. Gymn. Charl. Harb., p. 91.

Charleston Harbor (McCradj).

Eirene coerulea Agass.

Eirene ccerulea Agass. Cont. Nat. Hist. U. S., IV. p. 362. 1862.

The spherosome increases rapidly in thickness from the circular tube
to the peduncle, which tapers quickly, and when fully expanded does
not reach much beyond the level of the veil (Fig. 163) ; the ovaries
are linear, slightly convoluted, do not extend the whole length of the
Fig. 163. chymiferous tubes, but begin about half-

way up, between the circular tube and
the base of the peduncle, extending close
to the digestive sac, which is terminated
by four short lips with slightly fimbriated
edges ; the outline of the spherosome is
hemispherical ; the tentacles are numer-
ous, in the largest specimens measuring
an inch and a quarter across the disk,
and an inch in height ; there were as many as thirty to thirty-five
short tentacles between every two chymiferous tubes ; the gelatinous
disk has a slight tinge of blue. Found at Key West and the Tortugas
in April.

Florida, Key West (L. Agassiz).

Fig. 163. Eirene coerulea.

TIMA.

113

TIMA EscH.

Tima EscH. Syst. der Acal., p. 103. 1829.

Eircne EscH. (p. }).). Syst. tier Aral., p. 94. 1829.

Diatura Delle Cit. Mom. sulla Storia e Notomia. 1823-

Thna Less. Zooph. Acal., p. 333. 1843.

Tima Agass. Cont. Nat. Hist. U. S., IV. p. 362. 18G2.

29.

Tima formosa Agass.

Tima formosa Agass. Cont. Nat. Hist. U. S., IV. p. 362. 18S2.

Spherosome greater than a hemisphere, with edges slightly receding
from the polar axis, near the circular tube. The disk increases in
thickness very gradually to the bend of the chymiferous tul)es (Fig.
1G4), where the gelatinous disk extends in a broad cone, slowly dimin-
ishing in diameter, till it reaches somewhat beyond the level of the veil.
This peduncle is contractile, extending at times the diameter of the
inner cavity of the bell beyond the circular tube ; the sexual organs

Fig. 164.

Fig. 165.

Fig. 166.

M

1 1 ,,\u u,i,t^f -^

^^^^^

^i/^!:^^^

extend from the circular tube (Fig. 1G5) the whole length of the chy-
miferous tubes, and nearly to the end of the peduncle ; the four chymif-
erous tubes open into a short digestive cavity (c, Fig. 166) ; the acti-
nostome is surrounded by four very slender, long, lanceolate, fimbriated
lips. (/, Fig. 166.) There are thirty-two long contractile tentacles,
seven between every two chymiferous tubes, and one opposite each
tube ; the ovaries consist of series of little jjouches hanging down on

Fig. 1G4. Tima formosa, half natural size.
Fig. 1C.5. Quarter-disk, from the abactinal pole ; natural size.

Fig. 166. Digestive cavity and actinostome. ^ termination of chymiferous tube ; c, digestive
cavity ; /, one of the four fimbriated lips of the actinostome.
NO. II. 15

114

TIMA FORMOSA.

both sides of the chymiferons tubes (Fig. 167) ; the tentacles have a
Fig. 107. very prominent i^ouch, strongly compressed laterally, at the
point of junction with the marginal tubes ; between the
larger principal tentacles (J, Fig. 168) we find a number of
small pouclies, rudimentary tentacles [t', Fig. 168), which
are never developed fully, yet appear to be included in the
1/ regular cycle of tentacles, to judge from the number we
find at different stages of growth ; between the smaller
tentacles we find marginal capsules (c. Fig. 168), with four
to five granules arranged near the periphery ; the circular
tube is large and very prominent ; the spherosome is per-
fectly colorless, but the ovaries, as well as the base of the
tentacles, are of a beautiful milky white, which makes these Jelly-
fishes a very prominent object in the water ; they do not come near
Pi^, ics the surface, but remain usually

four or five feet below ; they
are found during the whole year,
adult specimens having been taken
in June, October, December, and
March. The young Medusa (Fig. 169) differs widely from the adult;
tliere are no ovaries in specimens measuring more than an inch in
diameter ; the chymiferous tubes extend along the short proboscis
{t, Fig. 170), opening into a digestive cavity, d, which terminates
with four rather simple lips, more like the actinostome of a Lafoea ;
there are but three large marginal tentacles between adjoining chy-
miferous tubes, and no signs of any further cycles of tentacles in

Fig. 170.

the specimen figured here ; marginal capsules were likewise not yei
developed. The young Medusa of Tima is another case to be added
to MeUcertum, Lafoea, and Atractylis, where tliere are no marginal

Fig. 167 Portion of the ovary, f, f, lobes running on either side of the chymiferous tubes.

Fig. 168. A magnified portion of the circular tube, t, t, principal tentacles ; t', rudimentary
tentacles ; c, marginal capsules.

Fig. 169. Young Tima formosa, natural size.

Fig. 170. Digestive cavity of Fig. 169. (, termination of chymiferous tubes; d, digestive
cavity.

TIMA FORMOSA.

115

Fig. 171.

capsules along the circular tube, and yet these MedusjB have all been

traced to a Canipanularian-like Hjdrarium. Tima diflTei-s from the

other genera just mentioned, in developing eventually these marginal

capsules, which are always wanting, at least in the shape of capsules

with limestone concretions, in the above-mentioned genera. See the

magnified portion of the circular tube of Tima (Fig. 168), and compare

this, crowded with marginal capsules, to the circular tube

of Melicertum and Lalbea. Having kept in confinement

males and females of this species, I succeeded in raising

from the eggs the Planula, and ultimately the Hydra-

rium, as in the case of Melicertum, where further details

will be found concerning the mode of development of

the Planula into the Hydrarium ; as this is identical in

both, I shall only describe the Planula and Hydrarium

as far as they differ from those of the Melicertum.

The Planula is more pear-shaped (]), Fig. 171) than
that of the Melicertum, and takes a fixr greater elongation before at-
taching itself {]j', Fig. 171.) The Hydrarium is also more slender,
the cup is more distinct, the tentacles are quite long and slender, and
are connected at the base by a
web (Fig. 172); this seems to
be a mere embryonic feature, as
I have noticed the same web in
several young Campanularians.
The Hydrarium here figured at-
tained its present features at the
end of six months. The com-
munities are very small tufts,
barely perceptible to the naked
eye ; they appeared like a few
slender threads on the side of
the glass vessel in which the
Planula was raised ; I did not
succeed in raising the Hydrarium to observe its further develop-
ment. ^

Massachusetts Bay (L. Agassiz).

Cat. No. 276, Cape Cod, March, 1862, A. S. Bickmore. Medusa.

Cat. No. 372, Nahant, September, 1863, A. Agassiz. Medusa.

Museum Diagram No. 17, after A. Agassiz.

Fig. 172.

Fig. 171. p, young planula ; p', planula immediately before attaching itself.
Fig. 1 72. Single Hydra of the tuft of a Tima Hydrarium, greatly magnified.

116

EUTIMA.

EUTIMA McCr.

Eutima McCn. G^-mn. Cliarl. Harbor, p. 87.

Eutima Agass. Cont. Nat. Ilist. U. S., IV. p. 363. 1862.

Eutima mira McCr.

Eutima mira McCr. Gymn. Charl. Harb., p. 88, PI. 11, Figs. 8, 9.
Eutima mira Agass. Cont. Nat. Hist. U. S., IV. p. 3C3. 1862.

Charleston, S. C. (McCrady).

Eutima variabilis McCr.

Eutima variabilis McCr. Gymn. Charl. Harb., p. 88.

Eutima variabilis Agass. Cont. Nat. Hist. U. S., IV. p. 363. 1862.

Charleston, S. C. (McCrady).

Eutima limpida A. Agass.

Eutima limpida A. Agass. ; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 3G3. 1862.

This species (Fig. 173) resembles closely the Eutima mira of
Charleston Harbor ; like it, it has only four long tentacles (with one
short cirrus on each side of the tentacle. Fig. 176), one opposite each
chymiferous tube, two large marginal cajjsules between each two ten-
Fig. 173. Fig. 174.

tacles (Fig. 174), arranged at equal distances round the marginal tube,
and a number of rudimentary tentacles which are never further devel-
oped. The gelatinous part of the disk, which projects in the proboscis
((/, Fig. 175), is shorter than in the Cliarleston species; it does not
extend much more than the height of the bell beyond the level of the
veil ; the tentacles also are shorter, and have no swelling ; the diges-

Fig. 1 73. Profile of Eutima limpida, reduced in size.
Fig. 174. Quarter-disk of Fig. 173.

EUTIMA LIMPIDA.

117

tive cavity (c, Fig. 175) is very short; it is situated at the extremity
of the narrow flexible sac, extending from g to c, Fig. 175, and termi-
nates in a flat quadrangular disk \d. Fig. 175), which is sometimes
folded in the shape of forceps, although generally kept stretched out
flat, like the sucking disk of a leech ; in the centre of this disk we find
the actinostome, which is a very small rosette-shaped opening, with
four loops. The genital glands (o. Fig. 175) are narrow; they rise
almost from the circular tube, and follow the chymiferous tubes along

Fig. 175

Fig. 176.

Fig. 177.

Fig. 178.

the gelatinous prolongation of the disk, nearly to the level of the veil,
(o'. Fig. 175.) The tentacles are hollow and have no swelling at the
base (Fig. 176), the walls being thicker and tapering gradually to the
extremity. In the marginal capsules (Fig. 177), which are so large
that they can be seen with the naked eye, there are ii-om twelve to
thirteen granules arranged in a circle near the periphery of the capsule.
The rudimentary tentccles [t, Fig. 178) are mere triangular expansions

Fig. 1 75. Magnified view of the proboscis and genital organs, g, terminal point of gelatinous
prolongation of the disk ; o, part of genital organs extending along the bell ; o', terminal point of
genital organs along the gelatinous prolongation of the bell ; c, digestive cavity ; d, actinostome in
its usual mode of expansion.

Fig. 176. JIagnified portion of the circular canal, with a primary tentacle and tentacular cirri,
to show the rudimentary tentacles between the chymiferous tubes and the capsules, c.

Fig. 177. Magnified marginal capsule, showing the circular arrangement of the granules.

Fig. 1 78. Still more magnified view of tho rudimentary tentacles, c, circular tube ; t, rudi-
mentary tentacles.

118 POLYORCHID^.

of the circular tube, c. The bell widens very rapidly towards the lower
floor, and is perfectly transparent ; the ovaries, as well as the tentacles
and the proboscis, are colorless ; the diameter of the bell is nearly two
inches, and the polar diameter about half an inch ; the proboscis is usu-
ally carried as in Fig. 173, and, as the digestive cavity is capable of but
slight contraction, it bears usually the proportions of that figure to the
diameter of the bell. Found in Buzzard's Bay durmg September.
Buzzard's Bay, Naushon (A. Agassiz).

Eutima pyramidalis Agass.

Eutima puramiJalis Agass. Cout. Nat. Hist. U. S., IV. p. 363. 1862.

The spherosome is hemispherical, and more heavy than in either
Eutima Umpkla or E. mira ; the proboscis is shorter, and tapers rap-
idly ; the tentacles are short ; the oral leaflets are rounded and sepa-
rated by an indentation from one another, the edge of the leaflets being
finely scalloped ; the digestive cavity is short.

Florida, Key West (L. Agassiz).

Family POLYOROHID^ A. Agass.

Pohjorchidw A. Agass. ; in Agassiz's Cont. Nat. Hist. tf. S., IV. p. 349. 1862.

This family is characterized by the jieculiar structure of the chymif-
erous tubes, which, sending ofi" diverticula at right angles to the main
tube,' give these Medusa a very peculiar aspect. With the exception
of Polyorchis, we know of only one other genus, Olindias Fr. Miill.,
which has the same structui-e of the chymiferous tubes. Miiller, at the
close of his description of O. sambaqulensis, says it is characteristic of
the uncertainty which still exists in the classification of Acalephoe, that
the attempt to assign to this Medusa its position in the systems of Esch-
scholtz, Forbes, or Liitken, places thein in families with which they have
no affinities, and we cannot even assign them to any of the families of
Gegenbaur ; the only genus to which it seems to have any relation is
Melicertum Oken. This suggestion of Miiller, as to the affinities of his
genus Olindias, is fully borne out by the examination of the Melicertum
jjeniciUatum of Eschscholtz, which has, like it, peculiar chymiferous
tubes, and also the discovery of Gonionemus, a genus having the gen-
eral appearance of Olindias without the ramifying chymiferous tubes.
Gonionemus shows us the close relation that exists between these
genera and Melicertum, although the differences existing between
Olindias and Polyorchis on one side, and Gonionemus and Melicertum
on the other, are such as to form very natural families.

POLYORCHIS.

119

POLYORCHIS A. Agass.

Polyorchis A. Agass. ; in^Agassiz's Cont. Nat. Hist. U. S., IV. p. 349. 1862.
Melicerlum Esch. (p. p-)- Syst. dcr Acal., p. 105. 1829.

Polyorchis peniciUata A. Agass.

Polyorchis penicillafa A. Agass. ; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 349. 1862.
Melicertum pcnicillatum Esch. Syst. der Acal., p. 106, PI. 8, Fig. 4. 1829.
Aglaura penicillala Bl. Man. d'Actinol., PI. 33, Fig. 4.
Melicertum peniciUata Less. Zooph. Acal., p. 293. 1843.

This strange Jelly-fish I first found in
great numbers, while becalmed at the
entrance of the Straits of San Juan de
Fuca, in October, in company with large
numbers of a Medusa which I suppose to
be the 3Iesonema {Zygodactyla) ccerides-
cens found b}^ Brandt in the latitude of
San Francisco, and which I had after-
wards occasion to observe again near
Punta de los Reyes, about twenty miles
northwest of San Francisco. It is also
quite common in the harbor of San Fran-
cisco during the winter months. It com-
bines the characters of several families,
has the long, pendent digestive cavity
of the Thaumantiadse (Fig. 179) ; the
ovaries hang independently,
four in number to each chy-
miferous tube (Fig. 180),
near the base of the diges-
tive cavity, as in the Tra-
chynemidtB. But what is
very peculiar is the struc-
ture of the chymiferous
tubes ; instead of being sim-
ple or forking tubes, as we generally
find in the H^^lroids, they remind us of
the structure of the chymiferous tubes in
Idyia, sending off short shoots into the
gelatinous disk at right angles, alternat-

Fig. 179. A profile view, somewhat magnified, of
Polyorchis peniciUata.

Fig. 180. Ovaries of one of the chymiferous tubes.

Fig. 179.

Fig. 180.

120

POLYORCHIS PENICILLATA.

Fig. 181.

ing with each other (Fig. 179) ; this gives to these Meduste a very
pecuhar appearance, differing entirely from any other family of Hy-
droids, and for which I would propose the name of Polyorchidaj. The
polar axis is the longest ; the sjiherosome has its greatest
width at the level of the ovaries (Fig. 179) ; from this
point it turns rapidly towards the abactinal pole, while it
scarcely tapers towards the actinostome, giving the sphero-
some the appearance of a cylinder with a rounded top ;
the thickness of the spherosome is very uniform, projecting
but slightly in the inner cavity of the bell (Fig. 181), at
the point of attachment of the digestive cavity ; the diges-
tive cavity is long, slender, and exceedingly movable, terminating in
four lobes (Fig. 182), and extending to the opening of the veil ; there
are four genital organs of unequal length, attached at the highest point
(Fig. 180) of the four chymiferous tubes, hanging freely in the cavity
of the bell ; they are arranged one behind the other, along the upjier
extremity of the chymiferous tubes, the longest equalling half the
height of the inner bell. The diverticula from the main tubes com-
mence immediately at the base of the ovaries, where they are quite
small ; they gradually increase in size for about half the length of the
chymiferous tubes, whence they continue nearly of the same size to the

Fig. 182

Fig. 183.

circular tube ; the offshoots are somewhat more numerous in the loAver
jiart of the tube. (Fig. 179.) The tentacles are very contractile (com-
pare Figs. 183 and 179) ; when drawn up, they are scarcely half the
length of the spherosome ; they project horizontally from the chymif-
erous tubes for a short distance, and from the point where a conical
dark-purple ocellus is placed are then bent at right angles to their
former direction ; it is only the lower part of the tentacle which is
capaljle of expansion ; when the tentacles are fully expanded, they
extend three or four times the length of the bell. The genital sacs,
the chymiferous tubes, the tentacles, and the digestive cavity, are of a

Fig. 181. Section of tlie bdl.

Fig. 182. Part of the disk of Fig. 179, seen from the abactinal pole.

Fig. 183. Two of the marginal tentacles in a contracted state.

LAODICEID^. 121

light reddish-brown color ; the bell has a yellowish tint. The motions
of this Medusa are rather sluggish ; they are very conspicuous in the
water on account of their wreath of dark-pur2:)le ocelli ; they are grega-
rious, move near the top of the water, the bell almost striking the
surface, and when disturbed return to the surface immediately. There
are thirty-six tentacles, eight between each of the four chymiferous
tubes, and one at the base of each tube ; the four lobes of the actinos-
tome are long, and Hare out considerably beyond the diameter of the
digestive cavity, which is of a uniform length, widening very gradually
to the point of junction with the chymiferous tubes ; the main chymif-
erous tubes are slightly winding ; the lower knotty, club-shaped diver-
ticula have a tendency to bend downwards towards the circular tube ;
the veil is narrow ; the ovaries are one third the length of the sphero-
some. These Jelly-fishes attain a height of nearly two inches ; but
smaller specimens, measuring only an inch in height, showed, except
the size, no diflerences ; the character of the marginal capsules of this
Medusa, if there are any, has not been examined.

This is undoubtedly the Ilellcertum pe)ticiUatum of Eschscholtz,
though from his description and figures the characteristic features of
this Medusa are not very evident.

California (Eschscholtz) ; Gulf of Georgia (A. Agassiz) ; San Fran-
cisco, Cal. (A. Agassiz).

Cat. No. 283, San Francisco, Cal., Dec. 1859, A. Agassiz. Medusa.

Cat. No. 284, San Francisco, Cal, Jan. 1854, T. G. Gary. Medusa.

Cat. No. 285, Gulf of Georgia, W. T., 1859, A. Agassiz. Medusa.

Family LAODICEID^ Agass. (emetid. A. Agass.).

Laodiceiilce Agass. Cont. Nat. Hist. U. S., IV. p. 350. 18G2.
Thaumantiadce Gegenb. ; in Zeit. f. Wiss. Zool., p. 23G. 1856.

The family name of Laodiceida? given to the Thaumantiadae Gegenl).
by Professor Agassiz, may, in its turn, yield to that of Lafoeadas, should
it be found that the Hydrarium of Laodicea Less, is invariably a Lafoea.
The name Laodiceidaj is here retained, as the Meduste, associated under
that generic name, present differences which, when the Hydrarium be-
comes known, may warrant our retaining the name Laodicea for some
of them, and thus the genus which has given the family name may
still be retained, even if for the present we substitute for some of the
species of Laodicea the older name of Lafoea of Lamouroux. The
Laodiceida3 are here extended to include the Melicertida?, which cer-
tainly are closely related, and can hardly be divided into distinct fami-
lies, if we are to judge from the young Medusae and the Hydrarium of
these genera.

NO. II. 16

122

LAFCEA.

LAFCEA Lamx.

Laf<ta Lamx. Expos. Meth. 1812.

Laf(ta Agass. Cont. Nat. Hist. U. S., IV. p. 351. 1862.

Lafma A. Agass. ; in Proc. Bost. Soc. Nat. Hist., IX. p. 91.

Alracli/lis Wright ; in Ann. & Mag., VIII. p. 129. 1861.

CampanuUna Van Bex.; in Bull. Acad, de Belg., XIV. No. 5. 1847.

Laodicea Agass. {p. p. non Less.). Cont. Nat. Hist. U. S., IV. p. 350. 18C2.

Fig. 134.

Lafoea calcarata A. Agass.

Laodicea calcarata A. Agass. ; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 350. 1862.
Lafa:a cornula Agass. {non Lamx.). Cont. Nat. Hist. U. S., IV. p. 351. 1861.
Campanularia dumosa Leidy. Mar. Inv. N. J. and R. I., p. 6.
Lafasa cornuta A. Ag.vss. ; in Proc. Bost. Soc. Nat. Hist., IX. p. 91, Fig. i.

The Medusa of Lafoea described in the Contributions of Professor
Agassiz, Vol. IV. p. 351, was referred by him to Lafoea cornuta of
Lamouroux. Havmg, however, since that time found at Nahant a
young Medusa closely allied to the one to be here described, I am
inclined to doubt this identification, even though I have not observed
its Hydrarium, as I have done for the Lafoea of Naushon ; the absence
of pigment-spots at the base of the tentacles, and the diffei'ent number
of tentacles at the time when the
Medusae are liberated from the repro-
ductive calycles, easily distinguishes
these two Medusas. The Lafoean Me-
dusa found at Naushon was also fol-
lowed in its more advanced stages,
till we could connect it with the
young of the Medusa before described
as Laodicea calcarata.

The largest specimens observed
were an inch in diameter ; the bell
is perfectly transparent (Fig. 184),
and, were it not for the four dark-
yellowish ovaries, it would readily
escape notice ; they hang down like
short curtains in close folds, extend-
ino; almost the whole leuQ-th of the
chymiferous tubes, from the digestive cavity where they run into the
folds of its base (Fig. 185), to the circular tube ; the digestive cavity
is short, and the actinostome divides into four thin, convoluted folds,
projecting beyond the edge of the digestive cavity to twice its diam-

Fig. 184. Adult Medusa of Lafoea calcarata ; magnified.

LAFCEA CALCARATA.

123

eter (Fig. 18G) ; the cliymiferous tubes are naiTOw ; the tentacles have
their greatest diameter directly at the circular tube ; they are, how-
ever, unequally developed, and vary greatly in character. The large
tentacles are very contractile ; near the base they have a swelling
which consists of small granular cells, with a spot of dark-violet pig-
mentrcells on its lower surface (Fig. 187) ; on the opposite side of this
bulb we find a spur-like projection (see t, Fig. 187), consisting of large,
ti'ansparent, polygonal cells ; from this point the tentacle tapers very
gradually, and is also made up of larger cells than the basal swelling ;

Fig. 185.

Fig. 186.

these cells are arranged in two rows, and through them runs a thin
tube to the tip of the tentacle ; the lasso cells are numerous, and run
in a zigzag manner all over the surface of the large tentacles. When
new tentacles are formed in the adult Medusae, it is the spur which is
first developed, and afterwards the swelling with the pigment^cells ; the
tentacle has then a triangular appearance, and is turned in the opposite
direction from the spur ; from this time it lengthens very rapidly, though
many of the tentacles are never fully developed. There are besides
long thread-like tentacles, which are not hollow, and are exceedingly

Fis. ISS.

contractile (c. Fig. 187) ; in adult specimens they are not distrilnited
regularly, but in yoimg specimens of a qviarter of an inch in diameter,
having not more than sixteen large tentacles, and sixteen smaller ones
(like the large ones) placed between them, we find on the side of each
of these sixteen larger tentacles one of these cirri (Fig. 194) ; but as
the number of tentacles increases, the cirri are not formed with the
same regularity. We find still a third kind of tentacle : club-shaped

Fig. 185. One of the ovaries and the actinostonie.
Fig. 18G. Actinostome, actinal view.

Fig. 187. Magnified view of a portion of the circular tube, t, one of the large tentacles, with
spur and pigment-cells ; c, one of the cirri ; k, club-shaped appendage.

Fig. 188. Actinostome and rudimentary ovaries of young Medusa, seen in profile.

124

LAFCEA CALCARATA.

ried along,

appendages {Tc, Fig. 187) made up of large polygonal cells, perfectly
transjmrent, one or two sometimes placed between each of the larger
tentacles. The large tentacles liave the same color as the ovaries.
The yomig Medusae differ from the adult in the extent of the ovaries,
which are limited to the upper part of the chymiferous tubes, close
to the digestive cavity (Fig. 188) ; the ovaries gradually extend
further towards the circular tube as they grow older ; the digestive
cavity is a simple cylinder pressed in, forming small lips ; the tentacles
also, as described above, are less numerous. The adult Medusa is very
Fig, 1S9. active, moving with great ra-

pidity, by drawing its tentacles
into the bell, throwing them
out again with violence, and
allowing itself to be carried
along by the momentum it has
acquired; twisting its tentacles
during that time, and spread-
ing them in every conceivable
manner. When it is lazily car-
tlie Isell often assumes strange attitudes ; the thick upper
part of the disk becomes rounded, and the thin portion of the lunbrella
is projected beyond it, like the rim of a four-cornered hat. (Fig. 189.)
At other times it seems as if the uml:)rella had been tied in the middle,
the upper and lower part of the disk almost joining in the middle at an
obtuse angle. The next moment the disk becomes perfectly flat, the
tentacles are drawn up in close knots or shortly-twisted coils, so that it
scarcely seems to be the same animal, which in a moment assumes
again a globular shape, and darts oft' to go through the same changes
of form.

The Medusa in its youngest stage resembles closely the figure given

by Wright of the Medusa of A. rejiens in the Edinburgh Philosophical

Journal. The Hydromedusarium differs so much, that it does not seem

Jig. 190. to belong to the same genus as

the English species ; it is found
growing along the stems of a
species of Dynamena, found
just below the line of low-
water-mark. The individuals
are arranged, in a quincunx manner, on both sides of a long, slender,
creeping stem, which does not branch. It resembles a true Campanu-
laria in having a transparent bell disconnected from the stem. Other-
Fig^. 189. Different attitiule of tlie Jlediisa of Fi;;. 184.

Fig. 190. Ilydrarimii of Lafoja calcarata ; the extremity of the reproductive calycle is some-
wliat injured. See Fig. 191.

LAFCEA CALCARATA.

125

Fig. 191.

wise the sterile Hydra reminds us of a true Sertularian, witli a few
thick tentacles, and a long digestive cavity, capable of great expansion.
The bell is attached to the stolon hy a short stem, a mere bend in its
lower portion, so that the sterile individuals are set off a short distance
from the main stem. (Fig. 190.) The repx'oductive calycles are gigan-
tic, compared to the size of the sterile individuals. (Fig. 190.) They
are few in numl^er, not more than two or three to a stem,
and resemble those of L. amphora ; only one or two Me-
dusa} are developed simultaneously, the more advanced
one filling the cavity of the capsule almost entirely.
(Figs. 190, 191.) The sterile individuals recall the Tiibu-
lai'ians, as do in fact all the Sertularians, in which the
connection between the bell of the sterile individuals and
the digestive cavity is not as intimate as in the true
Campanularians, giving us at the same time a measure
of the embrj'onic stanchng of the Tubularians, the Sertu-
larians, and the Campanularians ; the Medusas of this
Sertularian-like Hydromedusarium resemble more those
of the Tubularians than those of the Campanularians. The vertical
diameter of the Medusa is greater than the transverse ; the bell is of
moderate thickness, the abactinal part being slightly conical (Fig. 192) ;
the digestive cavity is short, and consists of four simple lobes, giving
the actinostome the shape of a cross. When it escapes from the re^Dro-
ductive calycle, it has only two long tentacles, two slightly developed

Fig. 192.

Fig. 193.

ones, and four more hardly perceptible in the middle of the space
between the four chymiferous tubes (Fig. 193) ; at the base of all the
tentacles, and over the whole surface of the digestive cavity, we find
large yellow cells scattered irregularly ; the long tentacles are highly
contractile ; a spiral of lasso cells, diminishing in size, and beginning at
a small distance from the sensitive bulb, winds round the tentacles ;

Fig. 191. Uninjured reproductive calycle.

Fig. 192. JlediLsa immediately after its escape from tlic repro'lnctive calycle.

Fig. 193. A Medusa somewhat mure advanced, from the abactinal pole.

126

LAFOEA DUMOSA.

Fig. 194.

mm"^

at the base of the tentacles the walls are thick, and the sensitive
swelling quite prominent, having a dark pigment-spot. The Medusa,
when it escapes from the reproductive calycle, has a vei'tical diameter
of about one twentieth to one sixteenth of an inch ; the Hydromedu-
sarium is from a quarter to an inch long.

In the next stage observed (Fig. 194) we find the rudimentary ten-
tacles of the previous stage fully developed, and at the same time the
thread-like cirri of the adult Lafoea. This stage is important, connect-
ing as it does, without any doubt, two Medusas
Avhich had thus far been placed in dift'erent
genera. The digestive cavity and the ova-
ries are nearly in the same condition as that
observed in young Medusae, where the spur
and the different kinds of marginal appen-
dages were as well developed as in the adult ;
we have as yet, however, in the present
stage (Fig. 194), no trace of the spur or of
the club-like appendages of the circular tube found in the adult.
These club-like appendages of Lafoea and of Ptychogena show that
the marginal capsules, the compound eyes, the cirri, and the difierent
rudimentary appendages, are only modified tentacles.
Buzzard's Bay, Naushon (A. Agassiz).
Cat. No. 151, Naushon, 1861, A. Agassiz.
Cat. No. 271, Naushon, 1861, A. Agassiz.
Cat. No. 438, Naushon, 1864, A. Agassiz.

Hydromedusarium.

Medusa.

Medusa.

xyVu^"- I

'- ll-jf^i,.::, .

Lafoea cornuta Lamx.

Lafma cornuta Lamx. Expos. Method. 1812.

Newfoundland (Lamouroux).

Lafcea dumosa Sars.

Lafiea dumosa Sars ; in Vidensk. Forh. 18C2.
Campanularia dumosa Johnst. Brit. Zooph. 1838.

Massachusetts Bay (A. Agassiz). Medusa.

Cat. No. 433, Sea-Coal Bay, N. S., Anticosti Expedition, 1861. Hy-
drarium.

Fig. 194. Young Medusa still further advanced than Fig. 193.

LAODICEA.

127

LAODICEA Less.

Laodicea Less. Zooph. Acal., p. 294. 1843.
Laodicea Agass. Cont. Nat. Hist. U. S., IV. p. 350. 1862.
Cosmedra Forbes. Brit. Nakud-eyed Medusa;, p. 42. 1848.
Tliaumantias Gegenb. (^non Esch.) ; in Zeit. f. W. Zool., p. 237. 185G.

Laodicea cellularia A. Agass.

Laodicea cellularia A. Agass. ; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 350. 18G2.

I am somewhat doubtful whether this species (Fig. 195) belongs to
the genus Laodicea, as the examination of the tentacles could not be
made sufficiently accurate to determine this point. The general form

Fig. 195

Fig. 196.

of the ovaries, howcA'er, is the same, beginning at the digestive cavity,
and running in the form of small hanging lobes along the chymiferous
tubes, close to the circular tulje. The digestive cavity is so short that
the edge, which extends in the shape of four long, narrow lips, deeply
frilled (Fig. 196), seems the continuation of the chymiferous tubes,
reminding us somewhat of the structiu-e of the actinostome of the
^quorida?, as in Stomobrachium. The epithelial cells are large, u'reg-
ular, and hexagonal, and can easily be seen with the naked eye. The
color of the spherosome is liglit violet, the ovaries and -digestive cavity
being of a darker color, and the base of the circular tentacles of a still
stronger shade. There are about twenty-four tentacles between each
of the four chymiferous tubes, and a tentacle opposite each tube. Found
in the Gulf of Georgia and at Port Townsend, from July to September.

Gulf of Georgia, W. T. (A. Agassiz).

Cat. No. 270, Gulf of Georgia, W. T., 1859, A. Agassiz. Medusa.

Fig. 1 95. Laodicea cellularia.

Fig. 196. One of the lips of the aet!no.stome. c, c, c, c, termination of the chymiferous tubes
into the iligestive cavity, d : /, fold of the actinostome connecting the lips of the actinostome.

128 MELICERTlDiE.

COSMETIRA Forbes.

A remarkable Hydroid Medusa, belonging to the genus Cosmetira of
Forbes, was brought home by the Anticosti Expedition.
Magdalen Islands, Gulf of St. Lawrence.
Cat. No. 371, Magdalen Islands, N. S., Anticosti Kxpedition. Medusa.

Family MELICERTID^ Agass.

MelicertidoR Agass. Cont. Nat. Hist. U. S., IV. p. 349. 1862.

GONIONEMUS A. Agass.

Gonionemus A. Agass.; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 350. 18G2.

Gonionemus has a general resemblance to Melicertum, but differs
from it by the shape of the ovai'ies and of the spherosome. The
s^iherosome is an oblate half-spheroid, cut from pole to pole ; the ova-
ries are in lobes alternating on the sides of the chymiferous tubes, and
extending their whole length, from the digestive cavity to the circular
tube ; the digestive cavity is long, and very flexible ; the tentacles are
numerous, large, and exceedingly contractile ; chymiferous tubes four
in number.

Gonionemus vertens A. Agass.

Gonionemus vertens A. Agass. ; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 350. 18G2.

This Medusa was quite commonly found during the month of July,
swimming in patches of kelp. It at once attracted my attention by
its peculiar mode of moving. I could see these Jelly-fishes, with the
tentacles spread out to their fullest extent, sinking slowly to the bot^
tom, the disk turned downward ; the moment a blade of kelp touches
the disk, they stop, bend their tentacles like knees, and remain at-
tached to the sea-weed by means of their lasso cells (Fig. 197), which
are ai'ranged in rings scattered thickly over the surface of the ten-
tacles ; after remaining attached in this way a moment, with their
tentacles extended and mouth turned upwards, they suddenly let go
their hold, turn upside down, contract their tentacles (Fig. l'J8) to a
third of their former length, and begin their upward movements by
means of short, rapid jerks, given by the sudden exjianding and con-
tracting of the tentacles as they are violently thrown out from the
cavity covered by the veil. They keep up this rapid motion until they
reach the surface of the water ; at the instant the ujiper pai-t of the

GONIONEMUS VERTENS.

129

disk touches the top of the water, the Medusa inverts itself, and sinks,
with its tentacles fully expanded, luitil it reaches the bottom, or an-
other piece of sea-weed, where it attaches itself, and after remaining
suspended a little while, repeats the same operation ; when attached,
it requires strength enough to break the tentacles to make them loose

their hold. I have never found single individuals, but have always
seen them in large numbers swimming among the sea-weed in the
manner described. The form of the spherosome is that of an oblate
spheroid, cut in two by a plane passing through the north and south
poles, the plane of intersection containing the circular tube ; thei'e are
sixty-four tentacles, fifteen between each chymiferous tube, placed so
closely together that they seem all to unite at the p;g. igg.

base. The tentacles, when contracted, resemble a
scythe fastened by a band to the circular tulje
(Fig. 199) ; the pigment-cells are numerous, and
give the circular tube the appearance of having
a large row of violet knobs, to which the tentacles
are attached. There is one part of the tentacle,
near the tip, which seems to be more thickly cov-
ered by lasso-cells, and by which the Jelly-fishes
attach themselves ; when the tentacles are fully
expanded, they always make an angle at that point, as if they had
been broken, and the parts joined together again. (Fig. 197.) The

Fig. 197. Gonioncraus rertens, as it appears when attached by its teutacles.
Fig. 198. Gonionemus yerteiis, in motion ; natural size.

NO. 11. 17

130

MELICERTUM.

ovaries are frill-like lobes (Fig. 200), passing from one side to tlie other
of the chymiferoiis canal ; the chymiferous tubes are slender, and ap-
pear like four dark-violet threads, connecting the different lobes of the

Fig. 201.

Fig. 199.

ovaries. (Pig. 201.) Tlie digestive cavity reaches about two thirds of
the length of the chymiferous tubes ; it is very flexible, but scarcely
contractile (Fig. 201), ending in four large lobes, capable of extend-
ing far beyond the main wall of the digestive cavity ; the veil is large,
leaving an opening of half the diameter across the circular tube.

Gulf of Georgia, W. T. (A. Agassiz).

Cat. No. 286, Gulf of Georgia, W. T., 1859, A. Agassiz.

MELICERTUM Oken.

Melicertum OKEy. Lehrb. tier Naturg. 1816.
MeUcertum Ag.\ss. Cont. Nat. Hist. U. S., IV. p. 349. 18G2.
Melicerla 7±R. et Les. {p. p.) ; in Ann. du Mus., XIV. p. 40. 1809.
Campanella Less, (non Bl.). Zooph. Acal., p. 281. 1843.
Stomobrachium Forbes Qion Br.). Naked-eyed Medusse, p. 30. 1848.

Melicertum campanula Esch.

MeUcertum campanula Escn. Syst. der Acal., p. 105. 1829.

Melicertum campanula Agass. Cont. Nat. Hist. U. S., IV. p. 349. 18G2.

MeUcertum ca7Hpanula A. AoASS. ; in Proc. Bost. Soc. Nat. Hist., IX. p. 96, Figs. 18, 19.

Melicerla campanula Per. et Les. ; in Ann. du Mus., p. 40. 1809.

Medusa campanula Fab. Fauna Griinlandica. 1 780. No. 360.

Medusa campanulata Bosc. Hist. Nat. d. Vers., II. p. 170.

Campanella Fahricil Less. Zooph. Acal., p. 281. 1843.

Campanella campamda MoKCii ; in Bcskriv. af Gronland, p. 95. 1857.

This Medusa, first mentioned by Fabricius, has, like many others so
characteristically described by him, escaped notice entirely, till it was

Fig. 199. The bend of a contracted tentacle. ^

Fig. 200. A portion of the genital organs.

Fig. 201. One chymiferous tube and half of the digestive cavity.

MELICERTUM CAMPANULA.

131

Fig. 203.

observed on the coast of New England. Undoubtedly a few others of
the Jelly-fishes he has enumerated will jnove identical with species
since described, on the coast of England and on our own shores. A
Medusa of this same genus was figured and described by Forbes under
the name of Stomohrachlum, octocostatum ; from the figure of Forbes
it is evidently not a Stomobrachium, and is probably this same Medusa
which he found in the North of Scotland. Fig. 202 is a profile view,
natural size, of the Melicertum, one of the most common of our naked-
eyed Medusae. In the fall, at the time of spawning, it literally swarms
at the surface, and on sunny days seems jjarticularly to delight to
come to the surface, where it remains in the afternoon until dark,
being one of the few Medusas
{Zygodactyla groenlandica has
the same habit) which are to
be met with in the after-
noon. The genus Melicertum
is closely related to the iEquo-
ridiB, by the number of its
radiating tubes (of which there
are eight), and to Stain-ophora,
by the blending of the genital
organs with the actinostome,
and the total absence of mar-
ginal bodies, such as ca2)sules,
cirri, and so forth. If the
small Medusas here figured
(Figs. 203, 204) are in reality
the young of Mehcertum, —
Melicertum being the only
Medusa allied to Staurophora

which has no eye-specks, — the close affinity between them is still
more strongly marked in the young of these two genera, which can
only be distinguished from one another by the presence or absence
of eye-specks.

From an examination of the Medusa of Lafaa orilcarata, I had
already come to the conclusion that the young Medusa Avas nearly
related to Staurophora and Melicertum. Having succeeded in finding
another Medusa evidently closely allied to it, I was not surprised in
recognizing a Melicertum of younger stage than any which I had
observed before. With the stage represented in Fig. 205, which has
been traced until there could be no doubt as to the genus to which
the young Medusa belonged, I was sufficiently familiar, from its frequent
occurrence in the latter part of the spring, to recognize at once in

Fig. 2(I2. Profile of Moliccrtuiu camiianula, natural size.

132

MELICERTUM CAMPANULA.

Fig. 203 only a somewhat younger form of the same Medusa,. "We
have thus established, by the observation of this Medusa, as well as
from the young Hydrarium of Melicertum and Lafcea, the probable
character of the Hydrarium from which Melicertum, Staurophora, and
those Medusae which have no marginal capsules, are developed ; show-
ing that they hold an intermediate position between the Campanu-

Fig. 203.

Fig. 2M.

means of distinguishing them with

larians and the Tuljularians, being more closely allied to the latter in
their embryonic condition, and assuming as adult Medusaa somewhat the
aspect of Camjoanularian Medusa?. The Trichydra jmdica of Wright
is also closely allied to Lafoea and Staurophora. In the young Medusa
we have at tirst only two jDrimary tentacles (Fig. 204) and two rudi-
mentary ones, and in the next stage there are sixteen. (Fig. 205.)

The presence of eye-specks at the base of the tentacles of the young
Medusas of Laf<xa calcctrata and of Sfmtrojihora laciniata are the surest

accuracy. The differences in the
shape of the bell between these youngest
MedusfB (Fig. 203) and somewhat older
stages (Fig. 205), are of a similar character
to those Ave are familiar with amonw the
young Cam2)anularian Medusae of other gen-
era. To judge from analogy, I strongly sus-
pect that the young Medusa of Staurophora
will in its turn be a Medusa, similar to these
Lafoean forms, having at first but two primary tentacles. In the next

Fig. 203. Profile view of very young Medusa of Melicertuui campanula ; Lafoean like. See
Fig. 192.

Fig. 204. Half the disk of the same, seen from the aetiiial pole.

Fig. 205. Young jMelieertum, with oiil}' tour completely formed chymifi-rous tubes. Ic, fu-st
set of chymiferous tubes ; 2c, second set ; 1, 2, 3, tentacles of the first, second, and third sets.

MELICERTUM CAMPANULA.

133

stage (Fig. 205), which is luidoubtedly a young Mehcertum, we find
the second set of four chyiniferous tubes developing (2e, Fig. 205) ;
they arise, as in the ^quoridiB, from the digestive cavity, and extend
towards the circular tube ; there are at this stage sixteen tentacles,
usually carried curled up, as in the accompanying figure. I have not
seen the young Melicertum in stages intermediate between those
slightly more advanced than Fig. 205, and when they are fully devel-
oped, as in Fig. 202, where the genital organs extend to the circular
tube, and the marginal tentacles have become exceedingly numerous.

Fig. 206.

Fig. 208.

The spherosome is regularly bell-shaped ; it is capable of very varied
expansion and contraction, appearing at some times almost rectangular,
then as if tied in the middle, swelling at both poles, again flaring at
the abactinal extremity, and strongly contracted at the circular tube,
or flattened like a quoit. The tentacles may expand several times the
polar diameter of the bell, or conti'act, by curling close to the circular
tube. The bell is of a light ochre color ; the genital organs, as well
as the base of the tentacles, are of a darker shade. When seen from
above (as Fig. 206), the radiating tubes open rig. 209.

into a sort of cavity, as in the ^quorida^, the
folds of one genital organ extending across to the
next, as seen in Figs. 207, 208 ; the ovaries are
convoluted (Fig. 207), extending from I, Fig.
207, to the circular tube, Avhere they have their
greatest diameter ; the lips of the actinostome
are carried in eight folds (Fig. 208), each one, I,
corresponding to one of the radiating tubes, c,
as in the iEquorida? ; the lips project but little
into the cavity of the bell. The tentacles are
hollow, somewhat dumb-bell shaped at the base

Fig. 206. Tlie same, seen from the abactinal pole, m, month ; o, genital organs ; t, tentacles.

Fig. 207. Magnified view of two chymiferous tubes and genital glands. /, lips of actinostome.

Fig. 208. Mode of carrying the lips of the actinostome. I, lips of actinostome ; c, chymiferous
tube.

Fig. 209. Magnified view of marginal tentacles.

134

MELICERTUM CAMPANULA.

(Fig. 209), and taper rapidly ; tliey are thickly covered with lasso-
cells.

Artificial fecundation of these Medusfe can be very readily made by
keeping males and females for a day or two together in a glass jar,
when we shall find, swimming near the bottom, innumerable spherical
embryos (Fig. 210), in which the spheres of segmentation are still

Fis- 311.

Fig. 312.

Fig. 213.

visible ; these elongate (Fig. 211), a cavity is formed at the blunt end,
and we have a somewhat pear-shaped embryo, strongly ciliated, with
walls of unifoi-m thickness (Fig. 212), swimming about with great ve-
locity ; these emljryos attach themselves by the blunt end (Fig. 213),
and soon elongate, as in the two middle figures of Fig. 213 ; the slen-
Kig. 214. der extremity next swells (Fig. 214), and this is the

first trace of the sterile Hydra head. The wall of
this swelling soon becomes somewhat indented, as
in Fig. 214, where we have some of the successive
stages of the sterile Hydra, until it forms a small
horny bell, covering only the base of the long, ster-
ile Hydra head, which terminates with ten stout,
short tentacles, connected by a web. This Hydra-
rium differs considerably from that of Lafoea, but it
still has sufficient resemblance to show their con-
nection ; it is one of the easiest to raise, the
Planulaj are very hardy, and the development of
the Hydrarium is readily followed. It grows in
small tufts, which after six months had not attained a greater height
than one third of an inch.

Greenland (Fabricius) ; Massachusetts Bay (Agassiz).
Cat. No. 351, Gi'and Manan, L. Agassiz. Medusa.
Cat. No. 373, Nahant, 1863, A. Agassiz. Medusa.
Cat. No. 448, Nahant, 1864, A. Agassiz. Medusa.
'^■' ■' '■ " ,

Fig. 210. Spherical emWyo.

Fig. 211. The same, somewhat more advanced.

Fig. 212. The same, immediately before becoming attached.

Fig. 213. Group of embryos attached, in different stages of development.

Fig. 214. Different stages of growth, beyond those of Fig. 213, till the sterile Hydra is fully
developed.

MELICERTUM GEORGICUM.

135

Melicertum georgicum A. Agass.

Meliccrtum georgicum A. Agass. ; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 349. 1862.

The Medusa (Fig. 215) is here figured to show the differences no-
ticed between it and the New England representative of the genus.
The pointed spherosome, the smaller number of the circular tentacles,
the longer actinostome, and the termination of the genital organs,
somewhat above the circular tube, are characters which readily distin-
guish the M. georgicfiim from its Eastern representative. The knowl-
edge of its complete development will settle this point definitely. The
close resemblance of the mode of attachment of the ovaries to that
of the .J<]quorida3, referred to in the preceding sjjecies, is readily seen

Fig. 216.

Fig.!

215.

^~

'tK

\ •

V\

P

AO

\ '• •

4^

1

'^^i

M

7

)} V.

/ '

;_/

1 / '• -y

J

-^

' j'

in Fig. 216. The genital folds are looped up on the upper side of the
interior of the bell in an octagonal outline (Fig. 216), opening into the
large cavity formed by the eight constrictions of the fips, I, of the acti-
nostome. The difference is simply in the number of the chymiferous
tubes, as well as in the mode of carrying the lips of the actinostome.
A simple flattening of the spherosome, and an increase in the number
of chymiferous tubes, would give us an jEquorea. This Medusa is
fomid, in the summer, in the Gulf of Georgia, "W. T.

Fig. 215. Profile of Melicertum georgicum, natural size.

Fig. 216. Digestive cavity and point of junction of the chymiferous tubes. /, lips of actinos-
tome ; p, abactinal point of attachment of genital organs ; c, opening leading into chymiferous
tubes. Magnified.

136

STAUROPHORA.

STAUROPHORA Brandt.

Staurophom Brandt (nnn Forbes) ; in Mem. Acad. St. Petersburg, II. p. 399.
Slawopliora Agass. ; in Mem. Am. Acad., IV. p. 300.
Staurophora Agass. Cont. Nat. Hist. U. S., IV. p. 351. 1862.
Staurophora Less. Zooph. Acal., p. 297. 1843.

1835.

Staurophora laciniata Agass.

SlauropJwra laciniala Agass. ; in Mem. Am. Acad., IV. p. 300, PI. 7. 1849.
Staurophora laciniala Agass. Cont. Nat. Hist. U. S., IV. p. 351. 1862.
Staurophora laciniata A. Agass.; in Proc. Boston Soc. Nat. Hist., IX. Figs. 1, 2, 3.
Slauro2}ho7-a laciniata Stimps. Mar. Inv. Grand Manan, p. 11. 1853.

The youngest Medusa of Staurophora which has been observed
(Fig. 215") resembles to such an extent the young Mehcertum (Figs.
rig.2i5». 203, 205), as readily to have been taken for dif-

ferent stages of the same Jelly-fish, did not the
absence of pigment eye-specks enable me to dis-
tinguish them sufficiently easily. The develop-
ment of the tentacles of the young Medusa ex-
plains itself from the accompanying figures (Figs. 216*, 217), as well
as the changes of form of the digestive cavity, as it passes from a simple
pendent pouch (Fig. 215") through the different stages (o, b, c, Fig.
218), where the digestive cavity loses Httle by. little its individuality,
the corners gradually extend along the chymiferous tubes, and in

Fig. 217.

Fig. 213.

quite young specimens (c, Fig. 218) the actinostome can no longer be
distinguished among the innumerable small folds of the genital pouches.
In Fig. 219 the young Staurophora has all the characters of the adult,
excepting the size of the different parts. The violet pigment-spots at
the base of the tentacles are quite apparent, being perceptible in

Fig. 215*. Young Staurophora, with eight tentacles.

Fig. 216'. Quarter of the disk of a young Staurophora, with sixteen large tentacles.
Fig. 217. Young Medusa, somewliat more advanced than Fig. 216".

Fig. 218. Different stages of the actinostome, intermediate between that of Figs. 215* and 219.
a, the youngest ; b, tlie nc.\t ; c, the oldest.

PTYCHOGENA. I37

younger stages. (Figs. 215% 216*, 217.) "igo^

This Medusa grows to a large size, meas-
lu'inu" often six to eia-lit indies in diameter.
It is one of the earhest Medustv to make
its apjiearance, attains its full size rapidly
from May to June, and by the end of
June the dead Medusa3 are found in large
numbers, floating about after storms ; by
the middle of July they have all disap-
peared. Found at Nahant.

Massachusetts Bay (Agassiz) ; Maine (Stimpson).

Cat. No. 275, Nahant, A. Agassiz. Young and old Meduste.

Cat. No. 359, Boston Harbor, L. Agassiz. Medusa.

Staurophora Mertensii Br.

Slaurophora Mertensii Br. ; in Mem. Acad. St. Petersb., IV. p. 400, Pis. 24, 25. 1838.
Staurophora Mertensii Less. Zooph. Acal., p. 297. 1843.

Norfolk Soimd (Mertens).

PTYCHOGENA A. Agass.

The Medusa for which this genus has been established shows the
intimate structural connection between Staurophora, Melicertura, and
Polyorchis. The structure of the genital organs is an intermediate
state of development between organs where the folds of the actinos-
tome are lost in the genital folds, as in Staurophora, and the other
extreme, where we have pendent genital organs attached to one ex-
tremity of diverticulate chymiferous tubes, as in Polyorchis.

Ptychogena lactea a. Agass.

The bell of this Medusa is rather high (Fig. 220), and the sphero-
some of considerable thickness, giving this species an appearance of
consistency, which is heightened by the striking contrast with the
water of the milky genital organs and numerous marginal tentacles.
The chymiferous tubes are broad ; at an equal distance on the abac-
tinal and actinal ends, the edges of the tube become hacked ; the
notches increase in size, and soon become long, sharp folds of the
walls of the chymiferous tubes, projecting at right angles from the
tubes (Fig. 221) ; the larger of these folds branch again. To these
folds the genital organs are attached, forming as many connecting

Fi^. 219. Young Staurophora, having the general aspect of the adult.

138

PTYCHOGENA LACTEA.

pouches as there are points to the projections of the chymiferous
tubes ; the folds become smaller and smaller (Fig. 222) towards the
abactinal pole, and are connected by a loose fold with the actinostome.
The openuig of the actinostome is large ; its folds are small, and do

Fig 221.

Fig. 220.

not form regular lips, but merely an irregular quadrangular frill. (Fig.
223.) The tentacles are extremely numerous, opening into a large circu-
lar tube ; they are very much flattened in one direction (/, Fig. 224) ;
between every two tentacles is found a club-shai^ed ai^jjendage, made

Fig 222.

FiK. 223.

Fig. 224.

up of large cells somewhat like those of Lafcea calcarata (h, Fig. 224) ;
the tentacles are capable of great expansion, and when contracted are
usually curled up tightly, as is the case in Melicertum and Staurophora ;
they are very frequently tied up in festoons, as in Fig. 220. This

Fig. 220. Profile view of Ptychogcna, somewhat reduced.

Fig. 221. JIagiiifieil view of the genital organs, seen from the abactinal pole.

Fig. 222. The same as Fig. 221, seen in ]iro(ile, on a somewhat smaller scale.

Fig. 223. Actinostome. a, opening of actinostome ; p, point of attachment of the digestive
cavity ; t, lips of the actinostome.

Fig. 224. Magnified base of tentacles and club-shaped appendages. /, swelling of tentacles ;
6, club-shaped appendages.

PLUMULARID.E. 139

Medusa, like Tima, swims at a considerable depth below the surface.
The action of the light and increase of temperature of the surfiice is
sufficient to kill them in the course of half an hour ; the moment they
are brought to the surfoce, the spherosome loses its transparency, the
genital organs become dull, and the Medusa is soon completely decom-
posed. This action is much more rapid than any thing of the kind
which I have noticed even in Ctenopliora?, Mertensia being the only
genus in which the decomposing effects of light and heat are at all
equal to what is produced here. This Jelly-fish must be a deep-water
species, as they have only been found during a single fall, and then
only for a few days, when they seemed quite abundant.
Massachusetts Bay, Nahaut (A. Agassiz).

Family PLUMULARIDiE] Agass.

PlumulmiihE Agass. Cont. Nat. Illst. U. S., IV. p. 358. 1862.
SertularidcE JoussT. (/). p.). Brit. Zooph., p. 89.

AGLAOPHENIA Lamx. {restr. McCr.).

Aglanphenia Lamx. (pars) ; in Bull. Soc. Phil. 1812.
Aylaophenia McCr. Gymnopli. Cliark'ston Harbor, p. 98. 1857.
Aglaophenla Agass. Cont. Nat. Hist. U. S., IV. p. 358. 1862.
Plumularia La.mk. (pars). Auim. s. Vert., U. p. 159.

Aglaophenia pelasgica McCk.

Aglaophenia pelasgica >IcCr. Gymn. of Charleston Harbor, p. 99. 1857.
Serlularia pelasgica Bosc. Hist. Nat. Vers., HI. p. 122.
Plumularia pelasgica Lamk. An. s. Vert., II. p. 167.
Dynamena pelasgica Blainv. Man. d'Actin., p. 484.

Cat. No. 253, Florida, 1858, L. Agassiz. Hydrarium.

Cat. No. 254, Tortugas, Fla, 1859, L. Agassiz. Hydrarium.

Cat. No. 255, Hayti, 1858, Dr. D. F. Weinland. Hydxarium.

Cat. No. 256, Gulf Weed, 1858, Dr. D. F. Weinland. Hydrarium.

Cat. No. 257, Gulf Weed, 1858, Dr. D. F. Weinland. Hydrarium.

Cat. No. 390, a hundred miles south of Cape Hatteras, A. S. Bick-
more. Hydrarium.

Cat. No. 391, a hundred miles south of Cape Hatteras, A. S. Bick-
more. Hydrarium.

140 PLUMULARIA.

Aglaophenia triflda Agass.

Ar/lanphenia trifida Ar.Ass. Cont. Nat. Hist. U. S., IV. p. 358. 1862.
Afjiaophenia cristata McCr. (non Lamk.). Gymn. Charl. Hai'b., p. 100.

Charleston, S. C. (L. Agassiz).

Cat. No. 252, Charleston, S. C, Jan. 1852, L. Agassiz. Hydrarium.

Aglaophenia tricuspis McCe,

Aglaophenia tricuspis McCr. Gjmn. Charleston Harbor, p. 101.

Charleston, S. C. (McCrady).

Aglaophenia franciscana A. Agass.

Plumuiaria franciscana Trask ; in Proc. Cal. Acad., March, 18.57, p. 101, PI. 4, Fig. 3.
Plumularia struthionides MuRR. ; in Ann. & Mag. N. H., V. p. 251. 1860.

San Francisco (A. Agassiz).

Cat. No. 259, San Francisco, Cal., December, 1859, A. Agassiz. Hy-
droniedusarium.

Cat. No. 2G0, San Francisco, Cal., December, 1859, A. Agassiz. Hy-
dromedusarium.

PLUMULARIA L.\mk. {resfr. McCr.}.

Plumularia Lamk. {p- p-) An. s. Vert., H. p. 159.
Plumularia McCr. Gymn. Charleston Harbor. 1857.
Plumularia Agass. Cont. Nat. Hist. U. S., IV. p. 358. 1862.

Plumularia quadridens McCr.

Plumularia qiiarlridens McCr. G}Tnn. Charleston Harbor, p. 97.
Plumularia quadridens Agass. Cont. Nat. Hist. U. S., IV. p. 358. 1862.

Charleston, S. C. (McCrady) ; Florida (L. Agassiz).

Cat. No. 251, Ship Channel, Florida, January, 1856, L. Agassiz.

Plumularia arborea Des.

Plumularia arhorea Des. ; in Proc. Bost. Soc. Nat. Hist., HI. p. 65. 1848.

Massachusetts Bay (Desor).

SERTULARIAD^E.

141

Family SERTULARIAD^ Johnst.

Sertulariadce Johnst. British Zoophj-tes, p. 5 7.

DYNAMENA Lamx. {restr. Agass.).

Dynamena Lamx. ; in Bull. Soc. Phil. 1812.

Dynamena Agas.s. Cont. Nat. Hist. U. S., IV. p. 355. 1862.

Dynamena pumila Lamx.

Dynamena pumUa Lamx. Cor. Flex., p. 179.

Dynamena pumila JoiixsT. Brit. Zooph., p. 66.

Dynamena pumila Agass. Cont. Nat. Hist. U. S., IV. pp. 326, 355, PL 32. 1862.

Dynamena pumila Pack.; in Can. Nat. & GeoL, Dec. 1863.

Sertularia pumila Morch ; in Beskriv. af Greenland, p. 97. 1857.

Serlutaria thuja Fab. {teste Moreb). Fauna Groenl., No. 456.

This is one of the few of our Hydroids (Fig. 225) which have been
compared in a Uving state with European specimens sent by Mr. Thos.
J. Moore to the Museum, and brought across the Atlantic by Captain
Anderson. Professor Agassiz, supposing it to be a distinct species, had
previously given it the name of Dynamena Fahricii ; and before he

Fig. 226.

had examined the development of the sessile Medusa (Fig. 226), sup-
posed it to be the Hydroid of our MeUcertum mmpamda. See, for the
Hydroid of MeUcertum, the description of that species.'

European and American shores of Atlantic Ocean (Ellis, Agassiz).

Cat. No. 1(33, New Brighton, England, 1860, H. J. Clark. Hydrarium.

Cat. No. 164, Liverpool, October, 1861, Thos. J. Moore. Hydromed.

Cat. No. 165, Lynn, Mass., May, 1852, H. J. Clark. Hydromedusarium.

Cat. No. 166, Nahant, July, 1862, A. Agassiz. Hydromedusarium.

Cat. No. 167, Nahant, May, 1862, A. Agassiz. Hydromedusarium.

Cat. No. 168, Nahant, July, 1861, A. Agassiz. Hydromedusarium.

Fig. 225. Cluster of Dynamena pumila.

Fig. 226. Magnified portion of stem of Fig. 225.

142 DIPHASTA.

Cat. No. 169, Naliant, June, 1855, H. J. Clark. Hydromeclusarium.

Cat. No. 170, Nahant, September, 1854, H. J. Clark. Hydrarium.

Cat. No. 171, Chelsea Beach, L. Agassiz. Hydrarium.

Cat. No. 172, Cohasset, Mass., L. Agassiz. Hydrarium.

Cat. No. 173, Nantucket, Mass., August, 1857, L. Agassiz. Hydrome-
dusarium.

Cat. No. 174, Grand Manan, August, 1857, J. K Mills. Hydromedu-
sarium.

Museum Diagram No. 18, after L. Agassiz.

Dynamena cornicina iMcCr.

Dynamena cornicina McCk. Gymn. Charl. Harb., p. 102.

Charleston, S. C. (L. Agassiz).

Cat. No. 175, Charleston, S. C, L. Agassiz. Hydrarium.

Cat. No. 176, Charleston, S. C, 1852, L. Agassiz. Hydrarium.

DIPHASIA Agass.

Biphasia Agass. Cont. Xat. Hist. U. S., IV. p. 355. 1862.

Diphasia faUax Agass.

Biphasia fallax Agass. Cont. Nat. Hist. U. S., IV. -p. 355. 1862.
Sertidaria fallax Jounst. Brit. Zooph., p. 73, PI. 11, Figs. 2, 5, 6.
Sertularia fallax Stuips. Mar. Inv. Grand Manan, p. 9. 1853.

Grand Manan (W. Stimpson) ; Massachusetts Bay.

Cat. No. 18.3, Eastport, Me., 1851, L. Agassiz.

Cat. No. 184, Eastport, Me., 1852, W. Stimpson.

Cat. No. 185, Massachusetts Bay, L. Agassiz.

Cat. No. 427, Eastport, Me., 1861, Anticosti Expedition.

Cat. No. 428, Eastport, Me., 1863, A. E. VerriU.

Diphasia rosacea Agass.

Diphasia rosacea Agass. Cont. Nat. Hist. U. S., IV. p. 355. 1862.

Scrtiilaria 7-osacea Linn. Svst. 1306.

Serlularia rosacea Johxst. Brit. Z/joph., p. 64.

Sertidaria rosacea Pack.; in Can. Nat, & Gool., Dec. 1863.

? Serlularia pliimea Des. ; in Prflc, Best. Soc. N. H., III. p. 66. 1S48.

"Nahant, Suisconset, Mass. (A. and L. Agassiz).

Cat. No. 180, New Brighton, England, Oct. 1860, H. J. Clark. Hy-
dromedusarium.

Cat. No. 181, Nahant, Mass., July, 1861, A. Agassiz. Hydromedusarium.

Cat. No. 182, Suisconset, Mass., July, 1849, L. Agassiz. Hydromedu-
sarium.

SERTULARIA. 143

Diphasia corniculata A. Agass.

Serttilaria corniculata Murray ; in Ann. & Mag. N. H., X. PI. XI. Fig. 3. 1860.

Bay of San Francisco (Murray).

SERTULARIA Linn, {emend. Agass.).

Sertularia Linn. Syst. Nat.

Sertularia Agass. Cont. Nat. Hist. U. S., IV. p. 356. 1862.

Sertularia abietina Linn.

Sertvlaria abietina LisTi. Syst. 1307.

Sertularia abietina Fad. Fanna Gropniandica. No. 453.

Sertularia abietina Johxst. Brit. Zoopli., p. 75.

Sertularia abietina Agass. Cont. Nat. Hist. U. S., IV. p. 356. 1862.

St. George's Bank, Newfoundland ; Mingan Islands.

Cat. No. 195, New Brighton, Eng., Oct. 1860, H. J. Clark. Hydrarium.

Cat. No. 196, Liverpool, Eng., 1861, Thos. J. Moore.

Cat. No. 197, St. George's Bank, W. Stimpson.

Cat. No. 419, Mingan Islands, 1861, Anticosti Expedition.

Sertularia cupressina Linn.

Sertularia cupresnina Linn. Syst. 1308.

Sertularia cupre.isina .JoiiNST. Brit. Zooph., p. 80.

Sertularia cupressina Leidy. Inv. R. I. and N. J., p. 6.

Sertularia cupressina Agass. Cont. Nat. Hist. U. S., IV. p. 356. 1862.

Absecom Beach (Leidy) ; Massachusetts Bay (Agassiz).
Cat. No. 202, New Brighton, Eng., October, 1860, H. J. Clark. Hy-
dromedusarium.

Cat. No. 203, Beverly, July, 1861, A. Agassiz. Hydromedusarium.
Cat. No. 204, Nahant, May, 1862, A. Agassiz. Hydromedusarium.
Cat. No. 205, Chelsea, May, 1862, H. J. Clark. Hydromedusarium.
Cat. No. 206, Eastport, Me., 1851, W. Stimpson. Hydromedusarium.
Cat. No. 207, Mount Desert, Me., W. Stimpson. Hydromedusarium.
Cat. No. 208, Suisconset, July, 1849, L. Agassiz. Hydromedusarium.
Cat. No. 209, Suisconset, Mass., L. Agassiz. Hydrarium.
Cat. No. 211, Lynn, Mass., Jan. 1861, H. J. Clark. Hydrarium.
Cat. No. 212, Massachusetts Bay, L. Agassiz.

144 SERTULARIA ANGUINA.

Sertularia argentea Ell. & Sol.

Sertularia argenlea Ellis & Sol. Zooph., p. 38.

Sertularia argenlea Johnst. Brit. Zooph., p. 79, PI. 15, Fig. 3 ; PI. 14, Fig. 3.

Sertularia argentea Agass. Cont. Nat. Hist. U. S., IV. p. 356. 1862.

Sertularia argentea Stimps. Mar. Inv. Grand !Manan, p. 8. 1853.

Sertularia argentea Morcil; in Besk. af Gronland, p. 97.

Sertularia fastigiata Fab. {teste Morcli). Fauna Gronlandica, No. 458.

Grand Manan (W. Stimpson).

Cat. No. 213, New Brighton, Oct. 1860, H. J. Clark. Hydrarium.

Sertularia falcata Linn.

Sertularia falcata Linn. Syst. 1309.

Sertularia falcata Agass. Cont. Nat. Hist. U. S., IV. p. 356. 1862.
Plumularia falcata Johnst. Brit. Zooph., p. 90, PI. 21, Figs. 1, 2.
Plumularia falcata Pack.; in Can. Nat. & Zool. Dec. 1863.
Plumularia falcata Stimps. Mar. Inv. Grand Manan, p. 8. 1853.
Sertularia tenerissima Stimps. Mar. Inv. Grand Manan, p. 8. 1853.

Grand Manan (W. Stimpson) ; Eastport, Me. (W. Stimpson) ; Mingan
Islands ; Massachusetts Bay (Agassiz).

Cat. No. 218, New Brighton, Eng., 18G0, H. J. Clark. Hydrarium.

Cat. No. 219, Grand Manan.

Cat. No. 220, Eastport, Me., 1853, W. Stimpson. Hydromedusarium.

Cat. No. 221, Grand Manan, W. Stimpson.

Cat. No. 222, Eastport, Me., 1851. Hydrarium.

Cat. No. 223, Suisconset, Mass., L. Agassiz. Hydrarium.

Cat. No. 224 (P. tenerissima), Grand Manan, W. Stimpson. Hydro-
medusarium.

Cat. No. 415, Mingan Islands, 1861, Anticosti Expedition. Hydrarium.

Cat. No. 416, Eastport, Me., 1861, A. E. Verrill. Hydrarium.

Cat. No. 417, Mingan Islands, 1861, Anticosti Expedition. Hydrarium.

Cat. No. 424, Eastport, Me., 1861, Anticosti Expedition.

Sertularia anguina Trask.

Sertularia anguina Trask ; in Proe. Cal. Acad. N. S., p. 100, Pl. 5, Fig. 1. 1857.
Sertularia labrata Murray ; in Ann. & Mag. N. H., V. p. 250, PI. XI. Fig. 2. 1860.

Bay of San Francisco (Trask, Murray); Monterey, Punta de los
Reyes, Tomales Point (Trask).

SERTULAEIA TURGIDA. 145

Sertularia gracilis A. Agass.

Plumularia gracilis Murray ; in Ann. & Mag. N. H., V. p. 251, PI. XII. Fig. 1. 1860.

Bay of San Francisco (Murray).

Sertularia myriopliylluni Linn.

Scrlularia mi/rioplii/Hum LlNX. Syst. 1309.
Plumularia ini/riojjiiijlluin Joiinst. Brit. Zooph., p. 99.

Cat. No. 214, Massachusetts Bay, L. Agassiz.
Cat. No. 418, Mingan Islands, Anticosti Expedition.
Cat. No. 429, Eastport, Me., A. E. Verrill.
Cat. No. 430, Eastport, Me., A. E. Verrill.

Sertularia latiuscula Stimps.

Sertularia latiuscula Stimps. Mar. Inv. Grand Manan, p. 8. 1853.

Grand Manan (W, Stimpson).

Sertularia filicula Ell. & Sol.

Sertularia filicula Ellis & Sol. Zoopli., p. 57, PI. 6, Figs, c, C.
Sertularia JiUcula Stuips. Mar. Inv. Grand Manan, p. 8. 1853.
Sertularia filicula Johnst. Brit. Zooph., p. 76, PI. 14, Fig. 1.

Grand Manan (W. Stimpson).

Sertularia furcata Trask.

Sertularia furcata Trask ; in Proc. Cal. Acad., March, 1857, p. 101, PI. V. Fig. 2.

San Francisco (Trask).

Sertularia turgida Trask.

Sertularia turgida Trask ; in Proc. Cal. Acad., March, 1857, p. 101, PI. IV. Fig. 1.

San Francisco (Trask).

Sertularia producta STi5n»s.

Sertularia producta Stimps. Mar. Inv. Grand Manan, p. 8. 1853.

Grand Manan ("W. Stimpson).

xo. II. 19

146 COTULINA.

AMPHITROCHA Agass.

■Amphitrocha Agass. Cont. Nat. Hist. U. S., IV. p. 356. 1862.

Amphitrocha rugosa Agass.

Amphilrocha rugosa Agass. Cont. Nat. Hist. U. S., IV. p. 356. 18G2.

Sertularia rugosa Linn. Syst. 1308.

Sertularia rugosa Fab. Fauna Gronlantlica. No. 454.

Sertularia rugosa Joiinst. Brit. Zoopli., p. G3, PI. X. Figs. 4-6.

Sertularia rugosa Sxmps. ]Mar. Inv. Grand Manan, p. 9. 1853.

Sertularia rugosa Mokch ; in Bcsk. af Griinland, p. 97.

Amphitrocha cincta Agass. Cont. Nat. Hist. U. S., IV. p. 356. 1862.

Massachusetts Bay (L. Agassiz) ; Grand Manan (W. Stim^ison).
Cat. No. 226, Nahant, April, 1855, H. J. Clark. Hydromedusarium.
Cat. No. 227, Nahant, May, 1855, H. J. Clark. Hydromedusarium.
Cat. No. 228, Nahant, August, 1854, H. J. Clark. Hydrarium.
Cat. No.' 229, Nahant, July, 1861, A. Agassiz. Hydrarium.
Cat. No. 230, Nahant, September, 1854, H. J. Clark. Hydrarium.
Cat. No. 406, Nahant, July, 1862, A. Agassiz.

COTULINA Agass.

Cotulina Agass. Cent. Nat. Hist. U. S., IV. p. 356. 1862.

Cotulina tricuspidata A. Agass.

Sertularia tricuspidata Alder (non Mun-ay). Cat. Zooph. Northumb. and Durham, p. 21, PI. U.

Figs. 1, 2. 1857.
Sertularia tricuspidata Pack. ; in Can. Nat. & Geol. Dec. 1863.

Massachusetts Bay (L. Agassiz).

Cat. No. 2.33, Massachusetts Bay, L. Agassiz.

Cat. No. 234, Massachusetts Bay, L. Agassiz.

Cat. No. 235, Eastport, Me., July, 1851, W. Stimpson.

Cat. No. 236, Eastport, Me., July, 1852, W. Stimpson.

Cotulina polyzonias Agass.

Cotulina polyzonias Agass. Cont. Nat. Hist. U. S., IV. p. 356. 1862.
Sertularia polyzonias Linn. Syst. 813.

Sertularia polyzonias Johnst. Brit. Zooph., p. 61, PI. X. Figs. 1-3.
Sertularia polyzonias Morch ; in Besk. af Gronland, p 9 7. 1857.
Sertularia polyzonias Stimps. Mar. Inv. Grand Manan, p. 9. 1853.
Sertularia polyzonias Pack.; in Can. Nat. & Geol. Dec. 1863.
Sertularia pinnala Gould. Rep. Inv. Mass., p. 350.

Eastport, Me. (A. E. Verrill) ; Mingan Islands (Anticosti Expedition);
Grand Manan (W. Stimpson).

HALECIUM. 147

Cat. No. 426, Eastport, Me., 1863, A. E. Verrill.

Cat. No. 434, Mingau Islands, 1861, Anticosti Expedition.

Cotulina tamarisca A. Agass.

Sertularia lamarisca Linn. Syst. 1307.

Sertularia tamarisca Johnst. Brit. Zooph., p. 74, PI. XIII. Figs. 2-4.

Eastport, Me. (A. E. Verrill ; Sea-Coal Bay, N. S. (Anticosti Expedi-
tion) ; Massachusetts Bay (Agassiz).

Cat. No. 231, Grand Manan, W. Stimjoson. Hydrarium.
Cat. No. 232, Massachusetts Bay, W. Stimpson. Hydrarium.
Cat. No. 425, Eastport, Me., 1863, A. E. Verrill.
Cat. No. 431, Sea-Coal Bay, N S., 1861, Anticosti Expedition.

Cotulina Greenei A. Agass.

Sertularia tricuspidata Murray {non Alder). Anii. & Mag., V. p. 200. 1860.
Sertularia Greenei Murray. Ann. & Mag., V. p. 504. 1860.

Growing in very thick clusters, resembling somewhat in their ap-
pearance fine brushes of Dynamena jmmila. It is supported by a very
slender stem, which branches near the base ; the branches rise verti-
cally, forming flxn-shaped tufts, in which all the stems reach one level ;
there is no prominent main stem. It attains a height of from two to
three inches. The secondary branches arise in a similar way, near the
base of the primary branches. The sterile hydrae have two prominent
exterior points to support the operculum, and two smaller ones near
the stem. The reproductive calycles are conical and slightly corru-
gated, attached by the apex, and terminate in a Ijottle-shaped neck.

San Francisco, Cal.

Cat. No. 436, San Francisco, Cal, Normal School, Salem.

HALECIUM Oken.

Halecium Oken. Lehrb. der Naturg. 1815.

Thoa Lamx. Pol. Cor. Flex. 1816.

Halecium Agass. Cont. Nat. Hist. U. S., IV. p. 357. 18S2.

Halecium muricatum Johnst.

Halecium muricatum Johnst. Brit. Zooph., p. 40, PI. IX. Figs. 3, 4.
Sertularia muricata Ellis & Sol. Zooj)!!., p. 59, PI. VII. Figs. 3, 4.

Cat. No. 421, Eastport, Me., 1863, A. E. Verrill.

148 THUIARIA.

Haleciura halecinum Johnst.

Halecmm halecinum JonxsT. Brit. Zoopli., p. 38, PI. VIII.

Halecium halecinum Agass. Cont. Nat. Hist. U. S., IV. p. 357. 1863.

Halecium halecinum Morch ; in Boskriv. af GronlanJ, p. 97. 1857.

Sertularia halecina Linn. Syst. 1308.

Sertularia halecina Fab. Fauna Gronlandica. No. 455.

Eastport, Maine ; Massachusetts Bay.

Cat. No. 243, New Brighton, England, Oct. 1860, H. J. Clark.

Cat. No. 244, Suisconset, Mass., L. Agassiz.

? Cat. No. 245, Nahant, Mass., Sept. 1854, H. J. Clark.

GRAMMAEIA Stimps.

Grammaria Stijips. Mar. Inv. Grand Manan, p. 9. 1853.
Grammaria Agass. Cont. Nat. Hist. U. S., IV. p. 357. 1862.

Grammaria gracilis Stimps.

Grammaria gracilis Stimps. Mar. Inv. Grand Manan, p. 9. 1853.

Grand Manan (W. Stimpson).

Gramraaria robusta Stimps.

Grammaria robusta Stimps. Mar. Inv. Grand Manan, p. 9, Fig. 3. 1853.

Grand Manan (W. Stimpson).

THUIARIA Flem.

Thuiaria Flem. British Animals. 1828.

Thuiaria thuja Flem.

Tlmiaria thuja Flem. British Animals, p. 545. 1828.
Sertularia thuja Linn. Syst. 1308.
Thuiaria thuja Johnst. Bi-it. Zooph., p. 83.

Mingan Islands, N. S.
Cat. No. 240, Norway, M. Sans.

Cat. No. 420, Mingan Islands, N. S., Anticosti Expedition, 18G1. Hy-
drarium.

TUBULARIJE. I49

Suborder TUBULARI^ Agass.

Tuhulariir Agass. Cont. Nat. Hist. U. S., IV. p. 338. 1862.
Tubularina Ehkenb. Corall. d. Rothen ]\Iecres.
Tubularina aud Hijdrina JonxsT. Brit. Zooph., p. 29.

Family NEMOPSID^ Agass.

Nemopsidm Agass. Cont. Nat. Hist. U. S., IV. p. 345. 18G2.

NEMOPSIS Agass.

Nemopah Agass. ; in Mem. Am. Acad., IV. p. 289. 1849.

Nemopsis McCr. Gymn. Charl. Harbor, p. 57.

Nemopsis Agass. Cent. Nat. Hist. U. S., IV. p. 345. 1862.

Nemopsis Bachei Agass.

Nemopsis Bochei Agass. ; in Mom. Am. Acad., IV. p. 289, Fig. 1849.
Nemopxls Bachei Agass. Cont. Nat. Hist. U. S., IV. p. 345. 1862.
Nemopsis Gibbesi McCr. Gymn. Charl. Harb., p. 58, PI. 10, Figs. 1-7.
Nemopsis Bachei A. Agass. ; in Proc. Bost. Soc. Nat. Hist., IX. p. 98, Figs. 26, 27.

Owing to the great changes through which Nemopsis passes before
it reaches its adult form (compare Figs. 227-230), it is impossible
to decide at present, before having seen the Nemoj^sis Gibbesi of
McCrady, found at Charleston, whether he has not described again,
under a new name, the JSF. Bachei found by Professor Agassiz in Vine-
yard Sound in 1848, and of which a wood-cut was i^uljlished in the
Memoirs of the American Academy for 1849. The circumstances under
which the drawing was made precluded the possibility of great accu-
racy ; it was a simple sketch ; and as this Medusa has not been ob-
served since, until the publication of McCrady 's paper on the Meduste
of Charleston Harbor, it is not astonishing that he should have described
it as a new species, having only for his guide that single wood-cut.

I have had, during the summer of 1861, the opportunity fig. 227.

of observing this Medusa, at the time when it had only
four tentacles to each marginal bulb (Fig. 227), no ova-
. lies, and was not more than a sixteenth of an inch in diam-
eter. The shape of the bell, and of the oral tentacles, the
mode of branching of the digestive cavity and of the tentacles, agree
so well with the drawings and descriptions of McCrady of similar stages
in N. Gibbesi, that I am inclined to consider them as identical. The

Fig. 227. Youngest Nemopsis observed, having four tentacles at the base of each chymiferous
tube.

150

NEMOPSIS BACIIEI.

Fig. -228.

Fig. 223.

only point which would throw some doubt upon this identification, is
the time of the year at which it appears in Charleston and in Vineyard
Sound ; in the former place it is a winter species,
found in December, while at Naushon it was very
com.mon in September. The marginal tentacles in-
crease in the same way as in Bougainvillia ; those
which are nearest the middle of the bulb, at its apex,
ai'e developed first, and new tentacles are constantly
growing near the base of the conical-shaped bulb.
(Figs. 228, 229.) They are at first slender-pointed
tentacles, but soon become rounded at the extremi-
ties, with sensitive eye-specks at the base, and change
into contractile tentacles, having a slight swelling at
the extremity ; this swelling, however, depends very much upon the
state of contraction of the tentacles. The
adult frequently swim about with the
marginal tentacles contracted to mere
knobs, rising from the sensitive bulb (Fig.
229); during their movements, which are
rapid and powerful, the oral tentacles
(Fig. 230) are thrown up and down at
each pulsation with great violence, and
seem to be important appendages in di-
recting the motions of the animal. With
the excej^tion that the tentacles, which are carried efect upon their
Pig 230. base, are not contractile like the others, and

have a more clavate appearance (Figs. 227-
230), they difl'er in no way from the others.
There are eye-specks at the base of the erect
tentacles, as well as at the base of the con-
tractile ones, and the supposition that in
this genus the eyes were supported upon a
peduncle, hke the eyes of a lobster, was
founded upon the dark club terminating this
pair of tentacles ; this color is due entirely
to a thickening of the extremity by contrac-
tion. Male specimens have been found meas-
uring moi'e than half an inch in diameter.
The proboscis projects well beyond the line of the genital organs (Fig.
231) ; at first, in young stages, the genital organs occupy but a very

Fig. 228. Ncmopsis somewhat more advanced than Fig. 227, having the second and third set
of tentacles developed.

Fig. 229. IMagnilied view of the sensitive bnlb at the base of one of the chvmiferons tubes, c.

Fig. 230. Nemojisis in wliich the genital organs extend a considerable distance along the chy-
miferous tubes.

ACAULIS. 151

small portion of the upper part of the chyiniferous tubes (Figs. 227,
228), but with advancing age extend farther down (Figs. 230, 231), and
in the adult they reach tlie circular tube. The genital organs remind
us, in their mode of growth, of what we find in Melicertuni and Stau-
rophora. The outline of the bell is but little changed from the earliest
stages to the more advanced ; it simply grows pig. 231.

somewhat more globular. The sensitive bulb
as well as the ovaries are slightly yellowish.

McCrady describes the Hydroid of this
Medusa as a free floating community ; I
greatly incline to the opinion of Professor
Allman, that we have in these free Hydroids
nothing but the detached head of some Tubu-
larian ; certainly the figures given by Mc-
Ci\idy of the Hydroid of Nemopsis, and by
Stimpson of Acaulis, remind us very forcibly
of detached heads of Tubularians. The heads
of our Pennaria (Globicejjs tiarella Ayres)
frequently drop off, and nothing is more common than to see, at the
time of breeding, several of these heads, covered with Medusa?, floating
about in the jars where the Pennariae are kept, and to have the Me-
dusa? buds come to maturity wliile the head is thus detached, and
would readily be mistaken for something like a free Hydroid. During
four successive summers I have hunted in vain in the hope of finding
one of these free Hydroids among the innumerable small Medusae
which must have just separated from the Hydrarium, which makes it
probable that the Hydrarium is fixed, and not floating.

Vineyard Sound (L. Agassiz) ; Buzzard's Bay (A. Agassiz) ; Charles-
ton Harbor (McCrady).

Cat. No. 44, Nantucket, Mass., June, 1849, L. Agassiz. Medusa.

Cat. No. 272, Naushon, Mass., Sept. 1861, A. Agassiz. Medusa.

ACAULIS Stimps.

Acaulis Stimps. Mar. Inv. Grand INIanan, p. 10. 1853.
Acaulis Agass. Cont. Nat. Hist. U. S., IV. p. 345. 1862.

Acaulis priraarius Stimps.

Acaulis primarius Stimps. Mar. Inv. Grand Manan, p. 10, PI. 1, Fig. 1.
Acaulis primarius Agass. Cont. Nat. Ilist. U. S., IV. p. 345. 18G2.

Grand Manan (W. Stimpson).

Cat. No. 162, Grand Manan, W. Stimpson. Hydromedusarium.

Fig. 231. M.ignified view of the genital organs, the actinostome, and the oral tentacles.

152 BOUGAINVILLE.^.

Family BOUGAINVILLEiE Ltitk.

BougainviUccc LuTic. ; in Vidensk. Meil., p. 29. 1849-50.
Bouf/ainviUkke Gegenb. ; in ZiMt. f. Wiss. Zool., p. 220. 1856.
Hippocrenldce McCr. Gynin. Cliarl. Harbor, p. 5G.
BougaiiwiUidce Agass. Cont. Nat. Hist. U. S., IV. p. 344. 1862.
Eudendroidce Agass. Cont. Nat. Hist. U. S., IV. pp. 282, 342. 1862.

BOUGAINVILLTA Less.

Bougainvillia Less. ; in Ann. dcs Sc. Nat., V. 1836.

Hippocrene Mert. ; (Preocc. ]Moll.) in Mem. Acad. St. Petersburg, p. 229. 1835.

Uippocrene Agass. ; in Mem. ^Vm. Acad., p. 250. 1849.

Bougainvillia Mertensii Agass.

Bougainvillia Mertensii Agass. Cont. Nat. Hist. U. S., IV. p. 344. 1862.

Hippocrene Boiigainvillei Br. Qion Less.) ; in Mem. Acad. St. Petersburg, p. 293, PI. 20. 1838.

If the Hyclrarium, collected at San Francisco, is the Hydrarium of
BougainviUia Mertensii, there can be no doubt of the specific differ-
ence between it and BoiigaiiivilUa siqierciliarls Agass. It grows quite
luxuriously, attaining a height of nearly two and a half inches ; the
stems are very stout, particularly the main hranch, which near the
base is exceedingly robust ; the branches are at least three times as
stout as those of the Hydrarium of our Bougainvillia, which is slen-
der, and always branches quite loosely. In the California species the
brandies succeed each other rapidly, and are crowded on the sides of
the main stem. This would seem to prove that this species, like the
Coryne rosaria, is the representative on the Pacific coast of its eastern
congener, and that neither the Coryne mirabilis nor the Bougain-
viUia snperciUaris are circuinpolar species, like the Toxojjneustes _ dro-
bachiensis.

This species is undoubtedly the Hipj)Ocrene BoiigainviUei Br. which
Mertens found at Mathaei Island, in Behring's Strait, and which is
figured in the Memoirs of the Academy of St. Petersburg for 1838,
Vol. II. The ramifications of the tentacles surrounding the actinos-
tome are very numerous, and the eye-sjDCcks at the base of the mar-
ginal tentacles small. Tlie spherosoine has a slight bluish tinge ; the
chymiferous tubes, the tentacles surrounding the mouth, and the mar-
ginal tentacles, are straw-colored ; the base of the tentacles is yellow-
ish-brown. This species is much larger than either BougainviUia su-
'perciliaris or B. macloviana ; it was quite common during the summer,
in the harbor of Port Townsend, at the northwest boundary, in the

BOUGAINVILLIA SUPERCILIARIS.

153

Gulf of Georgia, .and was also found in the harbor of San Francisco
during May and November.

Bein-ing's Strait (Brandt) ; Gulf of Georgia, W. T. (A. Agassiz).

Cat. No. 33, San Francisco, Cal., March, 1859, A. Agassiz. Hydrarium.

Cat. No. 49, GiUf of Georgia, W. T., May, 1859, A. Agassiz. Medusa.

Bougainvillia superciliaris Agass.

BougainviUia superciliaris Agass. Cont. Nat. Hist. U. S., IV. pp. 289, 291, Figs. 37-39; p. 344,

PI. 27, Figs. 1-7. 1862.
Hippocrene s'lperciliaris Agass. ; in Mem. Am. Acad., IV. p. 250, Pis. 1-3.
Hippncrcne superciliaris Stimps. Mar. In v. Grand Manan, p. 11. 1853.
BniKjainvilUa superciliaris A. Agass. ; in Proc. Bost. Soc. Nat. Hist., IX. Figs. 24, 25.
Hippocrene Bougainviltei Gould (hcc Br., nee Less.). Rep. Inv. Mass., p. 348. 1841.
? Tuhularia ramosa Gould. Rep. Inv. Mass., p. 350. 1841.
? Eudendrium cingulatum Stimps. Mar. Inv. Grand Manan, p. 9. 1853.

The development of the young Medusjje of the species, formerly re-
ferred to Bougainvillia, shows beyond doubt that the genera Bougain-
villia and Margelis are founded upon structural differences ; from the
earliest stages we can trace the peculiar short and long digestive cavities
so characteristic of these two genera, as well as the differences in the
form of the bell. Bougainvillia sujierciliaris (Fig. 232), of which a

complete description has already been given by Professor Agassiz, in
the Memoirs of the American Academy for 1849, is one of our most
common Medusoe, but readily escapes notice on account of its small size.
The Hydrarium (Fig. 233) has also been figured by Professor Agassiz in
Vol. IV. of his Contributions, but the development has not been traced
before. The Medusae buds are found along the stem below the heads ;
Figs. 234, 235 are early stages, when the bell is elongated, and inca-

Fig. 232. Magnified profile view of adult Bougainvillia superciliaris.

NO. II. 20

154

BOUGAINVILLIA SUPERCILIARIS.

pable of expansion and contraction. In Figs. 236, 237, which are some-
what older Medusae in diflerent attitudes, the digestive cavity is well

Fig. 233.

Fig. 235.

Fig. 234.

developed, and from the four corners of the actinostome bulge out four
club-shaped appendages, the first traces of the or-al tentacles. There

Fig. 238.

Fig. 237.

are two well-developed tentacles, which were at first a mere knob, with
distinct eye-specks. (Fig. 234.) The bell is quite thin at this stage, and

Fig. 233. Ilydromctlusarium of Bougainvillia superciliaris.

Fig. 234. Young elongated Medusa.

Fig. 235. Somewhat more advanced than Fig. 234.

Fig. 236. Appearance a short time before separating from the stem, in a contracted state.

Fig. 237. The same as Fig. 236, expanded.

Fig. 238. Young Bougainvillia, immediately after its liberation from the Ilydromedusarium.

MARGELIS. 155

of uniform thickness, the veil large and powerful ;
the abaotinal jiortion of the bell becomes somewhat
more thickened, and when it has separated from
the Hydrarium (Fig. 238), the tentacles far exceed
in length the diameter of the bell, the sensitive
bulb (Fig. 239) having become quite well defined
in outline ; it is somewhat quadrangidar, filled with
dark pigment cells, j)-. and at the base of each tentacle a Ijright eye-
speck, e, is formed ; the club-shaped oral appendages soon
begin to branch, additional tentacles appear in pairs on each
side of the original pair (Fig. 240), and the young Medusa
soon assumes all the principal features of th6 adult, as in Fig.
232, with the exception of the simpler character of the ten-
tacles of the actinostome.

Massachusetts Bay (Agassiz).

Cat. No. 27, Nahant, Mass., Sept. 1854, H. J. Clark. Hydrarium.

Cat No. 28, Beverly, July, 1861, A. Agassiz. Hydromedusarium.

Cat. No. 29, Nahant, July, 1861, A. Agassiz. Hydrarium.

Cat. No. 30, Newport, R I., Prof J. Leidy. Hydromedusarium.

Cat. No. 31, Newport, R. I, S. Powell. Hydromedusarium.

Cat. No. 408, Nahant, July, 1862, A. Agassiz. Hydromedusarium.

Cat. No. 447, Nahant, July, 1864, A. Agassiz. Hydromedusarium.

Museum Diagrams, Nos. 20, 22, after A. Agassiz.

MARGELIS Steenst.

Margelis Steenst.; in Vidensk. Medel. for 1849-50, p. iZ.
Margelis Agass. Cont. Nat. Hist. U. S., IV. p. .344. 1862.
BougainvlHia Less.; in Ann. Sc. Nat., V. 183C.
Hippocrene McCr. (jiec Mert. nee Agass.). Gymn. Charl. II:.ib., p. 61.

The structural differences observed in the European Bougainvillia
hrifaimica Forbes, and the H'qjpocrene caroUnensis McCrady, seem
sufficient to separate them from the genus Hippocrene, as has been
proposed by McCrady. The digestive cavity, instead of being a short,
rounded sac, attached at some distance below the highest point of
the chymiferous tubes, is long and slender, swelling slightly towards
its actinal end, and attached at the point of junction of the chymif-
erous tubes ; the peduncle of the actinostome is long, the oral tenta-
cles branch only two or three times ; these are more than specific
differences ; they are structural differences, unlike the differences we
find between species of the genus Bougainvillia, as between the

Fig. 2.39. Magnified view of sensitive bulb. /;, pigment-cells ; e, eye-speck.
Fig. 240. Tentacular bulb with the young tentacles, c, chymiferous tube ; 1,2, 3, 4, different
sets of tentacles.

156

MARGELIS CAROLINENSIS.

n'qipocrene superciliaris of the northeast coast, and the Hippocrene
Mertensii of the northwest coast, which are differences in the projior-
tion of the digestive cavity, its position, the thickness of the bell, and
the mode of branclung of the oral tentacles.

Margelis carolinensis Agass.

Margelis carolinensis Agass. Cont. Nat. Hist. U. S., IV. p. 344. 186 2.
Hippocrene carolinensis McCk. Gyinn. Charl. Harbor, p. 62, PI. 10, Figs. 8-10.

Adult females, taken at Naushon in September, measured about one
third of an inch (Fig. 241) ; the main stem of the four oral tentacles

Fij;. 241.

Fig, -HZ.

Fig. 242.

branches twice, and each of these branches twice (Fig. 242) ; the cav-
ity of the bell is small and globular ; the marginal bulbs are large and

conical, and give rise (Fig. 243) to ten or
twelve tentacles, which are long, slender, and
not usually carried curled up tightly near the
bulb ; the bulb is colored with brilliant red
pigment-cells, surrounded by a green edge,
bordered with bright yellow, and in the yel-
low border are placed the black eye-spots,
giving to the Ixase of the tentacles a very
striking appearance ; the digestive cavity is
brick red, and when the folds of the genital
glands are expanded by eggs, they hang down in four pouches, so as to
hide the peduncle of the digestive cavity. (Fig. 242.) The outline of

Fig. 241. Adult Margelis, seen in profile ; magnified.

Fig. 242. Digestive cavity, genital pouches, oral tentacles, and actinostome.

Fig. 243. Sensitive bulb at base of one of the chymiferous tubes.

MARGELIS CAROLINENSIS.

157

the bell is almost spherical ; the thickness of the disk is so great that
the cavity of the bell only extends to half the height of the vertical
axis. (See Fig. 241.)

In young specimens (one tenth of an inch in height) just liberated
from the Hydromedusarium, the outline of the disk is bell-shaped (Fig.
244), the cavity of the bell is large in jiroi^ortion, and the thickness of
the upper part of the bell is not one third of the height of the actinal
axis. The digestive cavity and the peduncle are one ; it is bottle-
shaped, cjdindrical, and not yet divided by four longitudinal furrows
into genital pouches. These small Medusa? have, like the young of
Bougainvillia, when freed from the Hydromedusarium, but two tenta-
cles at the base of each of the chymiferous tubes (Figs. 244, 245), the

Fig. 245.

Fig. 244.

digestive cavity terminates likewise with perfectly simple, stiff oral ten-
tacles, which begin to Ijranch only in somewhat more advanced stages.
The generic identity of Bougainvillia hritannica with our Margelis
earoUnensis is perhaps not better shown .than by the agreement of the
young Medusas in all their essential features, while the Hydrarium shows
that the specific difference between tlie English and American represen-
tatives is not to be questioned. See the observations of Dalyell on the
development of his Tuhularia ramosa, PI. XL Vol. I, Animals of Scot-
land, and the figures of Hodge of Podocoryne Alderi, which I presume
is only a young of one of the species of Bougainvillia (Margelis Steenst.)
of Forbes. It seems therefore perfectly justifiable to reconstruct the
genus Bougainvillia in such a way as to separate from it those species
which have a long, slender digestive cavity, with but slightly branching
tentacles, under the name of Margelis.

The oral tentacles are, in the youngest Medusse (Fig. 244), small,

Fig. 244. Young Margelis, having only two marginal tentacles at the base of each chymiferous
tube, and simple oral tentacles.

Fig. 245. Young Margelis, seen from the abactinal pole, in the condition of Fig. 244.

158

MARGELIS CAROLINENSIS.

Fig. 246.

simjile tentacles, terminating with a cluster of lasso-cells ; in somewhat
older Medusse the oral tentacles have two branches, as in Fig. 246,
when there are six tentacles to each marginal bulb, with a small )>undle
of lasso-cells at the extremity. As the young Medusa grows, the bell
loses its conical shape, and becomes more spherical.
The marginal tentacles of the young are carried
curved inwards towards the veil ; as they increase
in length they lose this tendency, and are stretched
out in every direction. The additional tentacles are
added at the base of the conical bulb, those which
are near the apex being always the longest and
oldest.

The Hydrarium (Fig. 247) grows to a very large
size, from eight to twelve inches in height ; it re-
sembles in its general mode of branching Etidcndr'mm rmnosuni. The
main stem is stout, and taj^ers gradually ; the main branches begin
close to the root, and thus form chisters of stems, from which branch
off irregularly secondary branches, which are quite slender, and ramify
but little. The Hydras are very large, and quite closely packed to-
gether, growing with equal profusion on the main stem and on the

Fig. 217.

Fig. 248.

branches. The Hydrarium is found growing attached to Fiicits vesicu-
losus in great abundance. The general color of the main stem is some-
what grayish green, the Hydras are of a delicate rosy tint. The Me-
dusae buds are developed, somewhat as in our BongainviUia stipercili-
aris, along the stem (Fig. 248), without, however, being limited to the
proximity of the Hydra head, as the Medusas make their appearance

Fig. 246. Proboscis of a Margelis, having already six tentacles at each sensitive bulb.
Fig. 247. Hydrarium of Margelis carolinensis, greatly reduced in size.
Fig. 248. Magnified heads and Medusse buds of Margelis carolinensis.

EUDENDRIUM. 159

all over the stem, resembling in tliis respect very strikingly the Peri-
gonimus of Sars, to which the Hydrarium also bears a close affinity,
from the size of its sterile Polypes.

Charleston Harbor (McCrady) ; Buzzard's Bay, Naushon (A. Agassiz).

Cat. No. 43, Naushon, Mass., Sept. 1861, A. Agassiz. Hydrarium.

Cat. No. 437, Naushon, Mass., 1864, A. Agassiz. Medusa.

EUDENDRIUM Ehrenb.

Eudendritim Ehrenb. Corall. d. Roth. Meeres. 1834.
Eudcndrhtm Agass. Cont. Nat. Hist. U. S., IV. p. 342. 1862.
Calamella Oken. Lehrb. der Naturg. Gesch. 181.').
Thoa Lamx. Pol. Cor. Flex. 1816.

Eudendrmm dispar Agass.

Eudendritim dhpar Agass. Cent. Nat. Hist. U. S., IV. pp. 285, 289, 342, Fig. 36 ; PI. 27, Figs.

10-21. 1862.
Thoa dispar Agass. Cont. Nat. Hist. U. S., IV. PI. 27, Figs. 10-16. 1862.

This Hydroid (Fig. 249) is closely allied to the ^l';^'^

Tuhularia ramea of Dalyell and the Coryne ini-
silla var. muscoides of Johnston. The male and
female communities are readily recognized by the
different color of the Medusa3 buds ; the male Me-
dusae buds are bright orange, while the females
are of a dull pink.

Massachusetts Bay (Agassiz).

Cat. No. 34, Nahant, Mass., Sept. 1854, H. J. Clark. Hydrarium.

Cat. No. 35, Suisconset, Mass., July, 1849, L. Agassiz. Hydrarium.

Cat. No. 36, Nahant, July, 1861, A. Agassiz. Hydrarium.

Cat. No. 37, Nahant, July 11, 1861, A. Agassiz.

Cat. No. 38, Naushon, Mass., September, 1861, A. Agassiz.

Cat. No. 405, Nahant, June, 1862, A. Agassiz. Hydromedusarium.

Cat. No. 423, Eastport, Me., A. E. Verrill.

Museum Diagram No. 23.

Fig. 24D. Female Medusae buds in different stages of development.

160

EUDENDRIUM RAMOSUM.

Eudendrium tenue A. Agass.

Fig. 250.

This species (Fig. 250) can at
once be distinguished from the
E. dispar Agass. (Fig. 249) by
its large clusters of Medusas,
while in the E. disjxtr the Me-
dusai buds are always somewhat
scattered, and never clustered to-
gether, as in E. tenue. This is
quite a small species, the tallest
specimens hardly rising more than
an inch to an inch and a half,
while the E. disjxir is a large
Hydroid, growing in tall stems,
branching but little; the E. tenue,
on the contrary, forms small colo-
nies of densely crowded individ-
uals, branching profusely. The color is light pinkish.

Massachusetts Bay, Nahant (A. Agassiz) ; Buzzard's Bay, Naushon
(A. Agassiz).

Cat. No. 39, Naushon, Sept. 1861, A. Agassiz. Hydrarium.

Cat. No. 40, Suisconset, July, 1849, L. Agassiz. Hydrarium.

Cat. No. 41, Suisconset, July, 1849, L. Agassiz. Hydrarium.

Cat. No. 402, Nahant, June 17, 1862, A. Agassiz. Hydromedusarium.

Eudendrium ramosum McCr.

Eudendrium ramosum McCr. Gymn. Charleston Harbor, p. 64.
? Eudendrium ramosum Johnst. Brit. Zooph., p. 46.

McCrady has identified this species with the English E. ramosum
Johnst. Specimens collected at Charleston by Professor Clark cer-
tainly show a great similarity to the English species, but it still
remains to be proved, as we do not know their development, that
these species are identical.

Charleston, S. C. (McCrady).

Cat. No. 42 Charleston, S. C, December, 1861, H. J. Clark.

Fig. 250. A part of a male colony ; magnified.

LIZZIA.

161

LIZZIA Forbes.

Lizzia Forbes. Brit. Nakcd-eycd Medusae, p. G4. 1848.
Lizzia Agass. Cont. Nat. Hist. U. S., IV. p. .S45. 1862.
Cylceis Sars (non Esch.). Beskriv., p. 28. 1835.

Lizzia grata A. Agass.

Lizzia grata A. Agass. ; in Proc. Bost. Soc. Nat. Hist., p. 100, Figs. 28, 29. 18G2.

The presence of a cluster of tentacles, intermediate between the
chymiferous tubes gives to Lizzia a totally different aspect from that
of Bougainvillia, which is the permanent embryonic type of Lizzia.
In a young Lizzia this middle cluster is wanting ; the character of the
development of the tentacles is totally different from that of Bougain-
villia ; we have an odd tentacle at first (Fig. 252), and then jjairs of

Fig. 251.

Fig. 252.

Pig. 263.

tentacles (Fig. 253), while in the Bougainvillia we have, for the first
set, as well as for the subsequent cycle.?, a pair of tentacles ; so that we
may have, as members of the same family, forms in which these clus-
ters are reduced to a minimum, as in Dysmorphosa (Fig. 259), where
the odd tentacle alone is developed.

In an adult Lizzia (Fig. 251) the chymiferous clu.ster of tentacles
consists of five, the intermediate cluster of three. The order of succes-
sion of the different tentacles in the young stages can easily be traced
in Fig. 252 ; at first there are four long tentacles opposite the chymif-
erous tubes, flanked by two short tentacles ; next the odd tentacle of
the middle cluster makes its appearance, and then after some time the
other pair of tentacles of the middle cluster. The sensitive bulb of the
adult is elongated, polygonal, and thickly covered with pigment-cells
(]), Fig. 253) ; the digestive cavity of the adult (Fig. 254) is nearly as
long as the cavity of the bell, into which a short projection of the bell

Fig. 2.51. Adult male Lizzia grata, seen in profile ; magnified.

Fig. 252. Quarter of the disk of a young Lizzia.

Fig. 253. Magnified view of the sensitive bulb, p, pigment-cells.
NO. II. 21

162

LIZZIA GRATA.

extends ; the genital pouches are on the sides of the digestive cavity,
extending nearly to its extremity. The actinostonie terminates in four
large lobes, edged with short oral tentacles, sui-mounted by a knob of

Fig. 255.

lasso-cells ; these lips are quite expansive and contractile, [t, t', t", f",
Fig. 255.) In the young Medusae the digestive cavity terminates with
only four club-shaped tentacles {t, Fig. 256) ; this soon branches in

Fig. 258.

somewhat older stages, as that of Fig. 252, and assumes the shape of
Figs. 257, 258, f, additional club-shaped oral tentacles being added in
the order in which they are numbered in Fig. 255.

Massachusetts Bay (A. Agassiz).

Cat. No. 446, Nahant, A. Agassiz. Medusa.

Fig. 254. Proboscis of male Lizzia ; magnified.

Fig. 255. One of the four lobes of the actinostonie, seen from above. (, /, /', I", t'", tentacles
of actinostorae.

Fig. 256. Actinal view of the proboscis of a young Lizzia. t, oral tentacle ; rf, digestive cavity.

Fig. 257. Actinal view of proboscis of an older specimen, a, actinostonie ; r/, genital pouches;
t, tentacles of actinostonie.

Fig. 258. Abactinal view of Fig. 257, somewhat less magnified, with the oral tentacles in a
different attitude ; lettering as above.

DYSMORPIIOSA.

163

DYSMORPHOSA Phil.

Dysmorpliosa Phil.; in Areliiv f. Nat., p. 37. 1842.
Podocorijne S.\RS. Fauna Lit., p. 4. 1846.

Sars has traced the development of a Medusa from Podocoryne
carnea which is very closely allied to Dysmorpliosa fidgurans here
figured. It corresponds, in its younger stages, while still attached to
the proboscis of its parent, to the different stages of our Medusa, in the
niunber, arrangement, and order of appearance of the tentacles, so com-
pletely, that I have referred it to the genus Dysmorpliosa of Philippi,
considered by Sars as identical with the Hydroid from which his
Medusa was developed. This identification is the more probable, as
Krohn has given us a complement to the observations of Sars on the
adult Medusa^, and traced the budding from the proboscis in exactly
the same manner as it is here given. The Lizzia figured by Claparede
in the tenth volume of Siebold u. Kolliker's Zeitschrift, in which he has
also traced the budding from the proboscis, appears to be identical with
the Podocoryne carnea of Sars.

Dysmorphosa fulgurans A. Agass.

This Medusa (Fig. 259) is sometimes so abundant that the whole sea,
when disturbed, is brilliantly lighted by the peculiar bluish jjhosjihores-
cent color which they give out. Their great number is easily accounted
for by their mode of reproduction and by its rapidity. Young Medusa)
are formed by budding on the upper extremity of the proboscis (Figs.
259, 260), and their development takes place in the course of three or

Fig. 259. Fig 200.

four days ; from three to four Medusae develop at the same time ; the
Medusa; buds of the third generation are already forming, while the
second is still attached. (Fig. 260.) The young Dysmorphosa has at
first four tentacles, the middle set developing later ; there are only four
oral tentacles, quite long and slender, and an accumulation of pigment-
Fig. 2.59. Adult Dysmorphosa ; magnified.
Fig. 2G0. ^lagnified proboscis, showing young MedusEe of the second and third generations.

164 NUCLEIFER.E.

cells at the base of the tentacles ; the abactinal part of the bell is quite
conical (Fig. 259) ; the tentacles of the adult Medusa are usually car-
ried rather stiffly (Fig. 260) ; but when the young Medusa is still at-
tached, they are frequently expanded several times the diameter of
the bell. (Fig. 260.) This Medusa resembles very much the young of
Turrifojjsis nutricula, and could readily be mistaken for it. It would
be most natural, therefore, to place this genus in the family of Nuclei-
ferae ; but the presence of the peculiar oral tentacles of Lizzia, added
to the fact that this is probably only a permanent embryonic stage of
Lizzia, induces me to place it among the Bougainvillidae.

Allman describes, in the fourth volume of the Ann. & Mag. of N. H.
for 1859, page 368, a Medusa as developing from Laomedea tenuis,
which resembles so strikingly Lizzia and Dysmorphosa that I suspect
there must be some error in his observation. Does it not rather come
from his Dycoryne stricta, which he found at the same time and at the
same place, and which would thus bring this Medusa, intermediate in
its characters between Lizzia and Dysmorphosa, to its proper place
among the Bougainvillidae ?

Massachusetts Bay, Naliant (A. Agassiz) ; Buzzard's Bay, Naushon
(A. Agassiz).

Family NUCLEIFERiE Less.

Niidelferce Less. Prod. Mon. Med. 1837.

Nucleiferm Agass. Cont. Nat. Hist. U. S., IV. p. .346. 1862.

Oceanldce EsCH. (p- p- non Agass.). Syst. der Acal., p. 9G. 1829

Occaniihe Gf.gexb.; in Zeitsohrift f. Wiss. Zool., p. 219. 1856.

Oceani(l(B McCr. Gymn. Charleston Harbor, p. 21.

Clavida McCr. Gymn. Charleston Harbor, p. 37.

Clavidm Agass. Cont. Nat. Hist. U. S., IV. p. 338. 1862.

TURRIS Less.

Turns Less. Prod. Mon. Med. 1837.

Tunis Agass. Cont. Nat. Hist. U. S., IV. p. 346. 1862.

Oceania AucT. {p- p- non Agass.). Medusa.

Clamila Wright. Hydra.

Turris vesicaria A. Agass.

Turris vesicaria A. Agass.; in Proc. Bost. Soe. Nat. Hist., IX. p. 97.

This Medusa I formerly supposed to be the 3fedusa digitalis of
Fabricius ; it certainly is not that of Forbes. Since that time I have
ascertained that the lledusa digitalis of Fabricius belongs to a dif-
ferent family, the Trachynemida\ (See page 57.) It has been found
but once at Nahant, in the early part of the spring, and probably

TURKIS VESICARIA.

165

having habits similar to those of Tima, it is only accidentally met
with. It has very much the same kind of coloring as our Tima, but
in Turris the color of the genital organs and the base of the tenta-
cles is somewhat more yellowish. The bell of Turris is exceedingly

Fig. 262.

thin, except at the abactinal pole (Fig. 261), where it forms a sort
of bladder, capable of more or less contraction at its base ; when the
Medusa is disturbed, the sides of the bell, below the bladder, contract,
and give it a polygonal outline, as is seen in Fig. 262. The genital

Fig. 263.

Fig. 264.

organs remind us somewhat of those of Ptychogena, only they are
attached to the abactinal part of the interior of the bell ; passing in

Fig. 261. Turris vesicaria, natural size ; seen in profile.

Fig. 2G2. The same, with the bell contracted.

Fig. 263. A portion of the disk, seen from the abactinal pole, a, opening of actinostome ; g,
point of attachment of the convoluted genital organs to the inner surface of the bell ; c, chymifer-
ous tubes ; c', continuation of convolution of genital organs, forming the sides of the chymiferous
tubes.

Fig. 264. Magnified profile view of genital organs and actinostome. I, lips of actinostome ;
yi, convoluted genital organs, extending from one side of the bell to the other ; (/, part of the geni-
tal organ on the other side of the chymiferous tube ; c', as in Fig. 263 ; r, base of bladder sur-
mountinsr the bell.

166

TURRIS VESICARIA.

deep festoons (Fig. 263) from one dn'mifei'ous tube to another; tliey
form a comj^act mass, and iill tlie whole of the upper part of the bell ;
from this are suspended four movable, deeply-frilled lips (/, Fig. 264),
leading into a short digestive cavity totally concealed by the genital
organs. The chymiferous tubes are broad and very flat, the two edges
of the tubes being irregularly cut (Fig. 265) ; transverse folds extend
from one side to the other ; the chymiferous tubes open into a
broad circular tube (Fig. 266), having a similar hacked edge ; with
the circular tul^e communicate five tentacles placed between the chy-
miferous tubes, and one op2)08ite each. The tentacles are broad at the
base, and taper very rapidly into a long slender lash ; at the base of

Fig. 266.

Fig 265.

Fig 267.

the bag of the tentacles is a large swelling, in the centre of which is
placed a distinct eye-speck. (Figs. 266, e; 267, 268.) The size of
the opening, leading from the circular tube to the tentacle, is readily
seen when examined from the abactinal side. (Figs. 263 ; o, 268.)
In the genera Turris, Ptychogena, Olindias of Midler, and Polyorchis,
we have strongly developed characters, which show their close rela-
tion ; in Turris and Ptychogena, the nature of the genital organs and
the character of the chymiferous tuljes ; in Olindias and Polyorchis,
the genital organs and branching tubes, being simply extreme cases
of what we have first hinted at in Turris, more strongly marked in
Ptychogena, in the mode of attachment of the genital organs, and

Fig. 26.5. Magnified view of a part of a chymiferous tube.

Fig. 266. Base of one of the chymiferous tubes, and part of the circular tube, c, chymiferous
tube; c'', circular tube; b, sensitive bulb of tentacle; e, eye-speck; t, lash of the tentacles cov-
ered with lasso-cclls.

Fig. 267. One of the tentacles in a semi-profile view.

Fig. 2G8. One ol' the tentacles, seen from the abactinal pole, o, opening leading from circular
tube.

TURRITOPSIS. 167

carried out in a very different direction in the genital pouches on the
pendent proboscis of Stomotoca.
. Massachusetts Bay, Nahant (A. Agassiz).
Cat. No. 274, Nahant, Mass., May 12, 1862, A. Agassiz.

TURRITOPSIS McCr.

Turritopxis !McCr. Gymnoph. Charlestou Harbor, p. 24. 1857.
Turritopsis McC'r. On Turritopsis, new species, .... p. 2. 1856.
Turritopsis Agass. Cont. Nat. Hist. U. S., IV. p. 347. 1862.

Turritopsis nutricula McCr.

Turritopsis nutricula JIcCr. Gjmn. Charleston Harbor, p. 25, Pis. 4, 5, 8, Fig. 1.
Turritopsis nutricula Agass. Cont. Nat. Hist. U. S., IV. p. 347. 1862.
Turritopsis nutricula A. Agass. ; in Proc. Boston Soc. Nat. Hist., IX. Figs. 22, 23.

The young Medusa) have only four stift' tentacles, with a long bottle-
shaped digestive trunk (Fig. 269), fastened by its base to the lower
part of a short prolongation of tlie bell, along Fig. 269.

which the chymiferous tubes run ; the digestive
cavity has four marked prolongations, surmounted
by bunches of lasso-cells ; along the upper part
of the digestive cavity, the genital organs are
developed in four bunches, placed along the pro-
longations of the actinostome. As the Medusa? increase in size, there
are four more tentacles formed, one in the middle of the space between
the chymiferous tubes ; the genital organs increase in length, and by
the time two additional tentacles (3, Fig. 270) have been formed, one
on each side of the tentacles of the second cycle, the genital glands
have become very much swollen, and occupy nearly the whole length
of the digestive cavity and proboscis. With rig. 2-0.

advancing size the gelatinous mass loses its
bell shape, and becomes more globular, the
tentacles (then sixteen in number) losing
somewhat their stiffiiess ; when it has only
four tentacles, the young Medusa resembles
so much Sarsia, in the shape of the bell and
of the digestive cavity, that Avere it not that
Sarsia carries its tentacles curled up close to the circular tube, while
in Turritopsis they stand stiffly out from the rim of the bell, like the
tentacles of Eudendrium, it would be difficult to distinguish them apart.
Not having traced this Medusa beyond the stage when it had sixteen

Fig. 269. Young Turritopsis nutricula, with four marginal tentacles ; greatly magnified.
Fig. 270. Somewhat more advanced Turritopsis, having sixteen tentacles.

168 STOMOTOCA.

tentacles, I am unable to determine whether it is a distinct species
from the' Turritopsis of Charleston ; the color of the proboscis and of
the sensitive bulb is different in the two ; the ovaries are light brown,
with darker lines in the furrows between them ; the ocelli are dark-
red brown. The shape of the tentacles and of the bell, however, are
the same in both, as well as their habits, and the changes which this
Medusa goes through with advancing age. From each side of the
base of the four tentacles, at the junction of the circular and of the
chymiferous tubes, runs a thread of bunches of lasso-cells, which reach
nearly to the abactinal pole, as in the young Medusae of many of the
Tubularians.

There is found at Nahant the young of a species of Turritopsis which
differs from the Turritojjsis nntrimla very essentially ; the bell, which
is remarkably thin, has a uniform thickness from the circular tube to
the abactinal pole ; the tentacles, even when there are only four, are
quite long, slender, and usually carried curled up along the sides of
the bell, giving these young Medusae a totally different aspect from the
yoimg of the T. mitricula. I might mention here that the trace of its
connection with a Hydroid stock was very distinct in young Meduste ;
the adult Medusa was not observed.

Charleston, S. C. (McCrady) ; Naushon, Buzzard's Bay (A. Agassiz).

Cat. No. 273, Naushon, September, 1861, A. Agassiz. Medusa.

Cat. No. 440, Naushon, July, 1864, A. Agassiz. Medusa.

STOMOTOCA Agass.

Slomoioca Agass. Cont. Nat. Hist. U. S., IV. p. 347. 1862.

^ajilienia Fokbes {non Eseh.). British Nakud-eyed Medusa, p. 25. 1848.

Stomotoca apicata Agass.

S/omotoca apicata Agass. Cont. Nat. Hist. U. S., IV. p. 347. 1862.
Saphenia apicata McCh. Gjmii. Charleston Harbor, p. 27, PI. 8, Figs. 2, 3.

Charleston, S. C. (McCrady) ; Newport (A. Agassiz).
Cat. No. 454, Newport, A. Agassiz. Medusa.

Stomotoca atra Agass.

Slomoioca aira A. Agass.; in Agassiz's Cont. Nat. Hist. U. S., lY. p. 347. 1862.

This Medusa (Fig. 271) is much larger than the one Forbes has de-
scribed as *S'. dlnema (Naked-eyed Medusa?, PI. II. Fig. 4), which meas-
ures only a quarter of an inch, while this species is from three quarters
to an inch in size ; it is much less elongated, the vertical and horizontal
diameters being the same ; it swells out to its greatest horizontal diam-

STOIIOTOCA ATRA.

169

eter almost iiumodiatoly above the circular tube, where it curves in
slightly, and then bends unifonnly towards the abactinal pole ; the
upper 25art is almost hemispherical, being very blunt at the abactinal
pole ; the peduncle tapers gradually froui the base to the ovaries ;
the ovaries are barrel-shaped, extending to the digestive cavity, which
is small at the point where the chymii'erous tubes empty into it, but
gradually bulges out, and passes into the lobes of the actinostome,
where it is three or four times as wide as at the base. Only two of
the chyniiferous tuljes have long tentacles ; between these larger tenta-
cles there are a number of small tentacles (in the specimen described
about eighty), hardly one sixteenth of an inch long. The ovaries are
placed on the abactinal extremity of a long peduncle ; they consist of
a double series of folds, occupying the middle third of the peduncle
(Fig. 272), and are of a dark-brown color; below them is placed the
digestive cavity, which is very contractile, of a lighter color, and end-

FiK. 271.

Fig 273.

Fig 272.

ing with an actinostome divided into four lips. While swimming, tliese
MedusfB move slowly, contracting alternately either one or the other of
their long tentacles ; when contracted, the tentacle has very much the
appearance of the contracted tentacle of a Pleurobrachia ; when floating
about motionless, the chymiferous tubes often contract, and this gives
to the Medusa the appearance of being deeply lobed (Fig. 273), the
intermediate portions of the periishery not seeming to be so highly
contractile as that which immediately adjoins the chymiferous tubes.
This Medusa was quite common in the Straits of Rosario, W. T., in the
beginning of June. I also found specimens of it during the summer,
till September, in different parts of the Gulf of Georgia, and in the
neighborhood of Port Townsend.

Gulf of Georgia, W. T. (A. Agassiz).

Cat. No. 50, Straits of Rosario, W. T., June, 1859, A. Agassiz. Medusa.

Fig. 271. Stomotoca atra, somewhat magnified ; seen in profile.

Fig. 272. Magnified view of genital organs.

Fig. 273. Stomotoca atra, in a different attitude.
NO. II. 22

170

RHIZOGETON.

RHIZOGETON Agass.

RMzogeton Agass. Cont. Nat. Hist. U. S., IV. p. 347. 18G2.

Rhizogeton fusiformis Agass.

RUzogeton fasiformis Agass. Cont. Nat. Hist. U. S., IV. pp. 224, 347, PI. 20, Figs. 1 7 - 23. 1862.

Massaeliii.setts Bay (Agassiz).

Cat. No. 52, Nahant, Mass., July, 1861, A. Agassiz. Hydrarium.

CLAVA Gmelin.

Clava Gmelin ; in Bescbiift. d. Berlin. Ges. Naturf. Freunde. 1775.

Fig. 274.

Clava leptostyla Agass.

Clava lepfosfi/la Agass. Cont. Nat. Hist. U. S., IV. pp. 218, 222,
Fig. 32 ; 338, PI. 20, Figs. 11 -IG"; PI. 21. I8(i2.

Clava mulliconiis Stimps. ISIar. In v. Grand !Manan, p. 11. 1853.

Clava multicornis Leidy. Mar. Inv. Rhode Island and New Jersey,
p. 3, PI. XI. Figs. 33, 34. 1855.

Clava multicornis Pack.; in Can. Nat. & Gcol. Dec. 1863.

The Clava lejjtostyla (Fig. 274) seems to differ
from the C. multicornis by the greater number of
its tentacles.

Point Judith (Leidy) ; Massachusetts Bay (Ag-
assiz).

Cat. No. 51, Kingston, Mass., July, 1851, H. J.
Clark.

Cat. No. 451, Nahant, Mass., A. Agassiz. Hydro-
medusarium.

Museum Diagram, No. 24, after L. Agassiz.

Fig. 274. Clava leptostyla ; greatly magnified.

WILLIAD^.

171

Family WILLIAD^ Forbes.

Wi/I!ni!a' Forbes. Britisli Naked-eyed Modusa;, p. 19. 1848.

Berenicidw Agass. (>. p. noii Esch.). Cout. Nat. Hist. U. S., IV. p. 345. 1862.

WILLIA Forbes.

Willsia Forbes. British Naked-eyed Medusa;, p. 19. 1848.
Willia Agass. Cont. Nat. Hist. U. S., IV. p. 346. 1862.

Willia ornata McCr.

Willia ornata McCr. Gymnoph. Charleston Harbor, p. 47, PI. 9, Figs. 9-11.

Will'm ornata Agass. Cont. Nat. Hist. U. S., IV. p. 346. 1862.

Willia ornata A. Agass. ; in Proc. Bost. Soc. Nat. Hist., IX. Figs. 20, 21. 1862.

The development of Willia presents some striking differences from
the mode in which tentacles are regularly developed in successive cy-
cles, among Polyps, and from what has been observed, in accordance
with that mode of development, among some of our naked-eyed Me-
dusae (Laomedea dicqjhana, Clytia bicojjhora, etc.). In very young
Willise, having only four simple chymiferous tubes and four tenta-
cles, — two much longer than the others, as we find them in Atractylis
and Lafoea-, — there are soon developed four additional tentacles ; these

Fig. 274».

Fig. 276.

do not appear in the middle between the adjoining chymiferous tubes,
but about one third of the distance. (Fig. 274^) When this second
cycle of tentacles can be readily distinguished as four well-marked
knobs along the circular tube, an offset branches off from the sim-
ple chymiferous tube, which soon extends to the circular tube, oppo-
site the rudimentary tentacle ; this offset takes its origin at two thirds
the length of the chymiferous tube from the circular tube ; at the same
time this branch is forming, the main tube is sliglitly bent in the op-
posite direction from that in which the branch diverges ; the offset

Fig. 274". Youngest Willia observed, having only the second set of tentacles developed. 2,
second set of marginal tentacles ; 2c, branch of chymiferous tubes leading to them.

Fig. 275. A young Willia, nearly in the stage of Fig. 276, seen from the abactinal pole. 3,
third set of tentacles ; 3^, chymiferous tube leading to them.

172

WILLIA ORNATA.

also is slightly convex, the convexity being tnrned towards the circular
tube. The next cycle, the third, consists only of four tentacles, which
all make their appearance on the other side of the main chymiferous
tube, just as ftir on the other side as the tentacles of the second
cycle were on this side of the main radiating tube ; the offsets of
the tube which reach these tentacles start slightly below the first, and

Fig. 276.

are likewise bent towards the circular tube. I was not able to observe
the formation of the additional branches and tentacles. I refer this
species at present to the Willia ornata of McCrady found at Charleston,
the specimens which I found (Fig. 276) not being advanced enough to
enable me to determine their difference or identity. The tubes which
contain the clusters of lasso-cells {I, Fig. 279), running in the thickness

Fig. 278.

of the spherosome from the circular tube to the height of the base of
the digestive cavity, were particularly well defined ; the longer tubes,
extending in the middle of the space between two chymiferous tubes,
contain three clusters of lasso-cells, made up of from four to five large
cells arranged in a chcle. Even at this early stage the ovaries were
well developed (Figs. 277, 278) ; they are elliptical bunches placed on

Fig. 276. Profile view of a youiifc Willia; magnified.

Fig. 277. Part of tlie eireular tube. /, tubes running into the thickness of the spherosome,
containing large lasso-cells.

Fig. 278. View of ovary of Fig. 276.

Fig. 279. The same as Fig. 278, seen from the abaetinal pole.

PROBOSCIDACTYLA.

173

both sides of the cross-shaped edges of the digestive cavity, giving it a
quadrangidar appearance, when seen from above. (Fig. 279.) Found
at Naushon the last part ©f September, one tenth to one eighth of an
inch in diameter.

Charleston Harbor (McCrady) ; Buzzard's Bay, Naushon (A. Agassiz).

PROBOSCIDACTYLA Brandt.

Pmhnsciflactyla Brandt ; in Mem. Acad. St. Petersbuiw, H. p. 228. ISSH.
Proliosciilacti/la Agass. Cont. Nat. Hist. U. S., IV. p. 346. 1862.

Proboscidactyla differs from Willia in the mode of branching of the
chymiferous tubes ; in the former genvis each main chymiferous tube
divides into two halves, branching symmetrically on both sides from
the two main branches, which is not the case in Willia.

Proboscidactyla flavicirrata Br.

Probosc!<!acti/!a Jlavicirrala Br. ; in Mem. Acad. St. Petcrsb., p. 390, PI. 19. 1838.
Prvboscidactijla flavicirrata Agass. Cont. Nat. Hist. U. S., IV. p. 346. 1864.

Fig. 280.

This small Medusa seems quite uncommon in the Gulf of Georgia.
I only found a couple of specimens, in the lat-
ter part of June, near Galiano Island. They
are so small and so transparent that it requires
the utmost attention to discover them. It seems
to be the species found by Brandt on the coast
of Kamtschatka ; he was unable to find any
actinostome in the trunk-hke prolongation (Fig.
280), which he represents as surrounded by a
large number of small tentacles ; the digestive
cavity opens by an actinostome, surrounded
by four large lobes, and these subdivide into a
number of smaller lobes, subordinate to the larger ones. (Fig. 281.)
The ovaries are attached to the abactinal extremity of the chymiferous
tubes, and extend but a short distance towards
the periphery along the four radiating tubes
(Fig. 281) ; the chymiferous tube runs sin-
gle for a short distance, before the principal
division into two branches takes place (&, Fig.
282) ; at the point of meeting of each of the
smaller branches with the circular branch,
there is a very marked eye-speck ; the tentacles are numerous, each

Fig. 280. Proboscidactyla flavicirrata ; magnified.
Fig. 281. Actinostome and digestive cavity.

Fig. 281.

174

PEOBOSCIDACTYLA FLAVICIRRATA.

Fig. 282.

chymiferous tube dividmg into two main branches, and each branch

subdividing again into eight, making in all sixty-
four branching tubes, and as many tentacles and
eye-specks. Between each of the oceUi there ex-
tends from the circular tube a small tube pene-
trating into the thickness of the edge of the
spherosome, which projects a considerable distance
beyond the circular tube. The color of the di-
gestive cavity is dirty yellow, the tentacles are
of a brilliant straw color, and the ocelli dark blue.
The whole exterior of the spherosome is densely
granulated, the projections being probably some-
thing similar to what we find on the disk of Ati-
relia JIavidiila, made up of large lasso-cells, only
much more densely crowded together. The shape
of the Ijell is almost perfectly thimble-shaped,

there being neither bulging nor striking indentations of the periphery.

The motions of this Medusa are very rapid ; the tentacles are capable

of but little contraction.

Petropolawsky (Mertens) ; Gulf of Georgia, W. T. (A. Agassiz).

Cat. No. 62, Gulf of Georgia, W. T., June, 1859, A. Agassiz. Medusa.

Fig. 282. Portion of disk, to show the mode of branching, b, first fork ; I, tubes containing
lasso-cells, as in WiUia.

SARSIADyE.

175

Family SARSIAD^ Forbes.

Sarsiadee Forbes (rexlr. Agass.). Brit. Naked-eyed Medusas, p. 54. 1848.
Sarsiadce Ac ASS. Cont. Nat. Hist. U. S., IV. pp. 184, 217, 339. 1862.

CORYNE Gart.

Coryne G.\rt. ; in Pall. Elen. Zooph. 1774. Hydra.

Sijiicoryna Ehrenb. {p. p.). Corall. des Rothen Mceres. 1834. Hydra.

Slipula Sars. Bidrarj til Soedyr. Nat. 1829. Hydra.

Hermia JoaysT. British Zoophytes, p. 111. 1838. Hydra.

Ceri/ne Agass. Cont. Nat. Hist. U. S., IV. p. 339. 1862. Hydra.

Sarsia Less. Zooph. Acal., p. 333. 1843. Medusa.

Slhenio Dr.j. : in Ann. Sc. Nat. 1845. Medusa.

Sarsia Agass.; in Mem. Am. Acad., p. 224. 1849. Medusa.

Fig. 284.

Fig. 285.

Coryne mirabilis Agass.

Coryne mirahi!!s Agass. Cont. Nat. Hist. U. S., IV. pp. 185 - 21 7, Figs.

9-31; PI. 20, Figs. 1-9; PI. 23», Fig. 12; HI. PI. 11«, Figs. 14,

15; Pis. 17-19. 18G0-62.
Snrsia mirabilis Agass. ; in Mem. Am. Acad., IV. p. 224, Pis. 4, 5.
Sarsia mirabilis Stimps. JIar. Inv. Grand Manan, p. 11. 1853.
Oceania tubuhsa Gould (non Sars). Inv. of Mass., p. 348. 1841.
Sarsia f/lacialis Morch ; in Beskriv. af Groenland, p. 95. 1857.
Tubularia slellifira Couth.; in Best. Journ. Nat. Hist., H. p. 56.
Tubularia stdlifera Goui.D. Inv. Mass., p. 350. 1841.

This Medusa (Figs. 283, 284, 285) is one of the
eai-liest visitants of our wharves. The ice has

scarcely gone from the shores
when numbers of young Me-
dusae, just freed from the
Hydrarium, swarm near the
surface on any sunny day.
Caj^tain Couthouy has de-
scribed, under the name of
Tubularia stelUfera, a Hy-
droid which is probably the
Hydroid of our Sarsia mira-
bilis ; as the specimens from
which his descriptions were
made have not been pre-

Fig. 283. Adult Coryne mirabilis, seen in profile ; one half natural
size.

Fig. 284. Coryne mirabilis, with proboscis contracted, t, tentacles ;
e, veil ; c, circular tube ; o, actinostome.

Fig. 285. Coryne mirabilis, with expanded proboscis, d, proboscis ;
a, b, thickness of the bell.

Tig. 283.

176

CORYNE ROSARIA.

served, I am unable to state this positively. It seems to make l)iit
little diflereiice to the Hydrarium (Figs. 286, 287, 288) or to the

Fig. 2S8.

Fig. 236.

Fig. 287.

Medusa whether they live in pure sea water, such as they find at
Nahant, or live in the more brackish waters of the inner harbor of
Boston ; they are equally abundant in both localities.

Massachusetts Bay (L. Agassiz).

Cat. No. 45, Nahant, Mass., May, 1862, A. Agassiz. Hydromedusarium.

Cat. No. 60, Nahant, May, 1862, H. J. Clark. Hydrarium.

Cat. No. 64, Nahant, March, 1862, H. J. Clark. Hydrariimi.

Cat. No. 268, Boston, April, 1862, A. Agassiz. Young Medusfe.

Cat. No. 269, Boston, May, 1862, A. Agassiz. Young Medusae.

Museum Diagrams, No. 20, 21, after L. Agassiz.

Coryne rosaria A. Agass.

Cori/ne rosaria A. Ag.\ss. ; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 340. 18G2.

I have but little doubt that the Hydroid here described is the larva
of Coryne rosaria ; this settles any doubt there may be concerning the
specific diflerences between this Medusa, and the European or American
representatives on the two sides of the Atlantic. The Hydrarium re-
sembles somewhat Coryne stijmla of Sars, but the ^proportions of the
individuals of these two Hydraria are totally different ; what is particu-
larly characteristic of Coryne stipula is the stoutness and great size of
the head and stem, compared to the size of the community ; in Coryne
rosaria the heads, which are quite slender, are supported by remark-
al)ly long and attenuated stems ; they branch also very profusely, and
it is not uncommon to find communities of this graceful Coryne reach-
ing a height of three to three and a half inches. Medusa3 buds were

Fig. 28G. Clusti'r of II)(lrana of Coi-\iic mirabllis.

Fig. 287. Youiin; Hydrarium.

Fig. 288. Magnified view of a head with Medusa bud, d, attached.

SYNDICTYON.

177

Fig. 239.

observed on the ITjflrarium in March ; no young Medusaj have been
observed ; the adults attain an enormous size, meas-
in-in-i; more than an inch in polar diameter, as in Fig.
289, Avhich is drawn the natural size.

The sjjherosome bulges very rapidly from the abacti-
nal pole (Fig. 280) till it reaches the point of junction
of the chymiferous tubes ; from there it tapers very
gradually towards the peripheric tube ; the chymiferous
tubes are exceedingly slender, the digestive cavity very
long, projecting one half its length beyond the circular
tube, swelling near the lower extremity, and then sud-
denly contracting, tapers gradually, in the form of a
conical projection, beyond the ovaries ; the sensitive
bulbs are large, the eye-specks small. The proboscis
and the tentacles are of a dirty-yellow color, the color
of the swelling of the proboscis and of the sensitive
bulbs being somewhat darker. It resembles Sarsla
tubulosa of the English coast more than Sarsia mira-
bilis of New England. Found in the Straits of Rosario
in May, and as late as the beginning of July in the
Gulf of Georgia, W. T., and also in the harbor of San Francisco during
November.

San Francisco, Cal. (A. Agassiz) ; Gulf of Georgia, W. T. (A. Agassiz).

Cat. No. 48, Gulf of Georgia, W. T., May, 1859, A. Agassiz. Medusa.

Cat. No. 49, San Francisco, Cal., March, 1860, A. Agassiz. Hydrome-
dusarium.

SYNDICTYON A. Agass.

Sijndicttjon A. Agass. ; in Agassiz's Cont. Nat. Hist. U. S., IV. p 340. 1862.

Syndictyon retieulatum A. Agass.

Syndictyon reiiculaium A. Agass. ; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 340. 1862.

The Hydrarium (Fig. 290) resembles that of Coryne mirabilis ; it is
much smaller, not being more than one tenth of an inch in height ; it
does not branch, or only occasionally once, near the base, in very old
specimens. The stem is slender, the head large, club-shaped, the tenta-
cles short, eight or ten in number. The Medusfe develop among the
tentacles in the lower part of the head ; this development is similar to
that of Sarsia ; when the Medusa is separated it is nearly as large as
the whole Hydrarium, measuring about one sixteenth of an inch in

Fig. 289, Coryne rosaria, natural size.
23

178

SYNDICTYON RETICULATUM.

diameter. The young Medusre resemble somewhat Zanclea (Fig. 291),
having the lasso-cells of the marginal tentacles arranged spirally in
large clusters on the surface of the tentacles ; the more advanced
Medusae lose this character. The bunches of lasso-cells increase in size
towards the extremity, where the tentacle terminates in a club-shaped
bunch (Fig. 292) larger than the others j the sensitive bulb is large, the

Fig. 292.

Fig. 290.

Fig. 291.

ocellus at the base of the tentacle (Fig. 293) is similar to that of Sarsia,
the spherosome is of a uniform thickness, and the proboscis (Fig. 294)
resembles somewhat that of DijDurena ; the whole surface of the sjjhero-
some is covered with clusters of large lasso-cells (Fig. 296), giving
it a granulated appearance ; the ground-work consists of minute gran-
ulation, which appears under a low magnifying power to be arranged

Fig. 293.

Fig. 294.

Fig. 290. Hydromeclusarlum of Syndictyon reticulatum, greatly magnified.

Fig. 291. Syndictyon reticulatum, immediate I3' after it has become freed from the Ilydrome-

dusarium ; in profile, magnified.

Fig. 292. One of the tentacles of Fig. 291, magnified.

Fig. 293. Sensitive bulb of Fig. 291.

Fig. 294. Digestive cavity of Fig. 291.

Fig. 295. Fig. 291, from the actinal side.

SYNDICTYON KETICULATUM.

179

in rows parallel to the circular tube, upon which are scattered large
lasso-cells. The actinal and jiolar axes are of about the same length ;
the veil is well developed (Fig. 295) ; the central part of the sphero-
some is uniformly arched outside ; the curve of the inner cavity is
concentric with it ; the proboscis extends somewhat
more than half the length of the height of the cav-
ity of the bell ; the circular and ch3'miferous tubes
are narrow (Fig. 296), of uniform diameter through-
out ; the sensitive bulb is ovoid, with a well-defined
lenticular-shaped concentration of black pigments
cells (Fig. 293); the bulb itself is colored lights
brown ; the walls of the tentacles are thick, the
tentacular tube tapering rapidly as it nears the ex-
tremity of the tentacle, where the walls increase in
thickness in proportion as the tube diminishes in bore ; the bunches
of lasso-ceUs begin at some distance from the base of the tentacle (one
fovu-th of the length of the tentacle), increase rapidly in size, being
packed closer and closer towards the extremity of the tentacle, where
they are large crescent-shaped masses, almost touching each other, and
composed of very elongated lasso-cells. (See Fig. 292.) The tentacles
are not very contractile ; usually they are about as long as the vertical
diameter of the bell, and I have seen them contracted to about half
that length ; .the peduncle is not contractile. The large lasso-cells of
the surface of the spherosome (Fig. 297) are round ; they are usually
scattered singly over the whole surface, while the fine granulation of
the surface of the bell consists of long, narrow cells,
dividing into smaller granules, which are small, un-
developed lasso-cells, forming a net-woi'k over the
surface of the spherosome ; the lasso-cells are not
as numerous near the abactinal pole as towards
the margin of the bell, above the circular tube. ,,|
The motions of the Medusa are similar to those
of Sarsia, the bell, owing to its thinness, being,
however, much more flexible. The bell has a
very light metallic-blue tinge. The Hydroid was found growing on
Diphasia rosacea. Young Meduste, similar to those developed from
the Hydroid, are found swimming freely about duruig June and
July.

The young Medusa described above gradually loses the characters
which distintjuished it from Sarsia, and as it becomes more advanced,
it resembles so closely Sarsia, that were it not for the invariable

Fig. 297.

Fig. 29G. FIij;. 291, from the abactinal pole.

Fig. 297. Part of net-work of the surface of the spherosome. c, large lasso-cells ; c', cluster
of smaller ones.

180

DIPURENA.

presence of the light reddish-brown eye-specks, which become red in
the adult, it would be difficult, without very close examination, to
distinguish them apart. The tentacles of the adult (Fig. 298) are
not as long as tliose of Sarsia ; they are likewise capable of much
greater contraction, being often carried in a club-shaped form, not
longer than half the vertical axis of the bell. (Fig. 299.) The acti-
nostome is also very diflFerent ; the lips (four in number) are quite
prominent {a, Fig. 300), though often carried in trumpet fashion, at

Fig 298.

Fig. 300.

the extremity of the digestive cavity (a, Fig. 300), and the sj^herosome
increases greatly in thickness at the abactinal pole.

Massachusetts Bay, Nahant (A. Agassiz).

Cat. No. 160, Nahant, Mass., July, 1861, A. Agassiz. Hydromedusa-
rium.

Cat. No. 348, Boston Harbor, May, 1862, H. J. Clark. Medusa.

Cat. No. 378, Nahant, 1863, A. Agassiz. Medusa.

DIPURENA McCr.

Dipurena McCr. Gymn. Charleston Harbor, p. 33.
Dipurena Agass. Cent. Nat. Hist. U. S., IV. p. 341. 1862.

McCrady established this genus from an investigation of two species
of Medusa?, which, though having all the characteristics of Slabberia of
Forbes, yet differed from it in the position of the sexual organs, which
are placed in Dipurena along the digestive trunk, as in Sarsia and the
like, while in Slabberia Forbes has figured genital organs along the

rig. 208. Adult Medusa, in a natural attitude.

Fig. 299. The same Jledusa as Fig. 298, with the tentaeles contracted.

Fig. 300. Actinostome of adult Medusa, a, when protruded, truuipet-shape ; a', showing the
lips of actinostome.

DIFURENA CONICA. 181

cliymiferoiis tubes. This is so contrary to wliat we have thus far found
to be uniformly the position of these organs among Tuljularian Medusae,
that tliere is probably some mistake in Forbes's drawing.

Dipurena strangulata McCk.

Dipurena strangulata McCit. Gymnopli. of Charleston Harbor, p. 33, PI. 9, Fig. 1.
Dipurena strangulata Agass. Cont. Nat. Hist. U. S., IV. p. 341. 1862.

Charleston, S. C. (McCrady).

Dipurena cervicata McCr.

Dipurena cervicata McCr. Gyran. Charleston Harbor, p. 34.
Dipurena cervicata Agass. Cont. Nat. Hist. U. S. IV. p. 341. 18G2.

Charleston Harbor (McCrady).

Dipurena conica A. Agass.

Dipurena conica A. Agass. ; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 341. 18G2.

In the young Medusa the shape of the bell is nearly sugar-loaf (Fig.
301); the cavity of the bell is formed by a rig. aoi.

similar cone, with rounded apex ; the disk di-
minishes rapidly in thickness towards the cir-
cular tube ; the digestive cavity does not ex-
tend quite to the level of the veil ; it is divided
by a constriction into two unequal cavities, the
upper one {u, Fig. 302) being about half the
size of the lower one {I, Fig. 302) ; the walls of this cavity are thick,
tapering gradually towards the actinostome, which is a simple opening,
without labial appendages ; the digestive cavity is scarce- fib. 302.
ly contractile ; the four marginal tentacles are short, the
sensitive bulb is large, consisting of minute granular cells,
the eye-speck being placed in a small button, standing
out slightly from the base of the tentacle on the upper
side (the abactinal side). (Fig. 303.) The walls of the ten-
tacles are thick ; they are made up of large elongated poly-
gonal cells, giving the tentacles a striated appearance ; the
tube running through the tentacles is exceedingly fine,
expanding slightly towards the extremity, where it joins
the cavity of the terminal club ; the large polygonal cells of the tenta-
cle decrease in size towards the extremity, where there is a crescent-
Fig. 301. Young Dipurena conica ; masuified.
Fig. 302. Digestive cavity of a young Dipurena conica. u, the upper part ; I, the lower.

182

DIPURENA CONICA.

Fig^ 303.

shaped row of large elliptical cells surrounding the upper end of the

terminal cavity, these cells being sur-
mounted by a thick coating of small
granular cells, extending along the sur-
face of the tentacle until they gradually
disappear ; these granular cells ai-e pig-
mentrcells, giving the terminal club a
reddish tinge ; the sensitive swelling at the base of the tentacles is
colored by similar cells, the eye-spot being black.

This species differs from the Dipurena strangnlata in the form of
the bell, the proportions of the digestive cavity and of the terminal
clubs of the tentacles, as well as the shape of the sensi- rig. 301.

tive bulbs ; according to McCrady, they are exceedingly
pointed in D. stranrjulata, while the sensitive bulb of D.
conica widens as it approaches the circular tube. The
largest sj^ecimens taken were one sixth of an inch in
diameter ; smaller specimens, not more than an eighth
of an inch, differed greatly from the more advanced.
The bell is almost globular, of uniform thickness ; the
digestive cavity is short and rectangular in shape. As
the young advance in age, the spherosome becomes more
and more bell-shajjed, and then conical ; as the digestive trunk increases
in length, it contracts near the base, and becomes pear-shaped towards
the extremity. When still quite young, the first appearance of the
constriction becomes visible ; larger and older specimens, measuring
one fourth of an inch, have a digestive cavity divided into two cavities,

separated by a constriction,

Fig. 305.

as in Fig. 304, where this

separation has become quite
prominent ; when the Medu-
sa is in violent motion, the
proboscis will assume a quad-
rangular shape, with a large
four-sided opening ; this flex-
ibility of the actinostome is
lost in older sj^ecimens. In
the oldest specimens which
have been found (Fig. 305),
the separation between the
upper and lower part of the digestive trunk has become such, that the

Fig. 303. Tentacle of Dipurena conica.

Fig. 304. Digestive cavity of a specimen in which the constriction has already separated the
upper and lower halves.

Fig. 305. Adult Dipurena conica, in which the two digestive cavities ai-e widely separated ;
greatly magnified.

ORTIIOCORYNID^E. 183

two parts are simply connected by a narrow tube as long as the diges-
tive cavities tlieniselves ; the narrow tube leading to the first digestive
cavity extends to the level of the veil ; the radiating tubes and the
circular tube are thin, but there is no difference in the shape of the
bell and of the tentacles of the different stages observed.

Buzzard's Bay, Naushon (A. Agassiz).

Cat. No. 439, Naushon, July, 1864, A. Agassiz. J/'^^^^U^ f^^-

Museum Diagram, No. 20, after A. Agassiz.

Family ORTHOCORYNID^ A. Agass.

I have ventured to separate the genus Zanclea from the Pennaridae,
with which it had been associated by McCrady and Professor Agassiz,
and to form a new family, on account of the oljservations of AUman on
the development of Zanclea from its Hydroid, Coryne impressa Aid.
The peculiar form of the H3'drarium, and the still more remai-kable
characters of the Medusa?, with their tentacles beai"ing pedunculated
knobs of lasso-cells, separate them from the square Medusa? of the
Pennarida^ while they remind us somewhat of the embryonic stages
of Syndictyon. From the resemblance of this Hydroid to Halocharis
and to Candelabrum, as well as owing to the close affinities of Cory-
nitis to Zanclea, I would propose to unite all these forms into one
fiimily, the OrthocorynidK. Does not also the Heterocordyle Cony-
bearei belong to this family ? The great difference between the rejiro-
ductive and the sterile individuals is another example of the polymor-
phism so remarkable in Hydractinia.

CORYNITIS McCr.

Corynitis McCr. Gymn. Charl. Harbor, p. 29. Medusa.

Corynhk Agass. Cont. Nat. Hist. U. S., IV. p. 340. 1862.

Halocharis Agass. Cont. Nat. Hist. U. S., IV. p. 239. 1862. Hydrarium.

Corynitis Agassizii McCr.

Coi-i/nilia Ar/nssizii McCr. Gymn. Charl. Harbor, p. 30, PL 9, Figs. 3-8.

Corynitis Ayassizii Agass. Cont. Nat. Hist. U. S., IV. p. 340. 1862.

Halocharis sijiralis Agass. Cont. Nat. Hist. U. S., IV. p. 239, PI. 20, Figs. 10, 10°. 1862.

Charleston, S. C. (McCrady).

184

GEMMARIA.

GExMMARIA McCr.

Gemmaria McCr. Gymn. Charl. Harbor, p. 49.
Zanclea McCr. (non Geg.). Gymn. Charl. Harbor, p. 48.
Zanrfea Agass. (p. /).). Cont. Nat. Hist. U. S., IV. p. 344. 1862.
Acrochordium Mey. ; in Nov. Ac. N. Aur XVI. 1834. Hydrarium '?

Gemmaria gemmosa McCr.

Gemmaria gemmosa McCr. Gymn. Charl. Harbor, p. 49, PI. 8, Figs. 4, 5.

Zanclea gemmosa McCr. Gymn. Charl. Harbor, p. 49.

Zanclea gemmosa Agass. Cont. Nat. Hist. U. S., IV. p. 344. 18G2.

McCrady has distinguished with reason tlie genus Gemmaria from
I'ig 306. the Zanclea of Gegenbaur. The form

of the bell of the digestive cavity and
of the tentacles are totally different in
the two genera. Very young specimens
(Fig. 306) of this species, observed at
Naushon, differed essentially from the
Gemmaria cladojjhora of Massachusetts
Bay, in the character of the tentacles
and the shape of the clusters of lasso-
cells ; in the present species, the clus-
ters of lasso-cells are attached by a short
peduncle, and are arrow-shajied ; the
great tenuity of the bell in the speci-
men here figured is a characteristic of the younger stages, which dis-
appears in older specimens. (See McCrady's figures.)

Charleston, S. C. (McCrady) ; Buzzard's Bay, Naushon (A. Agassiz).

Gemmaria cladophora A. Agass.

The shape of the inner bell of the adult Medusa of this species is
pecuhar; the outhne does not follow that of the outer bell (Fig. 307),

Fig. 30G. Profile view of half of a young Gemmaria gemmosa ; magnified.
Fig. 307. Profile view of Gemmaria cladophora ; magnified.

GEMMARIA CLADOPIIORA.

185

Fip;. 309.

but is curved in the opposite direction ; near the upper bend of the
chAiniforous tulies, it runs up into a point, making a sharp and deep
groove round tlie projection of the
spherosonie; the chymiferous tubes
(c', Fig. 308), as well as the circu-
lar tube, are verj' broad (Fig. 308),
opening into a conical digestive
cavity, -which at its base occupies
nearly the whole width of the up-
per part of the inner bell ; this cav-
ity tapers gradually till it reaches
the level of the veil, where the
edges flare a little ; the extremity
of the proboscis has a tendency to be slightly drawn in, so that the
opening of the cavity is flanked by the pouches formed by the partial
contraction of a portion of the walls ; the walls are thick, and open into
a quadrangular mouth (Fig. 309), surrounded by a
couple of concentric rows of large lasso-cells ; simi-
lar large cells extend on the outside of the chymif-
erous tubes, more than half-way up the sphero-
some. (Fig. 308.)

The tentacles are broad and thick, two of them
being more developed than the others (Fig. 307) ;
they are of a light-brown color, with orange pig-
ment-cells at the base ; the knobs of lasso-cells are attached to quite
long stems (Fig. 310) ; the walls of the digestive cavity are
thick ; the ovaries are placed in the upper part of the proboscis.
Found at Nahant in the beginning of August. When at rest,
the tentacles are stretched out very obliquely from the bell,
and they often remain perfectly motionless in this position ;
the Medusae are quite rapid in their movements. (Fig. 307.)

Professor Clark discovered at Nahant a Hydroid closely resembling
the Coryne imjjlexa of Alder, and which I suspect will prove to be the
nurse of our Gemmaria ; this would be in accordance with the observa-
tions of Allman on the development of Zanclea from Coryne in^ilexa.
Massachusetts Bay, Nahant (A. Agassiz).
Cat. No. 363, Nahant, 1862, A. Agassiz. Medusa.
? Cat. No. 63, Nahant, May, 1862, H. J. Clark. Hydrarium.
Museum DiaOTam, No. 20, after A. Agassiz.

Fig. 308. Quarter of the disk of G. cladophora, seen from the abactinal pole, c, circular
tube ; e', chymiferous tube ; 6, sensitive bulb, having a great accumulation of ])igment and lasso
cells extending along the chymiferous tubes ; c", opening leading into the chymiferous tubes from
the digestive cavity, o : g, g, genital organs ; r/', fatty globules at base of proboscis.

Fig. 309. Actinostome of Gemmaria, enlarged.

Fig. 310. Cluster of lasso-cells of the marginal tentacles.
NO. 11. 24

186 PENNARID^.

CANDELABRUM Blainv.

Candelahrum Blainv. Man. d'Actin., p. 307. 1834.
Candelabrum Agass. Cont. Nat. Hist. U. S., IV. p. 340. 18G2.
Mi/riotliela Sars. Reise i Lof. op; Fin., p. 14.
Sj)ailix Gosse; in Ann. & Mag. N. II., p. 125. 1855.

Candelabrum phrygium Blainv.

Candelahrtnn phriji/ium Blainv. Man. d'Actin., p. 317. 1834.
Lucernaria phri/i/ia Fab. Fauna Gronlandica. No. 333.
Lncernaria phnjrjia AoA.ss. Cont. Nat. Hist. U. S., IV. p. 341. 18G2.
Ci>njmorj}ha phrygia MoRCH. ; in Besk. af Gronland, p. 9G.

Greenland (Fabricius) ; Grand Manan (W. Stimjjson).

Cat. No. IGl, Grand Manan, W. Stiinp.son. Hydromedusarium.

Family PENNARIDiE McCr.

Pennaridfe McCiJ. (restr. A. Agass.). Gymn. Charl. Harbor, p. 4G.
PennaridCE Agass. {p. p-). Cont. Nat. Hist. U. S., IV. pp. 278, 344. 1862.

This family is restricted here to the single genus Pennaria, Zanclea
having been removed from this family since the discovery of its devel-
opment from a Coryne-like Hydi\arium by Allman.

PENNARIA GoLDF.

Pennaria Goldf. (non Oken). Handb. der Zoologie, p. 89. 1820.
Pennaria McCr. Gymn. Charl. Harbor, p. 50.
Pennaria Agass. Cont. Nat. Hist. U. S., IV. pp. 278, 344. 1862.
Glohiccps Aykes ; in Proc. Bost. Soc. Nat. Hist., IV. p. 193. 1852.
Glohwips Agass. Cont. Nat. Hist. U. S., IV. p. 344. 18G2.
Eucori/ne Leidy. Inv. N. J. and 11. I., p. 4. 1855.

I have not given to the Globicejjs tiarella of Ayres a new generic
name, although it is probable that it does not belong to the same
genus as the Pennaria gibhosa Agass., as the development of the latter
species requires renewed examination to decide the question.

Pennaria gibbosa Agass.

Pennaria glbJma Agass. Cont. Nat. Hist. U. S., IV. pp. 278, 344 ; III. Pi. 15, Figs. 1, 2.

Florida (L. Agassiz).

Cat. No. 19, Key West, Florida, March, 1853, L. Agassiz. Hydrome-
dusarium.

Cat. No. 20, Jeremie, Hayti, Dr. Weinland.

PENNARIA TIARELLA.

187

Pennaria tiarella JIcCr.

Pcnnaria liarclla McCit. Gynjn. Charleston Harbor, p. 51.

Glohiceps tiarella Ayres ; in Proc. Best. Soc. Nat. Hist., p. 193, PI. X. Figs. 1 -5. 1852.

Eucortjne elegans Leidy. Mar. Inv. N. J. and R. I., p. 4. 1855.

Globiceps tiarella Agass. Cont. Nat. Hist. U. S., IV. p. 344. 1862.

The Medusa of Glohiceps tiarella is

one of the most remarkable of our

naked-eyed Meduste. As in the Sarsi-

ada3, the Medusa bud is formed among

the tentacles (Fig. 311), between the

whirl of large and small tentacles ; the

mode of development of the bud is

similar to that of Coryne and Bou-

gainvillia ; the chymiferous tubes, how-
ever, never have the extraordinary

thickness which is noticed in Sarsia,

and the cavity of the bell is hollowed

out at an earlier period ; the Medusa bud gradually becomes very elon-
Fig. 312. gated as it becomes more mature.

Large Avhite eggs are developed from the pro-
boscis, fillmg the whole cavity of the bell as
they increase in size, and giving the Medusa an
opaque milky appearance ; the walls of the
sj^herosome become thinner and thinner, and
when the Medusa bud has attained its full de-
velopment, and is ready to be separated, the

walls have become so thin that the Medus;B rig. 313.

are almost always distorted, either on one side

or the other, by the eggs or bunches of sper-

niaries which have reached such a great size

that four or five of them completely fill the

inner cavity, at the same time pressing the

sides outward, wherever one of the larffe eggs

happens to be placed (e, Fig. 312) ; two or

three of the eggs generally escape before the

Medusa Ijud is liberated, and when they are

found detached, the cavity of the bells usually

does not contain more than one or two large

eggs ; folds appear on the inner surface of the

cavity of the bell after the eggs have escaped.

Fig. 311. A fe'rtile Hydra of Pfnnaria tiarella, showing the mode of budding ; magnified.
Fig. 312. A ilodiisa distended by an egg, e ; magnified.

Fig. 313. Profile view of Medusa of Pennaria tiarella; magnified. /, folds produced by the
distension of siiherosome.

188

PENNARIA TIARELL2\.

owing to their distension {f. Fig. 313) ; as soon as the eggs have all
escaped, and the Meduste have become detached, they move about with
great activity, their motions resemblmg the quick, restless movements
of Sarsia.

The size of the free Medusa is about one sixteenth of an inch ; the
walls of the spherosome are so thin that the Medusa will often assume
a quadrangular or octagonal outline (Fig. 314), with deep indentations
between the chymiferous tubes (Fig. 315) ; the digestive trunk is short,
bottle-shaped, not extending more than half the length of the inner
cavity of the bell; it is suspended by the narrow part (Fig. 313), the
connection of the digestive cavity with the Hydrarium dividing the
abactinal part of the Ijell in such a way that when seen in jirofile there
are two circular masses above the chymiferous tubes. As the Medusa
grows older, this open connection does not seem to diminish, as it does
in the Sarsiada?, Bougamvillea;, and others. The chymiferous tubes,

Fig. 314.

Fig 315.

four in number, are broad, running almost perpendicularly, after mak-
ing a sharp bend at the top, from the abactinal pole to the circular
tube ; there are also four well-developed sensitive bulbs ; the tentacles
on the contrary remain always in a rudimentary condition (Fig. 313),
being simply four small knobs scarcely projecting beyond the general
outline of the bell ; the opening of the veil is small.

What becomes of the Medusa after the eggs have escaped, I am not
able to say, though I am inclined to think that they do not undergo
changes of any importance, as I have kept them in confinement for
three weeks without noticing any striking differences. The color of
the Medusa, when freed from its eggs, is of the most delicate rose color;
the digestive trunk and the chymiferous tubes are a little darker, and a
line of rich crimson pigment-cells, running almost their whole length,
makes this Medusa one of the most brilliantly colored of our coast.
Found at Naushon, during the month of September.

Buzzard's Bay (Ayres, A. Agassiz) ; Massachusetts Bay (A. Agassiz) ;
New Jersey (Leidy) ; Charleston, S. C. (McCrady).

Fig. 314. A different attitude of the Medusa, seen from the actinal pole.
Fig. 315. Fig. 313, seen from the abactinal pole.

TUBULARIAD^. 189

Cat. No. 21, Suisconset, Mass., July, 1849, L. Agassiz. Hjdromedu-
sarium.

Cat. No. 22, Nauslion, Sept. 1861, A. Agassiz. Hydromedusarium.
Cat. No. 23, Newport, R. I., Prof. J. Leidy. Hydromedusariuin.
Cat. No. 24, Newport, R. I., S. Powell. Hydromedusarium. ^ZJif
Cat. No. 25, Beverly, Mass., T. Lyman. Hydrariiun.
Cat. No. 26, West Yarmouth, Mass., Aug. 1860, T. Lyman. Ilydrarium.
Cat. No. 407, Nahant, September, 1862, A. Agassiz. Hydrarium.

Family TUBULARIAD^E Johnst.

Tubuluriudfr JonxsT. (restr. Agass.) ; in Trans. Bei-wick Club, p. 107.
TubulariadfE Agass. Cont. Nat. Hist. U. is., IV. p. 342. 1862.

EUPHYSA Forbes.

Euphjm Forbes. British Naked-eyed Medusas, p. 71. 1848.
Euphysa Agass. Cont. Nat. Hist. U. S., IV. p. 343. 1862.

The outline of the bell of this genus is entirely different from that
of Corymorpha or of Hybocodon. It can at once be recognized by its
quadrangular shape, and the great thickness of the sjiherosome above
the base of the digestive cavity, which is short and cylindrical. The
tentacles also are always short and hollow, but are developed in the
same proportion as in Corymorpha, — one stout triangular one, a pair
somewhat less advanced, and an odd rudimentary one ; the large tenta-
cle never attains the size which it does in Hybocodon or in Corymorpha.
The pigment bands at the base of the tentacles are quite short, and
extend but little way along the chymiferous tubes. The ovaries are
placed on the sides of the proboscis ; the bell is symmetrical.

Euphysa virgulata A. Agass.

This Medusa attains a size of about half an inch ; the polar diameter
is nearly one third greater than the actinal (Fig. 316) ; the proboscis
(Fig. 317) is short, not more than half the length of the inner bell (Fig.
316) ; the veil is slightly indented (Fig. 318) ; the tentacles {t, f,
Fig. 318) are triangular, and covered with large granules of a milky
color, with a band of intensely pink pigment-cells extending a short
distance (^j. Fig. 319) along the chymiferous tubes, from the base of
the tentacles ; the proboscis is cylindrical, of a light yellow color, with
a perfectly smooth actinostome, and fatty globules generally accumu-
lated at the base [g, Fig. 317), as in Corymorpha and Hybocodon.

IDO

ECTOPLEURA.

The Medusa is exceedingly active, moving very rapidly and inces-
santly. Found at Nahant in the latter part of August.

Fig. 316.

rig. 317.

Euphysa is not, as Professor Agassiz has stated, the generation of
Medusae which become separated from the base of the I'eproducing
tentacle in Hybocodon. That generation of Medusae are identical with
the parent Medusa, as well as the second generation which bud froi^
the large tentacle of this first set of Medusae.

Massachusetts Bay, Nahant (A. Agassiz).

Cat. No. 452, Nahant, A. Agassiz.

ECTOPLEURA Agass.

Ectopleura Agass. Cont. Nat. Hist. U. S., IV. p. 342. 18G2.

In this genus I would include those sjjecies of the genus Sarsia (like
Oceania telostyla Geg., Sarsia turricula McCrady, and Sarsia rjcmmi-
fera Forbes) which have a short digestive trunk, and in which the
pigment-cells are not concentrated in one mass in the sensitive bulb,
but are scattered irregularly through the whole swelling at the base of
the tentacles.

Fig. 31G. Euphysa virgulata, seen in profile ; magnified.

Fig. 317. Proboscis of Euphysa. a, actinostome ; », ovaries ; g, fatty globules ; magnified.

Fig. 318. Actinal view of Euphysa, to show the character of the veil, t, the odd long tenta-
cle ; (', one of the pair of tentacles ; (", the odd small tentacle.

Fig. 319. One of the tentacles seen in profile, to show the character of the band of pigment
cells, ^, extending along the base of the chyniii'crous tube from the origin of the tentacle, I'.

ECTOPLEURA OCIIRACEA. 191

Ectopleura turricula Agass.

Eclnpleura turrkula Agass. Cont. Nat. Ilist. U. S., IV. p. 343. 1862.
Sarsia turrkula McC'r. Gyran. Charleston Harbor, p. 36, PI. 8, Figs. G - 8.

Charleston, S. C. (McCrady).

Ectopleura oehracea A. Agass.

Ectopleura oehracea A. Agass.; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 343. 18G2.

The bell is of uniform thickness from the circular tube as far as the
base of the digestive cavity ; here the outline tapers gradually towards
the abactinal pole (Fig. 320), giving Fig. 320.

the upper part of the bell a much
greater thickness, and a conical shape.
Near the base of the digestive cavity
there is a very marked constriction ;
it then bulges out towards the middle,
contractino; ao-ain towards the actinos-
tome, which is simple ; the opening is
formed by the abrupt termination of
the walls of the digestive cavity ; there
are no labial a^^pendages of any sort,
except small bunches of lasso-cells. The
tentacles are short ; when swimming
about they are usually carried tightly
curled up near the circular tube. This
species differs from the S. turricula McCr. in having the surface of the
tentacles covered irregularly with innumerable lasso-cells ; they are not
arranged in bundles, as in the Charleston species. From each side of
the base of the four tentacles there runs to the abactmal pole (Figs.
321, 322) a thread of bunches of lasso-cells (/, Fig. 320), like that of
Turritopsis. The bunches ai'e large near the actinal extremity, and
gradually diminish to the abactinal pole, where there is only one cell,
while near the base of the tentacles the bundles are made up of aggre-
gations of clusters of lasso-cells, consisting of two or three cells each.
An accumulation of bright yellow pigment-cells forms a ring round the
point of attaehmeut of the digestive trunk ; the digestive cavity itself
is of a delicate rose color, with whiti.sh launches of lasso-cells at the
actinostome, surmounted by a second light yellow ring immediately
above it ; the tentacles are of the color of the digestive trunk, but of a

Fig. 320. Profile of Ectopleura oehracea, magnified. /, thread of lasso-cells extending to ab-
actinal pole ; p, pigment-cells at base of tentacles.

192

CORYMORPHA.

lighter tint ; the pigment-cells in the sensitive bulb (p, Figs. 320, 323)
are purplish-orange upon a light-yellow ground. When the Medusaj

Fig, 321.

Fig. 322

Fig. 323.

move about, which they do with great rapidity, the tentacles are twisted
in knots, as stated above, but when at rest expand at right angles to
the disk, and then the Medusa will often remain, bal-
ancing itself upon its tentacles, perfectly motionless in
the water, appearing like a rosy tube, with its yellow
ring set in a rectangle of four brilliantly colored ocelli.

Found at Naushon in September, the largest speci-
men being one fourth of an inch in diameter ; young
specimens have a shorter digestive trunk, and the rows
of lasso-cells extending along the Outer surface of the
bell are more marked than in older specimens. The
Hydroid of this Medusa probably resembles the Tuhularia Dumortierii
Van Beneden, the Medusa of which is closely allied to the one found
on our coast.

Buzzard's Bay, Naushon (A. Agassiz).

Cat. No. 441, Naushon, Mass., A. Agassiz. Medusa.

CORYMORPHA Sars.

Cori/morpha Sar.s. Beskriv., p. 6. 1835.

Corijmorpha Agass. Cont. Nat. Hist. U. S., IV. p. 343. 18G2.

Corymorpha pendula Agass.

Con/morphn prndula Agass. Cont. Nat. Hist. U. S., IV. pp. 276, 343, PI. 26, Figs. 7-17.

Corymorpha nutana Stimps. Mar. Inv. Grand Manan, p. 9. 18.53.

Corymorpha pendula A. Agass. ; in Pi-oc. Bost. Soc. Nat. Hist., IX. p. 101, Fig. 31.

The Medusa of Corymorpha is, like Hybocodon, asymmetrical ; the
shape of the bell is more elongated (Fig. 324) and the tentacles more

Fig. 321. Fig. 320, seen from abactinal pole, to show the termination of the lasso threads.
Fig. 322. Fig. 320, seen from the actinal pole, showing the origin of the threads on eaeh side
of the base of the tentacles.

Fig. 323. The base of one of the tentacles, magnified, p, cluster of pigment-cells.

HYBOCODON.

193

Fig. 324.

developed, the long tentacle (Fig. 324) attaining a size two or three
times the length of the bell ; the proboscis is long, and stretches be-
yond the aperture of the veil; the long tentacles (1, 2, Fig. 324) are
capable of great contraction and expansion ; the lasso-
cells are arranged in groups upon them in such a manner
as to appear like heavy rings surrounding the thinner
thread , the outer wall of the proboscis is exceedingly
thick, as in the Medusa of Euphysa, and of a light-yellow
color ; the pigmentrcells at the base of the tentacles are
light pink. This Medusa attains a size of a quarter of an
inch, and is found at Nahant in the middle of May.

Although the separation of this Medusa from its Hy-
drarium has not been observed, yet their similarity to the
most advanced Medusae buds observed on our Corymor-
pha leave but little doubt on this point. Hodge has
observed the development of an English species of Corymorpha, which
resembles the Medusa here figured. (Fig. 324.)

Massachusetts Bay, Nahant (L. Agassiz).

Cat. No. 18, off Race Point, Cape Cod, Mass., March, 1862, A. S. Bick-
more. Hydromedusarium.

Museum Diagram, No. 24, after L. Agassiz.

HYBOCODON Agass.

Hijhocodon Agass. Cont. Nat. Hist. U. S., IX. p. 343. 1862.

Hybocodon proUfer Agass.

Hyhocodonprolifer Agass. Cont. Nat. Ilist. U. S., IV. pp. 243, 343, PI. 23\ Figs. 10, 11 ; PI. 25.
1862.

This is one of the few known Tubularians
found growing singly. (Fig. 325.) The char-
acter of the MedusiX! is particularly important
in a morphological point of view, giving us, as
it does, the clew to the probable character of
the scales (Deckstiick) of the Nanomia, de-
scribed below. The asymmetrical character of
the Medusa (Figs. 326, 327) is more marked
than in the Medusa of Corymorpha. The bud-
ding of Medusae (Fig. 328), similar to the parent

Fig. 324. ]\Iedusa of Corymorpha, seen in profile. 1, long odd tentacle ; 2, pair of tentacles ,
3, short odd tentacle.

Fig. 325. Single Hydra of Hybocodon. o, mouth surrounded with tentacles ; t, t, marginal
tentacles ; d, d, advanced Medusae buds ; a, stem.

NO. II. 25

194

PAEYPHA.

Medusa, from the base of the single largely-developed tentacle, is a
feature it has in common with other MedusiB which have been referred
by various writers to the genera Sarsia and Steenstrupia, and which
very probably are all derived from a Tubularian nurse similar to Hy-

rig. 326.

Pig. 328.

Fig. 327.

bocodon. Should the Diplonema of Greene prove to be one of these
asymmetrical Meduste, the name Ilybocodon must give way to that of
Diplonema.

Massachusetts Bay (L. Agassiz).

Cat. No. 61, Nahant, Mass., May, 1862, H. J. Clark. Hydrarium.

Museum Diagram, No. 23, after L. Agassiz.

PARYPHA Agass.

Parypha Agass. Cont. Nat. Hist. U. S., IV. p. 342. 1S62.
Pyxidium Leuck. ; in Archiv f. Nat., I. p. 31. 1856.

Parypha cristata Agass.

Parypha cristata Ag.\ss. Cont. Nat. Hist. U. S., IV. p. 342. 18G2.
Tubularia cristata ]McCr. Gynin. Charloston Harbor, p. 54.

Charleston, S. C. (McCrady).

Cat. No. 14, Sullivan's Islands, S. C, December, 1851, L. Agassiz.

?Cat. No. 16, Florida, 1850, L. Agassiz.

Fig. 326, Hybocodon prolifer Agass., seen from the broad side. !', proboscis; )•, o, radiating
tubes ; s, circular tube ; m, buds of !Medusic at base of long tentacle, (.

Fig. 327. Ilybocodon prolifer, seen facing the long tentacle, a, point of attachment to Hy-
drarium ; b, c, radiating tidies ; e, rows of lasso-ccUs extending from base of tentacle to abactinal
pole; 0, proboscis; /, Medusie budding from base of long tentacle, t.

Fig. 328. Medusa bud of Ilybocodon. a, base of attachment ; o, proboscis ; b, c, chymiferous
tubes ; d and near c, Medusae buds at base of tentacle, t.

THAMNOCNIDIA. 195

Parypha crocea Agass.

Pan/pha crnrca Agass. Cont. Nat. Hist. U. S., IV. pp. 240, 342, Pis. 23, 23», Figs. 1 - 7. 18G2.

Boston Bay (L. Agassiz).

Cat. No. 13, Warren Bridge, Boston, June, 1858, H. J. Clark. Hy-
dromedusarium.

Parypha microcephala A. Agass.

Eesembles in its general aspect the Paryjiha cristata Agass. ; the
stem is more slender than that of P. crocea, found in Boston Harbor ;
the head is much smaller than in either of the above-mentioned spe-
cies, though the stem grows to a size fully as great as in our Eastern
Parypha, giving it a very characteristic aspect. Found attached to
floatins; losrs round the wharves of San Francisco.

San Francisco, Cal. (A. Agassiz).

Cat. No. 15, San Francisco, Cal., October, 1859, A. Agassiz. Hydro-
medusarium.

Cat. No. 17, San Francisco, Cal., December, 1859, A. Agassiz. Hydro-
medusariimi.

THAMNOCNIDIA Agass.

Thamnocnidia Agass. Cont. Nat. Hist. U. S., IV p. 342. 1862.

Thamnocnidia spectabilis Agass.

Thamnocnidia speclabilis Agass. Cont. Nat. Hist. U. S., IV. pp. 271, 342, PI. 22, Figs. I - 20. 18G2.

Massachusetts Bay, Boston (L. Agassiz).

Cat. No. 6, Boston, August, 1851, H. J. Clark. Hydromedusarium.

Thamnocnidia tenella Agass.

Thamnocnidia tenella Agass. Cont. Nat. Hist. U. S., IV. pp. 275, 342, PI. 22, Figs. 21 - 30. 1862.

Massachusetts Bay, Nahant (L. Agassiz).

Cat. No. 7, Nahant, Mass., September, 1854, H. J. Clark. Hydrome-
dusarium.

Cat. No. 8, Nahant, July, 1861, A. Agassiz. Hydromedusarium.
Cat. No. 410, Eastport, Me., 1861, Anticosti Expedition.
Cat. No. 411, Eastport, Me., 1863, A. E. Verrill.
Cat. No. 412, Eastport, Me., 1863, A. E. Verrill.

196 TUBULARIA.

Thamnocnidia tubularoides A. Agass.

This species grows in clusters, which at first sight would readily be
mistaken for a species of true Tubularia, on account of the great diam-
eter of the stem, and the large size of the head. The structure of the
proboscis, however, shows plainly that it is a genuine Thamnocnidia,
which can at once be distinguished from its Eastern congeners by the
stoutness of the stem and size of the head, surrounded by as many as
from thirty and even forty tentacles in large sjiecimens. Found grow-
ing profusely on the bottom of the coal-barges which bring coal from
Benicia to the Pacific Mail Steamship Company's steamers at San
Francisco.

San Francisco, Cal. (A. Agassiz).

Cat. No. 11, San Francisco, Cal., December, 1859, A. Agassiz. Hy-
dromedusarium.

TUBULARIA Linn.

Tubularia LiNX. (reslr. Agass.). Syst. Nat. 1 756.
Tubularia Agass. Cont. Nat. Hist. U. S., IV. p. 342. 1862.

Tubularia larynx Linn.

Tubularia larynx Ellis. Cor., PI. 16, Fig. 6.

Tubularia lari/nx JonNST. Brit. Zooph., p. 50, PI. 3, Fig. 3 ; PL 5, Figs. 3, 4.

Tubularia larynx Stimps. Mar. Inv. Grand Manan, p. 9. 1853.

Grand Manan (W. Stimpson).

Tubularia Couthouyi Agass.

Tubularia Couthouyi Agass. Cont. Nat. Hist. U. S., IV. pp. 266, 342, PI. 23", Figs. 8, 9 ; Pis.

24, 26, Figs. 1-6. 1862.
Tubularia indivisa Stimps. Mar. Inv. Grand Manan, p. 9. 1853.
Tubularia indivisa Gould. Rep. Inv. Mass., p. 350. 1841.
Tubularia indivisa MoRCH ; in Besk. af Gronland, p. 96. 1857.

Massachusetts Bay (L. Agassiz).

Cat. No. 4, Boston, August, 1851, H. J. Clark. Hydromedusarium.
Cat. No. 5, Grand Manan, 1857, J. E. Mills. Hydromedusarium.
Museum Diagram, No. 24, after L. Agassiz.

HYDRAID^. 197

Family HYDRAID^ Gray.

Hi/draidw Gray. Syn. Brit. Mus., p. 7C. 1840.
I/i/ilrina EirRENB. (;;. p.). Corall. d. Roth. Meeres, p. 67.
Uydraidw JoiUfST. Brit. Zooph., p. 120, Second Edition.

HYDKA Linn.

Hydra Linn. Sjst. Nat. 1 756.

Hydra gracilis Agass.

Hjidm gracilis Agass. ; in Proc. Bost. Soc. Nat. Hist., III. p. 354.
Hijdra gracilis AvRES ; in Proc. Bost. Soc. Nat. Hist., V. p. 103.

Our fresh-Avater Hydra has as yet been studied so insufficiently,
that I am unable to add anything respecting the development of the
MedustB, or concerning its identity with the European Hydra viridis.
Agassiz has described two Eastern species under the name of Hydra
gracilis and H. carnea, and Ayres a California species. From the
character of the Medusa? of the Hydra, it seems to me that it finds
its natural place among the true Hydroids, and not among the Dis-
cophorae, with which it has usually been associated, on account of its
close resemblance to the Scyphistoma {Hydra tuba).

Cambridge (L. Agassiz).

Cat. No. 370, Cambridge, 1862, W. Glen.

Hydra carnea Agass.

Hydra carnea Agass. ; in Proc. Bost. Soc. Nat. Hist., III. p. 354.
Hydra carnea Ayres ; in Proc. Bost. Soc. Nat. Hist., V. p. 104.

Massachusetts and Connecticut (Agassiz ; Ayres).

Hydra tenuis Ayres.

Hydra tenuis Ayres ; in Proc. Bost. Soc. Nat. Hist., V. p. 104.

San Francisco, California (Ayres).

198

HYDRACTINID^.

Family HYDRACTINID^ Agass.

HydraclinidcE Agass. Cont. Nat. Hist. U. S., IV. p. 339. 1862.

HYDRACTINIA Van Beneden.

Hi/draclinia Van Beneden ; in Bull. Acad. Bel., VIH. 1841.
Hijdractinia Agass. Cont. Nat. llist. U. S., IV. p. 339. 18G2.
Synhydra Quat. ; in Ann. des Scien. Nat., XX. p. 230. 1843.

Hydractinia polyclina Agass.

Hydractinia pohjdina Agass. Cont. Nat. Hist. U. S., III. PI. IG ; IV. pp. 227-239, 339, Figs.

33-35 ; PI. 26, Fig. 18. 1862.
Hydra squamata Fab. Fauna Griinlandica. No. 338.
Alcyonhim echinalum GouLD. Rep. Inv. Mass., p. 351.

Hydractinia cckinata Leidy. Mar. Inv. New Jersey and Rhode Island, p. 3, PI. X. Fig. 35. 1855-
Hydractinia echinata Stimps. Mar. Inv. Grand Manan, p. 11. 1853.
Hydractinia echinata McCr. G}'mn. Charleston Harbor, p. 6G.
Claim Sf/nanuila Murcii ; in Beskriv. af Gronland, p. 96.
Hydractinia polyclina Pack.; in Can. Nat. & Geol. Dec. 18G3.

As such constant reference is made to Hydractinia in the comparison
of the free colonies of Nanomia to the fixed Hvdroids, fio;m'es of male

Fig. 330.

_ o

h

^.t> /J

(Fig. 329) and female (Fig. 330) colonies of this species are here intro-
duced to facilitate the comparison.

Point Judith (Leidy) ; Atlantic coast of Noi'th America (L. Agassiz).

Cat. No. 55, Grand Manan, 1859, A. E. Verrill.

Cat. No. 56, Grand Manan, October, 1857, J. E. Mills.

Cat. No. 57, Chelsea Beach, L. Agassiz.

Cat. No. 58, Swampscott, Mass., March, 1859, S. Tufts.

Cat. No. 59, Nantucket Shoals, July, 1849, L. Agassiz.

Cat. No. 403, Nahant, Mass., July, 1802, A. Agassiz.

Museum Diagram, No. 25, after L. Agassiz.

Fig. 829. Part of male community of Hydractinia. a, a, sterile indiWduals ; b, fertile indi-
vidual ; d, male Medusic ; o, o, proboscis ; (, elongated tentacle of sterile individuals.

Fig. 330. Part of female community, o, sterile individual ; b, fertile individual, producing
female Medusae, d, e, f, g, h, i ; o, peduncle of mouth ; c, individual with globular tentacles.

DIPHY^. 199

SuBOEDER DIPHYiE Cuv.

Diphyce Cvv. Regne Animal, IV. 1817.

CaUicophorklcB Leuck. {p. p.) ; in Aroliiv f. Nat., I. p. 256. 1854.

Dlphi/CE Ag.\ss. Cont. Nat. Hist. U. S., IV. p. 370. 1862.

For the reasons wliich have led me to adopt the old divisions of
Eschscholtz, and not the divisions of Leuckart, which have found such
universal approval, I would refer to the description of Nanomia given
below.

Family DIPHYID^ Esch.

Diphyida EscH. (reslr. Agass.). Syst. der Acal., p. 122. 1829.
Diphyidm Agass. Cont. Nat. Hist. U. S., IV. p. 371. 1862.

EUDOXIA Esch.

Eudoxia Esch. Syst. der Acal., p. 125. 1829.
Eudoxia Less. Zooph. Acal., p. 460. 1843.

Eudoxia alata McCk.

Eudoxia data McCr. Gymnoph. Charleston Harbor, p. 70, PI. 8, Figs. 9, 10.

Charleston Harbor (McCrady).

DIPHYES Cuv.

Diphyes Cvv. Regne Animal, IV. 1817.
Erscea Esch. Syst. der Acal., p. 127. 1829.
Cucullus Q. & G. ; in Ann. des Sc. Nat, X. 1829.
Diphyes Less. Zooph. Acal., p. 438. 1843.

Diphyes pusilla McCr.

Diphyes pusilla McCr. Gymn. Charleston Harbor, p. 72.

Charleston, S. C. (McCrady).

200 PHYSOPHOR^.

Suborder PHYSOPHOR^ Goldf.

Phi/sophora; GoLDF. Haiulb. d. Zool. 1820.

PhysophorcE Agass. Cout. Nat. Hist. U. S., IV. p. 3G7. 18C2.

Family AGALMID^ Brandt.

Agnbnid(v Br.\xi)T ; in Mem. Acad. St. Petersburg, p. 234. 1838.
Agahnce Less. Zooph. Aoal., p. 509. 1843.
Slephanomicc Less. Zooph. Acal., p. 475. 1843.
Stephanomiilce Ledck. ; in Arehiv f. Nat., I. p. 312. 1854.
Step!ianomid(E HuxL. Ocean. Hyd., p. 72. 18.')8.
Agalmidos Agass. Cent. Nat. Hist. U. S., IV. p. 3G8. 1862.

NANOMIA A. Agass.

Nanomia A. Agass.; in Proc. Boston Soc. Nat. Hist, IX. p. 181. 1863.

Nanomia cara A. Agass.

Nanomia cara A. Agass. ; in Proc. Bost. Soc. Nat. Hist., IX. p. 181. 1863.

This Siplionopliore is closely allied to the genus Agahnopsis of Sars,
but the nature of the tentacles of the feeding polyps, and the mode of
arrangement of the swimming-beUs, show undoubtedly that it cannot
be placed in the same genus as Agahnopsis, though closely related to
it, as also to Halistemma of Huxley. The small size of this species has
been of great advantage in enabling us to seize readily, at one glance,
the connection between the different parts of this community, while
the great size of many of the species hitherto observed has always been
more or less of a drawback in analyzing the relations of the individuals
of the community.

Fig. 331. The float, or swimming-bladder, (I shall use at present

the nomenclature usually adopted, and afterwards show to
what parts these organs correspond in an ordinary Hy-
droid,) is a large elliptical cavity (Fig. 331), entirely shut
off from the main cavity, which runs from the base of the
float, through the whole of the axis of the community. It
contains in this genus a bubble of oily sul^stance ; the na-
ture of the contents of the float varies in different families
of Siphonophorse, and this cavity may or may not be closed. In this
genus it is closed, and there is no access to the oil-bubble from with-
out ; the oil-bul)l3le by no means fills the whole of the cavity of the
float. The float is of a brilliant garnet color ; from it hangs the rosy-
Fig. 331. Oil-float of Nanomia ; magnified.

NANOMIA CARA.

201

colored axis, with its pale swimming-bells, and farther down, the scales,
protecting the diiierent kinds of feeding polyps, with their various
kinds of tentacles projecting in all sorts of angles and curves from the
main axis of the body, like the festoons of a chandelier ; the darker-
colored polyps, tipped and mottled with scarlet, being visible under-
neath the protecting scales. (Fig. 332.)

The swimming-bells are arranged in two vertical rows, consisting of
four to six large bells each ; they are placed obUquely, in such a way

that the wing-like projections of the spherosome encroach upon those
of the opposite row, and thus fit closely and compactly together, by a
sort of oblique dovetail arrangement ; these bells are only symmet-
rical when seen from one of the sides (Fig. 333), when they appear
somewhat heart-shaped, having a large cavity which opens externally
by means of an aperture (see Fig. 334) in a veil, similar to that of
genuine naked-eyed Medusae, and capable, like it, of beating up and

Fig. 332. Nanomia cara; natural size.

26

202

NANOMIA CARA.

Fig. 333.

clown, and forcing the water in or out of the cavity of the bell. From
the abactinal pole of this cavity diverge four chymiferous tubes, which
lead into a circular tube, connecting them all (c, Fig. 334) ; two of these
tubes, t', t', are straight, and run directly from the point of junction of

the four tubes [j, Fig. 334) to the circular tube,
while the other tubes, t, t, wind round before
joining the circular tube. The connection of
these chymiferous tubes with the tube into
which they run, and which connects them all
with the main cavity of the axis of the commu-
nity, can readily be traced by combining the
different views of the swimming-bell here given.
(Figs. 333-336.) In Fig. 333 the straight chy-
miferous tubes run perpendicularly to the circular 'tube, in continuation
of the tube passing through the abactinal pole of the spherosome ;
Avhile in Fig. 336, which is a view at right angles to that of Fig. 333,
we see the connection of the winding tubes with the connecting tube ;
the opening (/, Fig. 335) of the connecting tube {t", Fig. 335) is some-
what to one side of the point of junction of the chymiferous tubes

(j, Fig. 334), as is readily seen on examining Figs. 335, 336. Fig. 336
shows the wing-like expansions of the spherosome which clasp the axis,
giving the Medusa a conical appearance, when seen from that side ;
while when seen from the actinal or abactinal pole, as Figs. 334, 335,

Fig. 333. Swimming bell of Nanomia, seen facing the side of the straight chymiferous tubes.

Fig. 334. The same bell, seen from tlie actinal pole, somewhat more magnified. /, t, bent chy-
miferous tubes ; (', t', straight chymiferous tubes ; c, circular tube round veil ; j, point of junction
of tlie four chymiferous tubes.

Fig. 335. A portion of the same bell, seen from the abactinal pole ; lettering as in Fig. 334.
f, opening of tube, t", leading into the main a.xis connecting with one of the straight chymiferous
tubes.

NANOMIA CARA.

203

Fig. 336.

the sh.ipe of the swimmmg-bell is rectangular. There can ])e but Httle
doubt that the.se swinnning-bells, as I have called them, are genuine
Medusiv ; they have all the characters of Medusae, and when they be-
come detached, move like them, the only difference being the absence
of a proboscis to admit food. This, however, they do not need as long
as they remain connected with the main axis,
the cavity of which opens directly into the
chymifei'ous tubes, and thus circulates in
them whatever food is taken in at the feed-
ing mouths, and from them passed into the
cavity of the main axis. I have not been
able to detect any opening leading directly
into the system of chymiferous tubes. These
IMcdusre are the locomotive organs of the
community ; they force the water in and out
of their cavity, and thus propel the whole community by a sort of
alternating motion, resembling that of sculling a boat ; the bells on one
side of the axis are tilling with water, while those of the other side are
forcing the water out violently ; the motion begins at the bottom bell,
passes on to the top one of the same side, then begins at the bottom of
the other row, and so on, throwing the whole of the upper part of the
community violently from one side to the other, while the remainder
is dragging lazily after it. I have not found any specimens with more
than eigbt swimming-bells fully developed ; the younger bells are
added between the first-formed pair and the float, where we find a
cluster of swimming bells in different stages of development. These
vouno- bells are formed, as the Medusas buds of the Tubularians, by
folds of the outer wall, which gradually grow larger and larger, and
circumscribe parts of the main cavity to form chymiferous tubes.

In their younger stages, the swim-
ming-bells resemble still more the
Medusaj of Hydroids, when they
have not yet assumed an irregular
outline, and while their chymiferous
tubes are still straight. In the cluster
of young bells here given (Fig. 337),
we find a few of the different stages
through which one of these bells
passes, from the time it appears as
a mere bud, till it has gone through

Fig. 33G. The same bell as Fig. 3.33, seen from the other side, to show the course of the bent
tubes, and the mode of connection of the tubes leading into the main axis ; (, bent tube.

Fig. 337. Group of swimming bells, in dilTercnt stages of development, a, the chymiferous
tubes are simple sacs ; h, the tubes, having united, make a circuit ; c, first signs of bending of the
tubes, t, of the preceding figures.

FiR. 337.

204 NANOMIA CARA.

the different phases in which the chymiferous tubes are mere pouches
(rt, Fig. 337), then large tubes connected by a circular tube {b, Fig. 337),
till finally the bell becomes somewhat expanded at one pole, and the
tubes have a tendency to bend, as in c, Fig. 337, when the difference
between the two kinds of chymiferous tubes is quite marked, although
the mode of attachment of the Medusa and the shape of the bell remind
us strongly of Tubularian Medusaj buds, and we find no trace as yet of
the wing-shaped appendages, and of the difference of outline of older
Medusae, when seen from different sides.

As there is a portion of the axis, immediately beneath the float,
which is free from swimming-bells, we find also under the swimming-
bells a small pai't of the axis bare ; we soon, however, come upon a
cluster of small buds entirely different in character from those found
Fig. 338. under the float; these are polyps, or feeding-

mouths, in different stages of development. The
poljqDs (Medusa?) to which this set of buds give
rise are of very different characters ; they are of
three kinds, and nearly equally distributed along
the remainder of the axis, no part of the axis
being reserved for any special kind of polyjos ;
the most prominent kind, and the largest, are
the Hydra-mouths (Fig. 338), which are the most
active, and in which we find, at the point of junc-
tion with the axis, a cluster of long tentacles, along
the thread of which are fastened, by a short han-
dle, a knob-like appendage ; these are the tent<i-
cles which are so prominent, and assume such
manifold attitudes when the community is at rest
or in motion. The polyps are open at the distal extremity, the open-
ing being frequently expanded like the disk of a leech, or simply flai'ing
trumpetrshaped ; they are exceedingly contractile, and sometimes ex-
pand ftir beyond the axis in search of food ; they communicate by
means of a somewhat narrow neck with the m;iin axis, so that the food
which is taken in by any one of these mouths helps to feed the whole
community, and circulates freely in the main axis, and in every polyp
and swimming-bell. The clusters of tentacles are protected by a shield-
like scale (Deckstiick), to the nature of which I shall refer hereafter ;
this scale is triangular, with rounded extremities, and through the mid-
dle of it passes a thin tube, which connects with the main axis, making
a kind of knee immediately above the point of junction ; the upper
shield of Fig. 338 shows plainly the mode of connection. The knobs of

Fig. 388. Cluster of !Mo(liisa> (feodliif; polyps) of tlio first kind formed, in the younger stages,
with tentacular knol) an<l scale. In the upper jiart of the figure a closed bud, with an oil-bubble,
is seen ; this bud is ready to bo liberated and become an embryonic community, like Fig. 34G.

NANOMIA CARA.

205

this kind of tentacles are sole-shaped bodies, paved with a beautifully
arranged setting of large lasso-cells, edged in by a large set running
round the edge (Fig. 339) ■; these knobs are partly hollow, a portion of
the tube of the tentacle extending into it a short distance.

The second kind of feeding polyps (Medusae) (Fig. 340) resemble
the first in every respect except the tentacles ; they are, like them,
attached to the main axis, and protected by a scale, omitted in the
figure ; at the proximal end of the polyp we find, however, a cluster of
tentacles of a totally different nature from the club-bearing lashes of
the first kind ; they take their origin as diverticula of the wall of the
polyp, as those of the first kind ; they never grow long, scarcely
extending the length of the polyp, but are twisted closely when fully
developed, though in their earlier stages they are more corkscrew-
shaped, and coiled quite loosely. The whole surface of these tentacles

Fig. 341.

Fig. 339.

is covered by a regular pavement of lasso-cells of the same size ; the
lasso-cells in the young tentacles are only found on the edge ; as they
increase in length, the tentacles become more thickly covered, imtil,
when closely coiled, they have the pavement described above. There
are generally from five to six (Fig. 340) of these large tentacles, and
about as many more, in different stages of development, at the base of
each of these polyps ; while of the first kind of tentacles we rarely
find more than three long threads, though there is a thick cluster of
embryonic ones adjoining them ready to develop and take their place
if any accident should happen to the longer meshes.

The third kind of polyp (Medusae), which is found along the axis, are
polyps with closed extremities (Fig. 341), differing besides from the
others m having only one long, slender tentacle at the proximal ex-
Fig. 339. Enlarged view of the knob of a tentacle of the first kind of Medusje.
Fig. 340. The second kind of Medusse, having cork-shaped tentacles. The scales in this and
following figure are omitted ; they difTer in no respect frc^ni tliose of Fig. 338.

Fig. 341. Third kind of Medusa, having only a single thread-like tentacle, and a closed pro-
boscis. - .

206

NANOMIA CARA.

tremity, and being perfectly colorless ; this tentacle is three or four
times the length of the polyp, and is covered with patches of small
lasso-cells scattered irregidarly over its surface ; the walls of this polj'p
are thick, and are not capable of extensive expansion or contraction, or
of any remarkable alteration of shape, as the former kinds. There is
still a fourth kind of appendage formed here and there along the stem,
one of which is figured on the top of Fig. 338, which resembles this
last kind of polyp, being closed, like it, at the extremity, but having
neither scale nor tentacles of any kind, and in the proximal end of
which we notice an accumulation of oily matter ; these I sim2:)ly men-
tion here, and shall return to them hereafter.

The new j^olyps which are added to the community take their origin
from the cluster of buds situated beneath the swimming-bells ; like the
swimming-bells, they are formed by the bulging of the wall of the main
axis (Fig. 342) ; they very soon assume the general aspect of feeding
Fig. 342. polyP'^j though they remain

closed at their distal extremity
after they have attained a con-
siderable size {p, p' , J)", Fig.
342) ; the scarlet pigmentrcells
make their appearance at a
very early period, so that we
are able, in very young buds,
to recognize the nature of the
future polyps ; as soon as the
pol3^p buds are slightly more advanced than they are in the figure here
given (Fig. 342), the nature of the tentacular buds at the base, and the
total absence of pigment-cells in some of the larger closed buds, enables
us readily to decide to which kind of polyps (Medusas) these different
buds will give rise ; the peculiar sole-shaped knobs of one of the kinds
of tentacles are nothing but an exjiansion of the original diverticulum
at the base of the polyp; the different phases through which the. knobs
pass are very easily followed by examining the various stages of growth
found in a cluster of tentacles, such as is represented in Fig. 338 (some-
what enlarged in Figs. 343, 344), until they attain the shape repre-
sented in Fig. 339. They are at first a narrow bag, with a few scat-
tered lasso-cells (a, Fig. 343), then the thickness of the wall at the
extremity increases, the lasso-cells at the same time becoming large
(6, Fig. 343). In the next stage, when seen in profile, the sac has
assumed a hook-shaped form (c, Fig. 343). the bend becomes still moi'e
marked, and the lasso-cells 'are now arranged in a row along the ex-
tremity (cZ, Fig. 343) ; the walls become thicker as the lasso-cells

Fig. 342. Cluster of Medusae (feeding polyps) in different stages of development, before the
appearance of the scale or of the tentacles, p, oldest ; p\ somewhat younger ; p'\ still younger.

NANOMIA CARA.

207

become more numerous and larger, the knob assuming more a ladle-
shape (e, Fig. 3-44) ; there is then formed a still larger row of lasso-cells,
extending along the edge, and concealing the others (/, Fig. 344),
making a kind of binding when seen from above {g, Fig. 344), where
we find all the peculiar characteristics of the sole-shaped, lasso-paved
knob of Fig. 339, the only difference in the older knobs Ijeing the
greater size of the outer row of lasso-cells, and their closer packing,
Avhich conceals entirely the cavity running into the knob, while it is
plainly visible in younger tentacles.

The perfectly free and open communication we find between all the
parts of the connnunity, except the float, is one of their most striking
characteristics ; there is not an appendage into which the food taken in
by any one of these feeding polyps (Medusa3) cannot circulate into its
very extremity ; even the scales, which seem in their full-grown state

Fig. 345.

to consist of nothing but a gelatinous shield, with a very narrow tube
passing through the middle, are, when developing, open pouches leading
at once into the main cavity of the axis, and even after the buds can
distinctly be recognized as undeveloped scales (Fig. 345), the cavity
occupies a much greater part of the scale than in the adult, as is readily
seen in the different views of one of the scales {a, h, e, Fig. 345). In
the view from above, a, the triangular shape is already apparent ; a
profile view, h, shows its greater thickness than in a fully-developed
scale, while in an end view, c, it is still quite pentagonal.

Besides these different kinds of appendages, we find the sexual
individuals scattered in small clusters of abortive Meduste near the
lower extremity of the axis, generally in the third nearest the terminal

Fig. 343. a, h, c, d, tentacular knobs like those of Fig. 339, in tliffurent stages of development.
Fig. 344. e,f, //, the same tentacular knobs, still fiu-ther developeil.

In Figs. 343 and 344 all the figures are seen in profile, excejit /; of Fig. 343, and [/ of Fig. 344,
which are seen from the fiat side, to show the arrangement of the lasso-cells.
Fig. 340. Young scale ; seen from above, (( . in profile, b; and endways, c.

208 NANOMIA CARA.

polyp ; as has already been shown by Sars in Agalmopsis, the sexes are
distinct, so that we have whole communities, the sexual Medusa? of
which are either males or females. There is no great difterence be-
tween the appearance of the male and female Medusa3 ; they do not
(as is the case in Agalmopsis, according to Sars) separate from the com-
munity, and lead an independent existence ; they wither on the stem,
after having discharged their contents. The Medusae form bunches,
the single Medusae of which are directly attached to the main axis ;
they are somewhat pointed in outline, with four tolerably well defined
Fig. 346. chymiferous tubes, resembling quite closely the sessile Me-

Idusai of such Tubularians as Tubularia Couthouyi.
From the observations of Gegenbaur, there can be no doubt
that many of the Siphonophores are, like Nanomia, developed
directly from the egg, and that the embryo which comes from
the egg is one which is identical with those found floating
about in such immense numbers during the early part of
June, and which are figured in Fig. 346, consisting of a single closed
polyp and of an oil-float, separated by a partition, as in the adult (Fig.
331) ; this simple polyp is to be the axis of the future community.
But these young Nanomia? (Fig. 346) do not all arise from eggs, and
pass directly into an embryo like Fig. 346 ; we have a second kind
of development, that of budding. In Fig. 338 there is represented on
the top an appendage resembling somewhat a polyp without an open-
ing, having neither tentacle nor protecting scale. A bubble of oil is
collecting at the proximal extremity ; as this bubble increases in size,
the neck which connects the polyp with the main axis gradually
becomes narrower and narrower, until the connection is finally cut,
and we have a bud resemljling in every respect Fig. 346, wliich has
separated from the main community. By keeping in confinement.
Fig. 347, entirely isolated, an adult Nanomia having many of these

buds along the main axis, I have found after a few days
a large number of these buds liberated, which had as-
sumed the shape and structure of Fig. 346, and had
grown to be similar in every respect to the embryos I
was fishino; from the sea at the same time. From this
I should infer that we have two broods of adults, those
which are found in the fall, and which lay eggs in Octo-
ber and November, and those which are probably formed by budding
from the older ones during the summer and winter ; the embryos found
in earljr summer may have come from the eggs of either of these.

The young embryos (Fig. 346) readily keep alive in confinement,
and it is a comparatively easy thing to trace the successive stages of a

Fis^. 34 G. Youngest Nanomia foiinil swimming on surface.
Fi^r. 34 7. Soniewli;;t more advanced.

NANOMIA CARA.

209

further development ; the terminal Hydra of Fig. 346 increases greatly
in size ; a number of buds make their appearance on both sides of the
axis, immediately at the base of the float ; these buds are nothing but
the rudimentaiy swimming-bells, the so-called polyps and the tentacles.
(Fig. 347.) As the young Nanomia grows larger, these buds increase
in size, and we can soon trace in some of them undoubted polyps,
with an open mouth, and the rudimentary tentacular knobs accompa-
nying them ; immediately at the base of these polyps there is a small
transparent protuberance, the first appearance of the protecting scale.
The terminal polyp of this diminutive community increases greatly in
size, becomes open at the extremity, and covered irregularly with large

Fig. 349.

Fig. 343.

Fig. 360.

patches of scarlet pigment-cells ; the tentacles become longer, and when
they equal in length that of the community, from six to eight knobs
hang from the main threads. (Fig. 348.) In somewhat more advanced
specimens, we find protecting scales already quite well developed
(Fig. 349), and besides many additional polyps in' different stages of
development, such as are figured in Fig. 342 ; the buds immediately
imder the float, the nature of which seemed still doubtful in the last
stage (Fig. 348), are now seen to be rudimentary swimming-bells, some
of them nearly as advanced as those represented in Fig. 337 ; these
rudimentary parts grow now with great rapidity, the clusters of the

Fig. 348. The terminal Hydra is open, tentacles are developed, as well as clusters of sm.ill
swininiing-bells, like those of Fig. 337, and of Medusaj (feeding polyps), like those of Fig. 342.

Fig. 349. Still more advanced Nanomia.

Fig. 3.50. Young Nanomia, where we find several Aleduss (feeding polyps) of the fii-st kind,
Laving all the characters of those found in the adult (Fig. 332), and embryonic swimming-bells.

NO. II. 27

210 NANOMIA CARA.

different kinds of individuals taking the place we find them ocou]iying
in the adidt ; the swimming-bells are placed immediately under the
float, and the polyps between them and the primitive polyp. The
protecting scales increase rapidly, and in Fig. 350 we have a young
Nanomia having two well-developed polyps, as many scales, and as
many tentacles, one of the polyps being the first terminal one, and
the other a lateral polyp, at the base of which are found the rudi-
mentary tentacles, while immediately under the float we find a cluster
of rudimentary swimming-bells, as far developed as those of Fig. 337.

From this point there is no doubt that we have before us a young
Nanomia, and the future phases of the development are only changes
of quantity. The various members of the community have, however,
a very different degree of development. What is particularly charac-
teristic of the 3'oung Nanomia is that it is entirely composed of the
joolyp element, and of the polyps with knoblied appendages ; it is only
somewhat later that the scales make their appearance, and we then
have a sufficient number of these polyps added to make quite an exten-
sive community before any other kind is formed, and before the swim-
ming-bells are developed. We generally find a couple of large swim-
ming-bells preceding the appearance of the second kind of polyp (Fig.
339) ; it is not till still later that the Ilydrocysts (Fig. 341), as Huxley
has called the closed polyps, make their appearance. The remaining
swimming-bells are slow in their development ; we do not usually find
more than two in quite large specimens, and it is only in the adult,
where we find the buds which are to separate as young floats and
where the sexual individuals have begun to make their appearance,
that there are from four to six swimming-bells. (Fig. 332.)

From this slight sketch of the order of succession of the different
individuals, we have the means of dividing all the Siphonophores into
three great suborders, according to the degree of development of the
three principal elements. Lowest are those in which the float has the
greatest predominance, and in which the different individuals of the
community appear as secondary appendages, such as Porpita, A^elellii,
and Physalia ; in the second suborder we have the various stages of
combinations of the hydrarium and the swimming-bell elements, in the
following forms, — Rhisophyza, Apolemia, Agahna, Nanomia, Halistem-
ma, Stephanomia, and Forskalia ; while in the third and highest sub-
oi'der we find the greatest development of the swimming-bells, accom-
panied by a reduction in the number of individuals forming a single
community, and a further specialization of parts not found in the
preceding orders. The different appendages which are found along
the axis of these floating Hydroids have been considered by most
English investigators as simple organs, while the greater number of
German writers believe them to be different kinds of individuals, form-

NANOMIA CARA. 211

ing together a communitjr, and not a single animal, as maintained by
the former. The solution of this question has been considered in
various ways by Agassiz,. KoUiker, Vogt, Leuckart, Gegenljaur, and
Huxley. Professor Agassiz, who was the first to show the homology
existing between one of these floating communities and a fixed com-
munity of Hj-droids such as Hydractinia, has, it seems to me, given
the correct account of these animals. According to him, and the prin-
cipal points of this view have afterwards been proved independently
by Vogt, and also developed further, from Professor Agassiz's lectures,
by McCrady, a Siphonophore is neither a single animal, and its difieront
appendages simply organs, nor, according to the opposite and more
extreme view of Leuckart, does he push the polymorphism to such an
extent as to consider all the appendages, such as the tentacles and
scales, as independent individuals ; he compares one of these commu-
nities to the difterent kinds of individuals found in a Hydractinia com-
munity, and thus shows beyond doubt that the Siphonophores are not
a natural order of the Acalephs, but simjily diflerent suborders of the
order of Hj'droids ; the fact that they move about as free communities
does not separate them from the fixed Hydroids ; it would be as un-
natural to remove into different orders the free swimming Halcyonoids,
such as Eenilla, Veretillum, and the fixed Gorgonia or Halcyonium.
It has already been fully shown by Vogt that the swimming-bells of
Agalma and the like are only Medusa) differing from the Ilydroid
Medusaj in the absence of a free proboscis and of an opening commu-
nicating directly with the surrounding medium. The swimming-bells
of Nanomia are nothing but Medusae having complicated chymiferous
tubes, remaining almost always attached to the community, and per-
forming their part of the work. They are the locomotive individuals
of the community ; to them is mtrusted the carrying about the whole
of this fraternity, while different functions belong to the other indi-
viduals, some of them feeding the community, others serving to repro-
duce it by budding, while others again reproduce it by laying eggs.

The nature of the different kinds of polyps found along the axis
does not seem to have been correctly understood ; we can compare
them, in a general way, to the different kinds of individuals found in
a Hydractinia community ; it seems to me that the only parts which
can be homologized to one of these fixed Hydroids are the float, the
original polyp, and the buds (top of Fig. 338) which drop off. These
are in reality the floating Hydroid, and the other individuals, developed
as the axis or original Hydroid becomes larger, are not Polyps like the
original one, but Medusa3 in various stages of development, having a
different appearance from those we are accustomed to consider as such.
We have, in the suborders of Siphonophoraa, communities of different
kinds of Meduste, instead of having communities of different kinds of

212 NANOMIA CARA.

Ilycli'oicls, as in Hydractinia, only these Medusie never separate from
the original parent-stock from whicli the}' are produced. The iloat
corresponds to the part of the stem of the fixed Hydroids by -which
they are attached, and the different individuals arising from this single
Polyp are Medusae. To show the Medusa character of these individ-
uals, I must preface by saying that the tentacles, the Pol^yp, and the
scale are not so many independent individuals, but that these three
together form one individual, the Medusa. It is true this will appear,
at first sight, rather doubtful ; we are accustomed to associate witli
our notion of Medusa a regularly-shaped Ijell, chymiferous tubes, and
a proljoscis. But this is not the universal character of Medusa? ; the
abortive sessile Medusae of Sertularians, Campanularians, and Tubida-
rians are as much Meduste, though they have no proboscis and nothing
but rudimentary chymiferous tubes, as a free-swimming Sarsia or Bou-
gainvillia. The moment this is understood, a new light is thrown on
the nature of the individuals of our community. We find among the
Hydroids all the stages intermediate between a rudimentary Medusa,
as that of Laomedea or of Dynamena, and that of a symmetrical Me-
dusa like Sarsia. We have those in which the proboscis is quite well
developed, others in which the chymiferous tubes are always rudi-
mentary, others which are asymmetrical, as Hybocodon, and the dift'er-
ent spheromeres of which have not an equal degree of development.
This gives us the clew to the true understanding of the relation be-
tween the clusters of tentacles, the scale, and the Polyj) ; let us take
one of these Hybocodon Medusse, cut away the two lateral spheromeres
of the bell, and at the same time reduce the spheromere which bears
the long tentacle to its minimum, that is, bring the tentacle to the
point of junction of the proboscis and of the chymiferous tubes, cut
the remaining spheromere in any shape we please, triangular or pen-
tagonal, and we have a Medusa identical in every resj^ect to those of
our community. The cluster of tentacles corresponds to the single
tentacle, the scale with its tube corresponds to the remaining ,«phero-
mere and its chymiferous tube, while the proboscis and the Polypi are
identical, and perform one and the same function. The fact that there
is or is not a chymiferous tube extending through the scale, as in Fig.
338, does not invalidate this homology ; for the chymiferous tubes in
many Hydroid Medusa? are exceedingly rudimentary, and in tliat case
it would only be carrying out for free Hydroids what has become
j^erfectly familiar to us among the fixed Hydroids.

By reducing this proposition to a mathematical form, I may perhajis
give the reader a better idea of the process I am endeavoring to
explain, by supposing an equation of the nth degree to represent the
formula of a Hydroid Medusa, the roots of which are represented by
the difl'erent spheromeres ; they all become imaginary in our Nanomia,

NANOMIA CARA. 213

with the exceiition of one root, which is positive, and this Avould reiire-
sent the only remaining splieromere, tliat of the Deckstiick.

If this view is correct, it is evident that the opinion of Huxley, who
considers the scale as homologous to the urn of Campanularians can-
not be sustained. I have already hinted at the similarity of the em-
bryonic Nanomia, in the stage of Fig. 347, when it consists of only the
large Polyp and the float, with the early stages of the fixed Hydrarium
of Melicertum, where we have at first a single Polyp, from which are
developed, by budding, the branches and the other kinds of individuals
of the community ; supposing this community, instead of fixing itself,
as it does, to remain movable, the base of the stem to expand into a
float and become separated from the main cavity, we should have a
Siphonophore. The discovery by McCrady and Stimpson of the float-
ing Hydrarium of Nemopsis and Acaulis, where the Medusce are closely
related to genera the Hydrarium of which is always fixed, reduces still
further the distinction which has been made of Polypi Nechali. And
Avhen we find that there are genuine Medusas (Dysmorphosa) which
for four generations reproduce themselves by budding from the pro-
boscis, exactly in the same way in which we find additional individuals
arising along the walls of the original Polyp among Pliysopliorida% we
are at a loss to find any distinctions to separate the Siphonophores
from the true Hydroids, and we cannot consider them as anythino-
but floating Hydroid communities.

Massachusetts Bay, Nahant, and Newport, R. I. (A. Agassiz).

Cat. No. 365, Nahant, Mass., September, 1862, A. Agassiz.

Museum Diagram, No. 27, after A. Agassiz.

214

PORPIT^.

Suborder PORPIT^ Goldf.

Porpilfr Goj.TiF. Ilandb. dcr Zool. 1820.

Porpike and Pki/sriUre AoASS. Cont. Nat. Hist. U. S., IV. p. 366. 1862.

Chondrophorm Cham, et Eys. Acta Nova, X.

From a comparison of the young stages oF Nanomia with the known
Si^jhonophora^, I have been induced to extend the hmits of this sub-
order so as to include Physaha, forming thus three suborders among
Hydroids of the old order of Siphonophora3, the Diphytp, the Physo-
phora?, and the Porpitas.

Family PHYSALIDJE Brandt.

PhysaMcE Br. ; in Mem. Acad. St. Petersb., p. 236. 1835.
Phijsalidm Agass. Cout. Nat. Hist. U. S., IV. p. 366. 1862.

PHYSALIA Lamk.

Ph)/salia Lamk. An. s. Vert., III. p. 89. Second Edition.

Arethiitsa Brown. Nat. Hist. Jam.

Airthiixa Less. Zooph. Acal., p. 530. 1843.

Physalia Agass. Cont. Nat. Hist. U. S., IV. pp. 335, 366. 1862.

Fig 351.

Physalia Arethusa Til.

PJii/salm Arethusa Til. ; in Krasenst. Reise, PI. 23, Figs. 1-6. 1813,
J'/ii/xalid Arethusa Olf. ; in Mem. Berl. Acad., PI. 1. 1832.
Physalia Arethusa Agass. Cont. Nat. Hist. U. S., IV. pp. 335, 367,

PI. 35. 1862.
Physalia pelasgica Bosc. Hist. Nat. d. Vers, H. p. 168.
Physalia auriyera McCr. Gyran. Charleston Harbor, p. 74.

Physalia Arethusa (Fig. 351) is probably carried
by the Gulf Stream as far as the Azores. A spe-
cies has been described by Lesson as PhjsaUa
azoricum, which may be only the yomig of Phy-
salia Arethusa. (See Voyage de la Coquille, Plate
5, Fig. 4.) To facilitate the comparison of the
difterent kinds of individuals found in communi-
ties of this family with those of Nanomia, groups

Fig. 351. Physalia Arethusa Til. Figs. 351-354 are copied from
Professor Agassiz's Contributions, n, blunt end of air-sac supporting
the community ; h, open end of air-sac ; c, crest of air-sac ; m, bunches
of single individuals ; n, tentacle contracted ; (, t, tentacles of the lar-
gest kind expanded.

PHYSALIA ARETHUSA.

215

of Hytlrre and of Medusae (Figs. 352, 353, 354) are introduced
here.

Fig. 352.
Fig. 363.

Charleston (McCrady) ; Gulf of Mexico (Bro^vn, Sloane) ; Florida
(L. Agassiz) ; Cape Cod (A. Agassiz) ; Martha's Vineyard (W. H.
Forbes).

Cat. No. 305, Florida, 1850, L. Agassiz.

Cat. No. 306, Florida, 1850, L. Agassiz.

Cat. No. 307, Florida, 1850, L. Agassiz.

Cat. No. 308, Key West, Fla., February, 1858, L. Agassiz.

Cat. No. 309, Key West, Fla., March, 1858, L. Agassiz.

Cat. No. 310, Tortugas, Fla., February, 1858, L. Agassiz.

Cat. No. 311, New Providence, Bahamas, April, 1861, F. G. Shaw.

Cat. No. 312, Mobile, Alabama, L. Agassiz.

Cat. No. 313, 40° N. Lai, 60° W. Long., Captain W. H. A. Putnam.

Cat. No. 314, Naushon, Mass., 1861, W. H. Forbes.

Cat. No. 325, Tortugas, Fla., March, 1858, L. Agassiz.

Cat. No. 385, Beaufort, N. C, May, 1863, A. S. Bickmore.

Cat. No. 386, Bermudas, A. S. Bickmore.

Museum Diagram, No. 28, after L. Agassiz.

Fig. 352. Bunch of single Hydrse, and clusters of Jledusse, of Physalia Arcthusa Til. h, b,
Hydrffi, with their tentacles, c, c; d, d, bunches of tentacles.

Fig. 353. Bunch of Hydrae. a, hoUow base of attachment communicating with air-sac ; 6, h, b,
single HydriE ; c, c, tentacles.

Fig. 354. Bunch of Medusas in various stages of development, a, hollow base of attachment ;
b, Hydra ; d, d, Medusae buds.

216 VELELLID^..

Family VELELLIDiE Esch.

VeMUdm Escn. (restr. Agass.). Syst. d. Acal., p. 165. 1829.

Velellce Less. Zooph. Acal., p. 560. 1843.

VetellidiB Agass. Cont. Nat. Hist. U. S., IV. p. 366. 1862.

VELELLA L.VMK.

Velella Lamk. Anim. s. Vert., II. 1819.

Velella Lkss. Zooph. Acal., p. 562. 1843.

Velella Agass. Coiit. Nat. Hist. U. S., IV. p. 366. 1862.

lialarla Escn. Syst der Acal., p. 166. 1829.

Chrysomkra GeGenb. ; in Zeit. f. Wiss. Zool., p. 231. 1856. Medusa.

Linuche EscH. Syst. der Acal., p. 91. 1829. Medusa.

?Ratana Pagenst. ; in Zeit. f. Wiss. Zoo!., XII. p. 496. 1863.

Velella mutica Bosc.

Velella mutica Bosc. Hist. Nat. d. Vers, II. p. 158.

Velella mulica Less. Voyage de la Coquille, PI. G. 1829.

Velella mutica Less. Zooph. Acal., p. 571. 1843.

Velella mutica Agass. Cont. Nat. Hist. U. S., IV. p. 3C6. 1862.

The free Medusa of Velella resembles so exactly that produced by
some of the Tubularians — Euphysa and Globiceps, for example — that
it would seem the most natural thing to place these Medusaj among
Tubularians, as McCrady has done ; but the polymorphism of the

Pig. 357

Fig. 356.

r(L _^

Hydrae (Fig. 355) and the presence of the float (Fig. 356) associate
the Hydrarium with the Porpitae. The free Medusa is but another
link showing how close is the relation between the floating and fixed
Hydroids. The Medusa figured here (Fig. 357) is one which has just
freed itself The chymiferous tubes, as well as the proboscis, are of a

Fig. 355. An enlarged view of one of the fertile Ilydrs of Velella. a, base of attachment of
Hydra ; 6, end of Hydra ; d, d, clusters of Medusae. All these figures are copied from Professor
Agassiz's Contributions, Vol. III.

Fig. 356. Velella, seen from below, to show the Hy<lraB. »i, opening, so-called mouth ; a, fer-
tile Hydrae situated between the mouth and the outer tentacles, the sterile Hydr^.

Fig. 357. Magnified view of a free Medusa of Velella mutica Bosc. o, proboscis ; h, chymif-
erous tube ; c, circular tube.

VELELLA SEPTENTRIONALIS. 217

brilliant oclire color. Professor Agassiz has observed this Medusa four
days after it became free, when the Medusa had become quite globu-
lar, having lost entirely its- elongated shape.

Long Island Sound (A. Agassiz) ; Gulf of Mexico (Bosc) ; Coast of
Florida (L. Agassiz).

Cat. No. 29G, Florida, 1850, L. Agassiz.

Cat. No. 207, Fort Jefferson, Fla., April, 1859, Dr. D. W. Whitehurst.

Cat. No. 298, Key West, Fla., March, 1858, J. E. Mills.

Cat. No. 299, Cape Florida, April, 1858, G. Wurdeman.

Cat. No. 300, Cape Florida, G. Wurdeman.

Cat. No. 301, Tortugas, Fla., April 2, 1858, L. Agassiz.

Cat. No. 302, Tortugas, Fla., April, 1858, J. E. Mills.

Museum Diagram, No. 27, after L. Agassiz.

Velella septentrionalis Esch.

Velella septentrionalis Esch. Syst. der Acal., p. 171, PI. 15, Fig. 1. 1829.

Numerous specimens were collected at the entrance of the Straits
of Fuca. The proportions of this species are quite difierent from
those of our West Indian V. mutica. The figure given by Eschscholtz
gives a good idea of the almost square outline of the float.

In company with V. septentrionalis was always found a Physalia,
which I have been unable to refer to any of the described species.
As the specimens of both were lost, they are mentioned here for the
sake of the geographical distribution of these animals.

Northwest coast of America (Eschscholtz) ; Straits of Fuca (A. Ag-
assiz, October, 1859) ; San Francisco Bar (A. Agassiz, October, 1859).

NO. II. 28

218 PORPITID^.

Family PORPITID^ Guildo

Porpitidce Guild. ; in Ztx)l. Journ., XI. p. 403.
VelelliikE EscH. (p. p.). Syst. der Acal., p. 165. 18-29.
Porpitidce Agass. Cont. Nat. Hist. U. S., IV. p. 36G. 1862.
PorpitCE Less. Voyage de la Coquille, n. p. 55. 1829.

PORPITA Lamk.

Pnrpita 'Lmhth.. Anim. s. Vert., II. 1819.

Porpita Less. Zooph. Acal., p. 583. 1843.

Poipila Agass. Cont. Nat. Hist. U. S., IV. p. 366. 1862.

Poli/hrackiona Guild. ; in Zool. Journ., XI.

Palis Less. Zool. de la Coquille. 1829.

Acies Less. Zool. de la Cocpiille. 1829.

f Armenistarium Costa. Faune de Naples.

Porpita linnseana Less.

Porpita linna:ana Less. Zooph. Acal., p. 588. 1843.
Poli/brachionia tinnccana Guild.; in Zool. Journ., XI. Fig.
Porpita linnceana McCn. Gymn. Charleston Harbor, p. 42.
Porpita linna;ana Agass. Cont. Nat. Hist. U. S., IV. p. 366. 1862.
9 Porpita adantica Less. Voy. de la Coquille, PI. 7, Fig. 2.

West Indies (Guilding) ; Florida (L. Agassiz) ; Charleston, S. C.
(McCrady).

Cat. No. 289, Fort Jefferson, Fla., April, 1859, Dr. Wliitehurst.

Cat. No. 290, Pensacola, Fla.

Cat. No. 291, Key West, Fla., L. Agassiz.

Museum Diagram, No. 27, after L. Agassiz.

TABULATiE.

219

Suborder TABULATE Agassiz.

Tabulala; Agass. Sill. Journ., XXVI. p. 140. 1858.
Corallaria Tabulala Edw. & H.\niE. Archiv du Mas., V.
Madreporaria Tabidata Edw. & IIaime. Hist. CoralL, III. p. 223.
Tabulalce Agass. Cont. Nat. Hist. U. S., IV. p. 292. 1862.

1860.

Family MILLEPORIDiE Agass.

MILLEPOKA Linn.

Millepora Linn. Syst. Nat.

Millepora alcicornis Lra.

Millepnra alcicornis Lzy. Syst. Nat., X. 17.58.

Millepora alcicornis Dana. U. S. E.\. E.xp. Zoophytes, p. 543.

Milhporn alcicornis Edw. & Haime. Hist. Corall., III. p. 228.

Millepora alcicornis Agass. Cont. Nat. Hist. U. S., III. p. 292, PI. 15, Fijis. 3-13. 1860.

Millepora alcicornis Verrill ; in BuU. Mus. Comp. Zool., p. 59, No. 3. 1864.

The absence of radiating joartitions in the Tabulata3 seems to show,
without much doubt, that their true place is among the Hydroids. It
is true that Professor Agassiz has not observed the Medusaj buds on
the specimens he has figured (Fig. 358), yet the Hydroid character
of the animal, and their similarity to Halocharis-Uke Hydroids, is very

Fig. 353.

Fig. 360.

striking. It certainly is not more wonderful to have among AcaleiDlis
Hydroids which should deposit hard Umestone parts (Figs. 359, 360),
as Millepora and the like, than it is to find among the Polyps animals
in which we find partitions of every stage of hardness, from a gelati-
nous or a horny nature, to the most solid deposits of limestone. We
have already something of the same diversity in the formation of the

Fig. 358. JIagnified view of extended Hydroids of Millepora. a, a, small Hydroids ; h, larger
ones ; 711, mouth ; t, tentacles.

Fig. 359. Branch of Millepora alcicornis ; natural size.

Fig. 360. Transverse section of branch, o, a, pits of Hydroids.

220 MILLEPORA ALCICORNIS.

different kinds of sheaths of the Sertularians and of the Campanula-
rians, and especially in the great development of the horn-like net-
work forming the base of a Hydractinia colony, and the limestone
floors deposited by the base of the animal of Millepora is only an
extreme case for Acalephs, similar to the solid radiating partitions of
the Madrepores among Polyps.

Tortugas, Fla. (L. Agassiz).

Cat. No. 382, Tortugas, Fla., March, 1858, L. Agassiz.

GEOGRAPHICAL DISTRIBUTION.

For the sake of showing more strikingly the character of the dif-
ferent Acalephian Faunae of our coasts, lists have been prepared
embracing several species not enumerated in the Catalogue, to give
a better idea of the peculiar stamp of the regions into which our coast
has been divided. No names are here given to these faunal divisions,
as in a forthcomino- number of the Museum Catalog-ue the limits and
nomenclature of our Marine FaunaB will be fully discussed. For the
present I shall simply point out in a general manner some of the more
interesting points of the distribution of our Acalophs. Several species
have a very extensive range ; on the Atlantic side, from Greenland to
Long Island Sound, and from Grand Manan to Charleston, South Caro-
lina. In the Pacific Ocean we find species which range from Kamt-
schatka to the northern part of California. Within these extensive
belts there are other species more limited in range, extending only
from Massachusetts Bay to Eastport, from Charleston to Cape Cod,
from San Francisco to the Gulf of Georgia, or from the Gulf of Georgia
to Behring's Straits ; while a thii'd series of sj)ecies is still more lim-
ited, extending only along such portions of the shores as Nova Scotia,
Massachusetts Bay, Long Island Sound, the coast of Southern California,
the Gulf of Georgia, and the like.

The areas of disti'ibution of the different species overlap and enclose
one another so as to give us for the character of the Fauna of any pai*-
ticular locality three different elements of distribution ; first, the cos-
mopolitan species, spreading over Avide areas ; next, the species which
range over more limited areas ; and finally, the local species scattered
in the areas of the limited species. It is the peculiar combination of
these three elements which gives to a special locality what has been
called its fixunal character, but owing to the intricate crossing, overlap-
ping, and enclosing of these areas, we find it nearly impossible to draw
lines along our coast which should embrace homogeneous elements.
Such areas are found on our coast, extending approximately from
Greenland to the northern part of Nova Scotia, from Nova Scotia to
the northern part of Maine, and from Massachusetts Bay to Cape Cod ;
the coast of Long Island Sound and New Jersey, as far as Cape Hat>

222

GEOGRAPHICAL. DISTRIBUTION.

teras, presents features of its own ; the coast of the Carolinas and
Georgia has hkewise distinct faunal features, while Florida and the
West Indies have each their peculiar Acalephs, though the boundaries
of the distribution of many of the species, found in each of those divis-
ions, extend far beyond the limits we have here assigned to the regions.
On the Pacific side of North America, we find the great belt of the
Northern Pacific extending from the shores of Kamtschatka to British
North America ; the inland sea behind Vancouver's Island and the main-
land has a characteristic fauna, and along the coast of California itself
still different Medusae are foimd. The association of the three elements
mentioned above being so different at certain localities, we naturally
come to look upon them as centres from which the species of a fiiuna
are derived, while in reality it is only the peculiar combinations of the
geographical extension of each species which give the distinguishing
features to each locahty.

NORTH PACIFIC.

SITKA, Al/EUTIAN ISLANDS, BEHRING S STRAITS, KAMTSCHATKA.

BoUna septenlrionalis Mert.
Janira cucumis Less.
Dnjodora f/landiformis Ag.
Phaccllophora camtschatica Br.
Cyanea Postehii Br.
Ci/anea firruyinca Esch.
Pelayia Brandtii Ag.
Poh/bo.ftricha helfola Br.
Melanaster j)Ie7-tensn Ag.
A^f/inopsis Laurenlii Br.
Trachynema canitschaticuni A. Ag.
Staurophora Mertensii Br.
Diphasia (n/iyra-like)
Sertularia (abietina-Vikfi)
CotuUna Greenei A. Ag.
T/iuiaria (Miy'n-like)
Boiigainritlia Mertensii Ag.
Proboscitlactyla Jlavicirrala Br.

Behring's Straits. Mortens.

Sitka. Mfrtens.

Behring's Straits. ' Mortons.

Kamtschatka. Mortens.

Sitka. Mortens.
Aleutian Islands ; Kamtschatka. E.schscholtz.

Aleutian Islands. Mertens.

Aleutian Islands. Mortons.

Kamtschatka. Mortons.

Behring's Straits. _ Mertens.

Kamtschatka. Mertens.

Aleutian Islands. Mertens.

Behring's Straits. W. Stinipson.

Behring's Straits. AV. Stimpsun.

Behring's Straits. W. Stimpson.

Behring's Straits. W. Stimpson.

Behring's Straits Mortons.

Kamtschatka. Mortons.

GULF OF GEORGIA, W. T.

BdVuHi microptera A. Ag. A. Agassiz.

Pleurohrachia Bachei A. Ag. A. Agassiz.

Idyia cyalhina A. Ag. A. Agassiz.

Heccadecomma ambiguum Br. A. Agassiz.

Cyanea Postelsii Br. A. Agassiz.
Trachynema camtschaticum A. Ag. A. Agassiz.

Oceania gregaria A. Ag. A. Agassiz.

Crematoxlonia JIava A. Ag. A. Agassiz.

Z ygndactyla carulescens Br. A. Agassiz.

u'Eijuorea ciliata Esch. A. Agassiz.

Laoniedea pacijica A. Ag. A. Agassiz.

Polyorchi.i peniclUala A. Ag. A. Agassiz.

Laodicea cellularia A. Ag. A. Agassiz.

Gonionemus vertens A. Ag. A. Agassiz.

Melicertum georgicum A. Ag. A. Agassiz.

Botigainmllia Mertensii Ag. A. Agassiz.

Stomotoca atra A. Ag. A. Agassiz.

Proboscidactyla favirirrata Br. A. Agassiz.

Cnryne i-osaria A. Ag. A. Agassiz.

Pliys(dia sp. A. Agassiz.

Vclella septentrionalis Esch. A. Agassiz.

Porpita sp. A. Agassiz.

GEOGRAPHICAL DISTRIBUTION.

223

SAN FRANCISCO, CALIFORNIA,

Aiirelia hihinta Cham. & Eys.
PhacfllopJiora camtschatica Br.
Puli/boslricha hclcola Br.
Melanaster Mertensii Ag.
Laomedea rujida A. Ag.
Lanmedca pacifiai A. Ag.
Poll/orchis penicilliila A. Ag.
Ar/laophenia J'raiiciscaiia A. Ag.
Dipliasia corniculata A. Ag.
Sertularia anr/uina Trask.

J^. Agassiz.

Sertularia f/racilis A. Ag.

Trask.

A. Agassiz.

Sertularia /areata Trask.

Trask.

A. Agassiz.

Sertularia turyida Trask.

Trask.

A. Agassiz.

Cotulina Greenei A. Ag.

Murray.

A. Agassiz.

BougainvilUa Mertensii Ag.

A. Agassiz

A. Agassiz.

Coryne 7-osaria A. Ag.

A. Agassiz

A. Agassiz.

Paripha microcephala A. Ag.

A. Agassiz

A. Agassiz.

Tliainnocniflia tuhularoides A. Ag.

A. Agassiz

Murray.

Hydra tenuis Ayres.

Ayres.

Trask.

Phijsalia sp.

A. Agassiz

OcifToe macvlata Rang.
Jihjia nvata Lessi
Poli/clonia frondosa Ag.
Pelagia cyanella Per. et Les.
Cli/tia (ro/utj7«-like).
Laomedea (antijjatlies-Mke).
Laomedea ((;r(7C(7w-like).
Aylaoplienia pekm/ica McCr.
Agtaophenia trijida Ag.
Afjlaophenia acinaria Duch.
Aylaoplienia atlantica Duch.

WEST INDIES.

Rang. Dijnamena ostrearum Duch. Duchassaing.

Brown. Dijnamena (^disticha-Xike). Duchassaing.

Poey. Zelleria simplex Duch. Duchassaing.

Swartz. Tubularia Ehrenhergii Duch. Duchassaing.

Duchassaing. Tubularia Lamourouxii Duch. Duchassaing.

Duchassaing. Tubularia ylandutosa Duch. Duchassaing.

AVcinland. Tubularia pinnata Duch. Duchassaing.

Wcinland. Phijsalia Arethusa TiL Brown.

Weinland. Velclla mutica Bosc. Brown.

Duchassaing. Porpita Umueana Less. Guilding.

Duchassaing. Millepora alcicornis Lin. Linnaeus.

FLORIDA REEF.

Bolina vitrea Ag.

L.

Agassiz.

Idijopsis affinia Ag.

L.

Agassiz.

Pulijclonia frondosa Ag.

L.

Agassiz.

A urelia maryinalis Ag.

L.

Agassiz.

Pelagia cijanella Per. et Les.

L.

Agassiz.

Liriope tenuirostris Ag.

L.

Agassiz.

Clytia (^intermedia-like').

L.

Agassiz.

Clytia (yolubiiis-like).

L.

Agassiz.

Orthopyxis {poterium-Y\ke).

L.

Agassiz.

Laomedea (am/ilwra-Wke).

L.

Agassiz.

Laomedea (dichotoma-l\kc).

L.

Agassiz.

Ilheymatodes Jloriilan us Ag.

L.

Agassiz.

Z yyodaclyla cyanea Ag.

L.

Agassiz.

Eirene coerulea Ag.

L.

Agassiz.

Eutima pyramidcdis Ag. L. Agassiz.

Dynamena sp. L. Agassiz.

Pasithea sp. L. Agassiz.

Aylaoplienia pelasgica McCr. L. Agassiz.

Aglaophenia trijida Ag. L. Agassiz.

Plumularia quadridens McCr. L. Agassiz.

Plumularia sp. L. Agassiz.

Nigelastrum sp. L. Agassiz.

Pennaria gihhosa Ag. L. Agassiz.

Paripha cristata Ag. L. Agassiz.

Phijsalia Arethusa Til. L. Agassiz.

Velella mutica Bosc. L. Agassiz.

Porpita tinnccana Less. L. Agassiz.

Millepora alcicornis Linn. L. Agassiz.

CHARLESTON, SOUTH CAROLINA.

Bolina littoralis McCr. McCrady.

Afnemiopsis Gardeni Ag. L. Agassiz.

Beroe punctata Esch. McCrady.

Idyopsis Clarkii Ag. L. Agassiz.

Stomolophus meleagris Ag. L. Agassiz.

Cyanea versicolor Ag. L. Agassiz.

Foreolia octonaria A. Ag. ISIcCrady.

Persa incolorata McCr. ISIcCrad)'.

Liriope scutigera McCr. McCrady.

Oceania folleata Ag. _ McCrady.

Eucheilota ventricxdaris McCr. McCrady.

Clytia bicophora Ag. McCrady.

Platypyxis cyliiidrica Ag. L. Agassiz.

Eucope dioaricata A. Ag. L. Agassiz.

Obelia commissuralis McCr. McCrady.

Eirene gibbosa Ag. McCrady.

Eutima mira McCr. McCrady.

Eutima variabilis McCr. McCrady.

224

GEOGRAPHICAL DISTRIBUTION.

Agkwphcnia pelaar/ica McCr. McCraily.

AyJaophenia Irijida Ap;. L. Agassiz.

Aqliioplicnia tricuspls McCr. JlcCrady.

Plumularia quadndens MeCr. McCrady.

riunudaria (Cathwiiiii-Wkf). L. Agassiz.

Di/nainciia cornicina McCr. L. Agassiz.

Diphasia {nujra-X\kc). L. Agassiz.

Nemopm Bachei Ag. McCrady.

Mwr/elis cciroliiicnsh Ag. McCrady.

Eudenilriiim ramosiim McCr. ^McCrady.

Turrikijiais nulrkuUi McCr. ^IcCrady.

Stomoloca apicata Ag. McCrady.

WUl'ia onuita McCr. McCrady.

Dipitrena slranr/idafa ]\IcCr. McCrady.

Dipurena ceroicata McCr. McCrady.

Corynitis Agassizii McCr. McCrady.

Gemmaria gemmosa McCr. ^McCrady.

Pennaria tiarella McCr. ]\IcCrady.

Eclupleiira lurricida Ag. McCrady.

Paripha crislata Ag. L. Agassiz.

Hydractinia pmh/cliiia Ag. McCrady.

Eudoxki alala ISIcCr. McCrady.

Dipkyes pusilla McCr. McCrady.

P/iysalia Aretliuxa Til. McCrady.

Vck'lla mulica Bose. McCrady.

Porpita Unnieana Less. McCrady.

BUZZARD'S BAY AND LONG ISL.iND SOUND.

Mneminpsii: Leidyi A. Ag. A. Agassiz.

Lesuewia hyhoptera A. Ag. A. Agassiz.

Pleurohrackia rhododactyla Ag. A. Agassiz.

Cyanca arctica Per. et Les. A. Agassiz.

Ci/anea fulm Ag. A. Agassiz.

Dactyldinetm (jtiiiifiiiectrra Ag. A. Agassiz.

Tntchyncma digitate A. Ag. A. Agassiz.

Oceania languida A. Ag. A. Agassiz.

Eucheilota ventricularis McCr. A. Agassiz.

Euchcilota duodecimalis A. Ag. A. Agassiz.

Clylia ndidiilis A. Ag. A. Agassiz.

Clytia liieaplwra Ag. A. Agassiz.

Platijpyxis cylindi-ica Ag. A. Agassiz.

Eucope diaphana Ag. A. Agassiz.

Obelia commissuralis McCr. A. Agassiz.

Laomedea amphora Ag. A. Agassiz.

PJicgmatodes teiniis A. Ag. A. Agassiz.

Zy;/oi!ad!/la groerdandica Ag. ^ A. Agassiz.

Jiquorca alliida A. Ag. A. Agassiz.

Eutima limpida A. Ag. A. Agassiz.

Lafiea calcarata A. Ag. A. Agassiz.

Dynamena puinila Lamx. A. Agassiz.

Serhdaria cvpressina Lin. Leidy.

Nemopsis Bachei Ag. L. Agassiz.

Bougainvillia supercitiaris Ag. Leidy.

Margclis carolinensis Ag. A. Agassiz.

Eudendrium dispar Ag. A. Agassiz.

Eudendrium tenue A. Ag. A. Agassiz.
Dysmorphosa fulgurans A. Ag. A. Agassiz.

Modeeria up. A. Agassiz.

Turrilopsis nutricula IMcCr. A. Agassiz.

SlomSnca apicata Ag. A. Agassiz.

Clara leptoslyla Ag. Leidy.

Wdlia urnala McCr. A. Agassiz.

Dipurena cnnica A. Ag. A. Agassiz.

Gemmaria gemmosa l\IcCi-. A. Agassiz.

Pennaria tiarella McCr. Ayres.

Cordylophora sp. Leidy.

Ectopleura ochracea A. Ag. A. Agassiz.

Ilybocodon proli/er Ag. A. Agassiz.

Hydra carnea Ag. (Conn.) L. Agassiz.

Hydractinia pnlycUna Ag. A. Agassiz.

Nanomia cara A. Ag. A. Agassiz.

Physalia Arethusa Til. A. Agassiz.

MASSACHUSETTS BAY.

Bolina alata Ag. L. Agassiz.

Lesueuria hyhoptera A. Ag. A. Agassiz.

Mertensia orum Morcli. A. Agassiz.

Pleurobrachia rhododactijla Ag. L. Agassiz.

Idyia roseola Ag. L. Agassiz.

Aurelia flavidula Per. et Les. L. Agassiz.

Cyanea arctica Per. et Les. L. Agassiz.

Campanella pachyderma A. Ag. A. Agassiz.

Trachynema digitate A. Ag. A. Agassiz.

Halimocyathus platypus II. J. C. 11. J. Clark.

Manania auricula H. J. C. H. J. Clark.

Lueernaria qtiadricornis !MU11. L. Agassiz.

Haliclystus auricula H. J. C. L. Agassiz.

Tiarnpsis diademata Ag. L. Agassiz.

Oceania languida A. Ag. A. Agassiz.

Wrightia sp. L. Agassiz.

Clytia intermedia Ag. L. Agassiz.

Clytia hicophora Ag. L. Agassiz.

Clytia vnlubilis A. Ag. . L. Agassiz.

Platypyxis cylindrica Ag. L. Agassi/.

Orthopyxis poterinm Ag. L. Agassiz.

Eucope diaphana Ag. L. Agassiz.

Eucope alternata A. Ag. A. Agassiz.

Eucope parasitica A. Ag. A. Agassiz.

Eucope pobjgp-na A. Ag. A. Agassiz.

Eucope pyriformis A. Ag. A. Agassiz.

Eucope articulata A. Ag. A. Agassiz.

Eucope fusiformis A. Ag. A. Agassiz.

GEOGRAPHICAL DISTRIBUTION.

225

Obelia mmmi.fiitiralis McCr. L. Agassiz.

Laomedea amphora Ag. L. Agassiz.

Laomedea gitjantea A. Ag. H. J. Claik.

Laomedea reptaiis Lamx. L.'^ Agassiz.

Laomedea up. L. Agassiz.
Slomohrachitim tcntaculatum Ag. L. Agassiz.

Halopsi.i ocfttala A. Ag. A. Agassiz.

Halopsis cruciata A. Ag. A. Agassiz.

Zi/(;oda<'l>/la groenlandica Ag. L. Agassiz.

Zygodaclijla crassa A. Ag. A. Agassiz.

Tima formoaa Ag. L. Agassiz.

Lafma coniuta Lam.x. A. Agassiz.

Lafwa diimnsa Sars. A. Agassiz.
jSIdkertum campanula Per. et Les. L. Agassiz.

Staurophora laciniata Ag. L. Agassiz.

Pli/clior/cna lactea A. Ag. A. Agassiz.

Pltaiudaria arhorea Des. Desor.

Di/namcna piimila Lamx. L. Agassiz.

Lhjphasia fallax Ag. L. Agassiz.

Dyphasia rosacea Ag. L. Agassiz.

Sertularia cupressiiia L. L. Agassiz.

Sertularia argentea EU. & Sol. L. Agassiz.

Sertularia falcata L. L. Agassiz.

Sertularia m)/riop/i)/llum L. L. Agassiz.

AmphitrocMa rugosa Ag. L. Agassiz.

Colulina tricuspidata A. Ag. L. Agassiz.

Cotxdiua tamarisca A. Ag. L. Agassiz.

Ilalecium lialeciiium Johnst. L. Agassiz.

Bougainvillia superciliaris Ag. L. Agassiz.

Eudendrium dispar Ag. L. Agassiz.

Eudendrium tenue A. Ag A. Agassiz.

Eudendrium sp. A. Agassiz.

Li::ia grata A. Ag. A. Agassiz.

Dgsmorphrjsa fulgurans A. Ag. A. Agassiz.

Turris vesicaria A. Ag. A. Aga.ssiz.

Turrilopsis sp. A Agassiz.

Rliizngeton fusiformis Ag. L. Agassiz.

Clara leplostgla Ag. L. Agassiz.

Cortjne mirahiUs Ag. L. Agassiz.

Sgndictgon reticulcdum A. Ag. A. Agassiz.

Gemmaria cladophora A. Ag. A. Agassiz.

Pennaria tiarella McCr. A. Agassiz.

Euphysa virgulata A. Ag. A. Agassiz.

Ilghncodon prolifer Ag. L. Agassiz.

CorijmorpJia pendula Ag. L. Agassiz.

Paripha crocea Ag. L. Agassiz.

T/iamnocnidia spectahilis Ag. L. Agassiz.

Thamnocnidia tenella Ag. L. Agassiz.

Tuhnlaria Coulhoinji Ag. L. Aga.ssiz.

Hydra gracilis Ag. (Mass.) L. Agassiz.

Hydraclinia polyclina Ag. L. Agassiz.

Nanomia cara A. Ag. A. Agassiz.

NORTHERN COAST OF MAINE, GR.iND MANiOf, AND EASTPORT.

Ilolina alala Ag. W. Stimpson.

Merlensia ovum Mdrch. A. Agassiz.

Pleurobrachia rhododactyla Ag. W. Stimpson.

Jdyia roseola Ag. W. Stimpson.

Aurelia flaridula Per. et Les. AV. Stimpson.

Cyanea arctica Per. et Les. AV. Stimpson.

Manania auricula H. J. C. AV. Stimpson.

Lucernaria quadricornis Miill. AA''. Stimpson.

Haliclystus auricula H. J. C. AA'^. Stimpson.

Hcdiclystus salpinx H. J. C. AV^. Stimpson.

Oceania languida A. Ag. L. Agassiz.

Clytia voluhilis A. Ag. A. E. A'errill.

Clytia hicophora Ag. AV. Stimpson.

Orthopyxis poterium Ag. A. E. A'^errill.

Eucope diaphana Ag. A. Agassiz

Eucope pyriformi.i A. Ag. J. E. Mills.

Obelia commissuralis McCr. J. E. IMills.

Laomedea amphora Ag. J. E. jNIills.
Melicertum campanula P. et Les. L. Agassiz.

Staurophora laciniata Ag. AA^. Stimpson.

Dynamena pumila Lamx. A. Agassiz.

Diphasia fallax Ag. AV. Stimjison.

Sertularia abietina L. J. E. Mills.

Sertularia cujiressina L. AA'^. Stimpson.

Sertularia argentea L.
Sertularia falcata Ag.
Sertidaria latiuscula Stimps.
Sertularia myriophyllum L.
Sertularia Jilicula Ell. & Sol.
Sertularia pruducta Stimps.
Amphitrocha rugosa Ag.
Cotulina tricuspidata A. Ag.
Cotulina polyzonias Ag.
Cotulina lamarisca A. Ag.
Ilalecium halecinum Johnst.
Halecium muricatum Johnst.
Grammaria gracilis Stimps.
Grammaria robusta Stimps.
Acaulh primarius Stimps.
Eudendrium dispar Ag.
Coryne mirahilis Ag.
Clara Icptostyla Ag.
Candelabrum, phrygium Bl.
Corymorpha pendula Ag.
Thamnocnidia tenella Ag.
Tubularia larynx Ellis.
Tubularia Couthouyi Ag.
Hydraclinia polyclina Ag.

J. E. Mills.
AV. Stimpson.
AA^ Stimpson.
A. E. VerriU.
AV. Stimpson.
AA'. Stimpson.
AA'. Stimpson.
AA'. Stimpson.
A. E. VerriU.
AA^ Stimpson.
A. E. A'errill.
A. E. A'errill.
AA'. Stimpson.
AV. Stimpson.
AV. Stimpson.
A. E. VerriU.
AV. Stimpson.
AV. Stimpson.
AV. Stimpson.
AV. Stimpson.
A. E. VerriU.
AV. Stimpson.
AV. Stimpson.
A. E. A'erriU.

NO. II.

29

226

GEOGRAPHICAL DISTRIBUTION.

NOVA SCOTIA.

Bolina alata Ag.
Pleurobrachia rhododactyla Ag
Idyia roseola Ag.
A urdia flafklula Per. et Les.
Ci/anea arctica Per. ot Les.
UaViclystus anricula H. J. C.
Clijlia voluh'dis A. Ag.
Clytia bicophora Ag.
Orthopyxis poterium Ag.
Laomedea (^ilichotoma-Yike}.
Laomedea (^gelatinosa-\\kc).
Laomedea ((/enicidala-]ike).
Lafeea cornuta Lamx.
Lqfoea dumosa Sars.
Cosmetira sp.

Anticosti

Antifosti

Anticosti

Anticosti

Anticosti

Anticosti

Anticosti

Anticosti

Anticosti

Dawson.

Dawson.

Dawson.

Anticosti

Anticosti

Anticosti

Exp.
E.\p.
E.xp.
Exp.
Exp.
Exp.
Exp.
Exp.
Exp.

Exp.
Exp.
Exp.

Dynamena pumila Lamx.
Sertiitaria abielina L.
Sertularia argentea L.
Sertutaria plumea Dawson.
Sertularia fatcata L.
Sertularia myriophyllum L.
Sertularia latiuscida Stimps.
Cotulina tricuspidata A. Ag.
Colidina polyzonias Ag.
Colulina tamarisca A. Ag.
Halecium muricatum Johnst.
Thuiaria thuja Fleni.
Eudendri-Mn (rojHosum-like).
Txdndaria larynx Ellis.
Tuhularia Couthouyi Ag.

Dawson.
Anticosti Exp.
Dawson.
Dawson.
Anticosti Exp.
Anticosti Exp.
Dawson.
Anticosti Exp.
Anticosti Exp.
Anticosti Exp.
Anticosti Exp.
Anticosti E.xp.
Dawson.
Dawson.
Dawson.

]\fertensia oinim Morcli.
Pteurobrachia rhododactyla Ag.
Idyia cucumis Less.
Idyia borealis Less.
A urclia Jlariihda Per. ct Les.
Cyanea arctica Per. et Les.
Chrysaora heptcena Per. et Les.
Trachynema digitale A. Ag.
Manama auricula H. J. C.
Lucernaria quadricornis Miill.
Ilaliclystus auricula II. J. C.
Medusa bimorpha Fal).
TiaropsU diademala Ag.
Campanularia volubilis BIdrch.
Campanularia olivacea Lamx.
Eucope diapjhana Ag.

GREENLAND.

Fabricius. Zygodaclyla grocnlandica P. et Les. Fabricius.

Fabricius. Melicertum campamda Per. et Les. Fabricius.

Fabricius. Dynamena pumila Lamx. Fabricius.

Scoresby. Sertularia abietina L. Fabricius.

Fabricius. Sertidaria argentea L. Fabricius.

Fabricius. Amphitrocha rugosa Ag. Fabricius.

Martens. Cotulina jtobjzonias A^. Fabricius.

Fabricius. Halecium halecinum Johnst. Fabricius.

Fabricius. BougainrdUa stiperciliaris Ag. ISIorch.

Fabricius. Coryne mirabilis Ag. Sabine.

Steenstrup. Coryne pusilta Giirt. Mbrch.

Fabricius. Coryne muscoides Johnst. Morch.

Morch. Candelabrum j/hryi/ium Bl. Fabricius.

Morch. Tuhularia indivisa Linn. !M6rch.

Morch. Hydractinia polyclina Ag. Fabricius.
Morch.

SYSTEMATIC TABLE

OF THE ORDERS AND FAMILIES OF NORTH A51ERICAN ACALEPHJE
DESCRIBED IN THIS VOLOIE.

Order CTENOPHOR^ Esch. .
Suborder Lobat.e Efch.
Family Bolinida; Ar/.
Family OcjToese Less. .

Suborder Saccat.e Ag.
Family Mertensidse Ag.
Family Cydippidas Geg. .

Suborder Eurystom.e Leuck.
Family BeroidiE Esch.

Order DISCOPHOR.E Esch. .
Suborder Rhizostome.e Ag.
Family Rhizostomids Esch. .
Family Polyclonidse Ag. .

Suborder Sem.eostome.e Ag.
Family Aureliada; Ag.
Family Sthenouia; Ag. .
Family Cyaneidae Ag.
Family Pelagidse Geg. .

Suborder Haplostome.e Ag.
Family Thalassantheae Less. .

Suborder Trachynemid.e A. Ag.
Family Trachynemidae Geg. .
Family Leuckartids Ag. .

Suborder Lucerxari.e Johnst.
Family C'leistocarpida? //. J. C.
Family Eleutherocarpida; H. J. C.

PAGE

7

14

. 14

25

. 26

26
. 29

35
. 35

40

. 40

40

. 41

41
. 41

43
. 44

47

. 51
51

. 54

55
. 60

61

. 61

62

Order IIYDROID.E Johnst. .
Suborder SertularIjE Ag. .

Family Oceanidae Esch. .

Family Eucopidie Geg.

Family iEquoridas Esch. .

Family Geryonopsidse Ag. .

Family Polyorehidse A. Ag.

Family Laodiceida; Ag.

Fauiily Melicertida? Ag. .

Family Plumidaridffi Ag.

Family Sertulariadse Juhnst.
Suborder Tubulari^ Ag. .

Family Nemopsidje Ag. .

Family BougainvilleiB Liilk:

Family Nuoleiteraj Less. .

Family Williadse Forbes

Family Sai-siadaa Forbes .

Family Orthocorynidie .1. Ag.

Family Pennarida; McCr.

Family Tubulariadas Johnst.

Family Ilydraidae Gray .

Family Hydractinidse Ag. .
Suborder Dipiiy.e Cuv.

Family Diphyidse Esch.
Suborder Phtsophor.e Gold/.

Family Agalmida; Brandt .
Suborder Porpit.e Goklf. .

Family Physalidse Brandt .

Family Velellidse E.tch.

Family Porpitidse Guild.
Suborder Tabulate Ag. .

Family MilleporidEe Ag.

PAGE

. 64
68

. 68
81
95
112
118
121
128
ISO
141
149
149
152
164
171
175
183
186
189
197
198
199
199
200
200
214
214
216
218
219
219

INDEX OF GENERA AND SPECIES.

[Synonymes are in Italics.]

Acaulis Stimps

PAGE

. 151

priinarius Stimps. .

151

Acies Less

. 218

Acrochordium Met. .

184

jEf/inopsis J. !MuLL.

. 51

^ginopsis Br.

54

Lauivntii Bn.

. 54

.Slquorea Per. et Les. .

109

albida A. Agass.

. 110

ciliata Esch. .

109

glohularis MoRCH

. 103

groenlandica Per. et Les.

103

Aglaophenia Lamx. .

. 139

crUlafa McCr.

140

franciscana A. Agass.

. 140

pclasgica McCr.

139

trifida Agass.

. 140

trieuspis McCr.

140

Aglaura penicillata Bl. .

. 119

Alcinoe Less

14

vermicularis Gould .

. 15

Alcyonium echinatum Gould

198

Amphitrooha Agass.

. 146

cincta Agass. .

146

rugosa Agass. .

. 146

Anais Less. ....

14

Arethusa Brown . . . .

. 214

A nnenislarhim Costa

218

Alracl>/!ls Wright

. 122

Aurelia Per. et Les.

41

aurila Gould

. 42

flnvidula Per. et Les.

42

labiata Cham, et Eys.

. 43

marginalis Agass. .

43

sex-oeariis MoRCH

. 42

Beroe Brown.

35

cucuUus Mod. . ,

. 26

ciwumis Fab. .

36

cucumin Mert. .

. 34

glandiforniis Mert. .

34

ovata Esch.

. 35

ovum Fab.

26

pileus Fab

. 30

Beroe (^continued)

pileus ScOR. .

punctata Cham, et Eys,
Biblis Less.
Bolina Mert.

alata Agass. .

liUoralis McCr. .

mieroptera A. Agass.

septentrionalis Agass.

septentrionalis Mert.

vitrea Agass.
BougainvUUa Less. .
Bougainvillia Less. .

Mertonsii Agass.

superciliaris Agass.

CalamelJa Oken
Calicella IIincks .
Candelabrum Bl. .

phrygium Bl.
Campanella Less.
Campanella Bl.

campanula MiJRCH

Fabricii lyESS.

pacliydenna A. Agass.
Campanularia Lamx. .

diimosa Johnst.

dumosa Leidy .

noliformk McCr.

syringa Stimps. .

voluhiliti Alder

voluhUis Leidy .
CampanuUna Van Ben.
Cassiopea Til.

frondosa Esch. .

Pallns P:!ER. et Les.
Cephea rldzostoma GiBBES
Chrysaora Esch.

helvola Less.

melana.iter Br.
Chn/aomiira Geg. .
Circe Mert.

camlschatica Br. .

digitalis Morch

26

35

41

14

15

19

19

19

14

19

155

152

152

153

159

77

186

186

130

51

130

130

62

93

126

122

80

70

77

80

122

41
41
40
48
60
50
216
55
55
57

230

INDEX OF GENERA AND SPECIES.

Circe impatiena Agass. .

. 55

Clava Gmelin ....

170

k'ptostyla Agass.

. 170

multiconiis Stimps. .

170

si/uamata MoRCH

. 198

Clacula Wright

164

Clausira Less

. 41

Clytia Lamx

. 77, 81

bicophora Agass.

. 78

ci/Iindrica Agass. .

78

t'jlindrica Agass.

. 80

intfi'moiiia Agass. .

77

volubilis A. Agass.

. 77

Corymorpha Sars

192

nutans Stimps. .

. 192

pondula Agass.

192

p!iri/r/ia ]Sl6i;CH .

. 186

Coryne Gart.

175

luirabilis Agass. .

. 175

rosaria A. Agass. .

176

Corynitis McCr.

. 183

Agassizii McCr.

183

Cosmetira Forbes .

. 127

Cosmelira sp. ....

128

Cotulina Agass..

. 146

Greenei A. Agass. .

147

polyzonias Agass.

. 146

tamarisoa A. Agass.

147

tricuspidata A. Agass.

. 146

Crematostoma A. Agass. .

108

(lava A. Agass. .

. 108

Cucullus Q. & G.

199

Cunina EsCH.

51

octonaria McCr.

51

Cyanea Per. et Les. .

. 44

amhiijua Less.

43

arcticaPER. et Les. .

. 44

ferruginea EscH.

47

fulva Agass.

. 4G

Postelsii Br. .

47

Postel.iii Gould .

. 44

vei-sicolor Agass. .

46

Ci/aneopsis hehnnrjiana Br. .

. 47

Cydalisia Less

35

pimclata Less.

35

Ci/dippe EscH. . . .

29

cucullus EscH.

. 26

cucumis Less. .

26

ovum EsCH.

. 26

pileus Gould .

30

Cytceis S.\RS .

. 161

Dactylometra Agass. .

48

quinquccirra Agass. .

. 48

Diaruca Delle Ciiiaje .

113

Diancea Q. & G. .

. 60

Diamea Lamk

47

Diancea

cyanella Lamk. .

denticulate Lamk. .
Diphasia Agass.

corniculata Agass. .

lallax Agass.

rosaeoa Agass.
Diphyes Cuv. .

pusilla McCu.
Diplocraspedon Bn.
Dipurena McCr. .

cervicata McCr. .

conica A. Agass. .

strangulata McCr.
Dryodora Agass. .

glaiidiformis Agass.
Dynamena Lamx. .

cornicina McCr.

pclasf/ica Bl. .

pumila L.\MX.
Dysmorphosa Phil.

f'ulgurans A. Agass.

Eetopleura Agass.

turricula Agass. .

ochracea A. Agass.
Eirene Esch.

ceerulea Agass,

digitale EsCH.

gibbosa Agass.
Epenthesis McCr. .

folleata McCr.
Ephyra Per. et Les.

octolahata Gould .
Erscca Escii. .
Eschscholtzia Less. .

f/hindiformis Less.
Eucheilota McCr. .

duodi'cimalis A. Agass,

veiitricularis JMcCr.
Eucope Geg.

altornata A. Agass.

articulata A. Agass.

diapliana Agass. .

diaphana Agass.

divaricata A. Ag.\ss.

fusifbrmis A. Agass.

parasitica A. Agass.

polygcna A. Agass.

pyritbrmis A. Agass.
Eucoryne Leidy .

ehfidus Leidy
Eudendrium Ehrexb.

cinr/ulatum Stimps.

dispar Agass.

ramosum Johnst. .

ramosum McCr. .

Hi

47
47
142
143
142
142
199
199
41
180
181
181
181
34
34
141
142
139
141
163
163

190

191

191

, 113

112

57

112

70

70

41

42

199

34

34

74

75

74

83

86

89

83

86

91

90

87

86

88

186

187

159

153

159

160

160

INDEX OF GENERA AND SPECIES.

231

Eudendrium (r/mtiinied)

tonne A. Agass.
Eudoxia Escii. .

alata McCn. .
Euphysa Foudes

vii-gulata A. Agass.
Eurijhia Escii.
Eurijhiopsis Geg.
Eutima SIcCu. .

limpida A. Agass. .

niira IMcCn.

pyramidalis Agass.

variabilis McCk. .
Evagora Per. ct Les.

Foveolia Per. et Les.

octonaria A. Agass.

Gemmaria McCr.

cladophora A. Agass.

gemmosa McCu. .
Gcryonia EsCH. .
Gerijonopsis Forbes
Globiceps Ayres

tiarella Ayres .
Gonionemus A. Agass.

vfiteus A. Agass.
Grammaria Stimps.

gracilis .Stimps. .

robusta Sti.mps.

Halecium Oken^.

haleoinuin JonxsT.

muricatum JoiixsT.
Halielystus II. .J. Clark

auricula II. J. Clark

salpinx H. J. Clark
Halimocyathus II. J. Clark

plat\]ius H. J. Cl.\rk
Halocharis Agass.

spiralis Ag.4SS.
Halopsis A. Agass. .

cruciata A. Agass.

ocellata A. Agass.
Heccsedecomma Br. .

anibiguuni Br.
Hermia Johnst.
Ifippocrene McCr.
Hippocrene Mert.

Bougainvillei Br.

Boiigninvillei Gould

carolincnsis McCr.

supercilinris Agass.
Hybocodon Agass. .

prolifer Agass.
Hydra Linn.

carnea Agass.

Hydra {t-ontinued)

160

gracilis Agass.

199

tenuis Ayres

199

sipiamala Fab.

189

Hydractinia Van Ben.

189

echinata Leidy

60

polyclina Ag.\ss.

60

116

Idyia Flesi. .

116

borealis Less.

116

cucumis Less.

118

cyathina A. Agass.

116

ovata Less. .

41

roseola Agass. .

Idyopsis Agass. .

51

affinis Agass.

61

Clarkii Agass.

184

Janira Oken

184

cucumis Less.

184

60

Lafcea Lamx.

112

calcarata A. Agass.

186

cornuta AciASS. .

187

cornuta Lamx.

128

dumosa Sars

128

Laodicea Agass.

148

Laodicea Less. .

148

calcarata A. Agass.

148

cc'llularia A. Agass.

Laomedea Lamx. .

147

amphora Agass.

148

dichotoma Leidy

147

dicaricata McCr.

62

gelatinosa Leidy

62

gelatinosa Gould

64

gigantea A. Agass.

61

pacifica A. Agass.

61

rigida A. Agass. .

183

Lesueuria Edw. .

183

hyboptcra A. Agass

99

Linuche Escii.

102

Liriope Geg. .

99

scutigera McCr. .

43

tennirostris Agass. .

43

Iiizzia Forbes .

175

grata A. Agass.

155

Lueemaria Mull.

152

auricula F-\B. .

152

auricula Mull. .

153

Fabricii Agass.

156

fascicularis Flem.

153

ocloradiata Lamx. .

193

phrygia Fab.

193

quadricornis Mull.

197

typica Greene .

197

197
197
198
198
198
198

35
36
36
38
35
36
39
40
39

34

34

122

122

122

126

126

122

127

122

127

93

93

91

91

88

91

94

94

93

23

23

216

60

60

60

161

161

62

62

63

62

62

63

186

62

62

232

INDEX OF GENERA AND SPECIES.

Mauania 11. J. Clark

auricula II. J. Clark
Margelis Steenst.

carolineiisis Agass.
Sledea EscH.

fulgens EsCH.
Medusa Linn. .

cequorea