Illustrated catalogue of the Museum of Comparative Zoölogy, at Harvard Colleg

ALEX. AGASSIZ.

Hibrary of the Museum

OF

COMPARATIVE ZOOLOGY, |
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AT HARVARD COLLEGE, CAMBRIDGE, MASS,

Founded by private subscription, i 1861.

Deposited by ALEX. AGASSIZ.

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ILLUSTRATED CATALOGUEC*-~X 71%
MUSEUM OF COMPARATIVE ZOOLOGY,
AT HARVARD COLLEGE.

Published by order of the Legislature of Massachusetts. —

No. ITI.

NORTH AMERICAN ACALEPHA.

BY

ALEXANDER AGASSIZ.

CAMBRIDGE:
FOR SALE BY SEVER AND FRANCIS.
1865.

ILLUSTRATED CATALOGUE

OF THE

MUSEUM OF COMPARATIVE ZOOLOGY,

AT HARVARD COLLEGE.

Published by order of the Legislature of Massachusetts.

No. II.

NORTH AMERICAN ACALEPHA.

BY

ALEXANDER AGASSIZ.

CAMBRIDGE:
FOR SALE BY SEVER AND FRANCIS.
1865.

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HE publication of the Illustrated Catalogue of the Museum of
Comparative Zodlogy 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 facilitate 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 kingdom as are most fully represented in our collections,
and that it may, as far as possible, present to the scientific world
the results of the mvestigations carried on in the Museum with a
view of ascertaining the natural limits of the Faune at the present
time and in past ages, and the genetic relations which may exist
between the order of succession of organized begs upon the earth,
their mode of growth, and their metamorphoses during their embry-
onic life, and the plan and complication 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.

Je Jas ID (Gass

HE progress of our knowledge of the Class of Acalephs is at

present so closely lmked 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 Zodlogy 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 Medusa, 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 specimens 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 bearmg 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

ai 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 ordimary way, these valuable mate-
rials have been extensively used in the preparation of this Catalogue,
as forming actually a part 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.
Cary, and to Professor Agassiz. I have also to thank, for specimens and
valuable information, Professor Joseph Leidy, Dr. Fritz Miller 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.

CamBripG#, Mass., February, 1865.

List OF THE WOOD-CUTS

BIBLIOGRAPHY .
CTrENOPHORZ
DiscoPHORE

Hyprows

GEOGRAPHICAL DISTRIBUTION.
SysTEMATIC TABLE OF THE ORDERS

InDEX OF GENERA AND SPECIES

NO. Il.

CON tf ENTS:

re

AND

FAMILIES

.

LIST OF THE WOOD-CUTS.

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

PAGE
Young Borrma ALATA, seen from the narrow side. . : : : : a 6)
Bolina in state of Fig. 1, seen from the broad side : 0 6 : 6 16
Somewhat younger than Fig. 1, seen from the abactinal pole . : : : . 16
Young Bolina, seen from the abactinal pole, older than ee figures : é 16
Formation of lateral tubes in young Bolina : 16
Bolina in which lobes begin to appear, seen from hee narrow fit, same ae as Fig. 4 16
Somewhat more nilcemaail than Fig. 6, seen from the actinal side. 0 16
The tentacular ambulacra have united, and the lobes project well beyond the coe
ing of the mouth . 5 6 ; : 5 o ile
About in ‘the condition of Fig. 1, seen aoa the broad pac) eee c 5 A 12
Somewhat younger than Big. 8, seen from the broad side . F j . 4 > ile
Fig. 8, seen from the broad ieitle 0 é , : 17
Base showing first appearance of the sorte, seen Ba om the ibaa efile : ; o (ly
Bolina in stage of Fig. 12, seen from the narrow side. é : ‘ . ‘ 17
Fig. 13, seen from the actinal pole. 0 : 5 : . . : 5 5 lt}
Adult Bolina, seen from the broad side. (LL. Agassiz.) . : 6 : : j 18
Fig. 15, seen from the narrow side. (L. Agassiz.) . 5 : j E é . 18
Bolina, seen from the actinal pole. (L. Agassiz.) . : F : ; 9 6 18
Bolina, seen from the abactinal pole. (L. Agassiz.) . . : E ‘ 5 alts}
Bora VITREA, seen from the broad side. “GL: ‘eestin)) 3 : 2 : 19
MNeEmI0opPsis GARDENT, seen from the broad side. (LL. Ayassiz) ¢ : : P20)
Fig. 20, seen from the actinal pole. (1. Agassiz.) 3 . 0 ° 2 20
Myemiopsis Lripyt, seen from the broad side . ; é : : : : peal
Same as Fig. 22, seen from the narrow side . 0 : a 9 21
A part of the tentacular apparatus near the opening of ‘the saiinasione 5 3 ~ (22
LESUEURIA HYBOPTERA, seen from the broad side 0 5 : 6 5 o 24
Fig. 25, seen from the narrow side. : : A ‘ : 5 5 5 . 24
The same, seen from the abactinal pole . . : . : ; : . : 25
Seen from the actinal pole. é 5 0 0 0 saa 2 BB
Adult MERTENSIA OVUM, seen from the Bi oad fils 5 0 '° 0 : : 27
Young Mertensia, seen from the broad side : E 9 0 5 A 9 9 el
Fig. 30, seen from the abactinal pole. : . c ; : 27
Somewhat more advanced Mertensia, seen from ae narrow sftlo 6 é : 728
Same as Fig. 32, seen from the actinal pole . i : ° ; 0 4 28
Still more aalvernewil Mertensia, seen from the narrow mde : 5 : oS
Fig. 34, seen from the actinal pole . 5 ° 2 : 3 0 c 28
Still further advanced Mertensia, seen from the inal ade 3 0 0 29
Young Mertensia, about in the same condition as that of the preceding Pa, seen
from the narrow side c 0 0 > : oh)
Young PLEUROBRACHIA RHODODACTYL ie seen eon the nroad filo 3 ‘ 30
Same as Fig. 38, seen from the narrow side 4 : . 5 : . - - 30
Same as Fic. 38, seen from below . 0 0 3 . : ‘ o 6 30

Somewhat more advanced, seen from the broad idle 5 : : ° , 4 - 30

52.

55.

77.

82.

LIST OF THE WOOD-CUTS.

Fig. 43, seen from above. 5 5 6 5 5 3 : é

Fig. 42, seen from the broad side _ . . 0 5 5 5 5

Plamstedite, immediately before the escape from the ege . . 6 6

Fig. 44, somewhat less magnified, to show the relative ae of the egg-case and ite
embryo 5 : : ° 5 2 : 0 : :

Fig. 44, seen from the aniinell wale : : ST ® 3: 5

Pleur obrachia swimming freely about, seen Fah el Bread side . : : ‘

Somewhat less adlvameail than Fig. 47, showing the lateral tubes from the narrow
side, as a prolongation of the ambulacral cavity . : 5 S 5

Pleurobrachia about in state of Fig. 47, seen from the actinal was ¢ 2 : 5

Adult Pleurobrachia, natural size, Sho broad and narrow side

Adult Pleurobrachia in a natural attitude, natural size. a : : ;

Young Ipyra ROSEOLA, seen from the narrow side

Fig. 52, seen from the abactinal pole 2 3 ° ° 0

Tiana Idyia, with distinct ambulacral tubes, seen Gorn ne narrow eae

Fig. 54, seen from the abactinal pole ° : >

Somenhat more advanced than Fig. 54, seen fom ae inom ile : :

The long chymiferous tubes eioadl to the level of the actinostome . 6

The long chymiferous tubes have united with the lateral tubes; first trace of the
send Revo of the long tubes

The short ambulacra have nearly united with the cironline fate

The circuit is now complete between the short and long ambulacra ; ee spurs or
ramifications of the chymiferous tubes are numerous, sesentsltine somewhat
those of the adult : 5

Fig. 57, seen from the abactinal pole 2 : 5 : 5

Adult Idyia, reduced in size one half. (L. Reaedte, ye .

Ipyorsis CLARK, seen from the broad side. (L. Agassiz.) . af OU eta an

Fig. 63, seen from the abactinal pole. (L. Agassiz.) . : .

Profile view of AURELIA FLAVIDULA, much reduced. (L. Iespestina) : 5

Abactinal view of Aurelia flavidula. (lL. Agassiz.) .

CYANEA ARCTICA, very much reduced. (lL. Agassiz.) . : : . aque

PELAGIA CYANELLA. (lL. Agassiz.) . Ses > 6 oe

DaAcTYLOMETRA QUINQUECIRRA, reduced about one fereih 5 :

Profile view of CAMPANELLA PACHYDERMA 3 5

Actinal view of Fig. 70. . 5 : : ° Sabet

A somewhat more Taanithed view of Fig. i 0 0 c ° :

View of part of the actinal surface . . 5 . :

Magnified profile view of portion of the base of a onal d ° 5 0

View of basal portion of tentacle, seen from above .

Profile view of TRACHYNEMA CAMTSCHATICUM.

One of the genital organs . 5 : 5 3 0
Section of Treetmena ° : 6

Chymiferous cavity at the end of the pelatinons proboscis

View of Trachynema trom above . 6 : :

Adult female TRACHYNEMA DIGITALE, seen in protle 5 0 Seth
Actinal view of the veil and circular tube of a very young eine 0
Profile view of a part of the circular tube : 5 5 0

Profile view of a young Trachynema, about one eighth of an Ann in height
Somewhat more advanced than Fig. 84 . :

Young Trachynema, measuring over one third of an glh in neha

? Larrore SCUTIGERA. (L. Agassiz.) ¢ ee Bey Ph : :
HALICLYSTUS AURICULA, seen from the nafiel pole . 5 ° 5 6
Different attitudes of Haliclystus auricula, attached to eel-grass :

Young Haliclystus auricula, magnified . ; 0

TIAROPSIS DIADEMATA, natural size. (L. Agassiz.) . : : ; . 0
Young Tiaropsis, having twenty-four tentacles. 4

anne Tiaropsis, irene forty tentacles. (lL. Agassiz.) . 0

Two marginal agniaallas of OCEANIA LANGUIDA, with a sention of the cheung fae
Magnified view of the actinostome

53

100.
101.
102.
103.
104.
105.
106.
107.

107%.

108.
109.
110.
111.
112.
113.
114,
115.

116.
117.
118.
119.
120.
121.
122.
123.
124.
125.
126.
127.
128.
129.
130.
131.
132.
133.
134.
135.
136.
137.
138.
139.
140.
141.
142.
143.

144.
145.
146.
147.
148.
149.

150.

LIST OF THE WOOD-CUTS.

Young Medusa of OcEANIA LANGUIDA, immediately after escaping from the re-

productive calycle : 3 - : : i a ; é
The same, seen from the actinal pole . 9 3 ; 9 5 0 ° 0
Somewhat more advanced Medusa . 5 zi ‘ : : 2 a
Quarter of the disk of a still more advanced Ocenia 6 A c 3 .
Adult Oceania languida, natural size. 5 ; . 5 F 3 : r
Magnified view of an ovary . : 5 5 ‘ : 2
peesine attitude sometimes assumed by the Meds z . : 6 c 5
One of the four lips of the actinostome of OCEANIA GREGARIA : 5 5
EUCHEILOTA VENTRICULARIS . é 3 a 3 2 0 9
More magnified view of a quarter of ‘ike Fae 3 : 0 3 : : 6
Eucueriora DUODECIMALIS °
Junction of one of the chymiferous fies eth the Gaon fe 5
Female Medusa of Eucheilota duodecimalis . 0 : 0

CLYTIA BICOPHORA, immediately after its escape from the sgiieinetine aldle
A somewhat older Medusa. °

An adult Medusa, measuring a quarter BE an nal . 0 0 2 c

Sterile Hydra and nepradinasine calycle, seen from the broad side . 5

Reproductive calycle of PLATYPYXIS CYLINDRICA, seen from the broad side .

The same, seen from the narrow side. é ‘ 3 : z

Sterile Hydra of Platypyxis eylindrica.. (L. Avgossia: y" 5 0 .

A Evcorr DIAPHANA, seen in profile, just aha its escape Bean the repeed ane
ealycle . 6 - 6 5 3 i 5

Quarter of the disk of iiies same, seen oom above s : c : 3 °

A more advanced Eucope, with the second set of tentacles : :

An adult Eucope, seen in profile
Quarter of Fig. 118, more magnified . . 0
Magnified view of the circular tube of a young Eucope . : .

Spermaries of Eucope : ¢ : . : : - :

Female genital organs. 2 9 2 5 0 0

Proboscis of an adult Medusa. : : : 0 é . ° b
Hydrarium of Eucope diaphana, natural size . : : : 3 : 5
Magnified view of a sterile Hydra and reproductive eal clenae ° °
Magnified view of part of main stem of EUCOPE POLYGENA .

EvcorE PYRIFORMIS, seen in profile : : : : : 6 . °
Quarter-disk of same Medusa. : 5 ; 3 5 6 ; é 2
Portion of a Hydrarium of Fig. 127 . 2 5 : 0 : . :
Quarter-disk of EUCOPE ARTICULATA . ‘ ‘ ; 3 ‘ ; Ps
Portion of a Hydrarium of Eucope articulata . 0 : 3 5
Hydrarium of EucoPE FUSIFORMIS . 0 0 2 c c z 5
Quarter-disk of the Medusa of Fig. 132 . A : : 5 ; 5 F

Portion of stem of Hydrarium of OBELIA COMMISSURALIS .
Quarter-disk of the Medusa of Fig. 134 °
Profile view, natural size, of RHEGMATODES TENUIS

Quarter-disk of Fig. 136, seen from the actinal side . i P
Magnified portion of the circular canal . : : E ° : .
RHEGMATODES FLORIDANUS, natural size. (Li. Agassiz.) ° 3 : :

Actinostome of STOMOBRACHIUM TENTACULATUM, magnified
Stomobrachium tentaculatum, seen from the abactinal pole, natural size
Same as Fig. 141. seen in profile . 2 :

Portion of the disk of Hatopsis OCELLATA, seen Seon the eeceenal eels some-
what reduced 0 ¢ ° . z 5 . :

Cavity from which the chymiferous bes mainte 2 E ‘ :

Profile, natural size, of Halopsis ocellata : 5 ; 6 S

Magnified part of circular tube .

Magnified view of one of the eyes . c eat hrs : : : :

Vong Halopsis ocellata, natural size .
Young Halopsis ocellata, one fifth of an inch in height
Magnified portion of circular tube of Fig. 149 . 5 . 2

100
100
100
101
101
101
101
101

LIST OF THE WOOD-CUTS.

Profile view, somewhat magnified, of HALOPsIs CRUCIATA . P A 5
Natural attitude of the same Medusa (Fig. 151) . 5 : :
Abactinal view of ZYGODACTYLA GROENLANDICA . . :
Profile view of Fig. 153, half natural size. . : 9 call S33 0
Portion of the circular tube . 5 5 . c . 0 6
Young Zygodactyla, greatly magnified . 2 C . 5 5 6
Profile view of ZYGODACTYLA CRASSA, somewhat reduced in size. 0
Quarter-disk of Zygodactyla crassa . 0 : 6
Portion of the disk of ZyGODACTYLA CYANEA, Ween the sibpatiinel pole. ‘L. Ag.
. CREMATOSTOMA FLAVA, in profile . : ae : 0
Portion of the disk of AQuOREA ALBIDA, from the abactinal rails ,
A natural attitude of Zquorea albida . . : oi ens aau-S
Maenified view of the marginal tube : E 6 6 : 3 3 6
EIRENE C@RULEA. (lL. Agassiz.) 0 : : 5 : 0 ° 6
TIMA FORMOSA, half natural size. 3 3 ; 5 : 0 3
Quarter of the disk, from the abactinal pole, naturalsize . . . .
Digestive cavity and actinostome . : ¢ 3 6 0 6
peccen of the ovary . : 0 c 3 5 > . 0 :
Magnified portion of the circular tape 9° ° 6 . ° : c :
Young Tima formosa, natural size. : . . . 5 - : :
Digestive cavity of Fig. 169 . 0 : 0 : 6 A 5 6 0
aren Planule of Tima 0 : 6 5 0 : :
Stas Hydra of the tuft of a Time Hy Shentian, greatly magnified . 5 0
Pr ofile of EuTIMA Lrverpa, reduced in size 7 0 . 0 0 °
Quarter-disk of Fig.173 . 5 es 3 : é 0
Magnified view of Spualbosets and genital organs . . 6 : . o-
Magnified portion of a part of the circular cere ° 5 3 5 :
Maenified marginal capsule . ° 5 5 5 5 2 . 0
Magnified view of the rudimentary tentacles . . . 3 : 0
Profile view, somewhat magnified, of POLYORCHIS PENICILLATA : °
Ovaries of one of the cae tubes . : ° 0 : ° :
Section of bell. . 0 5 : 5 a 5
Part of disk of Fig. 179, seen ena the Streatiel walle . 0 : 5 6
Two of the maemetill tentacles in a contracted state . 9 0 0
Adult Medusa of LAr@a CALCARATA . : 0 0 3 . : :
One of the ovaries and the actinostome ° 0 : 0 c c .
Actinostome, actinal view g é : 5 :
Magnified view of a portion of the crealas tae 5
Nermortome and rudimentary ovaries, seen in profile. 6 0 O
Different attitude of Medusa of Fig. 184 . ° : : . 0
Hydrarium of Lafoea calearata. 0 9 0 ° ° . . 6
Reproductive calycle . : 0 5
Medusa immediately after its eco om the repr eon eagle 0
Medusa somewhat more advanced, from the abactinal pole . 0 : :
Young Medusa still further advanced than Fig. 193. : : 0 ° 0
LAODICEA CELLULARIA . . : : : : : : : 0
One of the lips of the actinostome . 0 2 : 5 : 0
GONIONEMUS VERTENS, attached by its ental 0 9 . 0
The same in motion, natural size. F : ; 5 5 9 :
Base of a contracted tentacle 3
A portion of the genital organs z o ° 0 : 5 0
One of the chymiferous als and half the Tasahine cavity .
Profile of MELIcERTUM CAMPANULA, sehanrell size .
Profile view of a very young Melicertum campanula. . 0 : 5
Half the disk of the same, seen from the actinal pole
Young Melicertum, having only four completely formed dramlienone fates :
Saag seen from the abactinal pole . : 5 0
Magnified view of the two chymiferous tubes and genital lew .
Mode of carrying the lips of actinostome . : ca Big Buh h Wot dM to

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LIST OF THE WOOD-CUTS.

Magnified view of marginal tentacles . 5 ; “ 0 5 . 5 5
Spherical embryo. : : : : : 0 . . .
The same, somewhat more advanced 5 i 9 ° 0 . 5 é
The same before it becomes attached 9 9 R f f

Group of embryos attached, in different stages of dosalopmen

Different stages of growth beyond those of Fig. 213.

Profile of Meticerrum GEORGICUM, Teil size : 9
Digestive cavity and point of junction of the chymiferous sib 5 9 5
SATO RATA LACINIATA, having eight tentacles 5

Quarter of the disk of a young Stan oli a, with sixteen large lonicules
Young Medusa somewhat more advanced than Fig. 216° : :
Different stages of actinostome intermediate between that of Figs. 215° and 219
Young Staurophora, having the aspect of the adult

Profile view of PrycHoGENA LACTEA, somewhat reduced

Magnified view of the genital organs, seen from the abactinal pole : 0
Same as Fig. 221, seen in profile. . 0 0 :
Aaiinasient® : 0 ° 3 0 0 9

Magnified base of ‘egmipallen and dbipstewall appendages :
Cluster of DyNAMENA PUMILA. (L. Agassiz.)
Maenified portion of stem of Fig. 225. (lu. Agassiz.)

Young Nemorsis Bacuet, with four tentacles . . 0 5 : :

Somewhat more advanced Nemopsis . : ° 0 5 : :

Magnified view of the sensitive bulb. 0 3 : °

Nemopsis i in which the genital organs extend a Feonbiderstle distance Alone the
chymifer ous tubes 5 9 9 . .

Magnified view of the genital organs, the dchinostome and He Gea tentacles .
Magnified profile view o adult BOUGAINVILLIA SUPERCILIARIS .
Hydromedusarium of Bougainvillia .

Young elongated Medusa. 0 D :

Somer yhat more advanced than Fig. 234 3 : 3 9

Appearance a short time before separating from the stem

Same as Fig. 236, expanded

° .

Young Rowmetiaralle, immediately after its Ber siftern fom the cyan ameduaaneen
Magnified view of sensitive bulb Q : ° : 0 0 :

Tentacular bulb, with young tentacles . . . . : :
Adult MarGELIS CAROLINENSIS, seen in profile, Toned).

Digestive cavity, genital pouches, oral tentacles, and actinostome . 5 5 2

Sonstitre bulb at base of one of the chymiferous tubes
Young Margelis, having only two marginal tentacles at the base ef sacl Ohya’

erous tube 0 9 ; 6
Young Margelis, seen from the eactnal pole, i in condition of F Fig. 244. . 3
Proboscis of a Margelis, having already six tentacles at each sensitive bulb
Hydrarium, greatly reduced in size. 5 0 . 5 : 5
Magnified heads and Medusz buds of Margelis earalitensis 5 6
Female Medusz buds of EupenDRIUM DISPAR, in different stages of development
Part of a male colony of EUDENDRIUM TENUE, magnified.

Adult male of Lizz1a GRATA, seen in profile, magnified . : 6
Quarter-disk of a young Lizzia é : 6 i 5 4 ci :
Magnified view of sensitive bulb . 0 6 4 0 5 : 9 : 5
Taibo of male Lizzia, magnified . 0 9 ° : 0

One of the four lobes of the actinostome, seen from shove F : 6 é %
Actinal view of proboscis of young Lizzia : 3 ; 5 0 2
Actinal view of proboscis of an older specimen. 5 2 5 0 :
Abactinal view of Fig. 257, somewhat less magnified ° : : :

Adult Disomanewa FULGURANS, navwontifaal 3
Magnified proboscis, showing young Medus of the second end thir d moan fione
TURRIS VESICARIA, mater size, seen in profile . ¢ 0 o 7 o :
The same, with the bell contracted . 0 : : 5 . : :

A portion of the disk, seen from the abactinal ale 5 0 : : : E

133
134
134
124
134
134
135
135
136
136
136
136
137
138
138
138
138
138
141
141
149
150
150

150
151
153
154
154
154
154
154
154
155
155
156
156
156

157
157
158
158
158
159
160
161
161
161
162
162
162
162
162
163
163
165
165
165

LIST OF THE WOOD-CUTS.

Magnified profile view of genital organs and actinostome . . . .

Magnified view of a part of a anyamlenare tube 0 9 ° 6

Base of one of the chymiferous tubes, and part of the circular nie

One of the tentacles, in a profile view . 5 5

One of the tentacles, seen from the abactinal mole ° 0 o

Young TURRITOPSIS NUTRICULA, with four marginal tentacles

Somewhat more advanced, having sixteen tentacles. 5 : : .

SroMoTOCA ATRA, somewhat magnified, seen in profile . : . co ae

Magnified view of genital organs . : : : : . : : Ser so

Stomotoca atra. 0 : 5 : 0 : 2 .

CLAVA LEPTOSTYLA. G. Aesestas) « 5 5
. Young WILLIA ORNATA, having only the pecondl set of feminlien Hevelonedl

Senne Willia, nearly in the stage of Fig. 276, seen from the abactinal pole. .

Profile view of a young Willia. : . 0 3 ° 3 c 5 0

Part of the circular tube. . 3 9 0 : ° 0

View of ovary of Fig. 276 0 ; c ° : 0 :

Same as Fig. 278, seen from the baeicel awe : ° c

PROBOSCIDACTYLA FLAVICIRRATA : oe

Actinostome and digestive cavity .

Portion of disk to Shor mode of Theanine of Chyaiterne tubes, onl ‘plbes con-
taining lasso-cells, as in Willia . 2 : 0

Adult CorYNE MIRABILIS, seen in profile. (L. Were) 3 6 9

Coryne, with proboscis contracted. (LL. Agassiz.) 0 :

Coryne, with expanded proboscis. (L. Agassiz.) . 0 :

Cluster of Hydraria of Coryne mirabilis. (LL. eossics) 2 c a

Young Hydrarium of Coryne. (L. Agassiz.) .

Magnified view of head, with Medusz buds iftauanl (L. apes) «

CorRYNE ROSARIA, natural size 0 .

Hydromedusarium of SyNpICTYON RETICULATUM, eral maalfedl 0

Syndictyon reticulatum, immediately after it has become Read from the Hydro-

medusarium, in profile. 5 2 - ° 5
One of the tentacles of Fig. 291, vimeattied 5 c : . a sO
Sensitive bulb of Fig. 291 . 5 § , F 5 3 . : : .
Digestive cavity of Fig. 291. 2 0 c 0
Fig. 291, from actinal pole . 0 0 : 0 5 0 0 0 : 5
Fig. 291, from abactinal pole .- eee i “Oe : : 0 0
Part of net-work of lasso-cells of surface of spherosome
Adult Medusa in a natural attitude . 5 c 5 5 ° 6
Same Medusa (Fig. 298) with the tentacles aonraial © ° 9 6
Actinostome of adult Medusa . . : 0 5 0 c 0 0 0
Young DipuRENA CONICA . : : 0 3 0 5 0 0 0 0
Digestive cavity of a young Dipurena conica . 5 ° o ° 5 0
Tentacle of Dipurena conica 3 0 . :
Digestive cavity of a Medusa in which the Coneeetion’ has rentiy senaated the
upper and lower halves. 0 6 5 E 0
Adult Dipurena conica, in which the two digestive cavities are idly senetiod
Profile view of half a young GEMMARIA GEMMOSA . : : : 5

Profile view of GEMMARIA CLADOPHORA, magnified
Quarter-disk of same, seen from the abactinal pole.

Actinostome of Gemmaria, enlarged . 5) tS Oa 2

Cluster of lasso-cells of the marginal tentacles.

Fertile Hydra of PENNARIA TIARELLA . © ° :

Medusa distended by eggs . 0 . 0 5 9

Profile view of Medusa of Pennaria Garcia 0 : 3 0 0 6
Different attitude of the Medusa, seen from the actinal walle,

Fig. 313, seen from the abactinal pole. 0 : 0 3 0
EvpPHYSA VIRGULATA, seen in profile. c : : 5 5 é
Magnified proboscis of Fig. 316 0 : 0 : : 0 0 0

Actinal view of Euphysa virgulata. 6 5 0

LIST OF THE WOOD-CUTS.

One of the tentacles, seenin profile . . . . atieys 5 A -
Profile of EcropLeuRA OCHRACEA, magnified . . Ay. 0 ary it's
The same, seen from the abactinal pole 4 : : 5 0 : ' 5
The same, seen from the actinal pole 5 F ° 0 5 . :
The base of one of the tentacles, magnified . athelnes : . : ; 5
Medusa of CoRYMORPHA PENDULA, seen in profile. (H. J. Clark.)
Single Hydra of HysBocopon Prorirer. (L. Agassiz.) . 2 : :
Hybocodon prolifer, seen from the broad side. (i. Agassiz.) . 5 5 0
Hybocodon prolifer, seen facing the long tentacle. (4. Agassiz.) 3 °
Medusa bud of Hybocodon prolifer. (du. Agassiz.) . : : é 3 5
Part of male community of Hypractinia potyciina. (L. Agassiz.) . :
Part of female community, (lL. Agassiz.) ° : ; o :
Oil-float of NANOMIA CARA, magnified . . 0 . A c
Nanomia cara, natural size. 4 Se tee ot al :
Swimming-bell of Nanomia cara, seen athe the side of the salah: chymiferous
tubes c 2 : : . 0 . 2 2 < 5
The same bell, from the eet pole . . 5 6 C 2 c f 5
Portion of the same bell, seen from the abactinal pole. . oo C
Same bell as Fig. 333, seen from the other side. 5 : : So :
Group of saintly in different stages of development . 5

Cluster of Medusa (Polyps) of first naval formed, with knob-shaped venindles :
Enlarged view of the knob of a tentacle of the first kind of Meduse . E
Second kind of Medusz, with cork-shaped tentacles. : 5 2 0 -
Third kind of Medusa, having a single thread-like tentacle. A

2. Cluster of Medusze Gane? in different stages of development, Betare) the oe

pearance of the scale and of the yoni: 0 : : .
Knobs like those of Fig. 339, in different stages of development . .
Same kind of knob, still further developed . —. - 5 - : 2 .

Young scale, seen from different sides. 0 0 : : 6
Youngest Nanomia found swimming on surface . 5 . - 5 ‘
Samer more advanced ; é , 0 : “
The terminal Hydra is open, tentacles are Berelered as alls as clusters ot al
swimming-bells . ‘ : C : : : . cl 5
Still more eaeerced Nanomia . 0 ¢ : 5
Young Nanomia, where we find several Media of the first endl j a 5
PHYSALIA Aretuusa Til. (L. Agassiz.) . 0 .
Bunch of single Hydre and clusters of Meduse of Pheeala! (L. Agassiz)
Bunch of Hodes! (L. Agassiz.) . : c -
Bunch of Medusz in various stages of dowseoments (L. Reapesing E C
Enlarged view of one of the fertile Hydre of VELELLA MuTICA. (L. Agassiz.)
Velella, seen from below, to show the Hydre. (i. Agassiz.) . : :
Magnified view of a free Medusa of Velella mutica. (iL. Agassiz.) . 2 :
Magnified view of extended Hydroids of MittEPoRA ALCICORNIS. (L. Agassiz.)
Bence of Millepora alcicornis, natural size. (L. Agassiz.) . c c - :

Transverse section of a branch. (L. Agassiz.) io, SSR aire ere

NORTH AMERICAN ACALEPHA.

7 iD _ a mn
i 7 = : flee i)
nT -
ral rs
= Sy
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: f
; > f
‘ ;
nw) 8
\

fa

BIBLIOGRAPHY.

No memoirs published previous to 1860 have been included in this list, as they can
be found in Acassiz’s Bibliographia Zoologie et Geologie, and in Carus and ENGEL-
mann’s Bibliotheca Zoologica.

Agassiz, A.

Agassiz, L.

“ce

“

The Acalephian Fauna of the Southern Coast of Massachusetts, Buzzard’s Bay ; in
Proc. Bost. Soc. Nat. Hist., VIII. p. 224. 1861.

Mode of Development of the Marginal Tentacles of the Free Meduse of some Hy-
droids ; in Proc. Bost. Soc. Nat. Hist., UX. p. 81. 1862.

Nanomia cara; in Proe. Bost. Soe. Nat. Hist., TX. p. 181. 1863.

Halopsis ocellata ; in Proe. Bost. Soc. Nat. Hist., IX. p. 219. 1863.

Contributions to the Natural History of the United States (Acalephe). Vols. II.
and IV. Boston. 1860-1862.

Methods of Study in Natural History. Boston. 1863.

ALDER, J. Supplement to a Catalogue of Zoophytes of Northumberland and Durham ; in Trans.

“

“

it

Tyneside Nat. Club, V. p. 225.

“ Description of some New and Rare Zoophytes found on the Coast of Northumberland ;

in Ann. & Mag. N. H., IX. p. 311. 1862.

“ Observations on British Zoophytes ; in Edinb. New Phil. Journ., p. 144. 1862.
“Descriptions of a Zoophyte and two Species of Echinodermata new to Britain; in

Ann. & Mag. N. H., V. p. 73. 1860.

ALLMAN, J. G. On Laomedea tenuis; in Rep. Br. Ass. Ady. Se. for 1859, p. 143. Trans. See.

“

On the Generative Zooid of Clavatella; in Br. Ass. Adv. Se. for 1862, p. 100.

Note on the Structure and Terminology of the Reproductive System in the
Corynidz and Sertularide ; in Ann. & Mag. N. H., VI. p. 1. 1860.

On the Reproductive System in the Hydroidea; in Rep. Br. Ass. Adv. Se. 1863.
London. 1864. p. 351.

Note on Carduella cyathiformis ; in Ann. & Mag. N. H., VI. p. 40. 1860.

On the Structure of Carduella cyathiformis, a Contribution to our Knowledge of
the Lucernariade ; in Trans. Mic. Soc., p. 125. London. 1860.

Notes on the Hydroid Zoophytes ; in Ann. & Mag. N. H., VIII. p. 168. 1861.

Notes on the Phosphorescence 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-
ide ; in Proc. Roy. Soc. Edinb., IV. p. 519, Jan. 1862. Same in Edinb.
New Phil. Journ., 1862, XV. p. 287.

On the Structure of Lucernariadz ; in Rep. Brit. Ass. Adv. Sc. for 1859, p. 143.
London. 1860. Trans. See.

On Dicoryne stricta, a new Genus and Species of the Tubularide ; in Rep. Br.
Ass. Adv. Se. for 1859, p. 142. London. 1860. :

Notes on the Hydroidea. I. On the Structure of Corymorpha nutans. IL. Diag-
nosis of new Species of Tubularide obtained, during the Autumn of 1862,
on the Coasts of Shetland and Devonshire; in Ann. & Mag. N. H., Jan.
1863, XI. p. 1. be

Notes on the Hydroidea; in Ann. & Mag. N. H., July, 1864.

On the Structure of Corymorpha nutans; in Rep. Br. Ass. Adv. Sc. for 1862,
p- 101. Trans. See.

4 BIBLIOGRAPHY.

AtiMmAN, J. G. On the Construction and Limitation of Genera among the Hydroidea; in Ann.
& Mac. N. H., XIII. 1864.

ce be On some new British Tubularidie ; in Rep. Br. Ass. Adv. Se. for 1862, p. 101.
« a Rep. on the Reprod. Syst. in the Hydroidea; in Rep. Br. A. A. S. f. 1863, p. 351.
“ “ On the Occurrence of Amzbiform Protoplasm, and the Emission of Pseudopodia

amone the Hydroidea; in Ann. & Mag. N. H. March, 1864.

Beneven, J. P. van. On the Strobilation of the Scyphistomata; in Ann. & Mag. N. H., 1860,
V. p. 504. From Acad. Belg.

Borck, Cur. Beskrivelse over en Tubularie fra Belsund paa Spitzbergen, Tubularia regalis, in
Forhandl. Vid. Selsk. (Aar 1859.) Christiania. 1860. pp. 59, 66, 151.

Bronn, H. G. Die Klassen u. Ordnungen des Thier-Reichs (Actinozoa). Leipzig u. Heidel-
berg. 1860.

Busk, G. Onanew Hydroid Polype belonging to the Genus Cordylophora All., discovered by
Senator Kirchenpauer of Ritzebiittel ; in Mic. Jour., p. 283. 1861.

CLaparepeE, A. R. E. Beitriige zur Fauna der Schottischen Miiste ; in Zeits. f. Wiss. Zool., X.

p- 401. 1860.

“ a Beobachtungen itiber Anatomie u. Entwickelungsgeschichte Wirbelloser
Thiere. Leipzig. 1863.
ce ae in Bibliog. Univ. de Geneve, XV. p. 150. 1862.
Crark, H. J. Lucernaria, the Ccenotype of Acalephe ; in Proc. Bost. Soc. N. H., p. 47. 1862.
03 Prodromus of the History, Structure, and Physiology of the order of Lucernariz ;
in Journ. Bost. Soc. Nat. Hist., VII. 1863.
« Us Lucernaria, ....; in Am. Journ. Arts and Sciences, May, 1863.
te ce a ....3; in Ann. & Mag. N. H., XII. p. 19. 1863.
& e in Agassiz’s Contrib. Nat. Hist. U. 8., Vols. III. and IV. passim.
“ “ Tubularia not Parthenogenous ; in Am. Journ. Arts and Sciences. Jan. 1864.

Cuaus, C. Neue Beobachtungen iiber die Structur u. Entwickelung der Siphonophoren ; in Zeit.
f. Wiss. Zool., XII. p. 536. Jan. 1863.
« «~~ Ueber Physophora hydrostatica, nebst Bemerkungen iiber andere Siphonophoren ; in
Zeit. f. Wiss. Zool., X. p. 8. 1860.
Dawson, J. W. Zoological Classification, or Celenterata and Protozoa versus Radiata; in Can.
Nat. & Geol., VII. p. 438.
ce a Elementary Views of the Classification of Animals; in Can. Nat. & Geol.,
Aug. 1864.
Epwarps, H. Mizner et Hare, J. Histoire Naturelle des Coralliaires, T. I. Paris. 1860.
Furr, C. B. In Journ. Portland Soc. N. H., I. pp. 64, 91. 1862.
2 Report on Marine Zodlogy ; in Second Annual Report Nat. Hist. & Geol. of the
State of Maine, p. 129. 1863.
GrGEenBAuR, C. Neue Beitriige zur Niheren Kenntniss der Siphonophoren ; in Nova Acta Acad.
Nat. Cur. 1860.
Gossr, P. H. Evenings with the Microscope. New York. 1864.
Ce Ge The Blue Cyanea; in Intellectual Observer, Oct. 1863.
% c On the Lucernaria cyathiformis of Sars; in Ann. & Mag. N. H., V. p. 480. 1860.
GREENE, J. R. Manual of the Sub-kingdom Celenterata. London. 1861.
3 ee Recent Contributions to the Literature of the Sub-kingdom Ceelenterata ; in Nat.
Hist. Rev., I. 1861.
ie ae Review of Agassiz’s Contrib. to Nat. Hist. U. S.; in Nat. Hist. Rey. III. 1863.
us ce On Sertularia tricuspidata, and on the Genus Huxleya; in Ann. & Mag. N. H.,
VY. p. 431. 1860.
© a A Word on Embryology, with Reference to the Mutual Relations of the Sub-
kingdoms of Animals; in Rep. Br. Ass. Ady. Sc., p. 132. 1860. Trans. Sec.
Gruse, E. Ausflug nach Triest u. dem Quarnero. Berlin. 1861.
Hrxcxs, Tuos. On New Australian Hydrozoa; in Ann. & Mag. N. H., VIL p. 279. 1861.

G ub On the Production of similar Medusoids by certain Hydroid Polypes belonging to
different Genera; in Rep. Br. Ass. Ady. Se. f. 1862, p. 107. ‘Trans. See.

oe ce On Clavatella, a new Genus of Corynoid Polyps, and its Reproduction ; in Ann.
& Mag. N. H., VIII. p. 73. 1861.

a ae A Catalogue of Zoophytes of South Devon and South Cornwall; in Ann. &

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

BIBLIOGRAPHY. 5

Hincxs, Tuos. Catalogue of Zoophytes of South Devon and South Cornwall; in Ann. & Mag.
N. H., IX. pp. 22, 200, 303, 467. 1862.

« ae On the Production of Similar Gonozodids by Hydroid Polyps belonging to dif-
ferent Genera; in Ann. & Mag. N. H., X. p. 459. 1862.

& a Catalogue of the Zoophytes of South Devon and South Cornwall; in Ann. &
Mag. N. H., X. p. 360. 1862.

ce “ On some new British Hydroids ; in Ann. & Mag. N. H., XI. p. 45. 1863.

«s a On the Development of the Hydroid 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. Ass. Adv. Science, p. 145. 1861.
Trans. Sec. F
Hover, Gro. Contributions to the Marine Zodlogy of Seaham Harbor. Occurrence of Cory-
morpha nutans at Seaham; in Trans. Tyneside Nat. Field Club, V. Pt. II.
p- 78. 1861. :
co cc On a new Hydroid Zoophyte (Podocoryne Alderi) ; in Trans. Tyneside Nat. Field
Club, V. Pt. I. p. 82. 1861.

Hoveuton, W. On the Hydra rubra of Mr. Lewes; in Ann. & Mag. N. H., V. p. 228. 1860.

Huxiey, Taos. H. Elements of Comparative Anatomy. London. 1862.

Jacer, G. Ueber das spontane Zerfallen der Siisswasserpolypen nebst einigen Bemerkungen
uber Generationswechsel ; in Sitzb. d. Akad. Wien., XX XIX. p. 321. 1860.

Jourpary. Note sur les organes génitaux de la Cyanea aurita Cuv. ; in Comptes Rendus, Vol.
LV. p. 834. 1862.

Kererster, W. Untersuchungen ueber niedere Seethiere ; in Zeits. f. Wiss. Zool., XII. p. 1.

June, 1862. IJ. Ueber die Gattung Lucernaria O. I’. Miiller ; in Zeits. f.
Wiss. Zool., XII. p.1. I. Ueber einige Quallen; in Zeits. f. Wiss. Zool.,
XII. p. 26.

we “« —u. Enters, E. Auszug aus den Untersuchungen vom Mittelmeer ; in Wieg-
mann’s Archiv, 1860. I. p. 324.

Gb «Same in Nachricht. der Univ. u. Ges. d. Wiss. Gottingen, No. 23, p. 25. 1860.

Kircuenraver. Die Seetonnen der Elbmiindung. Ein Beitrag zur Thier u. Pflanzen Topo-
graphie ; in Abhandl. d. Naturh. Vereins, [V;- Hamburg. 1862.

Kroun, A. Beobachtungen iiber den Bau u. die Fortpflanzung der Eleutheria Quatref.; in

Wieg. Archiv, 1861. I. p. 157.
“ Observations on the Structure and Reproduction of Eleutheria Quatref.; in Ann. &
Mag. N. H., IX. p. 1. 1862.
Lacaze-DuTuters, H. Embryogénie des Rayonnés, Reproduction généagénitique des Porpites ;
in Comptes-Rendus, LY. p. 851. Noy. 1861.
fe “On the Reproduction of Porpita; in Ann. & Mag. N. H., p. 186. 1862.

Levucxkart, R. Bericht ueber die Leistungen in der Naturgeschichte der niederen Thiere ; in
Archiv fiir Nat. 1860-1863.

Lewes, G. H. New British Species of Hydra; in Ann. & Mag. N. H., V. p. 71. 1860.

Litken, Cur. F. Forvandlingerne i Dyreriget ; in Tids. for pop. Frem. af Nat. 1861-62.

McAnprew, R. List of the British Marine Invertebrate Fauna; in Rep. Br. Ass. Ady. Se.,
p- 217. 1860.

Metrennermer, C. Ueber die Gesichtsorgane des violetten Seesterns, nebst Beobachtungen
uber die Ohrenqualle u. Versuchen iiber die Motilitiit derselben; in Archiv f. Anat. u.
Phys., p. 214. 1862.

Meyer, A.u. Mosius, K. Kurzer Ueberblick der in der Kieler Bucht von uns beobachteten wir-
bellosen Thiere, als Vorliufer einer Fauna derselben ; in Archiv f. Nat., 1862. I. p. 229.

Mttter, Fr. Cunina Kollikeri F. Mill. ; Beitrag zur Naturgeschichte der Hginiden; in Archiv

f. Nat., I. p. 42. 1861. :

“ « Polypen it. Quallen v. Santa Catharina, Olindias sambaquiensis; in Archiv f. Nat.,
1861. I. p. 312.

su “ Ueber die Angebliche Bilateralsymmetrie der Rippenquallen ; in Archiv f. Nat.,
1861. I. p. 320.

a “Ueber die System. Stellung der Charibdeiden ; in Archiv f, Nat., 1861. I. p. 302.
ce “On the Systematic Position of the Charibdeide ; in Ann. & Mag. N. H., X. p.6. 1862.
a “Ueber die Ursache der Stromungen in der Leibeshdle der Sertularien; in Archiv

f. Nat., I. p. 34. 1863.

6 BIBLIOGRAPHY.

Murray, A. Descriptions of New Sertularide from the Californian Coast; in Ann. & Mag.
N. HL, V. p. 250. 1860.
ue “ On Sertularia trieuspidata ; in Ann. & Mag. N. II., V. p. 504. 1860.
Norman, A. M. On Undeseribed British Hydrozoa, Actinozoa, and Polyzoa; in Ann. & Mag. N.
H., XIII. p. 82. Jan. 1864.
x a On the Crustacea, Echinodermata, and Zoophytes obtained in a Deep-Sea
Dredging, off the Shetland Islands in 1861; in Rep. Br. Ass. Ady. Sc.,
p- 151. 1861. Trans. See.

Packarp, A. §.Jr. <A List of Animals dredged near Caribou Island, Southern Labrador ; in
Canadian Nat. & Geolog. Dec. 1863.

PaGenstecner, H. Untersuchungen iiber niedere Seethiere aus Cette; VIII. Zur niheren
Kenntniss der Vellelidenform Rataria, nebst Betrachtungen tiber die Velleliden im Allge-
meinen ; in Zeits. f. Wiss. Zool., XII. p. 496. Jan. 1863.

Peacnu, C. W. On the Zoophytes of Caithness; in Rep. Br. Ass. Ady. Se., p. 155. 1859,
Trans. Sec.

Peters, W. C. H., Carus, J. V.,& Gersrarcker, C. E. A. Handbuch der Zoologie. Leip-
zig. 1863.

Price, Jonny. On the Genus Cydippe ; in Rep. Br. Ass. Ady. 8. 1859, p. 155. London. 1860.
Trans. Sec.

QuatrrEFAGES, A. DE. Métamorphoses de ’homme et des animaux. Paris. 1862.

Sars, M. Ueber das Ammengeschlecht Corymorpha und seine Arten, nebst den von diesen aufee

ammten Medusen ; in Archiv f. Nat., 1860. I. p. 341.

“ « Bemaerkninger over norske Ceelenterater; in Vidensk. Selks. Forh., p. 140. Chris-
tiania. 1860.

« « Tegninger af og Oplysninger om nogle Celenterater fra Norges Kyster; in Skand.
Naturf. Mode i Kjobenhavn. 1860. p. 690.

« «Qn the Nurse Genus Corymorpha and its Species, together with the Medusze produced
from them; in Ann. & Mag. N. H., VIII. p. 353. 1861.

« « Bemaerkninger over d. norske Hy droider; in Videns. Selks. Forhand. 1862.

“ « Geologiske og zoologiske Jagttagelser anstillede paa en Reise i en Deel af Trondhjems
Stift. Christiania. 1863.

Sresotp, K. Tu. vy. Ueber Parthenogenesis. Miinchen. 1862.

Semeer, K. Reisebericht von Dr. Karl Semper, Briefliche Mittheilung, an A. Kolliker; in Zeits.
f. Wiss. Zool., X. p. 558.

Sreenstrup, J. B. Om de ved Norges Kyst forekommende Arter af Slaegten Lucernaria ; in

Forhand. Vid. Selsk. i Christiania, Aar 1860. Christiania. 1861. p. 145.
a 35 Bidrag til Kundsab om de nordiske Lucernarier ; in Vidensk. Med. 1859,
p- 106. Kjobenhayn. 1860.

Troscner, F. H. Handbuch der Zoologie. Berlin. 1864. 6% Auflage.

Verrity, A. E. List of Polyps and Corals sent by the Museum of Comparative Zoology to other
Institutions in Exchange, with Annotations; in Bulletin Museum Comparative Zodlogy,
No. 3. Cambridge. 1864.

Wrient, T. S. On the Reproduction of Thaumantias inconspicua ; in Quart. Journ. Mie. Scien.,

p. 221. 1862.

a Ws Observations on British Zoophytes and Protozoa; in Edinb. New Phil. Journ.,
XVI. p. 154. 1862.

“ ce Observations on British Zoophytes ; in Quart. Journ. Mic. Scien., p. 45. 1863.

cS a On the Reproduction of Aiquorea vitrea; in Edinb. New Phil. Journ., XY. p.

144, 1862.
a Oe Observations on British Protozoa and Zoophytes ; in Ann. & Mag. N. H., VUI.
p- 120. 1861.

a @ On Hermaphrodite Reproduction in Chrysaora hyoscella; in Ann. & Mag. N. H.,
VII. p. 3857, 1861.
3 “ Observations on British Zoophytes and Protozoa; on Atractylis coccinea; in

Edinb. New Phil. Journ., XTV. p. 150. 1861.
Woop, W. In Journ. Portland Soc. Nat. Hist., I. p. 63. 1862.

NORTH AMERICAN ACALEPHA,

OrpeER CTENOPHOR Esc.

Ctenophoree Escu. Syst. der Acalephen, p. 20. 1829.

Ctenophore GEGENBAUR. Archiv. f. Naturg., 1856. I. p. 163.
Ctenophore AGAss. 1860, Cont. Nat. Hist. U. S., III. p. 289. 1860.
Ciliogrades Buainv. Man. d’Actin., p. 143. 1830.

Beroides Luss. Zooph. Acal., p. 61. 1843.

The affinities of the Ctenophorz have become one of the most fertile
topics of discussion among recent investigators. Vogt, following Quoy,
remoyes them from the Acalephs altogether. Huxley places them in
close 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 Ctenophore are based upon very different
grounds, and are urged with more or less force in accordance with the
degree of importance attached by investigators to the details of struc-
ture upon which they separate the Ctenophorze from the Acalephe, and
refer them to other classes of the Animal Kingdom ; the apparent bilat-
erality so strongly developed in some of the families (as Cestum, Bolina,
and Mertensia) being urged by Vogt as the principal ground for re-
moving them from Acalephs, and associating them with the Mollusks ;
while 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 as 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 ob-
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 I hope to be able to show that the development of the Ctenophorz
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 Muller,
Wright, Boeck, and Price, that the Ctenophorz were probably all repro-

8 CTENOPHORZ.

duced from eges, and that at an early age they gave unmistakable
siens of their parentage. McCrady’s observations showed us how great
were the changes of figure their young undergo before they assume
the aspect of the parent. It has been my good fortune to trace these
changes in several of our species of Ctenophorse somewhat in detail,
and I shall make use of the material thus afforded in discussing the
position of these animals, as well as their pretended bilaterality, and,
by comparing their mode of development with that of Polyps, Acalephs,
and Echinoderms, 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 branch
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 Echimoderms 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 Echinoderms ; taking, for instance,
the three axes as we find them in some of the Spatangoids, we have a
vertical axis, a coeliac axis, and a diacceliac 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 Ctenophore that we can distinguish
between the coeliac and diacceliac ; 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 Hydroids and Discophore.
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 up 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 plane, nor into a
cylinder; the equations representing each of these figures include, it
is true, all the possible 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

CTENOPHORA. 9

apparently aberrant types, constantly met with among animals, has
been the main cause of our difficulty in referring them to their proper
plan. 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 Im 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 examples 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 features of bilater-
ality. Such is eminently the case in the larve of Echinoderms, and to
a less degree in the imitations of Echinoderm larve, the Ctenophore.
Bilaterality seems at first sight to be the plan upon which these animals
are built; but an elimination of the deceptive coefficients will show the
plan of radiation underlying this apparent bilaterality.

The figures here given of very young Ctenophore 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 promi-
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 appendages develop-
ing into immense lobes, as in the adults, can as yet be detected. The
characteristic feature of the eggs of the Ctenophore 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 by
segmentation into the embryo; this at an early period 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
pole, 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 flappers
descend somewhat along the spheromeres, and we find at the opposite

NO. I. 2

10 CTENOPHORZ.

extremity from the eye the first trace of a small cavity (the digestive
cavity of the adult), which increases in size till it becomes spherical. At
about this time there is found, between the four clusters of the locomo-
tive flappers, a second cavity, which has at first no connection whatever
with 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 difference is barely perceptible in the adult
Pleurobrachia ; it is well marked in Mertensia, still better in Idyia,
quite prominent in Lesueuria, and takes its greatest development in
Bolina, where 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 predominence of some of the sphero-
meres over the others, is the unequal development of these two sets of
tubes, which may or may not extend into lobes, thus giving to the
Ctenophorz the appearance of bilateral animals. But examine this
same development in another class of Radiates, among the Hchino-
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 Ctenophorz, owing to the
peculiar manner in which the difference between the chymiferous tubes
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 Ctenophorz 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 Agassiz’s Contributions, Vol. V. p. 60, by A. Agassiz.

CTENOPHORZ. 11

sight suppose the long tubes of Pleurobrachia, of Mertensia, 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 in 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 corresponds 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 which give to some members of the Ctenophore their
remarkable bilateral appearance. It is simply a modification of what is
perfectly familiar to us among Echinoderms, and especially among the
Spatangoids ; but owing to the bilateral character of their develop-
ment, the Ctenophore make us lose sight entirely of the original radi-
ate plan upon which these animals are built. Viewing, however, this
differentiation of the axis in all its stages, as we find it in Pleurobra-
chia, in Idyia, in Mertensia, in Lesueuria, in 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 wonderful 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 Ctenophorze
as the prophetic type of those still more wonderful beings, the Echino-
derm larve, 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 Ctenophorz we are constantly reminded
of the general appearance of Echinoderm larve, in which the radiate
structure should still be so far apparent as not to be concealed by the
bilateral symmetry.

Looking at the Ctenophore 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 in the Echino-
derm larvze ; the separation of a sort of alimentary canal, in Ctenophoree,

12 .CTENOPHOR®.

from the rest of the digestive apparatus, exactly corresponding to what
exists in Echinoderm larvae. The connection between the water system
and the digestive system is likewise precisely similar to that of Echino-
derms in their larval state ; for although in the adult Star-fish, or Sea-
urchin, or Ophiuran, there is no apparent connection between the am-
bulacral and the digestive system, yet in the young larvee 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
Kchinarachnius, in Mellita, and in Clypeaster.

It was only after the embryos of Echinoderms had been compared
with Ctenophorz that undoubted evidence of their identity of plan was
obtained. The embryological development of Ctenophore leaves no
doubt as to the Acalephian character of the order. It remains only for
us to see whether the Ctenophorx form a group of equal value with the
rest of the Acalephs, or stand simply as an equivalent of the other two
orders, the Discophorze 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
whether the Discophorze and Hydroids are independent orders, or wheth-
er the distinction established between the Discophore and Hydroids is
merely a subordinal division in a great order, including these two. If
so, this order might be called the Medusid, in opposition to the Cteno-
phorz, which are an order perfectly and accurately circumscribed ; the
presence of locomotive flappers being as characteristic for the Cteno-
phore, and as constant a feature of Ctenophore among- Acalephz, 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 Miller and Agassiz have
shown that it is hardly natural to associate the Charibdeide and Aigi-
nidze with the Hydroids, and the latter has proposed to unite them with
Discophore, while the former would make a separate order of them.
This seems hardly justifiable, as there are as many reasons — their mar-
ginal appendages, genital organs, &c.— for uniting them with Disco-
phore, as for leaving them with the Hydroids, — the shape of the bell,
the great development of the veil. If, in addition, we take into account
what we have observed in the Trachynemide, it will be seen that we
ean no longer draw the line between the Discophorze 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 us 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 Hginide and the Trachynemide among

CTENOPHOR&. 13

the Discophore, 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 Medusxe. If the. Discophore are
to be united with the Hydroids, we shall have to divide the Acalephs
into two orders, Ctenophorz: and- Meduside ; the different suborders of
the latter division including all the suborders of the Discophor of
Eschscholtz, and those of the Hydroids as limited by Professor Agassiz.

The remarkable changes of form the Ctenophorz undergo until they
attain their adult state, will necessitate at no very distant time a com-
plete revision of the Ctenophore, 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 Ctenophore, a standard for an embryological classification of
the Ctenophore. 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 sinsee + ; all such
species as the Cydippe quadricostata of Sars (Bolina ne ea), the
Cydippe brevicostata of Will (Chiqja multicornis M. Edw.), and the
Sicyosoma rutilum of Gegenbaur, are undoubtedly undeveloped stages
of some of the well-known Ctenophorz of the Northern Ocean, the
Adriatic, and the Mediterranean. From what has been shown of the
transformations of Bolina alata, I should even be inclined to consider
the Cydippe hormiphora of Gegenbaur as one of the stages of growth
of Huramphea 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 Bolina alata. The material at my com-
mand is too imperfect to attempt anything more definite than the few
hints here thrown 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 Ctenophore. 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 LOBATZ.

SusorDER LOBAT/Z Escu.

Lobate Escu. Isis., p. 741. 1825.
Lobate AGass. Cont. Nat. Hist. U. S., III. p. 289. 1860.
Mnemiide Escu. Syst. d. Acalephen, p. 29. 1829.

In the Lobatz we find that the diameter passmg 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 Saccate. The spheromeres at the extremity of the longer trans-
verse axis, the coeliac axis, develop into lobes.

Family BOLINIDA Agassiz.

Bolinide Acass. Cont. Nat. Hist. U. S., II. pp. 200, 289. 1860.

The family of Bolinide has here a somewhat different cireumscrip-
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 Mnemiide to the Bolinide.
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 Bolinide, and not the
Mnemide.

BOLINA Mert.

Bolina Mert. Meém. Acad. St. Petersb., II. p. 513. 1833.
Bolina Acass. Mem. Am. Acad., IV. p. 349. 1849.
Bolina Acass. Cont. Nat. Hist. U. S., II. p. 249. 1860.
Mnemia Sars (non Esch.). Beskriv., p. 32. 1835.
Aleinoe LEss. (non Rang). Zooph. Acal., p. 88. 1843.
Anais Less. Zooph. Acal., p. 101. 1843.

Bolina septentrionalis Merr.

Bolina septentrionalis Merv. (non Agass.). Acad. St. Petersb., p. 515, Pl. VII. 1833.
Bolina septentrionalis Luss. oh. Acal., p. 83. 1843. e

Off Mattheei Island, Behring’s Straits (Mertens).

BOLINA ALATA. 1S

Bolina alata Acass.

Bolina alata Acass. Mem. Am. Acad., Vol. IV. Pt. 2, p. 349, Pls. 6, 7, 8. 1849.

Bolina alata AGAss. Contrib. Nat. Hist. U. $., Vol. III. pp. 249, 289.

Alcynie vermicularis GOULD (non Rang). Inverteb. of Mass., p. 349. 1841.

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

Bolina alata Packp. A List of Animals dredged near Caribou Island, Can. Nat. & Geol. 1863.

It is quite remarkable that there should be 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 Ctenophore 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 farther 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 different 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 younger stages
of this Medusa are so unlike the adult, that it would
be 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 compared 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

Fig. 1.

Tn all the young Ctenophore the following lettering has been adopted: d, digestive cavity ;
a, anal rosette ; 1, tentacle; c, long ambulacral tube (longitudinal ambulacra) ; c’, short ambulacral
tube (lateral ambulacra) ; ¢, eye speck; f, funnel; 0, ambulacral cavity ; J, lateral tubes. c! is the
longest tube at first, and ¢ the shorter; , lobes of spherosome ; the names are taken from the adult.
Fig. 1. Young Bolina, seen from the narrow side.

16 BOLINA ALATA.

with age. (Fig. 4, which is Fig. 6 seen from abactinal side.) We soon
perceive in the young of this species changes of shape similar to those
to be described in Idyia and Pleurobrachia: the outline becomes more
elongated ; the lateral tubes, at first simple diverticula from the ‘main

Fig. 3.

ambulacral tubes (J, 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 the junc-
tion of the two lateral am-
bulacra (Figs. 9, », 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 rapidly m 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 the broad side.

Fig. 3. Somewhat younger than Fig. 1, seen from the abactinal pole.

Fig. 4. Young Bolina, seen from the abactinal side, somewhat older than previous figures.
Tig. 5. Formation of lateral tubes in young Bolina.

Fig. 6. Bolina in which lobes begin to appear, seen from narrow side, same state as Fig. 4.
Fig. 7. Somewhat more advanced than Fig. 6, the tube c’ not yet having formed the circuit ;
seen from the actinal side.

BOLINA ALATA. 17

the long 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
find that they reach almost to
the lower end of the lobe;
when there, they make a sharp
angle, turn upward, and form
thus the beginning (Figs. 12,
15) of the complicated system
of windings which we find in
the lobes of the adult Bolina.
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 lengthening
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.

Fig. 11.

Fig. 8. The tentacular ambulacra have united, and the lobes (m) 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. Il. 3

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 first they
are more rapid im their growth,
but are afterwards outstripped
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 positions.
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. 14.

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.

Fig. 14. “ Fig. 13 seen from the actinal pole, and more magnified. 7, circular tube ; m, auri-
cles.

Fig. 15. Adult Bolina seen from the broad side. a, f, longitudinal ambulaera ; g, h, lateral
ambulacra; 0, eye-speck ; 7—m, digestive cavity ; i—0, funnel; v, lateral tube leading to tentacular
apparatus just on level of mouth, m; 7,7, auricles; ¢, t, prolongation of the longitudinal ambulacra ;
n, n, same tubes turning upwards, bending down at 2, «; 2, 2, point of junction of tubes from oppo-
site sides ; w, prolongation of tubes from the lateral ambulacra. About half natural size.

Fig. 16. Fig. 15 seen from the narrow side. a, b, longitudinal ambulacra; c, h, lateral ambu-
lacra ; other letters, as in Fig. 15.

Fig. 17. Bolina seen from the actinal pole ; lettering as above.

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

MNEMIOPSIS. 19

Bolina vitrea Acass.

Bolina vitrea AGass. Contrib. Nat. Hist. U. S., Vol. III. pp. 269, 289, Fig. 93. 1860.
2 Bolina littoralis McCr. On the Development of two Species of Ctenophorz, 1857; Proc. Elliot
Soc. N. H., p. 1. 1858.

The Bolina littoralis McCr. is probably either this
species, or one of our species of Mnemiopsis ; but
not having the means to determine this point, a
figure (Fig. 19) of the Bolina vitrea Agass. is added
here, to serve as a basis for its identification here-
after.

Reef of Florida (Agassiz) ; Charleston (McCrady).

Fig. 19.

Bolina microptera A. Acass.

Bolina septentrionalis AGAss. (non Mertens). Cont. Nat. Hist. U. S., II. p. 289. 1860.

The discovery of several species of Bolinid on the eastern coast of
North America, belonging to different genera, which had all been con-
founded together, has induced me to examine 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. septentrionalis 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 ambulacra.
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 Rosario, Washington Territory.

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

MNEMIOPSIS Aaass.
Mnemiopsis AGass. Cont. Nat. Hist. U. S., III. pp. 269, 290. 1860.

The genus Mnemiopsis is remarkable among the Bolinidz 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. 1?, 17, long ambulacra; J’, 1°, short ambue
lacra; f, funnel; d, digestive cavity ; ¢, tentacular tube ; x’, x°, auricles ; /, J, anterior and poste-
rior lobes ; i’, tentacle.

20 MNEMIOPSIS LEIDYI.

Mnemiopsis Gardeni Acass.

Mnemiopsis Gardeni Acass. Cont. Nat. Hist. U. S., ILL. pp. 269, 290, Figs. 95, 96. 1860.

The accompanying figures (Figs. 20, 21) of
Mnemiopsis Gardent Agass. are here introduced
to show how striking are the differences in the
proportions of the two Medusz of this genus
found upon our coast. The great length of the
digestive cavity, together with the size of the
auricles and lobes, enable us at once to distin-
guish this species from its ally, the Mnemiopsis
Leidyi A. Agass. The genus Mnemiopsis had
been placed by Professor Agassiz among the
Mnemiidze, 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 Mnemiopsis Gardeni, are far from
being marked when we compare Golina alata and Mnemiopsis Leidyi.

Charleston, 8. C. (L. Agassiz).

ee

Mnemiopsis Leidyi A. Acass.

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 separating 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 Mnemiopsis Gardeni Agass.

This species grows very large, specimens measuring six and even
eight inches in length are frequently found. Like the other Cteno-
phore 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 Medusx, 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 up 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. 0, mouth; J+, 1°, lateral ambulacra; x‘, x’, auri-
cles ; /?, 1°, 1°, 1", anterior and posterior ambulacra.

MNEMIOPSIS LEIDYI. a1

handle can plainly be seen, on dark nights, by the light produced
by this llumination. 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 Medusx 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 (0, Fig. 22), taking their origin
on a level with the eye-speck (a, Fig. 22). The prolongation of the
chymiferous 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 Bolina alata (Fig. 16). Bolina
alata ranks among the most perishable of all our Meduse ; 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 Mnemiopside,
after passmg 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,
resembled so closely the young of Pleurobrachia, which were develop-:
ing at the same time in another bottle, 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. 0, starting-point of branch of tentacu-
lar apparatus extending along the furrow, f, to a, the base of the auricles.
Fig. 23. The same as Fig. 22, seen from the narrow side.

99 MNEMIOPSIS LEIDYI.

an

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 1s 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 im 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
Mnemiopsis 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 fan-shaped on both sides of the bulb. We
have a rather small tentacular bulb placed
Evie at the end of a long, slender tube, a short
distance above the opening of the actino-
stome (0, Fig. 22). This tentacular bulb
is protected by a kind of two-lapped hood
(Fig. 24), the folds of which extend on
each side along a groove towards the abac-
tinal pole, to the very origin of the auri-
cles, at a, 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, protected 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 irregularly 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 remember 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
intestmal worm (Scolex acalepharum) upon a large species of Mnemia
(IL norvegica Sars), ten and even twelve specimens being found at-

Fig. 24. A part of the tentacular apparatus, near the opening of the actinostome, to show the
mode in which the branches of the tentacle extend, under cover of a lappet, towards the abactinal
extremity.

.

LESUEURIA. 23

tached to the inner wall, near the upper part of the furrow, separating
the lobes from the spherosome. Foster, in 1841, found a species of
Filaria, which he called Zetrastoma Playfairii, upon a species of Cy-
dippe; Greene and others have also seen parasites upon Hydroid
Meduse ; 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, attaming 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 worms 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 separated
from the Meduse.
Naushon, Buzzard’s Bay (A. Agassiz).

LESUEURIA Mie Epvw.

Lesueuria Minne Epw. Ann. Se. Nat., XVI., 1841, p. 199.
Lesueuria Less. -Zooph. Acal., p. 90. 1843.
Lesueuria AGAss. Cont. Nat. Hist. U. S., III. p. 290. 1860.

Lesueuria hyboptera A. Acass.

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,
which 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 lobes of Bolina are small projections
scarcely reaching below the level of the mouth, and in which all we

24 LESUEURIA.

ya)

find corresponding to the complicated windings of the longitudinal
ambulacra are a few short, straight projections of the ambulacral tubes,
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 outline 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. Lesueuria 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 durmg September, large numbers being visible
on almost any clear, hot day. Its phosphorescence is a very peculiar
bluish light, of an exceedingly pale steel color, but very intense.

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

Fig. 25.

Spry

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

5. Lesueuria seen from the broad side, natural size.

6, Fig. 25 seen from the narrow side.

OCYROEZ.

spherosome. The lateral tubes are also very attenuated, and bulge

well out from the digestive 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 Ctenophorz. 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.

Fig. 27.

Family OCYROEZ Less.

Ocyroce Lmss. Zooph. Acal., p. 98. 1843.
Ocyroee AGass. Cont. Nat. Hist. U. §., If. p. 292. 1860.

OCYROE Rane.

Ocyroe RANG (non Pér. et Les.). Mém. de la Soc. d’Hist. Nat., IV. p. 170. 1829.
Ocyroe Luss. Zooph. Acal., p. 98.° 1843.
Ocyroe AGAss. Cont. Nat. Hist. U. S., IIL p. 292. 1860.

Ocyroe maculata Rane.

Ocyroe maculata RANG. Mém. Soc. d’Hist. Nat. de Paris, IV. 1829, Pl. 20, Fig. 1.
Ocyroe maculata Less. Zooph. Acal., p. 99. 1848.
Ocyroe maculata AGass. Cont. Nat. Hist. U. S., II. p. 292. 1860.

Antilles (Rang).

Fig. 27. Lesueuria seen from the abactinal pole.

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

ambulacra.
NO. I. 4

26 SACCATZ.

SuporpER SACCAT/ AGasstiz.

Saccate AGAss. Cont. Nat. Hist. U. S., Ill. p. 293. 1860.
Callianiride Escu. Syst. der Acal., p. 21. 1829.

Family MERTENSIDA Agass.

Mertenside AGass. Cont. Nat. Hist. U. S., Il. pp. 196, 293. 1860.

MERTENSIA Less.

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

Mertensia ovum Morcu.

Cydippe (Mertensia) ovum Morcu. In Nat. Bid. til en Besk. af Gronland, p. 97. 1857.
Beroe ovum Fas. Faun. Groenl. 1780. No. 355.

Beroe cucullus Mop. Svensk. Vet. Ak. Nya Handl., XI. 1790.

Beroe pileus Scor. (nee Fab. nec Miill.). Arct. Reg., IL. Pl. XVI. Fig. 4. 1820.
Cydippe ovum Escu. Syst. d. Acal., p. 25. 1829.

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

Mertensia Scoresbyi Less. Zooph. Acal., p. 100. 1848.

Cydippe cucumis Less. (syn. not correct). Zooph. Acal., p. 105. 1843.

Mertensia cucullus AGAss. Cont. Nat. Hist. U. S., IL. p. 293. 1860.

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 which the lateral chymiferous tubes are
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 apparatus seeming to give rise to
this long, slender tube, enclosing the digestive cavity m 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 appa-
ratus, that it seems, in adult 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 enables one to distinguish them
readily from that genus, while swimming in the water. The color, also,
is of a light-pmk 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. Ni

edges smooth ; the circumscribed area is quite small; the tentacles are
but moderately long, apparently not capable of as
great expansion as Pleurobrachia. 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 ovwm of Fabricius.
The difference between the tentacular chy-
miferous tubes 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 ambulacra, 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 young 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. Fig. 31.

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 were almost equally developed; the funnel has become

Fig. 29. Adult Mertensia seen from the broad side.
Fig. 30. Young Mertensia seen from the broad side, with a simple tentacle.
Fig. 31. The same as Fig. 30, seen from the abactinal pole.

28 MERTENSIA OVUM.

formed, the digestive cavity (d) and the lateral tubes (7) are well de-
fined. (Fig. 32.) Ina 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.54),
the ambulacra have
assumed still more
the aspect of tubes,
the funnel has elon-
gated, the tentacles
have begun to send
out lateral processes,
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 better circumscribed. In the next stage the development of the acti-
nal part of the spherosome (Figs. 36, 37) has become so striking, that we

i sraeeas: 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. 57), a totally different aspect.
The tentacular apparatus differs from that of Pleu-
robrachia 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 m the
adult. (See Figs. 29, 36.) The ambulacra are very nearly equally
developed, the tentacular pairs and the median tubes differmg but
slightly m length. The tentacles are lashed and covered with large
orange pigment-spots, similar to those of the rows of locomotive

Fig. 32. Somewhat more advanced Mertensia, seen from the narrow side ; the lateral tubes, /,
are present.

Fig. 33. The same as Fig. 32, seen from the actinal pole.

Fig. 34. Still more advanced Mertensia, seen from the narrow side.

Fig. 35. The same as Fig. 34, seen from the actinal pole; the tubes are circumscribed, and
the tentacular apparatus isolated.

CYDIPPID. 29

flappers. The pigment-spots become smaller and less conspicuous with
advancing age.

Fig. 36.

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 Eastport, Me. (A. Agassiz).

Museum diagram No. 3 after Alex. Agassiz.

Family CYDIPPIDA Gegenb. (rest. Ac.)

Cydippide GEGENB. Archiv f. Nat., 1856, I. p. 196.
Callianiride Escu. (p. p.) Syst. d. Acal., p. 21. 1829.
Cydippide AGass. Cont. Nat. Hist. U. S., Il. p. 293. 1860.

PLEUROBRACHIA Fie.

Pleurobrachia Firm. Phil. Zodl., I. p. 612.

Cydippe Escu. Syst. der Acal., p. 29. 1829.

Cydippe Less. Zooph. Acal., p. 104. 1843.

Pleurobrachia AGAss. Mem. Am. Acad., IV. 1849, p. 314.
Pleurobrachia AGAss. Cont. Nat. Hist. U. S., II. p. 203. 1860.

Fig. 36. Still further 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.

30 PLEUROBRACHIA RHODODACTYLA.

Pleurobrachia rhododactyla Acass.

Pleurobrachia rhododactyla AGAass. Mem. Am. Acad., IV. p. 314, Pls. 1, 2, 3, 4, 5.
Pleurobrachia rhododactyla AGAss. Cont. Nat. Hist. U. S., III. pp. 2038, 294, Pl. 2%. 1860.
Beroe pileus FAB. (non Flem., Miill., and Esch.). Faun. Grénl. 1780. No. 354.

Cydippe pileus Goutp. Rep. Inv. Mass., p. 349. 1841.

Pleurobrachia rhododactyla Stimrs. Mar. Inv. Grand Manan, p. 11. 1853.

Cydippe pileus Morcu. In Naturhist. Bid. til en Besk. af Gronland, p. 97. 1857.
Pleurobrachia Scoresbyi Morcu. In Naturh. Bid. til en Besk. af Gronland, p. 98. 1857.
Pleurobrachia 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, ¢), and has a very large transparent sphere (e) with two or

Fig. 38. Fig. 39.

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. 41. Fig. 43.

Fig. 42.

the base of the tentacular (Fig. 41, ¢) 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 seen from the broad side.

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

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.

PLEUROBRACHIA RHODODACTYLA. 31

ties of any kind. The position of the ambulacral system is early well
defined by four short double rows of combs, each row not having more
than three or four combs (Figs. 388-41). The spherosome early shows
the great difference in the size of the longitudinal and cceliac diameters,
the tentacular diameter being nearly twice as long as the other (Figs.
40, 42). The locomotive rows extend rapidly to the level of the upper
part of the digestive cavity. At this time the ambulacral cavity makes
its appearance 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, 0). 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, 0, d). In
the next stage the two cavities differ in their
outline, the ambulacral cavity becoming 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 ambulacral 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, f/), 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 bulb becomes more isolated,
the tentacle is about three times as long as the polar diameter. 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

Oo?
its escape from it; while at other times the young Medusa remains

Fig. 44.

Fig. 45.

Fig. 44. Pleurobrachia in which 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 embryo.

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
dividing wall, and at the same time a
depression at the actimal 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
flappers into two very distinct rows. At the same time, when facing
the tentacular bulb, we see a small triangular
pouch extending along the digestive cavity,
which, when seen in profile, plainly appears
to be nothing but a coecum of the ambulacral
cavity, formed exactly as in Bolina (Fig. 5).
These pouches are the rudimentary lateral
chymiferous tubes so characteristic of Cteno-
phore. At this stage the ambulacral flappers
are not as near the abactinal pole as im
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, 2),
while the forking of the ambulacral 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 longitudmal 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 Fig. 44, seen from actinal side.

In all the preceding figures the embryo 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

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

Fig. 48. Fig. 49.

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 surface of the ambulacral tubes (Fig. 49).

The difference 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 cceliac
and diacceliac 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 bulb, and there are at
first but two or three at the base of each tentacle.

Greenland (Fabricius) ; New England (Agassiz).

Cat. No. 366, Nova Scotia, Anticosti Expedition, 1861.

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

Fig. 51.

Marahrut tpy- / I &
Fig. 48. Somewhat less advanced than Fig. 47, showing the lateral tubes from the narrow
side, as a prolongation of the ambulacral cavity.
Fig. 49. Pleurobrachia about in condition of Fig. 47, seen from actinal pole.
Fig. 50. Adult Pleurobrachia, from the head and narrow side, natural size.
Fig. 51. Adult Pleurobrachia in a natural attitude, natural size.

NO. Il. 0)

34 DRYODORA.

Pleurobrachia Bachei A. Acass.

Pleurobrachia Bachei A. AGASS.; in Agassiz’s Cont. Nat. Hist. U. S., II. p. 294. 1860.

Pleurobrachia 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 Plewrobrachia rhododactyla. 'The cceliac 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 Plewrobrachia 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.,
during 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 Oxen.

Janira OKEN. Lehrb. d. Naturg., III. 1815.

Janira cucumis Less.

Janira cucumis Less. Zooph. Acal., p. 104. 1843:
Beroe cucumis Mrrv. (non Fab. n. Esch.). Mém. Ac. St. Pet., p. 522, Pl. VIII. 1843.
Janira cucumis AGAss. Cont. Nat. Hist. U. S., III. p. 294. 1860.

Between Sitka and Unalaschka (Mertens).

DRYODORA Aagass.

Dryodora Acass. Cont. Nat. Hist. U. S., II. p. 196. 1860.
Eschscholtzia Luss. (ex. p.). Zooph. Acal., p. 102. 1843.
Mertensia GEGENBAUR (non Less.). Archiv f. Nat., 1856. I. p. 198.

Dryodora glandiformis A«cass.

Dryodora glandiformis AcAss. Cont. Nat. Hist. U. S., III. p. 294. 1860.
Beroe glandiformis Mert. Mém. Acad. St. Pet., p. 530, Pl. XI. 1833.
Eschscholizia glandiformis Luss. Zooph. Acal., p. 102. 1843.

Mertensia glandiformis GEGENB. Archiv f. Nat., 1856, I. p. 198.

Behring’s Strait (Mertens).

EURYSTOMZ. 35

SusorDER EURYSTOM A Leucx.

Eurystome Leucx.; in Van d. Hoeven Handbuch d. Zool. German Transl. 1850.
Eurystome AGass. Cont. Nat. Hist. U. S., HI. p. 295. 1860.

Family BEROIDA Esch.

Beroide Escu. Syst. d. Acal., p. 38. 1829.
Beroide AcaAss. Cont. Nat. Hist. U. S., III. p. 295. 1860.

BEROE Brown.

Beroe Brown. Nat. Hist. Jam., p. 384. 1756.

Medea Escu. (ex p.). Syst. d. Acal., p. 38. 1829.
Cydalisia Less. Zool. de la Coq., p. 101. 1829.
Cydalisia Less. Zooph. Acal., p. 138. 1843.

Beroe Acass. Cont. Nat. Hist. U. S., HI. p. 295. 1860.

Beroe punctata Cuam. & Eysen.

Beroe punctata Cuam. & Eys. Noy. Act., X. p. 361, Pl. 31, Fig. 1.
Beroe punctata Escu. Syst. d. Acal., p. 37. 1829.

Beroe punctata Buatny. Man. d’Actin., Pl. 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., III. p. 295. 1860.

McCrady has identified a species of Beroe found at Charleston with
the B. punctata Esch. I am inclined to think that it may prove to be
one of the species of Idyopsis found on the coast of Florida.

Charleston, 8. C. (McCrady).

IDYIA Frem.

Idyia FreM. Nouv. Bull. Soc. Phil., 1809, p. 329.

Medea Escu. (ex. p.). Syst. d. Acal., p. 38. 1829.

Idyia Less. Zooph. Acal., p. 132. 1843.

Idyia Mert. Meém. Acad. St. Petersb., I. p. 532. 1833.
Idyia AGass. Cont. Nat. Hist. U. S., III p. 295. 1860.

Idyia ovata Less.

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

Beroe Brown. Nat. Hist. Jam., p. 384. 1756.

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

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

Idyia ovata AGAsS. Cont. Nat. Hist. U. S., III. p. 295. 1860.

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

6 IDYIA ROSEOLA.

(st)

Idyia cucumis Less.

Tdyia cucumis Less. Zooph. Acal., p. 133. 1843.

Beroe cucumis Fas. Fauna Gronl., 1780, No. 353.

Beroe cucumis Escu. Syst. d. Acal., p. 36. 1829.

Medea fulgens Less. Zooph. Acal., p. 136. 1843.

Beroe cucumis Morcu; in Naturh. Bid. af Gronland, p. 98. 1857.

Tdyia cucumis AGAss. Cont. Nat. Hist. U. S., III. p. 296. 1860.
? Idyia 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 Jdyia
cucumis and Idyia borealis Less. by Professor Agassiz, are probably
all identical with the Beroe cucumis of Fabricius.

Baffin’s Bay (Fabricius).

Idyia roseola AGass.

Idyia roseola AGass. Cont. Nat. Hist. U. S., II. pp. 270, 296, Pls. 1, 2. 1860.
Idyia roseola Pack. List of Animals dredged near Caribou Island. 1863.

In the youngest Idyia which I have had the opportunity 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. 62.

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 (2), and find that the inequality
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 Ctenophore.

Fig. 52. Young Idyia, seen from the narrow side.
Fig. 53. Fig. 52, seen from abactinal pole.
Fig. 54. Young Idyia, in which the ambulacral tubes are distinct, seen from the narrow side.

IDYIA ROSEOLA. 37

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

Fig. 57.

Fig. 55.

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.

from above (Fig. 55). The manner in which the ambulacral tubes are
formed, by the drawing up into loops of the original chymiferous cavity,
is very easily followed in Idyia. It is the same in all the Ctenophorz

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

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

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

Fic. 58. The chymiferous tubes, c/, have united with the lateral tubes, and formed a circular
tube, towards which the short ambulacra, c, are fast pushing their way. First trace of the ramifi-
cations on the long tubes, c!. Figs. 58—60 are seen from the broad side.

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

Fig. 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.

38 IDYIA CYATHINA.

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 ambulacra
with the lateral chymiferous
tubes, a circular tube round the
mouth. (Fig. 60.) The distine-
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.

/ wh. ? 2.2 2

Fig. 61.

Idyia cyathina A. Acass.

Tdyia cyathina A. AGASS.; in Agassiz’s Contrib. Nat. Hist. U. S., Vol. III. p. 296. 1860.

This species differs from the Zdyia 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, anal opening; 3, lateral radiating tube ;
¢, circular tube ; d, e, f, g, h, vertical rows of flappers. 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 spermaries are much longer sacs than in J.
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 OREN and
great activity in its adult condition.

Northwest coast of North America (A. Agassiz).

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

IDYIOPSIS Acass.
Idyiopsis AGAss.- Cont. Nat. Hist. U. S., III. pp. 288, 296. 1860.

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 very striking. (Agassiz.)

Idyiopsis Clarkii Acass.

Idyiopsis Clarkii AGAss. Cont. Nat. Hist. U. S., II. pp. 288, 296, Figs. 101,102. 1860.

It remaims yet to be shown
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. Idyiopsis Clarkii seen from the broad side. f, funnel; 1?, 1’, anterior and posterior
ambulaera ; /*, J°, lateral ambulacra ; .d, digestive cavity ; 0, mouth ; c, the lateral tube.

Fig. 64. Fig. 63, seen from the abactinal pole. c, circumscribed area; J}, 1°, 1‘, 1°, lateral
ambulaera ; 1°, /*, 1°, 1", anterior and posterior ambulacra.

40

DISCOPHORA.

Idyiopsis affinis Acass.

Tdyiopsis afinis AcAss. Cont. Nat. Hist. U. S., III. pp. 288, 296. 1860.

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

OrpeR DISCOPHORZ Escu.

Medusarie LAMK. (p. p.). 1816.

Meéduses Pir. et LEs. (p. p.). 1809.

Discophore planerocarpe Escu. Syst. d. Acal. 1829.

Discophore cryptocarpe Escu. Syst. d. Acal. 1829.

Pulmograda Bu. (p. p.). Manuel d’Actinologie. 1830.

Meduside Br. (p. p.). Mém. Acad. St. Petersb. 1833.

Meduse Less. (p. p-) Zooph. Acal. 1843.

Steganophthalma Fores. Brit. Nak. Meduse. 1848.

Acraspeda GEGENB. Syst. d. Med.; in Z. f. W. Zool. 1856.
Craspedota GEGENB. (p. p-)- Syst. d. Med.; in Z. f. W. Zool. 1856.
Lucernariade Hux. (non Johnst.). Lectures on Genl. Nat. Hist.... 1856.
Discophore Acass. Cont. Nat. Hist. U. S., ITV. 1862.

SuporpDER RHIZOSTOME AGass.

Rhizostomee AGAss. Cont. Nat. Hist. U. S., Vol. IV. pp. 9,131. 1862.
Rhizostomide Escu. Syst. der Acal., p. 42. 1829.

Polystome Br. Mém. Acad. St. Petersb. 1835, Prod., p. 228.
Rhizostomidees Less. Zooph. Acal., p. 404. 1843.

Family RHIZOSTOMIDA Esch.

Rhizostomide Escu. Syst. der Acal., p. 42. 1829.
Rhizostomide AGAss. Cont. Nat. Hist. U. S., Vol. IV. p. 149. 1862.

STOMOLOPHUS Agass.
Stomolophus AGAss. Cont. Nat. Hist. U. 8., Vol. IV. pp. 138, 151. 1862.

Stomolophus meleagris Acass.

Stomolophus meleagris AGass. Cont. Nat. Hist. U. S., Vol. IV. pp. 138, 151; III. Pl. 14.
Cephea rhizostoma GiBBEs (non 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.

SEM ZOSTOME&. AL.

Family POLYCLONIDA Agass.

Polyclonide Acass. Cont. Nat. Hist. U. S., Vol. IV. pp. 140, 159. 1862.

POLYCLONIA Br.

Polyclonia BR. Meém. Acad. St. Petersburg, p. 396, Pls. 21-23. 1838.
Polyclonia AGAss. Cont. Nat. Hist. U. S., IV. p. 139. 1862.

Polyclonia frondosa Acass.

Polyclonia frondosa AGAss. Cont. Nat. Hist. U. S., Vol. IV. pp. 139, 159, II. Pls. 13, 13°.
Medusa frondosa Patu. Spicil. Zool., p. 30, Pl. 2, Figs. 1-3.

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

Cassiopea frondosa Escu. Syst. d. Acal., p. 43. 1829.

Cassiopea Pallas Pir. et Les. Hist. Gén. d. Méd.; in An. Mus., XIV. p. 45.

Medusa frondosa Bosc. Hist. Nat. d. Vers., II. p. 170.

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

West Indies (Pallas); Florida, Key West, and Key Largo (L. Agassiz).
Cat. No. 352, 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. HE. Mills.
Cat. No. 346, Florida, L. Agassiz.

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

Museum diagram No. 8, after L. Agassiz.

SuporDER SEMAZOSTOME AaGass.

Semceostomee Acass. Cont. Nat. Hist. U. S., Vol. IV. pp. 9,159. 1862.

Family AURELIADA Agass.

Aureliade Acass. Cont. Nat. Hist. U. S., Vol. IV. pp. 80,159. 1862.

AURELIA Per. et Les.

Aurelia PER. et Les. Ann. du Mus., XIV. p. 45. 1809.
Aurelia Less. Zooph. Acal., p. 348. 1843.
Aurelia Acass. Cont. Nat. Hist. U. S., 1V. p. 159. 1862.
Medusa Linn. Faun. Suec., p. 511.
Medusa Escu. Syst. der Acal., p. 61. 1829.
Ephyra Pr. et Les. Hist. Gén. des Méd., p. 42.
Ocyroe PER. et Les. Hist. Gén. des Méd., p. 43.
Evagora Pir. et Les. Hist. Gén. des Méd., p. 31.
Scyphistoma Sars. Bidrag til Soedyrenes Nat. 1829.
Rhizostoma Escu. Syst. d. Acal., p. 45. 1829.
Strobila Sars. Beskriv.... over Polyp,...p.16. 1835.
Diplocraspedon Br. Prod. Mém. Acad. St. Petersburg, p. 226. 1835.
Monocraspedon Br. Prod. Mém. Acad. St. Petersburg, p. 225. 1835.
Claustra Less. Zooph. Acal., p. 378. 1843.
Biblis Less. Zooph. Acal., p. 339. 1843.
No. I. 6

42, AURELIA FLAVIDULA.

Aurelia flavidula Pfr. et Lrs.

Aurelia flavidula Pkr. et Les. Ann. Mus., XIV. p. 47. 1809.
Aurelia flavidula Less. Zooph. Acal., p. 376. 1843.
Medusa aurita Fas. Faun. Gron., No. 356. 1780.
Aurelia aurita Goutp. Rep. Inv. Mass., p. 348. 1841.
Aurelia flavidula Goutp. Rep. Inv. Mass., p. 348. 1841.
Ephyra octolobata Goutp. Rep. Inv. Mass., p. 348. 1841.
Aurelia aurita Strmps. Mar. Inv. Grand Manan, p. 11. 1853.
Aurelia aurita Morcu ; in Nat. Bid. til en Besk. af Gronl., p. 95. 1857.
Aurelia sex-ovariis M6rcu ; in Nat. Bid. til en Besk. af Gronl., p 95. 1857.
Aurelia flavidula AGAss. Cont. Nat. Hist. U. S., III. Pls. 6, 7, 8, 9, 11, 11, 11>; Pl. 10, Figs. 18,
22, 31, 32, 36; Pl. 10%, Figs. 4%, 13, 15", 16-41; Pl. 11°, Figs. 1-13; IV. pp. 10, 160.

Aurelia flavidula Packarp. <A List of Animals... 1863. : “tine!

ies 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
European Aurelia aurita.
But this, as well~as the
identity of Cyanea arctica
with the European represent-
ative, 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. 337, 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, I, III, IV, are the ambulacral zones ; A, B,
C, D, the interambulacral zones ; 1, 2, 3, 4, a, b, the respective halves of these systems.

STHENONIA. 43

Aurelia labiata Cua. et Eysrn.

Aurelia labiata CHAM. et Eysenu. N. Acta, X. p. 358, Pl. 38, Fig. 1.
Medusa labiata Escu. Syst. d. Acal., p. 64. 1829.

Ocyroe labiata Bu. Man. d’Actinol., Pl. 42, Figs. 1, 2. 1834.

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

Aurelia labiata AGAss. Cont. Nat. Hist. U. S., IV. p. 160. 1862.

Many of the Discophore 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 harbor of
San Francisco. Further north, however, in the Gulf of Georgia, the
Discophore pass the winter in their hydra state.

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

Aurelia marginalis Acass.

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

Florida, Key West (L. Agassiz).
Cat. No. 352, Key West, Fla., L. Agassiz.

Family STHENONIA Agass.

Sthenonie AGass. Cont. Nat. Hist. U. S., Vol. IV. pp. 115,161. 1862.

HECCAXDECOMMA Br.

Heccedecomma Branpt. Mém. Acad. St. Petersb., p. 300. 1838.
Heccedecomma Acass. Cont. Nat. Hist. U. S.,1V. p. 161. 1862.

Heccedecomma ambiguum Br.

Heccedecomma ambiquum Br. Mém. Acad. St. Petersb., p. 300, Pls. 27, 28. 1838.
Heccedecomma ambiguum AGAss. Cont. Nat. Hist. U. 8., 1V. p. 161. 1862.
Cyanea ambigua 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).

4A CYANEIDA.

PHACELLOPHORA Br.

Phacellophora Br. (non Huxl.). Prod. Mém. Acad. St. Pet., p. 223. 1835.
Phacellophora Less. Zooph. Acal., p. 343. 1848.
Phacellophora AGAss. Cont. Nat. Hist. U. S., 1V. p. 161. 1862.

Phacellophora camtschatica Br.

Phacellophora camtschatica Br. Mém. Acad. St. Petersb., p. 366, Pl. 8. 1838.
Phacellophora camtschatica Less. Zooph. Acal., p. 344. 1843.
Phacellophora camtschatica AcAss. Cont. Nat. Hist. U. 8., TV. p. 161. 1862.

The number of species of large Discophorous Medusx 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 CYANEIDA: Agass.

Cyaneide Acass. Cont. Nat. Hist. U. S., Vol. IV. pp. 114, 161. 1862.

CYANEA Per. et Las.

Cyanea Pr. et Les. Ann. du Mus., XIV. p. 51. 1809.
Cyanea Escu. Syst. der Acal., p. 67. 1829.

Cyanea Cuv. Reg. An. 1818.

Cyanea Less. Zooph. Acal., p. 379. 18438.

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

Cyanea arctica Pir. et Lus.

Cyanea arctica P&R. et Les. Ann. Mus., XIV. p. 51. 1809.

Cyanea arctica AGass. Cont. Nat. Hist. U. S., IV. pp. 87, 162; Vol. TII., Pls. 3, 4, 5, 5*; Pl. 10,
Figs. 1-17, 19-21, 23-30, 33-35, 37-38 ; Pl. 10°, Figs. 1—4*, 5-12, 14, 15, 17-40.

Medusa capillata Fax. (non Lin.) Faun. Groenl. No. 358. 1780.

Cyanea Postelsii GouLD (non Br.). Rep. Inv. Mass., p. 347.

Cyanea Postelsti Strmps. Mar. Inv. Grand Manan, p. 11. 1853.

Cyanea arctica Morcu. In Naturh. Bid. til en Besk. af Gronl., 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 attamed 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 Discophore is due to their peculiar habits. As has already been
suggested, they probably remain a great part of the time groping about

only in their

accidentally visited the wharves of Province-

CYANEA ARCTICA.
apparently coming to the surface

the bottom of the sea,
adult condition. Having

/
/
/
j ;
j a
Nis
We
“A
) G
, \>Sl
x
Ass

)

= y
<=

ZS

——————— ==
2SaF ¢ 3

a,

I was aston-

ished to perceive what a large number of young Cyanex were floating

town harbor early one morning, between four and five,
Fig. 67. Cyanea arctica very much reduce

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 surface, 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 Sound, Vine-
yard Sound (A. Agassiz).

Cat. No. 526, Chelsea Beach, Oct. 1851, L. Agassiz.
Cat. No. 527, Nahant, Aug. 1858, L. Agassiz.
Cat. No. 528, Nahant, Aug. 1858, L. Agassiz.

Cat. No. 369, Gulf of St. Lawrence, 1861, Anticosti Expedition.
Museum diagrams Nos. 12, 13, after L. Agassiz.

Cyanea fulva Acass.

Cyanea fulva AGAss. Cont. Nat. Hist. U. 8., IV. pp. 119, 162. 1862.

The youngest specimer 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 arctica—the periodic appearance of adult
Medusz 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
Cyaneide. It has but few marginal tentacles, the centre one being
developed far above the others; the separate lobes of the actinostome
are, however, 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 Cyaneid and Pelagide, the latter bemg only per-
manent forms resembling somewhat embryonic Cyaneide.

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

Cat. No. 531, Naushon, A. Agassiz, Sept. 1861. Young.

Cyanea versicolor Acass.

Cyanea versicolor AGass. Cont. Nat. Hist. U. 8., IV. pp. 119,162. 1862.

South Carolina (L. Agassiz). Py
Cat. No. 329, Charleston, 8. C., 1852, L. Agassiz.

PELAGIDZ.

Cyanea Postelsii Br.

Cyanea Postelsii Br. Meém. Ae. St. Pet., p. 375, Pl. 12, 13, 13". 1838.

Cyanea Postelsii AGAss. Cont. Nat. Hist. U. 8., TV. p. 162. 1862.

Cyaneopsis behringiana Br. Meém. Ac. St. Pet., Pl. 11, Fig. 1. 1838. Young ?
2 Cyanea ferruginea Escu. Syst. d. Acal., p. 70. 1829.

Cyanea Postelsii Luss. Zooph. Acal., p. 387. 1843.

AT

This species is extremely abundant during 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 PKLAGIDA Geg.

Pelagide GEGENB. Zeitsch. f. Wiss. Zool., VIII. p. 210. 1856.
Pelagide AGass. Cont. Nat. Hist. U. S., IV. pp. 121, 1638. 1862.

PELAGIA Per. et Les.

Pelagia P&rR. et Les. Ann. du Mus., XIV. p. 37. 1809.
Pelagia Escu. Syst. der Acal., p. 72. 1829.

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

Pelagia AGAss. Cont. Nat. Hist. U. S., IV. p. 163. 1862.
Dianea Lam. Syst. An. s. Vert., II. p. 507.

Pelagia cyanella Pér. et Lrs.

Pelagia cyanella Pir. et Lys. Ann. du Mus., XIV. p. 37. 1809.
Pelagia cyanella Escw. Syst. der Acal., p. 75. 1829.
Pelagia cyanella Bosc. Hist. Nat. des Vers., II. p. 140, Pl. 17, Fig. 3.

Pelagia cyanella AGAss. Cont. Nat. Hist. U. S., IV. pp. 128, 164, III. Pls. 13, 13%, Pl. 12.

Medusa pelagia Swartz. Konig. Vetensk. Akad. 1788.

Medusa pelagia LOorruinc. Reise, p. 105.

Medusa pelagia Lin. Syst. Nat.

Pelagia americana PER. et Les. Ann. du Mus., XIV. p. 39. 1809.
Pelagia noctiluca CHAM. ; in Choris’ Voyage Pittoresque, p. 3.
Pelagia denticulata PER. et Les. Ann. du Mus., XIV. p. 38.
Dianea cyanella LAMK. An. s. Verteb., Il. p. 507.

Dianea denticulata Lamx. An. s. Verteb., Il. p. 507.

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

Caribbean Sea (Swartz, Loffling); Coast of Florida,
Tortugas (L. Agassiz).

Fic. 68. Pelagia cyanella Pér. et Les. (copied from Agassiz’s Contributions). a, umbrella ;

m, actinal appendages ; ¢, marginal tentacles.

48 DACTYLOMETRA.

Pelagia Brandtii Acass.

Pelagia Brandiiti AGAss. Cont. Nat. Hist. U. S., IV. p. 164. 1862.
Pelagia denticulata Br. (non Pér. et Les.). Mém. Acad. St. Pet., p. 383, Pl. 14, Fig. 2. 1838.

Aleutian Islands (Mertens).

DACTYLOMETRA Aaass.

Dactylometra Acass. Cont. Nat. Hist. U. 8., IV. pp. 125,166. 1863.

Chrysaora ESCH. (p. p.).

Syst. d. Acal., p. 78. 1829.

Dactylometra quinquecirra Acass.

Dactylometra quinquecirra AGASS.

Cont. Nat. Hist. U. S., IV. pp. 125, 166. 1862.

Pelagia quinquecirra Dus. 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

Fig. 69.

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 the
large tentacles arise, and the space between this large lobe and the
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 lobes. 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 Medusz are nocturnal in their hab-
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 torpid 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 im the folds of the fringes of the actinostome,
moving along with the jelly-fish, which, when they are pushed off
accidentally, rush 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 by being swallowed, without 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 specimens 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-
cophore. 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 Meduse which have been
observed are found in the brighest sunshine only, or in very dark
nights. arly in the morning, and till about ten o’clock, even on clear
days, Medusz do not make their appearance, while from eleven till one
or two o'clock 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 fact, is one of the
- most favorable for collecting, in spite of the darkness.

Nantucket Bay (Desor); Naushon (A. Agassiz); between Bermudas
and Azores (J. Drayton).

Cat. No. 343, Naushon, Mass., Sept. 1861, A. Agassiz.

Cat. No. 388, Bermudas, A. 8. Bickmore.

NO. Il. 7

50 MELANASTER.

POLYBOSTRICHA Br.

Polybostricha Br. Mém. Acad. St. Petersb., p. 384. 1838.
Polybostricha AGAss. Cont. Nat. Hist. U. S., TV. pp. 126, 166. 1862.

The species of Polybostricha and Melanaster which are here enumer-
ated were observed during a calm off 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 marme
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 will prove, on closer examination, to be identical with them.

Polybostricha helvola Br.

Polybostricha helvola Br. Mém. Acad. St. Petersb., Pl. 15, p. 384. 1838.
Polybostricha helwola AGAss. Cont. Nat. Hist. U. S., 1V. 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.). Mém. Acad. St. Petersb., p. 385. 1838.

Melanaster Mertensii Acass.

Melanaster Mertensiti AcAss. Cont. Nat. Hist. U. 8., IV. p. 166. 1862.
Chrysaora melanaster Br. Mém. Acad. St. Petersb., Pls. 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., 1V. p. 166. 1862.

Kamtschatka and Avatska Bay (Mertens); off San Francisco Bar
(A. Agassiz). -

HAPLOSTOMES, 51

SusorDER HAPLOSTOME AGass.

Haplostomee AGaAss. (excl. Lucernarie A. AG.). Cont. Nat. Hist. U. §., IV. p. 167. 1862.

Family THALASSANTHEZ: Less.

Thalassanthee Luss. Zooph. Acal., p. 298. 1848.

Thalassanthee AGAss. Cont. Nat. Hist. U. S., IV. p. 167. 1862,
AEginide GEGENB. Zeits.. f. W. Zool., VIII. p. 258, 1856.
Aiginide McCr. Gymn. Charl. Harb., p. 107.

FOVEOLIA Pér. et Les.

Foveolia Pir. et Lus. Ann. du Mus., XIV. p. 27. 1809.
Foveolia Acass. Cont. Nat. Hist. U. 8., TV. p. 168. 1862.
Cunina Escu. Syst. d. Acal., p. 116. 1829.

Cunina Bu. Man. d’Actinol., p. 279. 1834.

Cunina Less. Zooph. Acal., p. 301. 1843.

Cunina LAMK. Syst. Anim. s. Vert., III. p. 142.

‘Cunina GEGENB. Zeit. f. Wiss. Zool., p. 259. 1856,
Cunina McCr. Proce. Elliot Soc., p. 108. 1857.

Foveolia octonaria A. Acass.

Cunina octonaria McCr. Proce. Elliot Soe., Pl. XII. Figs. 4, 5, p. 109.
Cunina octonaria AGAss. Cont. Nat. Hist. U. S., IV. p. 168. 1862.
Cunina octonaria McCr. P's. 4, 5, 6, 7, for Embryolog. Hist.; Elliot Soc., pp. 1-36. 1856.

Charleston, 8. C. (McCrady).
Museum diagram No. 15, after McCrady.

CAMPANELLA Bt.

Campanella Bu. (non Less.). Man. d’Actin., p. 286. 1834.
Campanella AGAss. Cont. Nat. Hist. U. S., IV. p. 169. 1862.
Aiginopsis J. MULL. (non Br.). Archiv f. Anat., p. 272. 1851.

Fritz Miller was the first to show (Wieg. Archiv., 1861) that the
position of the Al%ginidee and Charybdeidz among the Hydroids was
not a natural one. He proposed for the reception of these groups a
new division equivalent to the Discophors and Hydroids. But as he
considers the Ctenophorze and Hydromeduse as the two great divisions
of the Acalephs, his group of Alginese would hold very nearly the same
rank as that which we are induced to assign to it here, — that of a
suborder among Discophore. From the examination of the only spe-
cies of Campanella thus far found on our coast, and a comparison

52 CAMPANELLA PACHYDERMA.

with the two species of Trachynema here enumerated, I am inclined to
add, near this suborder, two other families, the position of which in the
different systems of classification has always been a great puzzle. I
mean the Trachynemidz and the Geryonide (Persa, Aglauride).* The
peculiar solid character of the bell of these families, incapable of con-
traction to any extent, is in strikmg contrast with the transparent filmy
disk of the true Hydroids, reminding us of the solid mass of the larger
Discophore. 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 Trachynemidee, so different from anything
found among the true Hydroids, and which resemble so closely those
of the Charybdeide, is another character in favor of this division, as
well as the nature of the veil, which ts a thick, solid, folded membrane,
approaching somewhat in character the actinal pouches formed by the
veil of Campanella.

Campanella pachyderma A. Acass.

This small Medusa is particularly interesting on account of the light
it throws on the systematic position of the Aiginide. Having the gen-
eral appearance of the Alginide, it has, however, distinctly marked
radiating and circular tubes; the genital organs are developed, as in
that family, in horseshoe-shaped pouches 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 surface. 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 Discophore, as the Lucer-
nariz and Cuninide, for instance, where they form an elongated lobed
rosette round the centre. The genital pouches extend im 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 the 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), the chymiferous tubes, as well as the circular tube,

* From the figure given by Gegenbaur of the pedunculated marginal bodies in Aglaura, the
affinity to Trachynema (Circe) is unquestionable.

CAMPANELLA PACHYDERMA. 53

can readily be seen through 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.

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 are thrown out
beyond the circular tube. p is the outer wall of the proboscis ; g, the genital pouches; f, the place
of attachment of the veil, as seen from the actinal side ; f’, one of the pouches formed by the veil ;
Jf", 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 ;
i, 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, J, clus-
ters of lasso cells ; 0, outer wall of bulb.

BA TRACHYNEMID&.

t

margin of the circular tube (Fig. 72), while at other times it is closely
hemmed in on all sides. (Fig. 75.) The base of the tentacles swells
out above and below the chymiferous tube, forming a large bulb, in the
upper portion of which pigment-cells of a brownish-red color (Fig. 75, m)
are loosely scattered, while in the lower portion (Figs. 74, 75, p”) 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, 7) similar to those of young Tubularian Medusz, 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.

ZEGINOPSIS Br.

Eginopsis Br. (non J. Miller). Prod. Mém. Acad. St. Petersburg, p. 222. 1835.
AEginopsis AGAss. Cont. Nat. Hist. U. S., TV. p. 170. 1862.
Aiginopsis Less. Zooph. Acal., p. 304. 1843.

figinopsis Laurentii Br.

Aginopsis Laurentii Br. Mém. Ac. St. Petersb., Pl. 6, p. 363. 1838.
Eyinopsis Laurentii Less. Zooph. Acal., p. 304. 1843.
Aginopsis Laurentii AGAss. Cont. Nat. Hist. U. S., 1V. p. 170. 1862.

Laurent Bay, Behring’s Straits (Mertens).

SusorpeER TRACHYNEMID A. AGass.

Forbes, in his Natural History of the British Naked-eyed Meduse,
characterized as a family the Circeide ; at that time only a few other
species of this group were known, but so imperfectly described that
even at the present day the natural affinities of these Meduse are far
from being well ascertained. Gegenbaur, who has studied Medusz
which I suppose to be only the young of closely allied forms, has also
separated his young Meduse as a distinct family, under the name of
Trachynemide. The Diana conica of Lesson may even prove to be
the adult of his Zrachynema ciliatum, 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 Trachy-
nema ciliatum (Geg. Pl. TX. Fig. 6) with the young specimens of Circe
here figured, will show the close affinity of these two Meduse. The
family name of Trachynemide ought therefore yield to that proposed

* Ann. Scien. Nat., Vol. X. Pl. 6, Fig. 3.

TRACHYNEMA CAMTSCHATICUM. 55

by Forbes ; unfortunately, the name Circe had already been applied to
a genus of Mollusks, before Brandt proposed it in 1838, and we have
therefore retamed the name of Gegenbaur. Gegenbaur placed these
Meduse in the vicinity of the Eucopidx ; but a close examination of
their characters, to which I have already referred when speaking of
Campanella, leads us to remove them—as well as the Aglauride,
Geryonide, and Leuckartidee — to the Discophorss Haplostomes, as a
separate suborder closely allied to the Aiginide. 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 Trachynemidz (Circeans) with the Discophore.

Family TRACHYNEMIDA Gegenb.

Trachynemide GEGENB. Zeit. f. Wiss. Zool., VIL. p. 249. 1856.
Circeide Forbes. Brit. Naked-eyed Meduse, p. 34. 1848.
Circeide AGass. Cont. Nat. Hist. U. S., IV. p. 348. 1862.
Trachynemide Acass. Cont. Nat. Hist. U. 8., IV. p. 365. 1862.

TRACHYNEMA Gecens.

Trachynema GEGENB. Generationswechsel, p. 50. 1854.

Circe Mertens. Br. Mém. Acad. St. Petersb., p. 219. 1835. (Preoccupied in Moll.)
Circe Forbes. Brit. Nak. Medusa, p. 34. 1848.

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

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

Trachynema camtschaticum A. Acass.

Circe camtschatica Br. Mém. Acad. St. Pet., p. 354, Pl. I. Figs. 1-5. 1838.
Circe camtschatica AGAss. Cont. Nat. Hist. U. S., IV. p. 348. 1862.

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

Circe impatiens AGAss. Cont. Nat. Hist. U. S., IV. p. 349. 1862.

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 (Fie. 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 cayity is especially long, and extends to the

56 TRACHYNEMA CAMTSCHATICUM.

actinal pole in the 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 pomt where the

Fig. 77. Fig. 78.

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 appear
as if they had been knotted. The general color is very
pale pink ; the ovaries, ambulacral tentacles, and the pro-
boscis being of a light-brown 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
C. camtschatica ; 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. 80. ,

Fig. 76. Profile view of Trachynema camtschaticum, slightly magnified.
Fig. 77. One of the genital organs. g, point of attachment to chymiferous tube.
Fig. 78. Section of Trachynema to show the size of the gelatinous prolongation, p, and the
mode of attachment of the genital organs, g.

Fig. 79. Chymiferous cavity of Trachynema at the end of the gelatinous proboscis.

Fig. 80. View of Trachynema from above, to show the shape of the lips of the actinostome.
c, chymiferous cavity at base of proboscis into which the tubes lead; p, gelatinous part of pro-
boscis ; J, lips of actinostome ; 0, opening formed by contraction of part of the chymiferous cavity.

TRACHYNEMA DIGITALE. 57

Trachynema digitale A. Acass.

Medusa digitalis Fas. Faun. Groenl. No. 361. 1780.
Turris (Circe) digitalis Morcu (non Forbes). Besk. af Gronl., p. 95. 1857.
Ejirene digitale Escu. Syst. der Acal., p. 95. 1829.

There is considerable doubt as to the specific difference of this spe-
cies of Trachynema from the English Circe of Forbes, and from the
Circe camtschatica of Brandt, the series of young observed at Nahant
bemg 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 developed ; in the north-

“a

aN Cd Yo He
YUNA

Is

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¢, ¢, ¢, ¢,
tentacles opposite the chymiferous tubes ; greatly magnified.

Fig. 83. Profile view of a part of the circular tube to show the folds of the veil. , one of the
pedunculated marginal capsules; ¢, young tentacle ; v, folds of the veil; somewhat more magnified
than Fig. 82.

NO. Il. 8

58 TRACHYNEMA DIGITALE.

the level of the circular tube, and the small size of the digestive cavity.
The eight chymiferous tubes are broad, and their course can readily be
traced along the proboscis. The summit of the bell is quite conical ;
the chymiferous tubes lead into a broad circular tube, opening into the
tentacles, which are 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 ascertain 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, ¢, ¢ ¢, . .
Fig. 82, bemg a view from the actinal side of the youngest Circe
observed ; between the chymiferous tubes there are in these young
Medusz 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, garnet-colored bodies, enclosed
in a fold, standing out from the 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 slight contractility of the bell of these Medusz, they use the veil as

Fig. 84.

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 Medusee. In an adult, when seen in profile, the folds
of the veil are so thick that they are easily mistaken for rudimentary
tentacles (v, 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 which hang down from near the upper part
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 be-

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

TRACHYNEMA DIGITALE. 59

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

The young Medusz are very different in shape from the adults.
Small specimens, 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 down 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 ciliatum of Gegenbaur. When Fig. 86.
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 development,
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 further. The adult medusz attain 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 Medusz, supposed a species of Turris to
be identical with it; after a careful perusal of the description of Fa-
bricius, | 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 Medusz of Greenland, retains the generic name of Forbes, and makes
it synonymous with Circe ; this is certainly a very different interpreta-
tion of the genus Turris of Lesson from what it has received thus far
by any writer on Acalephs.

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

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

Cat. No. 8377, Nahant, Mass., A. Agassiz. Medusve.

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

Museum diagram Nos. 16, after Alex. Agassiz.

Fig. 86. Young Trachynema, measuring over one third of an inch in height; the veil is
thrown out beyond the level of the circular tube.

60 LEUCKARTIDZ.

PERSA McCr.

Persa McCr. Gymn. Charl. Harb. 1857.
Persa AGass. Cont. Nat. Hist. U. S., IV. p. 349. 1862.

Persa incolorata McCr.

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

Charleston Harbor (McCrady).

Family LEUCKARTIDA Agass.

Leuckartide AGass. Cont. Nat. Hist. U. S., IV. p. 364. 1862.
Geryonide Escu. (p. p.). Syst. d. Acal., p. 86. 1829.

LIRIOPE Gzcens.

Liriope GEGENB. (non Less.). Zeit. f. W. Zool., p. 256. 1856.
Geryonia Less. Zooph. Acal., p. 329. 1843.

Geryonia Escu. (p. p.). Syst. d. Acal., 1829. (Von Pér. et Les.)
Dianea Q. and G. Voyage de l’Uranie, p. 566.

Eurybia Escu. Syst. d. Acal., p. 118. 1829. Young ?
Eurybiopsis GEGENB. Zeit. f. Wiss. Zool., p. 247. 1856.

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

Liriope tenuirostris Acass.

Liriope tenuirostris AGass. Cont. Nat. Hist. U. S., Vol. IV. p. 365. 1862.
Florida, Key West (L. Agassiz).

Liriope scutigera McCr.

Liriope scutigera McCr. Gymn. Charl. Harb., p. 106.
Liriope scutigera AGass. Cont. Nat. Hist. U. S., IV. p. 365. 1862.

tical.

Charleston, 8. C. (McCrady).

Fig. 87. Liriope scutigera McCr. ?

In company with Liriope tenwirostris is found
another species of Liriope (Fig. 87), which may
prove identical with the Luriope seutigera 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 Miller, with which it may prove iden-

LUCERNARLE. 61

SusorDER LUCERNARLZ Jouwnst.

Lucernariade Jounst. (non Huxl.). Brit. Zooph., p. 244, Second Edition.
Calycozoa Luck. Morphol. u. Verwandtschaft der Wirbell. Thiere, p. 20. 1848.
Podactinaria Epw. and Harmen. Brit. Foss. Corals. 1850.

Lucernariade AGAss. Cont. Nat. Hist. U. S., IV. p. 175. 1862.

Lucernarie H. J. Cuarx. Proc. Bost. Soc. Nat. Hist., p. 47. 1862.

Lucernarie H. J. Chark. Journ. Bost. Soc. Nat. Hist., p. 531. 1863.

Clark has made of the Lucernariz an order equivalent to the Hy-
droids and the Discophore ; but it should be remembered at the same
time that his Acalephz correspond to the Hydroid and Discophorous
Medusz of other authors, and do not include the Ctenophore. We
would reduce this group to the level of a suborder; for, as Professor
Agassiz has very justly said, the Lucernariz are only pedunculated
Discophoree, and have no claim to be considered as a group of a higher
yalue than a suborder. They seem to bear the same relation to the
free Discophorz which the Pentacrinidz do to the Comatulide. Their
mode of development may show that their separation as a distinct sub- _
order is giving even too much weight to their embryonic character ;
and we may find, with future investigations, a somewhat similar rela-
tion between them and the Strobila, from which free Discophore are
produced, as that which we have between the free and sessile species
of Tubularians.

Family CLEISTOCARPIDA: H. J. Clark.

Cleistocarpide H. J. CLarK. Journ. Bost. Soc. Nat. Hist., p. 535. 1863.

HALIMOCYATHUS AL. J. CLARK.

Halimocyathus H. J. Cuarx. Journ. Bost. Soc. Nat. Hist., p. 536. 1863.

Halimocyathus platypus H. J. Crark.

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

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

MANANIA H. J. Crarx.

Manania H. J. Cuarx. Journ. Bost. Soc. Nat. Hist., p. 541. 1863.

62 ELEUTHEROCARPID.

Manania auricula H. J. Ciark.

Manania auricula H. J. CharKx. Journ. Bost. Soc. Nat. Hist., p. 542. 1862.
Lucernaria auricula Fas. (non Mill.). Fauna Groenl., 1780, No. 332.
Lucernaria typica GREENE. Nat. Hist. Rev., p. 132. 1858.

Lucernaria Fabricii AGAss. Cont. Nat. Hist. U. 8., 1V. p.176. 1862.

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

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

Family ELEUTHEROCARPIDA H. J. Clark.

Eleutherocarpide H. J. CLARK. Journ. Bost. Soc. Nat. Hist., p. 536. 1863.

LUCERNARIA Mttt.

Lucernaria Mtxu. Prod. Zool. Dan. 1776.
Lucernaria AGASS. (p. p.). Cont. Nat. Hist. U. 8., IV. p. 175. 1862.
Lucernaria H. J. CLark. Journ. Bost. Soc. Nat. Hist., p. 551. 1863.

Lucernaria quadricornis Mux.

Lucernaria quadricornis Muu. Zool. Dan., I. p. 51, Pl. 39, Figs. 1-6.

Lucernaria quadricornis Sars. Fauna Littor., p. 20, Pl. 3, Figs. 1-7.

Lucernaria quadricornis Jounst. Br. Zooph., p. 252, Pl. 15, Figs. 3-7.
Lucernaria fascicularis Fuem. Wern. Soc., I. p. 248.

Lucernaria quadricornis AGAss. Cont. Nat. Hist. U. S., IV. p. 175. 1862.
Lucernaria quadricornis Strmps. Mar. Inv. Grand Manan, p. 8. 1853.
Lucernaria quadricornis H. J. CLARK. Journ. Bost. Soc. Nat. Hist., p. 551. 1863.
Lucernaria quadricornis Epw. & Haime. Hist. des Cor., Ill. p. 459.

Grand Manan (W. Stimpson); Massachusetts Bay, Chelsea Beach,
and Swampscott (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. Crark.

Haliclystus H. J. Cuarx. Journ. Bost. Soc. Nat. Hist., p. 559. 1868.

HALICLYSTUS AURICULA. 63

Haliclystus auricula H. J. Cuarx.

Haliclystus auricula H. J. Crarx. Journ. Bost. Soc. Nat. Hist., p. 559. 1863.
Lucernaria auricula Miz. Zool. Dan., Pl. 152.

Lucernaria auricula Mont. Lin. Trans., IX. Pl. 7, Fig. 5.

Lucernaria auricula Jounst. Br. Zooph., p. 246, Second Edition.

Lucernaria auricula Sars. Bidr. Sée. dyr., Pl. 4, Fig. 1-13.

Lucernaria octoradiata LAMK. An. s. Vert., I. p. 414. 1816.

Lucernaria auricula Epw. & Harmer. Hist. d. Coralli, TI. p. 458.

Lucernaria auricula AGAss. Cont. Nat. Hist. U. S., IV. p. 176. 1862.
Haliclystus auricula Pacx. List of Animals. 1863.

Without attempting a critical revision of the Lucernarix, which has
become necessary in consequence of the somewhat contradictory state-
ments of Sars, Edwards, Allman, Gosse, Keferstein, and Clark, and for
which 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 Lucernaride do not belong
to a single genus, but that several genera can very justly be distin-
guished upon the single genus of Lucernaria of previous authors.

Fig 89.

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
papers quoted above.

The young of our Lucernaria (Fig. 90) shows how
much still remains to be done respecting the changes
which it undergoes. In a small Lucernaria, of one

Fig. 88. Hialiclystus 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 an inch in height. a, anchors still
retaining the shape of the tentacles, ¢.

64 HYDROIDA.

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 m clus-
ters, but placed at recular 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 (¢, Fig. 90) of the disk, showmg plainly that the
anchors, as Professor Clark has proved, are only modified tentacles ; the
peduncle is also quite short, and stout in proportion to the disk. The
young Lucernaria 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. 521, Chelsea Beach, L. Agassiz.

Cat. No. 322, Mount Desert Islands, Mame, W. Stimpson.

Cat. No. 323, Anticosti Island, Anticosti Expedition, August, 1861.

Cat. No. 380, Anticosti Island, Anticosti Expedition, August, 1861.

Haliclystus salpinx H. J. Crark.
Haliclystus salpinz H. J. CuarK. Journ. Bost. Soc. Nat. Hist., p. 563. 1863.

Mount Desert Islands, Maine (Stimpson).

OrDER HYDROID ZA JoOuNST. (mod. Acass.).

Anthozoa Hydroida Jounst. Brit. Zooph., Second Edition, p. 5.

Gymnophthalma ForBes. Brit. Naked-eyed Meduse. 1848.

Coralliaria Tabulata, Rugosa, and Hydraria Mitne Epw. & HaAIMe.

Hydromeduse et Siphonophore Voat. Siph. de Nice.

Hydroidea, Medusida Craspedota, and Siphonophora GEGENB. Zeit. f. W. Zool. 1856.
Hydroide McCr. (p. p-). Proce. Elliot Soc. 1857.

Hydrozoa Hux. Ray Soe. 1859.

Hydroide AGAss. Cont. Nat. Hist. U. S., TI. 1860. 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 young Hydroid Medusx and of the young Hydraria. From the ob-
servations of Wright on the development of Thaumantias imconspicua,
of Aquorea, 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 Tubularianlike Hydroids stand
lower than the Campanularians ; while such forms as the Hydroids of

HY DROID. 65

Melicertum, of Trichyra, and Lafoea, stand intermediate between them.
Resembling the youngest stages of the Campanularian Hydrarium we
have such forms as Clava and Rhyzogeton ; while the more branching
forms, Eudendrium 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, reminding
us of the free communities 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 standing 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
ean be obtained by comparmeg the young Medusx 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 Medusz, 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, different species
by the number of tentacles, of marginal bodies, or the size of the ova-
ries. The main characteristic of the greater number of Tubularians,
when first liberated, is the totally different 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 Meduse, have taken a development corresponding to their age.
Applying this to the standing of the different Tubularians, we should place
genera such as Clava and Eudendrium, in which the Medusz 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 Medusz losing almost entirely their embryonic character.
From these we pass to Sarsia, Syndictyon, Dipurena, Saphenia, Turris,
and Turritopsis. We then have families where the localization of the ten-
tacles, the position of the ovaries along the proboscis, 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
Medusz, and where the genital organs are intimately connected with
the digestive cavity. The young of these Medusz (Melicertum and

NO. II. 9

66 HYDROIDA.

Staurophora) have, like the young Tubularian Meduse, a deep bell and
few tentacles; these characters they lose with advancing age. The
young Meduse of the greater part of the Campanularian Hydroids,
with the exception of the Hucopidee and some of the Aiquoride, 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 different 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 Eucopidz the number of tentacles with
which the young Meduse are liberated is far greater, the marginal cap-
sules being constant in young and old. The same is the case with the
/Equoride ; they are liberated with many tentacles, and the disk, like
that of the Eucopide, is quite flat. We find also among the Campanu-
larians, m some genera, a tendency to localization of the tentacles, as in
EKucheilota; 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 Kutima, 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 Geryonopside, all
these having tolerably deep bells and few tentacles, more resembling the
Tubularians ; next the AZquoridee, some of which, in their young stages
(Halopsis), resemble the Medusze of Tubularians, with their high bell and
few tentacles ; next would come the Eucopide, having still a large num-
ber of tentacles, but where the marginal capsules are limited in number,
and in which the young Medusz at no time resemble the young Me-
duse of Tubularians ; finally, highest of all the Campanularians would
stand the Oceanide, 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 chymiferous tubes in Tima and
the Geryonopside ; in the Acquoride they take their origin from the
base of the digestive cavity ; in the Eucopide they are limited, as well
as in the Oceanide, to definite parts of the chymiferous tubes.

Were we to judge simply from the nature of the Medusx of the so-
called Siphonophorze, the swimming bells and the sexual Meduse, we
should be justified im unitine 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 Siphonophore, as recently modified by some naturalists. There
is perhaps no stronger case to be brought up in confirmation of this
view, than the fact that the free Medusz of Velella are so closely allied

HY DROID. 67

to the Medusx of some of our Tubularians, that McCrady even proposed
to separate the Velellide from the Siphonophore, and to place them
next the Tubularians; the sexual Medusa, also, of several of these free
Hydroids resemble very closely other Medusz, as those of Hybocodon,
Corymorpha, and the like. When 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 subdivisions of Eschscholtz, the great master im the classifica-
tion of the Acalephe, whose views seem to stand out brighter with
every fresh investigation. For certainly the subdivision by Leuckart
of the Siphonophor 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 im 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 different orders of the old group of Siphonophorz among the
Hydroids, we cannot fail to consider them as lowest in the series; they
form communities, the different individuals of which never attain the
high degree of complication and the individuality so characteristic of
the Campanularian Meduse, and they must therefore rank lowest, next
to Hydractinia and the like, which form the connecting lnk 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 Medusz 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 Medusz, seems to
preclude the idea of separating them as distinct families, notwithstand-
ing the great difference of form between the adult Medusee. 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, produce Medusz 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 far as
we 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 Acalephe. This view of the proper method to
be followed in the classification of Hydroids has been frequently em-

68 SERTULARLZ.

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. Allman, in a recent paper on the Classification of Hy-
droids, has carried the same method out for the Tubularians.

SuBoRDER SERTULARIZ AGass.

Sertularie AGcaAss. Cont. Nat. Hist. U. 8., IV. p. 348. 1862.
Sertularina EuRENB. Corall. des roth. Meeres.
Sertularina Jounst. Brit. Zooph., p. 56.

Family OCEANID:® Esch. (rest. Ac.).

Oceanide Esc. Syst. d. Acal., p. 96. 1829.
Eucopide GkGENB. (p. p.). Versuch eines Syst. d. Med., p. 241. 1856.
Oceanide AGAss. Cont. Nat. Hist. U. 8., IV. p. 352. 1862.

The free Medusz 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 tubes, 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, contaimed in it
Medusz belonging to several genera. Forbes first proposed to divide
it, and suggested the name Cosmetira for his Zhawmantias 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 Eucopide.

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-
cuished in these Acalephs. It seems to me doubtful whether the genus
Hpenthesis of McCrady can be retamed, and I think it will eventually
prove identical with Oceania, if we limit the genus to such species as
Thaumantias hemispherica of Forbes. The Hydra of Oceania is a
Wrightia ; that of the Hucope diaphana of our coast is a Laomedea,
resembling the Z. 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 chymiferous 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 AGAss. Mem. Am. Acad., IV. p. 289. 1849.
Tiaropsis AGAss. Cont. Nat. Hist. U. S., IV. p. 355. 1862.

Tiaropsis diademata Acass.

Tiaropsis diademata AGAss. Mem. Am. Acad., IV. p. 289, Pl. 6.

Tiaropsis diademata AGass. Cont. Nat. Hist. U. S., Ill. p. 354, Pl. 31, Figs. 9-15; IV. pp. 308
—311, Figs. 45-48. 1862.

Tiaropsis diademata A. AGAss. Proc. Bost. Soc. Nat. Hist., IX. p. 93, Fig. 10.

Tiaropsis diademata Morcu. ; in Beskriv. af Groenland. 1857.

This Medusa is one of the earliest visitants of our wharves in the
spring. In company with Sarsia and Syndictyon, it occurs im 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 Meduse (Fig. 92), which are fully described in Pro-

Fig. 91.

fessor Agassiz’s Contributions, are exceedingly numerous. The tentacles
develop independently of the eyes, while the latter never increase 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. 93. Young Tiaropsis, having forty tentacles. c, eye-speck; f, digestive cavity ; g, chy-
miferous tube; e, primary tentacles ; a, middle tentacle ; b, third set of tentacles in pairs; a, fourth
and fifth sets of pairs of tentacles.

70 OCEANTA.

this is really the case, as we have nothing of the sort among any of the
other Hydroid Medusz.

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 Per. et Las.

Oceania PER. et Les. Ann. du Mus., XIV. p. 32. 1809.

Thaumantias Escn. Syst. d. Acal., p. 79. 1829.

Oceania Less. Zooph. Acal., p. 318. 1843.

Phialidium Leuck. Arch. f. Nat., I. 1856.

Epenthesis McCr. Gymn. Charl. Harb., p. 89.

Oceania AGAss. Cont. Nat. Hist. U. S., IV. p. 352. 1862.

Wrightta Acass. Cont. Nat. Hist. U. 8., IV. p. 354. 1862. Hydrarium.

Oceania folleata Acass.

Oceania folleata AGAss. Cont. Nat. Hist. U. S., IV. p. 353. 1862.
Epenthesis folleata McCr. Gymn. Charl. Harb., p. 89.

Charleston Harbor (McCrady).

Oceania languida A. Aaass.

Oceania languida A. AGAss.; in Agassiz’s Cont. Nat. Hist. U. S., IV. p. 353. 1862.

Hydrarium. The American species of Wrightta mentioned in a note by Professor Agassiz, in
Cont. Nat. Hist. U. S., IV. p. 354. 1862.

2 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 Harbor. McCrady observed only a
single specimen, and his description is too short not to leave some doubt

Fig. 94. on this point. His single specimen, moreover, was
not in a normal condition, as he says there were
five labial appendages. From the-fact that there
is but one marginal capsule between each tentacle
im the Charleston species, and rarely two, while
there are always two, 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 the ten-
tacles (6, 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 ; 6, 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 (f, 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 bemg separated by a constriction, and a granule devel-
oped in it (¢, 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. 96) 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 probable
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 from 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 well known, Wrightia, the
name given to the Hydrarium by Professor Agassiz, must be rejected.
We have on our coast two species of Wrightiz, one of which produces
planulze, and resembles, in its general appearance and mode of branch-
ing, the Laomedea acuminata figured by Wright in the Edinbtirgh New
Philosophical Journal for 1856; the latter, however, produces Medusz,
while the second species is closely allied to the European Campanularia
syringa ; it has reproductive calycles similar to the calycles of the
Campanularia fastigiata Alder ; it differs considerably from the figure
of the C. syringa given by Van Beneden, the stolon of our species
bemg as strongly ringed as the pedicel ; the calycle is likewise slightly
constricted in the middle. This species has not been found with

Fig. 95.

Fig. 95. Magnified view of the actinostome. 7, chymiferous tube ; f, 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 Oceania (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
bicophora ; 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. gr

Fig. 96! Fig. 98.

Medusa by the absence of ovaries, the two long tentacles (¢, Fig. 97),
and by what characterizes at once this genus, the position of the mar-
gimal capsules (c, Fig. 97) on each side of the primary tentacles (¢ ¢,
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 halfway between the
chymiferous tubes, 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 (¢, Fig.
99), and in which we can trace the position of
the remaining sixteen tentacles (¢”, Fig. 99),
the ovaries have also taken a greater development, and are now ellipti-

3 Fig. 99.

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, ¢, 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, where the remaining tentacles
of the adult (7) are developing between the tentacles, #, t*, @, t, ?, as well as additional marginal
capsules, c.

OCEANIA LANGUIDA. ie

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), Te 0,

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
thirds the length of the chymiferous tubes ;
when distended with eges, 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 simply some-
what darker brownish-colored than the ova-
ries. These Medusze are among the most
common on our shores; they attain their
full size durmg September, when they are
frequently met in immense shoals on warm,
still, sunny days, collected together for spawning. The young (Fig. 96)
make their appearance as early as the end of May. The adult Medusze
assume the most extraordinary attitudes as they float along, carried
about by the current; the disk is so Fig. 102.

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 former activity im younger
stages (Fig. 96), when they move through the water with short,
rapid jerks, stopping only to take a more vigorous start. The
young Medusz 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 Meduse the temperament of the adult. Young
Medusze of Bougainvillia, Lizzia, and Zanclea are lazy, like the adult ;

Fig. 101.

a

Fig. 100. Adult Oceania languida, natural size.
Fig. 101. Magnified view of an ovary. a, abactinal part of the genital organ.
Fig. 102. Peculiar attitude sometimes assumed by these Medusz.

NO. Il. 10

vA EUCHEILOTA.

while Sarsia, Nemopsis, and Margelis are as active when young as
when 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.

| by A
LA wta/t

Mv

Oceania gregaria A. Acass.
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 lips
Fig. 108. of the actinostome (Fig. 105); the color of
the genital organs and of the sensitive bulb
of the tentacles is a beautiful pale yellow;
in strong contrast to the dark coloring, of
our species ; the marginal tentacles are only
moderately contractile. The whole surface
of the water for several miles was often thickly covered with these
Medusz. 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 McCz.

Eucheilota McCr. Gymn. Charl. Harb., p. 84.
Eucheilota AGAss. Cont. Nat. Hist. U. S., IV. p. 353. 1862.

Eucheilota ventricularis McCr.

Eucheilota ventricularis McCr. Gymn. Charl. Harbor, p. 85, Pl. 11, Figs. 1-3; Pl. 1, Figs. 1, 2.
Eucheilota ventricularis AGAsSs. Cont. Nat. Hist. U. S., IV. p. 353. 1862.
Bucheilota 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

bell, with tentacular cirri well developed ; two marginal capsules be-
tween each tentacle, and rudiments of four additional tentacles half
way between the capsules. (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 simple long Fig. 105,
tube, hanging stiffly in the interior of the bell, which has
a very small circular opening ; the chymiferous 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 which had already eight
tentacles, found more than one granule, except in a single case two, in
one of the capsules.

Charleston, 8. C. (McCrady) ; Buzzard’s Bay, Naushon (A. Agassiz).

Mer ee

Eucheilota duodecimalis A. Acass.

Eucheilota duodecimalis A. AGASS.; 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 (¢, Fig. 107), and one
in the middle of the circular tube (Fig. 106); there are four long ten-
tacles, with lateral cirri (¢, Fig. 107) Fig. 106.
and long slender lashes, which are
covered with lasso cells; the chymif-
erous tubes are wide, and from their
point of junction with the circular tube
arise ribbon-shaped genital organs (0,
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 Figs. 104, 105.
Fig. 106. Eucheilota duodecimalis A. Agass.; greatly magnified.

76 EUCHEILOTA DUODECIMALIS.

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 7. ventricularis ; there is
only a single granule in each of the marginal capsules.
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 proboscis; the thickness of the
bell and its shape is totally different 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 Medusz, showing that, in spite of its
well-developed ovaries, it must have but recently been liberated from its
Hydrarium. The character of the differ-
ence between the young of these two spe-
cies of Eucheilota makes it highly probable
that the #. duodecimalis may form, when
its adult is known, the basis for a separate
genus ; we find in the arrangement of the
capsules differences similar in character to
those observed between the young of Oce-
ania and of Clytia, the adult Medusze of which are generically distinct,
I cannot help surmising that we shall find differences of a like nature
when the adult of /. duodecimalis becomes known. This is the more
probable now that we know the young of /. ventricularis, 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. 107s.

Fig. 107. Junction of one of the chymiferous tubes with the circular tube. 0, spermary; ¢,
marginal capsule ; ¢, one of the four primary tentacles ; #/, tentacular cirri.
Fig. 107%. Female Medusa of Eucheilota duodecimalis; greatly magnified.

Cini 77

CLYTIA Lamx.

Clytia Lamx. Bull. Soc. Phil.

Clytia AGAss. Cont. Nat. Hist. U. S., IV. pp. 297, 354. 1862.
Calicella Hixcxs.

Trochopyxis AGAss. Cont. Nat. Hist. U. S., IV. pp. 297, 354. 1862.
2 Platypyxis AGASS. Cont. Nat. Hist. U. S., 1V. pp. 306, 354. 1862.

The adult Medusa of Platypyxis cylindrica of Professor Agassiz is
not known; he has separated this genus from Clytia from the character
of the reproductive calycles only. The young Meduse are very much
alike, and we may have a case here, the reverse of what we find in
Sarsia and Syndictyon, of Medusz very similar in their younger stages,
but totally different in the adult forms.

Clytia intermedia Acass.

Clytia intermedia Acass. Cont. Nat. Hist. U. S., IV. p. 305, Pl. 29, Figs. 10,11. 1862.

Cat. No. 143, Nahant, Mass., April, 1855, H. J. Clark. Hydrarium.

Clytia volubilis A. Acass.

Campanularia volubilis ALDER (non Auct). Cat. Zooph. Northumb. and Durham, p. 35.

Alder was the first to distinguish the several species which have
been confounded under the name C. volubilis by different authors.
Specimens in no way to be distinguished from the European C! volu-
bilis 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. Hydromedusarium.

Cat. No. 146, Cape Cod, June, 1857, Captain N. HE. Atwood. Hydro-
medusarium.

Cat. No. 452, 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 Aaass.

Clytia bicophora AGass. Cont. Nat. Hist. U. S., IV. pp. 304, 354, Pl. 27, Figs. 8, 9 (as C. cylin-
drica) ; Pl. 29, Figs. 6-9. 1862.

Clytia bicophora A. AGAss. Proc. Boston Soc. Nat. Hist., IX. Figs. 14, 15.

Clytia cylindrica AGASS. (p. p.). Cont. Nat. Hist. U. 8., IV. Fig. 14. 1862.

Under the name of Zucope campanulata, Eucope Thaumantoides, and
EHucope affinis, Gegenbaur has described three species, which, to judge
from the development of a similar Medusa of our coast, Clytia bicoph-

Fig. 108. ora, are probably only different 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 difference of form which Gegenbaur
has found 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 in 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 Imes 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- Fig. 109.
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 globular 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

re a 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 pigment-cells 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. 108. Clytia bicophora, immediately after its escape from the reproductive calycle.
Fig. 109. A somewhat older Clytia bicophora.
Fig. 110. An adult Clytia bicophora, measuring one quarter of an inch.

CLYTIA BICOPHORA. 79

glands, extending towards the base of the proboscis. The Hydrarium
(see figure of Professor Agassiz in Vol. IV. Pl. 29, Fig. 6) grows from
three quarters to an inch in height, in small tufts attached to Fucus; the
calycles are strongly compressed (Fig. 111), and differ as much in their
proportions as those of C. cylindrica, when seen from the broad or from
the narrow side. This species may yet prove identical with the Clytia
Johnstoni of Alder. According to the figure of Wright of the Medusa
of Campanularia Johnston, it can hardly be distinguished from the
Medusa of our Clytia bicophora ; the Medusa of C. volubilis figured by
Hincks resembles also closely our Clytia Medusxe. The Medusa figured
by Dalyell as the young of IZ fimbriata, on PI. Fig. 111.
62, Fig. 4, Rare and Remarkable Animals of
Scotland, is undoubtedly a young Medusa of C.
Johnston, 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 but little question as to their specific
difference ; the peculiar species figured by Gosse
has, however, not been noticed by other English
observers. The Meduse of Clytia cylindrica and
of Clytia bicophora are so alike, immediately after
their escape from the reproductive calycles, that
when the development of Olytia cylindrica was first discovered, the
Medusz which are here figured as Clytia bicophora (Fig. 41, Agassiz’s
Cont. Nat. Hist., p. 307) were mistaken for the adult of the Medusz of
Clytia cylindrica. As the Clytia bicophora is very common at Nahant,
the complete development of the Medusa has been traced, and the
error is here corrected.

Eastport, 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, 1861, A. Agassiz. Hydrarium.

Cat. No. 135, Vineyard Sound, July, 1849, L. Agassiz. Hydromedu-
sarium.

Cat. No. 136, Grand Manan, August, 1857, J. E. 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, 1862, A. Agassiz. Hydromedusarium.

Cat. No. 445, Nahant, June, 1864, A. Agassiz. Medusa.

Museum diagram No. 17, after L. and A. Agassiz.

Ain fo \- OLY

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 Acass.

Clytia (Platypyzis) cylindrica AGAss. Cont. Nat. Hist. U. 8., IV. pp. 306, 354 (non Pl. 27, Figs.
8,9); p. 307, Figs. 42-44 (non Fig. 41). 1862.

Campanularia volubilis Lerpy. Mar. Iny. Faun. N. Y. and BR. 1., p. 6. 1855.

Campanularia noliformis McCr. Gymn. Charl. Harb., p. 92, Pl. 11, Fig. 4. ?

The reproductive calycle is conical, smooth, strongly compressed in
one direction, with a slight constriction near the free end, which flares
outwards (Fig. 112); there are from three to four young Medusze
developing 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 space; there is nothing here like the corrugations which

Fig. 114.

Fig. 112.

Gosse has figured in his C. volubilis, 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, 8. C. (McCrady); Point Judith (Leidy) ; Massachusetts
Bay, 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. 113. The same, seen from the narrow side.
Fig. 114. Sterile Hydra of P. cylindrica.

EUCOPID&. 81

ORTHOPYXIS Aaass.

Orthopyzis AGASS. Cont. Nat. Hist. U. S., IV. pp. 297, 355. 1862.
Clytia LAMX (p. p.). Bull. Soe. Phil. 1812.
2 Silicularia MEYEN. Nov. Act., XVI. 1834.

Orthopyxis poterium Acass.

Orthopyzis poterium AGass. Cont. Nat. Hist. U. S., IV. pp. 297, 302, Fig. 40; p. 355; Pls. 28, 29,
Figs. 1-5. 1862.

Massachusetts Bay (Agassiz) ; Nova Scotia (Anticosti Expedition).
Cat. No. 125, Nahant, April, 1856, 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. 130, 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. 8., Anticosti Expedition, 1861.
Museum Diagram No. 18, after L. Agassiz.

Family EUCOPIDA: Gegenb.

Eucopide Gre. (emend Agass.). Zeit. f. Wiss. Zool., p. 241. 1856.
Eucopide 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 impos-
sible to distinguish, at certain stages of growth, young Meduse, it
by no means follows that these Meduse, which have developed from
Campanularians easily distinguished, are identical. (Compare the dif
ferent Campanularians figured in the sequel.) Whenever we succeed
in tracing the complete 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. 1. 11

82 EUCOPID.

identica.; as, for example, the Meduse of Hucope polygena, Hucope
diaphana, Eucope pyriformis, and Eucope articulata. The strongest
case we can cite is perhaps that of Syndictyon and Coryne, the adult
Medusx 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 complete development of the former genus, which
will be found given in its place im. this Catalogue. Hincks, after
some observations limited to two genera of Hydroids, came to the
conclusion that we could have Meduse, 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 Medusxz
described by Hincks is fully known, 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 Eucopidz found on our coast, of which we
know the development, explain many of the contradictory statements
of European writers concerning the mode 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
Planulz, and on the other by Meduse ; and now it is found that the
Medusxe produced from Hydroids which have been considered identi-
cal species, develop into very different adult forms. See, for example,
the differences in the Medusee of Laomedea geniculata, 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 Hucope
diaphana and EHucope articulata. The Laomedea gelatinosa of Van
Beneden has twenty-four tentacles and ovaries, as in our Hucope pyri-
formis, to which it is closely allied, while the Medusa of Laomedea
gelatinosa 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 thorough acquaintance with the de-
velopment of their Meduse.

The Laomedea dichotoma of Dalyell is probably the same as the
Campanularia gelatinosa of Van Beneden. The same confusion oc-
curs in the fourth volume of Professor Agassiz’s Contributions; the
Eucope which is there figured as Hucope diaphana Agass., and the
Campanularian of that name (Plate 34), is not the Hydroid of Hw-
cope diaphana, as will be seen in the description of the latter. The

EUCOPE. 83

Hucope diaphana of the fourth volume (not that of the Memoirs of the
American Academy) is probably identical with the English Hucope
geniculata of Wright, not that of Gosse, and it may hereafter be desig-
nated as Hucope alternata.

KUCOPE Gecrns.

Eucope GrcEns. Versuch eines System ; Zeit. f. Wiss. Zool., p. 241. 1856.
Eucope AGAss. Cont. Nat. Hist. U. S., IV. p. 3851. 1864.

Eucope diaphana Aaass.

ELucope diaphana AGAss. (ex p.). Cont. Nat. Hist. U. S., IV. Pl. 33, Fig. 2. Hydrarium. 1862.
Thaumantias diaphana AGass. Mem. Am. Acad., IV. p. 300, Figs. 1, 2.:

Eucope diaphana A. AGAss. Proc. Bost. Soc. Nat. Hist., IX. p. 92, Figs. 7-9.

Lhaumantias diaphana Mércu ; in Beskriv. af Gronland, p. 96. 1857.

This is by far the most common of our Jelly-fishes ; it does not grow
to a large size, adult specimens not measuring vig. 116.
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 (¢, ¢, 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 root-like projection at their Fig Ut.
base ; this is only developed in older tentacles
of more advanced Meduse. (See Fig. 120.) With
advancing age the Meduse lose the habit 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. 116.

Fig. 115. A Evcope diaphana just after its escape from the reproductive calycle, seen in
profile.

Fig. 116. One quarter of the disk of the same, seen from above. 1, tentacle opposite chymif-
erous tube ; //, t/, tentacles with capsules.

Fig. 117. A more adyanced Eucope, in which the second set of tentacles (2) is developing
between the original tentacles (1).

84 EUCOPE DIAPHANA.

short 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. 118. from above, shows the extraordinary increase of
the number of tentacles, and the position of the
genital organs near the circular tube. As the
Medusz become older, a sort of sensitive bulb is
formed at the base of the tentacles, in which a little pigment matter
is accumulated (b, Fig. 120); this bulb is hardly perceptible in younger

+ Fig. 119. Fig. 120.

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 Meduse, just escaped from the calycle. When
examining a part of the circular tube of a Eucope 7M
somewhat more advanced than the stage represented in
Fig. 117, we find only a great increase in the sensitive
bulbs and the root of the tentacles (7, 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, ¢, ¢, Fig. 116, and ¢,
Fig. 120. The capsules (c, Fig. 120) have the same
shape and position they had in younger Meduse. The

Fig. 122. genital organs, at first mere swellings of the chymiferous
tubes (Fig. 117), soon develop into, regular pouches,
which hang down on both 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”, Fiv. i21.) The shape of the spermaries has

Fig. 121.

Fig. 118. An adult Eucope diaphana cen in profile.

Fig. 119. A quarter of Fig. 118, mor magnified.

Fig. 120. Magnified view of the circular tube of a young Eucope. 4, sensitive bulb; 7, root
of tentacle ; c, capsule ; 7’, tentacle with capsule.

Fig. 121. Spermaries ; a’, seen from above ; a’, in profile ; a’”, different attitude from above.

Fig. 122. Female genital organs.

EUCOPE DIAPHANA. 85

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 number of eggs in an adult female gig. 45,
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 Medusze, almost the only change bemg the greater
mobility of the lips of the actinostome ; the veil is totally
wanting in young Medusz, 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

long tentacles. These Meduse appear as early as
March, and are found as late as November. The
Hydrarium (Fig. 124) 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 rmged 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 Meduse develop in each calycle. Found at Fig. 125.
near low-water-mark, attached to the base of Fucus
vesiculosus.

It may be that the Medusa of Laomedea geniculata
of Gosse, figured on Plate IV. of his “ Devonshire,”
may prove to be the young of Thaumantias lucida 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 Medusa fimbriata of Dalyell (Pl. 52, Figs. 6, 7)
the same as the Medusa of Laomedea geniculata, and is it not also
identical with the ZThauwmantias 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.

Murer TAY |
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. Acass.

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 Thawnantias 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. 594, Nahant, July, 1862, A. Agassiz. Hydromedusarium.

Cat. No. 395, Nahant, June, 1862, A. Agassiz. Hydromedusarium.

Eucope polygena A. Aaass.

The only adult Medusa of the genus Eueope, of which we know
the complete development, being Hucope 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 Meduse, 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 Medusz of Hucope articulata,
E. pyriformis, E. alternata, and E. polygena, all these species having
twenty-four hollow tentacles, and ovaries close to the base of the pro-
boscis, at the time they escape from the reproductive calycles ; while
in /. diaphana and £. geniculata Gosse we have twenty-four tentacles,
nearly solid, and no ovaries in the younger stages. Another type
occurs in Obelia commissuralis 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 Hucope fusiformis
and Laomedea divaricata of MeCrady, 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 be premature to make all these divisions until we know,

EUCOPE PARASITICA. 87

from actual observations, in what manner these differences of the
young Medusz are carried out in the adult. The Hydrarium and the
Medusa of several species 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.

Hucope polygena is remarkable for the short stems of the sterile
Hydra, the stoutness of the main Fi TOR
stem, and the great number of Me-
dusze 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 Hu-
cope diaphana, in Vol. IV. Pl. 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 Laminaria, in small branching tufts, of one to two
inches in height.

Cat. No. 393, Nahant, June, 1862, A. Agassiz. Hydromedusarium.

Cat. No. 399, Nahant, June, 1862, A. Agassiz. Hydromedusarium.

Eucope parasitica A. Acass.

This species is closely allied to the EZ. polygena ; it has, like it, short
branches, composed of not more than three or four rings, supporting
the sterile Hydre ; the inner walls of the stems are parallel to the
outer wall; the sterile Hydre 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.

Eucope pyriformis A. Acass.

Laomedea gelatinosa LEiDy (non Auct.). Mar. Inv. New York and Rhode Island, p. 6. 1855.

Fig. 127.

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
Obelia 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 calycles
assume the shape of an elongated ellipse, with
a pointed cap, and three or four deep constric-

Fig. 129.

Fig. 127. E. pyriformis, seen in profile ; greatly magnified.
Fig. 128. Quarter of disk of same Medusa.
Fig. 129. Portion of Hydrarium of E. pyriformis ; magnified.

EUCOPE ARTICULATA. 89

tions. There are from nine to twelve Meduse growing in each calycle
at once.

This species is clesely allied to the Campanularia gelatinosa of Van
Beneden, and to the Campanularia dichotoma 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, Pl. 1, Fig. 1, Campanulaires de la Cote d’Ostende, and the
figures of the Medusz 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. Acass.

This species is so closely allied to Hucope pyriformis that the Me-
dus can hardly be distinguished. The Medusa of EHucope 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 Medusx of Eucopide. The

Fig. 131.

Fig. 130.

Hydrarium is at once recognized by the extraordinary length of the
ringed branch supporting the sterile Hydre, the cups of which are quite
deep and narrow. The reproductive calycle (Fig. 131) resembles in
shape that of Obelia commissuralis, but is in addition supported upon

Fig. 130. 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 Hydrz, placed as in the figure (Fig. 131), m pairs at the
base of the reproductive calycle. The Hydrarium grows to about the
size of the Hucope pyriformis, from three to four and even five inches
high, and is readily mistaken for the Hydrarium of Obelia commissu-
ralis. It grows in pools on rocks at low-water-mark.

Cat. No. 396, Nahant, June, 1862, A. Agassiz. Hydromedusarium.

Cat. No. 397, Nahant, June, 1862, A. Agassiz. Hydromedusarium.

Eucope ? fusiformis A. Acass.

Eucope? A. Acass.; in Proc. Bost. Soe. 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

Fig. 132,

branching to that of Hucope diaphana, but in which the
Hydre, remarkable for their small bell, 6, are attached
to the main stem by short branches, not having more
than three or four rings (Fig. 152), is produced a small
Medusa of a sixteenth of an inch in diameter, having,
when hatched, four long fusiform ovaries (Fig. 153), oc-
cupying nearly the whole length of the chymiferous
tubes, and forty-eight long, slender tentacles, having
well-developed rootlets, usually carried quite stiffly, with
two marginal capsules between each pair of chymifer-
ous tubes, occupying the same position as in /. diapha-
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 Eucopide, thus far described, can easily be distin-

Fig. 133.

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 #. diaphana
which I had occasion to examine, I have only
found two in which there were not twenty-four
tentacles on hatching, and in the Obelia commis-
suralis and E. pyriformis 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. 132. Hydrarium of Eucope fusiformis ; magnified.
Fig. 133. Quarter of the disk of the Medusa of Eucope fusiformis ; greatly magnified.

_

OBELIA. BE

Eucope ? divaricata A. Acass.

Laomedea divaricata McCr. Gymn. Charl. Harb., p. 93.

An examination, by Professor Clark, of the reproductive calycles of
specimens collected at Charleston by Professor Agassiz, shows that the
Medusz have forty-eight tentacles. The Hydrarium is closely related
to that of the Hucope pyriformis, which, together with the present
species, will probably form the basis for a new genus.

Charleston, §. C. (. Agassiz).

Cat. No. 82, Charleston, 8. C., January, 1852, L. Agassiz.

OBELIA Per. et Les.

Obelia Pir. et Les. ; in Ann. du Mus., XIV. p. 43. 1809,
Obelia AGAss. Cont. Nat. Hist. U. S., IV. p. 351. 1862.
Obelia McCr. Gymn. Charl. Harb., p. 94.

Obelia commissuralis McCr.

Obelia commissuralis McCr. Gymn. Charl. Harb., p. 95, Pl. 11, Figs. 5-7.

Obelia commissuralis AGAss. Cont. Nat. Hist. U. S., IV. pp. 315, 351, Pls. 33 (non Fig. 2), 34,
Figs. 10-21. 1862.

Obelia commissuralis A. AGAss. Proc. Bost. Soc. Nat. Hist., IX. p. 91, Fig. 5.

Laomedea dichotoma Leipy (non Auct.). Mar. Iny. N. J. and R. I, p. 6, Pl. XL. Fig. 36. 1855.

Laomedea gelatinosa Stimes. (non Auct.). Mar. Iny. Grand Manan, p. 8. 1853.

Laomedea gelatinosa Goutp. Rep. Inv. Mass. Bay, p. 350. 1841.

The Obelia commissuralis of McCrady, which extends from Charleston
to the coast of New England, and even as far as Grand Manan, has an
exceedingly slender polypidon and Fig. 134.
branches very profusely ; the branches,
stretching in graceful curves on both
sides of the main stem, reach their
greatest length about 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. 154); they bear from ten to

Fig. 134. Portion of stem of Hydrarium of Obelia commissuralis.

92 OBELIA COMMISSURALIS.

twelve and even sixteen Meduse. The young Medusa (Fig. 135), when
hatched, has sixteen tentacles, four chymiferous tubes, a rather long
cylindrical digestive cavity, with four labial lobes; there are no ovaries
yet developed. I have not found these Medusxe im a more advanced
condition, though they become free in the first weeks of July, and are
found durmg the whole summer, as late as September,
but im no case were there any ovaries developed. In
confinement they do not prosper, and after a few days
die, without assuming a different shape from that in
which they become free. The tentacles are slender, as
long as the diameter of the disk ; im two of the tentacles
there are large marginal capsules in a swelling on the under side ; the
re-entering 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 thimner
and more slender; it remains yet to be seen whether any further spe-
cific differences can be detected in the Meduse. If Van Beneden’s
figure of the Campanularia geniculata is correct, the European and the
American 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, 8. C., January, 1852, L. Agassiz. Hydrome-
dusarium.

Cat. No. 66, Charleston, 8. 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. 1, Dr. Leidy. Gé,_,

Cat. No. 392, Nahant, July, 1862, A. Agassiz,

Fig. 135. Quarter-disk of the Medusa of Obelia commissuralis.

LAOMEDEA. 93

LAOMEDEA TLamx.

Laomedea LAMX.; in Bull. Soe. Phil. 1812.
Laomedea AGAss. Cont. Nat. Hist. U. 8., IV. p. 352. 1862.
Campanularia LAMK. (p. p.). An.s. Vert., II. p. 129.

Laomedea rigida A. Acass.

This species is remarkable for its peculiar mode of growth. At first
glance it would readily be mistaken for a species of Dynamena, so
regular is the succession of the hydrzx along the stem, and also on
account of the absence of branches. The sterile and reproductive hy-
drz 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
nature is noticed only after a careful examination. The sterile hydre
resemble those of Laomedea amphora, while the reproductive calycles
are identical in shape with those of Obelia commissuralis. 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 amphora Aeass.

Laomedea amphora Acass. Cont. Nat. Hist. U. S8., IV. pp. 311, 314, Fig. 50; p. 352, Pls. 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, R. 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 LAOMEDEA PACIFICA.

Laomedea gigantea A. Acass.

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 off only short branches from the stout principal stem,
so that m its general appearance it resembles somewhat Sertularia
cupressina ; the branches, however, are very closely arranged round the
main stem; near the extremity we often find, in very large specimens,
the branches spreading out somewhat fan-shaped. It can readily be
distinguished from its congener, the LZ. amphora, 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 Z. amphora.

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 pacifica A. Acass.

This is another gigantic species closely allied to Laomedea amphora ;
the reproductive calycles are similar in both; the main stem of this
species is exceedingly stout; the mode of branching resembles that of
L. gelatinosa. Specimens of this species have been collected by Dr.
Stimpson, of the North Pacific Explormg 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.

QUORIDE. 95

Family AiQUORIDA: Esch. (rest. Ac.)

Aquoride Escu. (emend. Agass.). Syst. d. Acal., p. 108. 1829.
Aiquoride AGAss. Cont. Nat. Hist. U. S., IV. p. 359. 1862.

RHEGMATODES A. Aagass.
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 umbrella 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 Aquorea forbes-
zana belongs; it is closely allied to Stomobrachium Brandt (non Forbes),
and differs 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 Aiquorea 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 im Florida, bv Professor Agassiz, and the other at Naushon.

Rhegmatodes tenuis A. Acass.

Rhegmatodes tenuis A. AGASS.; in Agassiz’s Cont. Nat. Hist. U. S., IV. p. 361. 1862.

This is a large species ; specimens measuring between three and four
iches have frequently been found. The spherosome is thick (Fig. 136)

along the polar axis, bulging, in the shape of a rounded obtuse cone,

Fig. 136.

Fig. 136. A profile view, natural size, of Rhegmatodes tenuis.

96 RHEGMATODES TENUIS.

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 cay-
ity, to about one tenth the
length of the 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 (#4, 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, bemg a button
scarcely to be recognized when the tentacle is
already quite well formed; there are usually only rudimentary tenta-

Fig. 137.

Fig. 138.

Fig. 137. Quarter of the disk of Fig. 136, seen from the actinal side.
Fig. 138. A magnified portion of the circular canal, showing the position of the spur of the
tentacles, s, s, and of the marginal capsules, c, 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
adjoiming tentacles. These Medusz are slow in their movements, allow-
ing themselves to be carried along with the current, after one or two pul-
sations ; they swim 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 Acass.

CH, ,

Rhegmatodes floridanus AGAss. Cont. Nat. Hist. U. S., IV. p. 361. 1862.

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 Fig. 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 bemg 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 Adquoride are developed from
the digestive cavity, as has already been shown by Kolliker, and
not from the vertical tube, as is the case in the branching tubes of
Willa. They are at first simple short sacs, which gradually extend in
length till they become long tubes, 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 very irregularly formed, and nothing is more common

Fig. 139. Rhegmatodes floridanus, natural size.
NO. IT. 13

98 STOMOBRACHIUM.

than to find specimens having twenty or twenty-two chymiferous tubes,
instead of the normal number. The same is the case im the order of
development of the chymiferous tubes of Zygodactyla, and the other
ABquoridze 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 species are evidently not full-grown, as the
ovaries were but imperfectly developed.

Key West, Florida (L. Agassiz).

STOMOBRACHIUM Branor.

Stomobrachium Br. (non Forbes). Prod.; in Mém. Acad. St. Petersb., p. 220. 1835.
Stomobrachium Less. Zooph. Acal., p. 315. 1843.
Stomobrachium AGAss. Cont. Nat. Hist. U. S., IV. p. 361. 1862.

Stomobrachium tentaculatum Acass.

Stomobrachium tentaculatum AGAss. Cont. Nat. Hist. U. S., IV. p. 361. 1862.
Stomobrachium lenticulare GouLD (non Br.). Rep. Inv. Mass., p. 349. 1841.
2 Medusa bimorpha Fas. Fauna Gronlandica, No. 356. 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

Fig. 141.

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 Stomobrachium tentaculatum, magnified to show 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 capable of great expansion, and when short-
ened, the extremities are curled up. The ovaries, which are linear,
extend along the chymiferous tubes in such a way as to leave both the
actinal and abactinal extremities free (Fig. 142); the spherosome in-
creases very gradually im thickness from the circular tube towards the
abactinal pole. This species differs
from the S. lenticulare of the Falk-
land Islands, in having a smaller SZ <<
free area, longer chymiferous tubes, ly ea YP a
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 Meduse 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 Medusee known
have been formed.

Massachusetts Bay, Nahant (lL. Agassiz).

WV ews wt Car

rey meme mn

HALOPSIS A. Aaass.
Halopsis A. AGAss.; in Proc. Bost. Soc. Nat. Hist., IX. p. 219. 1863.

The genera Berenix and Carisochroma have been placed by Professor
Agassiz among the Williadee on account of their forking chymiferous
tubes. The discovery of Halopsis shows this association to be un-
natural, and that most probably, when the genera Berenix and Cariso-
chroma are better known, they will be associated with Halopsis into a
distinct family, the Berinicidee of Eschscholtz. Whatever may be the
result, it is at least highly probable that their closer relations are with
the Aiquoride, and not with the Tubularian family of the Williade.

Halopsis ocellata A. Acass.

Halopsis ocellata A. AGAss.; in Proc. Bost. Soc. Nat. Hist., IX. p. 219. 1863.

The genus Halopsis differs from the other Aiquoride by the presence
of large compound eyes, as in Tiaropsis, from three to six between
every two of the chymiferous tubes. There are hkewise long tentacu-
lar cirri; the 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 Aiquoride. Two species are found on our coast,

Fig. 142. The same as Fig. 141, seen in profile.

100 HALOPSIS OCELLATA.

which are so closely allied that, were not the complete history of their
Fig. 143. earlier stages known, they would readily have
been mistaken for different ages of the same

species.

The first species, Halopsis 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, ike the
spokes of a fan (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 profile, 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 (¢, ¢, 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
compound eyes is similar to those of Tiaropsis.
These Medusx are exceedingly sluggish in their
movements ; they are colorless, the genital organs
having a slight grayish tinge at the time of spawning. Found at Nahant,
from July to September, quite commonly. In young specimens, meas-

Fig, 145. 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 the

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. d, opening of actinostome ; c,
chymiferous tube ; 6, connecting fold between the point of attachment of two chymiferous tubes ;
J, lips of actinostome.

Fig. 145. Profile of Halopsis ocellata ; natural size.

HALOPSIS OCELLATA. 101

adult. Specimens measuring an inch and a half in diameter have
as many as twelve chymiferous
tubes, the cavity from which the
tubes originate being irregularly
shaped ; it is not till the Medusa
measures from two to two and a
half inches in diameter, that it
takes the regular star-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 Adquoride. It 1s
quite a common thing in this species to have two actinostomes, in speci-
mens where the central cavity is very elongated and irregular in 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 Ziaropsis diademata ; see the draw-
ings of the young of that species), we find already four eyes between
Fig. 150.

Fig. 146.

Fig. 149.

Fig. 148.

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 spaces; on each side of these rudimentary tentacles
are long cirri; there are no ovaries. It is interesting to see that among
the Aiquoride, the flattest of our Medusx, the young have 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 Aiquorea figured hereafter, which resembles

Fig. 146. Magnified part of circular tube. c, tentacular cirri ; e, compound eye ; ¢, 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. 149. c, ¢, ¢, c, eurri; at base of each is
placed an eye.

102 HALOPSIS CRUCIATA.

more a EKucope. This may eventually show us two modes of develop-
ment among the Aiquoride into forms, forming groups corresponding to
those of the Oceanidz and Eucopide 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 flat 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. Acass.

During the early part of the summer there is frequently found a
Medusa, at first supposed to be the young of Halopsis ocellata ; a com-
parison of the size, the character of the genital organs, and the number

Fig. 151. of tentacles, shows this to be im-
possible. HZ. 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 lobed pouch-
es, hanging down in folds from the
chymiferous tubes ; there are only
three compound eyes between ey-
ery two of the chymiferous tubes ;
these three eyes are already pres-
ent in the youngest Meduse ob-
served, which measure hardly half an inch in diameter, and in which
the genital organs are already well developed, while m the young of
H. ocellata, im specimens measuring nearly two inches, and having as
many as twelve chymiferous tubes, we find no trace of them. The bell
of these young Medus is very high; the eyes
differ from those of . ocellata, having only four
or five granules 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 bell.

S \ \

PTET ITT TUT TTT TY TREE TT i os
me [CRT NN)
Ui gam eee

Fig. 151. A profile view, somewhat magnified, of Halopsis crucia
Fig. 152. A natural attitude of the same species ; both females.

ZY GODACTYLA. 103

May not the 7. gibbosa of Forbes be a young Halopsis? They re-
semble the young of this species; also 7. globosa, and perhaps 7. pilo-
sella. We have here again 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 the
Hydrarium will settle the point. HW. 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
Oceanide ; while the tentacular cirri and the arrangement of the com-
pound eyes place it in the closest relationship to ZZ. ocellata.

Massachusetts Bay, Nahant (A. Agassiz).

Cat. No. 374, Nahant, 1865, A. Agassiz. Medusa.

Cat. No. 379, Nahant, June, 1862, A. Agassiz. Medusee.

Cat. No. 445, Nahant, June, 1864, A. Agassiz. Meduse.

ZYGODACTYLA Branpr.

Zygodactyla Br. Prod.; in Mém. Acad. St. Petersburg, p. 221. 1835.
Rhacostoma AGASs.; in Proc. Bost. Soc. Nat. Hist., Ill. p. 342. 1850.

Zygodactyla groenlandica Acass.

Zygodactyla groenlandica AGAss. Cont. Nat. Hist. U. S., IV. p. 360. 1862.
_ASquorea groenlandica PER. et Les.; in Ann. du Mus., XIV. p. 27. 1809.
Medusa equorea Fas. Fauna Groenlandica. No. 357. 1780.

Rhacostoma ailanticum AGAss.; in Proc. Bost. Soc. Nat. Hist., II. p. 342. 1862.
Aquorea globularis Morcu.; in Besk. af Gronland, p. 96. 1857.

LEquorea 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 Meduse. 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 tubes
(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 (Fis.
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.

the bulging part of the spherosome, the free space left in the centre
Fig. 153. having a radius of about
Pras 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, taper very
suddenly, are hollow (Fig. 155), the walls of the tentacles are thin,
and the lasso cells are arranged irregularly over the whole surface in
small clusters. At the base Fig. 154.
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 hay-
Fig. 155. 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. 153. Abactinal view of Zygodactyla groenlandica.

Fig. 154. Profile view of Fig. 153, half natural size.

Fig. 155. Portion of the circular 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 Zygodactyle 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 1s 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 observa-
tions of Wright on the Hydrarium of @quorea vitrina.

Among the numerous young Eucopide, daily examined, are fre-
quently found exceedingly small Medusz, not larger than the head
of a pin, which I suppose to be the young of Zygodactyla. They
resemble the Eucopide, but differ in having Vig. 156.
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 Medusx 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 Aiquoride,
probably of our Zygodactyla. The small size of these Medusx, coupled
with their habit of living at the bottom, till late in the fall, when
they make their appearance as full-grown Medusa, will readily account
for their having escaped our notice thus far. These young Atquoridz
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. It. 14

106 ZYGODACTYLA CRASSA.

Greenland (Fabricius) ; Mame, and Massachusetts Bay (L. Agassiz) ;
Naushon (A. Agassiz).
Cat. No. 277, Naushon, September, 1861, Alex. Agassiz. Medusa.

Zygodactyla crassa A. Acass.

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, hangmg 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. groentan-
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. 157. Profile view of Zygodactyla crassa, somewhat reduced in size.

ZYGODACTYLA CYANEA.

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 Acass.

Zygodactyla cyanea AGAsS. Cont. Nat. Hist. U. S., IV. p. 361.

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 pot 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. 158. Quarter-of the disk of Z. crassa.

1862.

Fig. 159.

Fig. 159. Portion of the disk of Zygodactyla cyanea, from the abactinal pole.

108 CREMATOSTOMA.

carried curled tightly to the edge of the disk. Found in great num-
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 coerulescens Br.

Zygodactyla cerulescens BR. ; in Mém. Acad. St. Petersb., p. 360, Pl. 5. 1838.
Zygodactyla cerulescens AGASsS. Cont. Nat. Hist. U. 8., IV. p. 360. 1862.
Mesonema cerulescens Br. ; in Mém. Acad. St. Petersb., p. 360. 1838.
Mesonema caerulescens Less. Zooph. Acal., p. 307. 1843.

_Entrance of Straits of Fuca (A. Agassiz).

CREMATOSTOMA A. Aaass.
Crematostoma A. AGASs.; in Agassiz’s Cont. Nat. Hist. U. S., IV. p. 360. 1862.

The genera of Aiquoride 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 Aiquorea 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 in that genus, and hangs always
far below the level of the circular 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. Aeass.

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, 1s 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 sae 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

ZEQUOREA. 109

length of the chymiferous tubes, they are linear (Fig. 159*) ; opposite
each of the chymiferous tubes there is one large tentacle, very con-
tractile, with a slight swelling at the base; between the chymifer-
ous tubes, one smaller tentacle and marginal capsules ; the chymiferous
tubes, near the base of the Fig. 1509.
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.

JEQUOREA Per. et Les.

Equorea Pér. et Les. ; in Ann. du Mus., p. 22. 1809.
Aiquorea LEss. (p. p-). Zooph. Acal., p. 305. 1848.
4Equorea AGAss. Cont. Nat. Hist. U. S., IV. p. 359. 1862.

A&quorea ciliata Escu.

4iquorea ciliata Escu. Syst. der Acal., p. 109, Pl. 9, Fig. 1. 1829.
Equorea ciliata AGass. Cont. Nat. Hist. U. S., 1V. p. 359. 1862.
Equorea ciliata Less. Zooph. Acal., p. 306. 1843.

Northwest Coast of North America, Lat. 41° to 51° N. (Hschscholtz) ;
Straits of Fuca (A. Agassiz).

Fig. 159", Crematostoma flava A. Agass.

110 ZEQUOREA ALBIDA.

f#quorea albida A. Acass.

ABquorea albida A. AGASS.; in Agassiz’s Cont. Nat. Hist. U. S., IV. p. 359. 1862.

The genus Aiquorea, as generally received, includes species which
have been separated from it, under the name of Zygodactyla, by
Brandt, and to which the dquorea vitrina of Gosse also belongs. The
long pendent membrane of the digestive cavity, with the actinostome

Fig. 160. surrounded with numerous lanceolate and strongly
fimbriated folds, at once distinguishes this genus
from Rhegmatodes, which includes such species as
Rhegmatodes tenwis and floridanus, and the dfquorea
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
Zygodactyla, the lips of the actinostome being short
and simple folds. Aquorea 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 opening, without appendages such as we find in Zygodactyla,
Stomobrachium, and others, having only slight indentations formed
along its margin, giving the opening a somewhat polygonal shape

Fig. 161. (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.
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. 160. A portion of the disk of Aquorea albida, from the abactinal pole.
Fig. 161. A natural attitude of ASquorea albida.

ZEQUOREA ALBIDA. 111

marginal capsules, two for every large tentacle, between the tubes,
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 prominence, 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
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 expanded, 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 Meduse the appearance
of having numerous long tentacles (Fig. 161) arising from a small cir-
cular tube, 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, Semsneg, Mass., Sept. 1861, A. Agassiz. Medusa.

Wiens hive ty « x
Fig. 162. “Magnified view a part of the marginal tube. c, capsule ; s, spur of the tentacles, 7.

112

GERYONOPSIDZ.

Family GERYONOPSIDA Agass.

Geryonopside AGAss. Cont. Nat. Hist. U. S., IV. p. 362. 1862.
Geryonide Escu. (p.p.). Syst. der Acal., p. 86. 1829.

Ejirene Escu.

EIRENE Escu.

Syst. der Acal., p. 94. 1829.

Geryonopsis FoRBES. Naked-eyed Meduse, p. 39. 1848.

Phortis McCr.
Ejirene AGASS.

Gymn. Charl. Harb., p. 90.
Cont. Nat. Hist. U. S., IV. p. 362. 1862.

Hirene gibbosa Acass.

Evrene gibbosa AGAss. Cont. Nat. Hist. U. S., IV. p. 362. 1862.
Phortis gibbosa McCr. Gymn. Charl. Harb., p. 91.

Charleston Harbor (McCrady).

Birene ccerulea Acass.

Eirene cerulea 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. irene cerulea.

TIMA. 113

TIMA KEscz.

Tima Escu. Syst. der Acal., p. 103. 1829.

Ejirene Escu. (p. p.). Syst. der Acal., p. 94. 1829.

Dianca Devte Cu. Mem. sulla Storia e Notomia. 1823-29.
Tima Less. Zooph. Acal., p. 333. 1843.

Tima Acass. Cont. Nat. Hist. U. S., IV. p. 362. 1862.

Tima formosa AGass.

Tima formosa AGAss. Cont. Nat. Hist. U. S., IV. p. 362. 1862.

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 tubes (Fig.
164), 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.

extend from the circular tube (Fig. 165) 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. (Z, 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 pouches hanging down on

Fig. 164. Tima formosa, half natural size.

Fig. 165. Quarter-disk, from the abactinal pole ; natural size.

Fig. 166. Digestive cavity and actinostome. t, termination of chymiferous tube ; ¢, digestive
cavity ; J, one of the four fimbriated lips of the actinostome.

NO. Il. 15

114 TIMA FORMOSA.

both sides of the chymiferous tubes (Fig. 167); the tentacles have a
Fig. 167. very prominent pouch, strongly compressed laterally, at the
point of junction with the marginal tubes; between the
larger principal tentacles (¢, Fig. 168) we find a number of
small pouches, rudimentary tentacles (¢, Fig. 168), which
are never developed fully, yet appear to be included in the
recular 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
Fig. 168. the surface, but remain usually

four or five feet below; they
are found during the whole year,
adult specimens having been taken
t ! in June, October, December, and
March. The young Medusa (Fig. 169) differs widely from the adult ;
there are no ovaries in speciinens measuring more than an inch in
diameter ; the chymiferous tubes extend along the short proboscis
(¢, 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 adjoming chy-
miferous tubes, and no signs of any further cycles of tentacles in

Fig. 169. Fig. 170.

the specimen figured here ; marginal capsules were likewise not yet
developed. The young Medusa of Tima is another case to be added
to Melicertum, Lafoea, and Atractylis, where there 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, principal tentacles; 7’, rudimentary
tentacles ; c, marginal capsules.

Fig. 169. Young Tima formosa, natural size.

Fig. 170. Digestive cavity of Fig. 169. 1%, termination of chymiferous tubes; d, digestive
cavity.

TIMA FORMOSA. 115

capsules along the circular tube, and yet these Meduse have all been
traced to a Campanularian-ike Hydrarium. ‘Tima differs 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 Vig. 171.

of Melicertum and Lafcoea. 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 (p, Fig. 171) than
that of the Melicertum, and takes a far greater elongation before at-
taching itself. (p’, 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 Fig. 172.
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. 572, Nahant, September, 1863, A. Agassiz. Medusa.

Museum Diagram No. 17, after A. Agassiz.

ig. 171. Pp, young planula ; p!, planula immediately before attaching itself.
Fig. 172. Single Hydra of the tuft of a Tima Hydrarium, greatly magnified.

116 EUTIMA.

HUTIMA McCr.

Eutima McCr. Gymn. Charl. Harbor, p. 87.
Eutima Acass. Cont. Nat. Hist. U. S., IV. p. 363. 1863.

Kutima mira McCr.

Eutima mira McCr. Gymn. Charl. Harb., p. 88, Pl. 11, Figs. 8, 9.
Butima mira AGass. Cont. Nat. Hist. U. S., IV. p. 363. 1862.

Charleston, 8. C. (McCrady).

Eutima variabilis McCr.

Eutima variabilis McCr. Gymn. Charl. Harb., p. 88.
Eutima variabilis AcaAss. Cont. Nat. Hist. U. 8., IV. p. 363. 1862.

Charleston, 8. C. (McCrady).

Eutima limpida A. Acass.

Eutima limpida A. AGass.; in Agassiz’s Cont. Nat. Hist. U. S., IV. p. 363. 1862.

This species (Fig. 173) resembles closely the Hutima 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 capsules 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
(g, Fig. 175), is shorter than in the Charleston 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. 173. 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 ¢, 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 (0, Fig. 175) are narrow; they rise
almost from the circular tube, and follow the chymiferous tubes along

Fig. 175 91

Fig. 176.

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 from twelve to
thirteen granules arranged in a circle near the periphery of the capsule.
The rudimentary tentacles (¢, Fig. 178) are mere triangular expansions

Fig. 175. Magnified view of the proboscis and genital organs. g, terminal point of gelatinous
prolongation of the disk; 0, part of genital organs extending along the bell; 0’, 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. Magnified 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. 178. Still more magnified view of the rudimentary tentacles. c, circular tube ; ¢, rudi-
mentary tentacles.

118 POLYORCHID A.

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 during September.
Buzzard’s Bay, Naushon (A. Agassiz).

Eutima pyramidalis Acass.

Eutima pyramidalis AGass. Cont. Nat. Hist. U. S., IV. p. 363. 1862.

The spherosome is hemispherical, and more heavy than in either
EHutima limpida or EF. 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 POLYORCHIDZ: A. Agass.

Polyorchide A. AGAss.; in Agassiz’s Cont. Nat. Hist. U. S., IV. p. 349. 1862.

This family is characterized by the peculiar structure of the chymif-
erous tubes, which, sending off diverticula at right angles to the main
tube,'give these Medusze a very peculiar aspect. With the exception
of Polyorchis, we know of only one other genus, Olindias Fr. Mill,
which has the same structure of the chymiferous tubes. Miiller, at the
close of his description of O. sambaquiensis, says it is characteristic of
the uncertainty which still exists in the classification of Acalephee, that
the attempt to assign to this Medusa its position in the systems of Esch-
scholtz, Forbes, or Liitken, places them 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
penicillatum 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.
Melicertum Escu. (p. p.). Syst. der Acal., p. 105. 1829.

Polyorchis penicillata A. Acass.

Polyorchis penicillata A. AGASs.; in Agassiz’s Cont. Nat. Hist. U. S., IV. p. 349. 1862.
Melicertum penicillatum Escu. Syst. der Acal., p. 106, Pl. 8, Fig. 4. 1829.

Aglaura penicillata Bu. Man. d’Actinol., Pl. 33, Fig. 4.

Melicertum penicillata Luss. Zooph. Acal., p. 293. 1843.

Fig. 179.

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 Mesonema (Zygodactyla) cerules-
cens found by 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 Thaumantiade (Fig. 179); the

Fig. 180. 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-
chynemide. 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 Hydroids, 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 penicillata.
Fig. 180. Ovaries of one of the chymiferous tubes.

120 POLYORCHIS PENICILLATA.

ing with each other (Fig. 179); this gives to these Medusz a very
peculiar appearance, differing entirely from any other family of Hy-
droids, and for which I would propose the name of Polyorchidxe. The

Re teL polar axis is the longest ; the spherosome 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, termimating 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 pomt
(Fig. 180) of the four chymiferous tubes, hanging freely in the cavity
of the bell; they are arranged one behind the other, along the upper
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 lower
part 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
capable 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 the bell.

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&. 191

=

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-purple 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 flare 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 differences ; the character of the marginal capsules of this
Medusa, if there are any, has not been examined.

This is undoubtedly the Melicertum penicillatum 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. Cary. Medusa.

Cat. No. 285, Gulf of Georgia, W. T., 1859, A. Agassiz. Medusa.

Family LAODICEIDA: Agass. (emend. A. Acass.).

Laodiceide AGAss. Cont. Nat. Hist. U. 8., IV. p. 350. 1862.
Thaumantiade GEGENB. ; in Zeit. f. Wiss. Zool., p. 236. 1856.

The family name of Laodiceidze given to the Thaumantiade Gegenb.
by Professor Agassiz, may, in its turn, yield to that of Lafoeadse, should
it be found that the Hydrarium of Laodicea Less. is invariably a Lafoea.
The name Laodiceide is here retained, as the Meduse, 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
Laodiceidze are here extended to include the Melicertide, which cer-
tainly are closely related, and can hardly be divided into distinct fami-
lies, if we are to judge from the young Meduse and the Hydrarium of
these genera.

NO. II. 16

122 LAFGA.

LAF@A Lamx.

Lafea LaMx. Expos. Méth. 1812.

Lafwa AGass. Cont. Nat. Hist. U. S., IV. p. 351. 1862.

Lafwa A. AGASS.; in Proc. Bost. Soc. Nat. Hist., IX. p. 91.

Atractylis Wricgut ; in Ann. & Mag., VIII. p. 129. 1861.

Campanulina VAN Ben.; in Bull. Acad. de Belg., XIV. No. 5. 1847.
Laodicea AGASS. (p. p. non Less.). Cont. Nat. Hist. U. S., IV. p. 350. 1862.

Lafoea calcarata A. Aaass.

Laodicea calcarata A. AGAssS.; in Agassiz’s Cont. Nat. Hist. U. S., IV. p. 350. 1862.
Lafea cornuta AGAss. (non Lamx.). Cont. Nat. Hist. U.S., TV. p. 351. 1861.
Campanularia dumosa Lerwy. Mar. Inv. N. J. and R. I., p. 6.

Lafwa cornuta A. AGass.; in Proc. Bost. Soc. Nat. Hist., IX. p. 91, Fig. 4.

The Medusa of Lafoea described in the Contributions of Professor

Agassiz, Vol. IV. p. 351, was referred by him to Lafea cornuta of
Lamouroux. Having, 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 different number
of tentacles at the time when the Fig. 184,
Medusz are liberated from the repro-
ductive calycles, easily distinguishes
these two Medusz. 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 calearata.

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-
‘ing almost the whole length 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 Lafcea calearata ; magnified.

LAF@A CALCARATA. 123

eter (Fig. 186); the chymiferous tubes are narrow ; 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-
ment-cells on its lower surface (Fig. 187); on the opposite side of this
bulb we find a spur-like projection (see ¢, Fig. 187), consisting of large,
transparent, 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 Medusa, 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

Fig. 187.

contractile (c, Fig. 187); m adult specimens they are not distributed
recularly, but in young specimens of a quarter 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 actinostome.

Fig. 186. Actinostome, actinal view.

Fig. 187. Magnified view of a portion of the circular tube. 1, one of the large tentacles, with
spur and pigment-cells ; c, one of the cirri; &, club-shaped appendage.

Fig. 188. Actinostome and rudimentary ovaries of young Medusa, seen in profile.

124 LAF@A CALCARATA.

appendages (xk, Fig. 187) made up of large polygonal cells, perfectly
transparent, one or two sometimes placed between each of the larger
tentacles. The large tentacles have the same color as the ovaries.
The young Medusz differ from the adult im 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. 189. active, moving with great ra-
pidity, by drawing its tentacles
into the bell, throwmg 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-
ried along, the bell often assumes strange attitudes; the thick upper
part of the disk becomes rounded, and the thin portion of the umbrella
is projected beyond it, like the rim of a four-cornered hat. (Fig. 189.)
At other times it seems as if the umbrella 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 off 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. repens in the Edinburgh Philosophical
Journal. The Hydromedusarium differs so much, that it does not seem

Fig. 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 lime 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 attitude of the Medusa of Fig. 184.
Fig. 190. Hydrarium of Lafcea calearata; the extremity of the reproductive calycle is some-
what injured. See Fig. 191.

LAFGi:A CALCARATA. 125

wise the sterile Hydra reminds us of a true Sertularian, with a few
thick tentacles, and a lone digestive cavity, capable of great expansion.
The bell is attached to the stolon by 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 reproductive calycles are gigan-
tie, compared to the size of the sterile individuals. (Fig. 190.) They
are few in number, not more than two or three to a stem, Fig. 191.

and resemble those of LZ. amphora; only one or two Me-
dusze are developed simultaneously, the more advanced
one filling the cavity of the capsule almost entirely.
(Figs. 190, 191.) The sterile individuals recall the Tubu-
larians, 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 embryonic standing of the Tubularians, the Sertu-
larians, and the Campanularians; the Medusz 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 repro-
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. Medusa immediately after its escape from the reproductive calycle.
Fig. 193. A Medusa somewhat more advanced, from the abactinal pole.

126 LAFGA DUMOSA.

at the base of the tentacles the walls are thick, and the sensitive
swellmg quite prominent, having a dark pigment-spot. The Medusa,
when it escapes from the reproductive calycle, has a vertical 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-

Fig. 194. ing as it does, without any doubt, two Medusze
which had thus far been placed in different
genera. The digestive cavity and the ova-
ries are nearly in the same condition as that
observed in young Medusx, 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 oP 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 different
rudimentary appendages, are only modified tentacles.

Buzzard’s Bay, Naushon (A. Agassiz).

Cat. No. 151, Naushon, 1861, A. Agassiz. Hydromedusarium,

Cat. No. 271, Naushon, 1861, A. Agassiz. Medusa.

Cat. No. 438, Naushon, 1864, A. Agassiz. Medusa.

Lafoeea cornuta Lamx.
Lafea cornuta LAMX. Expos. Méthod. 1812.

Newfoundland (Lamouroux).

Lafcea dumosa Sars.

Lafea dumosa Sars; in Vidensk. Forh. 1862.
Campanularia dumosa Jounst. 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 Lass.

Laodicea Luss. Zooph. Acal., p. 294. 1843.

Laodicea AGass. Cont. Nat. Hist. U. S., IV. p. 350. 1862.

Cosmetira Forses. Brit. Naked-eyed Meduse, p. 42. 1848.
Thaumantias GEGENB. (non Esch.) ; in Zeit. f. W. Zool., p. 237. 1856.

Laodicea cellularia A. Acass.
Laodicea cellularia A. AGass.; in Agassiz’s Cont. Nat. Hist. U. S., IV. p. 350. 1862.
IT 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, however, 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 tube. 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 structure of the actinostome of the
Aquoride, as in Stomobrachium. ‘The epithelial cells are large, wreg-
ular, and hexagonal, and can easily be seen with the naked eye. The
color of the spherosome is light 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. 195. Laodicea cellularia.
Fig. 196. One of the lips of the actinostome. , c, ¢, c, termination of the chymiferous tubes
into the digestive cavity, d; J, fold of the actinostome connecting the lips of the actinostome.

128 MELICERTID&.

COSMETIRA Forpzs.

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 Expedition. Medusa.

Family MELICERTIDA Agass.

Melicertide AGAss. Cont. Nat. Hist. U. S., IV. p. 349. 1862.

GONIONEMUS A. Aaass.

Gonionemus A. AGASS.; in Agassiz’s Cont. Nat. Hist. U. S., IV. p. 350. 1862.

Gonionemus has a general resemblance to Melicertum, but differs
from it by the shape of the ovaries and of the spherosome. The
spherosome is an oblate halfspheroid, cut from pole to pole; the ova-
ries are in lobes alternating on the sides of the chymiferous tubes, and
extending their whele 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. Acass.

Gonionemus vertens A. AGASS.; in Agassiz’s Cont. Nat. Hist. U. S., IV. p. 350. 1862.

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, smking 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 arranged 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. 198) to a
third of their former length, and begin their upward movements by
means of short, rapid jerks, given by the sudden expanding 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 upper part of the

GONIONEMUS VERTENS. 129

disk touches the top of the water, the Medusa inverts itself, and sinks,
with its tentacles fully expanded, until 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

Fig. 197.

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 ; there are
sixty-four tentacles, fifteen between each chymiferous tube, placed so
closely together that they seem all to unite at the Fig. 198.

base. The tentacles, when contracted, resemble a
scythe fastened by a band to the circular tube
(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. Gonionemus vertens, as it appears when attached by its tentacles.
Fig. 198. Gonionemus vertens, in motion ; natural size.
NO. I. 17

130 MELICERTUM.

ovaries are frilllike lobes (Fig. 200), passing from one side to the other
of the chymiferous canal; the chymiferous tubes are slender, and ap-
pear like four dark-violet threads, connecting the different lobes of the

ovaries. (Fig. 201.) The digestive cavity reaches about two thirds of
the length of the chymiferous tubes; it is very flexible, but scarcely
contractile (Fig. 201), endig 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 OKEN. Lehrb. der Naturg. 1816.

Melicertum AGass. Cont. Nat. Hist. U. S., IV. p. 349. 1862.
Melicerta Pir. et Les. (p. p.); im Ann. du Mus., XIV. p. 40. 1809.
Campanella Lxss. (non Bl.). Zooph. Acal., p. 281. 1843.
Stomobrachium ForBEs (non Br.). Naked-eyed Medusze, p. 30. 1848.

Melicertum campanula Escu.

Melcertum campanula Escu. Syst. der Acal., p. 105. 1829.

Melicertum campanula AGass. _ Cont. Nat. Hist. U. S., IV. p. 349. 1862.

Melicertum campanula A. AGASs.; in Proc. Bost. Soc. Nat. Hist., IX. p. 96, Figs. 18, 19.
Melicerta campanula P&r. et Les.; in Ann. du Mus., p. 40. 1809.

Medusa campanula Fan. Fauna Groénlandica. 1780. No. 360.

Medusa campanulata Bosc. Hist. Nat. d. Vers., II. p. 170.

Campanella Fabricii Less. Zooph. Acal., p. 281. 1843.

Campanella campanula Mércu ; in Beskriv. af Grénland, 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

observed on the coast of New England. Undoubtedly a few others of
the Jelly-fishes he has enumerated will prove 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 Stomobrachiuwm 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 Medusez. In the fall, at the time of spawning, it literally swarms
at the surface, and on sunny days seems particularly to delight to
come to the surface, where it remains in the afternoon until dark,
being one of the few Medusze
(Zygodactyla groenlandica has
the same habit) which are to
be met with in the after-
noon. The genus Melicertum
is closely related to the Aiquo-
ride, by the number of its
radiating tubes (of which there
are eight), and to Staurophora,
by the blending of the genital
organs with the actinostome,
and the total absence of mar-
ginal bodies, such as capsules,
cirri, and so forth. If the
small Medusze here figured
(Figs. 203, 204) are in reality
the young of Melicertum, —
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 Lafea calcarata, I had
already come to the conclusion that the young Medusa was nearly
related to Staurophora and Melicertum. Having succeeded in finding
another Medusa evidently closely allied to it, 1 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

Fi

g. 202. Profile of Melicertum campanula, 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 Lafoea, the probable
character of the Hydrarium from which Melicertum, Staurophora, and
those Medusz which have no marginal capsules, are developed ; show-
ing that they hold an intermediate position between the Campanu-

Fig. 204.

s
3
:
j

larians and the Tubularians, being more closely allied to the latter in
their embryonic condition, and assuming as adult Medusze somewhat the
aspect of Campanularian Meduse. The Zrichydra pudica of Wright
is also closely allied to Lafoea and Staurophora. In the young Medusa
we have at first only two primary 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
Meduse of Lafea calcarata and of Stawrophora laciniata are the surest
means of distinguishing them with accuracy. The differences in the
shape of the bell between these youngest
Medusze (Fig. 205) and somewhat older
stages (Fig. 205), are of a similar character
to those we are familiar with among the
young Campanularian Medusz of other gen-
era. To judge from analogy, I strongly sus-
pect that the young Medusa of Staurophoré
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 Melicertum campanula; Lafcean like. See
Fig. 192

Fig. 204. Half the disk of the same, seen from the actinal pole.

Fig. 205. Young Melicertum, with only four completely formed chymiferous tubes. Ie, first

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 undoubtedly a young Melicertum, we find
the second set of four chymiferous tubes developing (2,, Fig. 205) ;
they arise, as in the Aiquoride, 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. 207.

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 contract, 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
into a sort of cavity, as in the A‘quoride, 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 J, Fig.
207, to the circular tube, where they have their
greatest diameter; the lips of the actinostome
are carried in eight folds (Fig. 208), each one, J,
corresponding to one of the radiating tubes, c,
as in the Aiquoride ; the lips project but little
into the cavity of the bell. The tentacles are
hollow, somewhat dumb-bell shaped at the base

Fig. 206. The same, seen from the abactinal pole. m, mouth; 0, genital organs; #, tentacles.

Fig. 207. Magnified view of two chymiferous tubes and genital glands. J, lips of actmostome.

Fig. 208. Mode of carrying the lips of the actinostome. J, lips of actinostome ; c, chymiferous
tube.

Fig. 209. Magnified view of marginal tentacles.

134 MELICERTUM CAMPANULA.

(Fig. 209), and taper rapidly; they are thickly covered with lasso-
cells.

Artificial fecundation of these Medusz 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, imumerable spherical
embryos (Fig. 210), in which the spheres of segmentation are still

Fig. 211. Fig. 212. Fig. 213,
Fig. 210

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 uniform thickness (Fig. 212), swimming about with great ve-
locity ; these embryos attach themselves by the blunt end (Fig. 213),
and soon elongate, as in the two middle figures of Fig. 213; the slen-
Fig. 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
Planule 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, Grand Manan, L. Agassiz. Medusa.

Cat. No. 573, Nahant, 1865, A. Agassiz. Medusa.

Cat. No. 448, Nahant, 1864, A. Agassiz. Medusa.

Fig. 210. Spherical embryo.

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.

Melicertum 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 JZ georgicum 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 Aiquoride, referred to in the preceding species, is readily seen

Fig. 215. Fig. 216.

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 lips, /, 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 Adquorea. This Medusa is
found, 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. J, lips of actinos-
tome; p, abactinal point of attachment of genital organs; c, opening leading into chymiferous
tubes. Magnified.

136 STAUROPHORA.

STAUROPHORA. Branpt.

Staurophora BRANDT (non Forbes) ; in Mém. Acad. St. Petersburg, I. p. 399. 1835.
Staurophora AGASS.; in Mem. Am. Acad., IV. p. 300.

Staurophora AGASS. Cont. Nat. Hist. U. §., IV. p. 351. 1862.

Staurophora Less. Zooph. Acal., p. 297. 1843.

Staurophora laciniata Acass.

Staurophora laciniata AGASS.; in Mem. Am. Acad., TV. p. 300, Pl. 7. 1849.
Staurophora laciniata AGAss. Cont. Nat. Hist. U. §., IV. p. 351. 1862.
Staurophora laciniata A. AGASS.; in Proc. Boston Soc. Nat. Hist., IX. Figs. 1, 2, 3.
Staurophora laciniata Stimps. Mar. Iny. Grand Manan, p.11. 1853.

The youngest Medusa of Staurophora which has been observed
(Fig. 215") resembles to such an extent the young Melicertum (Figs.
Fig. 215% 203, 205), as readily to have been taken for dif-

Me €6=s 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 (a, b, ¢, Fig.
218), where the digestive cavity loses little by little its individuality,
the corners gradually extend along the chymiferous tubes, and in

Fig. 217.

Fig. 216%.

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, somewhat more advanced than Fig. 216°.

Fig. 218. Different stages of the actinostome, intermediate between that of Figs. 215° and 219.
a, the youngest ; b, the next; c, the oldest.

PTYCHOGENA. 137

younger stages. (Figs. 215%, 216%, 217.)
This Medusa grows to a large size, meas-
uring often six to eight inches in diameter.
It is one of the earliest Medusze to make
its appearance, attains its full size rapidly
from May to June, and by the end of
June the dead Medusz 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 Meduse.
Cat. No. 359, Boston Harbor, L. Agassiz. Medusa.

Staurophora Mertensii Br.

Staurophora Mertensii Br.; in Mém. Acad. St. Petersb., IV. p. 400, Pls. 24, 25. 1838.
Staurophora Mertensti Less. Zooph. Acal., p. 297. 1843.

Norfolk Sound (Mertens).

PTYCHOGENA A. Agass.

The Medusa for which this genus has been established shows the
intimate structural connection between Staurophora, Melicertum, 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. Acass.

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, formimg as many connecting

Fig. 219. Young Staurophora, having the general aspect of the adult.
NO. I. 18

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 opening of the actinostome is large; its folds are small, and do

Fig 221.

Fig. 220,

fac

sen

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 (f, Fig. 224) ;
between every two tentacles is found a club-shaped appendage, made

Fig. 223. Fig. 224.
b

up of large cells somewhat like those of Lafea calcarata (b, 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 Ptychogena, somewhat reduced.
Fig. 221. Magnified view of the genital organs, seen from the abactinal pole.
22

Fig. 222. The same as Fig. 221, seen in profile, on a somewhat smaller scale.

Fig. 223. Actinostome. a, opening of actinostome ; p, point of attachment of the digestive
cavity ; /, lips of the actinostome.

Fig. 224. Magnified base of tentacles and club-shaped appendages. /f, swelling of tentacles ;
b, club-shaped appendages.

~ Ww

PLUMULARID®. 139

Medusa, like Tima, swims at a considerable depth below the surface.
The action of the light and increase of temperature of the surface is
sufficient to kill them in the course of half an hour; the moment they
are brought to the surface, 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 Ctenophorx, 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, Nahant (A. Agassiz).

Family PLUMULARIDZ Agass.

Plumularide Acass. Cont. Nat. Hist. U. S., IV. p- 358. 1862.
Sertularide JOUNST. (p. p.). Brit. Zooph., p. 89.

AGLAOPHENTA Lamx. (restr. McCr.).

Aglaophenia LAMX. (pars) ; in Bull. Soc. Phil. 1812.
Aglaophenia McCr. Gymnoph. Charleston Harbor, p. 98. . 1857.
Aglaophenia AGass. Cont. Nat. Hist. U. S., IV. p. 358. 1862.
Plumularia LAMK. (pars). Anim. s. Vert., II. p. 159.

Aglaophenia pelasgica McCr.

Aglaophenia pelasgica McCr. Gymn. of Charleston Harbor, p. 99.- 1857.
Sertularia pelasgica Bosc. Hist. Nat. Vers., Ill. p. 122.

Plumularia pelasgica LAMK. An. s. Vert., Il. p. 167.

Dynamena pelasgica Buatxy. 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. Hydrarium.

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. 8. Bick-
more. Hydrarium.

Cat. No. 391, a hundred miles south of Cape Hatteras, A. S. Bick-
more. Hydrarium.

140 PLUMULARIA.

Aglaophenia trifida Acass.

Aglaophenia trifida AGAss. Cont. Nat. Hist. U. S., IV. p. 358. 1862.
Aglaophenia cristata McCr. (non Lamk.). Gymn. Charl. Harb., p. 100.

Charleston, 8. C. (L. Agassiz).
Cat. No. 252, Charleston, 8. C., Jan. 1852, L. Agassiz. Hydrarium.

Aglaophenia tricuspis McCr.
Aglaophenia tricuspis McCr. Gymn. Charleston Harbor, p. 101.
Charleston, S. C. (McCrady).

Aglaophenia franciscana A. Acass.

Plumularia franciscana TRASK; in Proe. Cal. Acad., March, 1857, p. 101, Pl. 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-
dromedusarium.

Cat. No. 260, San Francisco, Cal., December, 1859, A. Agassiz. Hy-
dromedusarium.

PLUMULARIA Lame. (restr. McCr.).
Plumularia LAMK. (p. p.) An. s. Vert., II. p. 159.

Plumularia McCr. Gymn. Charleston Harbor. 1857.
Plumularia Acass. Cont. Nat. Hist. U. S., IV. p. 358. 1862.

Plumularia quadridens McCr.

Plumularia quadridens McCr. Gymn. Charleston Harbor, p. 97.
Plumularia quadridens AGAss. Cont. Nat. Hist. U. 8., IV. p. 358. 1862.

Charleston, 8. C. (McCrady) ; Florida (L. Agassiz).
Cat. No. 251, Ship Channel, Florida, January, 1856, L. Agassiz.

Plumularia arborea Des.

Plumularia arborea Dxs.; in Proc. Bost. Soc. Nat. Hist., II. p. 65. 1848.

Massachusetts Bay (Desor).

SERTULARIAD®. 141

Family SERTULARIADA Johnst.

Sertulariade Jounst. British Zoophytes, p. 57.

DYNAMENA Lamx. (restr. Agass.).

Dynamena LAMx.; in Bull. Soc. Phil. 1812.
Dynamena AGAss. Cont. Nat. Hist. U. S., IV. p. 355. 1862.

Dynamena pumila Lax.

Dynamena pumila Lamx. Cor. Flex., p. 179.

Dynamena pumila Jounst. 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 Morcu ; in Beskriv. af Greenland, p. 97. 1857.

Sertularia thuja Fan. (teste Morch). Fauna Groenl., No. 456.

This is one of the few of our Hydroids (Fig. 225) which have been
compared in a living 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 Fabricu ; and before he

had examined the development of the sessile Medusa (Fig. 226), sup-

posed it to be the Hydroid of our Melicertum campanula. See, for the

Hydroid of Melicertum, the description of that species.
European and American shores of Atlantic Ocean (Ellis, Agassiz).
Cat. No. 163, 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.

5. Cluster of Dynamena pumila.
26. Magnified portion of stem of Fig. 225.

142 DIPHASIA.

Cat. No. 169, Nahant, June, 1855, H. J. Clark. Hydromedusarium.

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. E. Mills. Hydromedu-
sarium.

Museum Diagram No. 18, after L. Agassiz.

Dynamena cornicina McCr.
Dynamena cornicina McCr. Gymn. Charl. Harb., p. 102.

Charleston, 8. C. (L. Agassiz).
Cat. No. 175, Charleston, 8. C., L. Agassiz. Hydrarium.
Cat. No. 176, Charleston, 8. C., 1852, L. Agassiz. Hydrarium.

DIPHASIA Agass.

Diphasia AGass. Cont. Nat. Hist. U. S., IV. p. 355. 1862.

Diphasia fallax Acass.

Diphasia fallax AGAss. Cont. Nat. Hist. U. §., IV. p. 355. 1862.
Sertularia fallax Jounst. Brit. Zooph., p. 78, Pl. 11, Figs. 2, 5, 6.
Sertularia fallax Stimps. Mar. Inv. Grand Manan, p. 9. 1853.

Grand Manan (W. Stimpson); Massachusetts Bay.

Cat. No. 183, 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. Verrill.

Diphasia rosacea Acass.

Diphasia rosacea AGAss. Cont. Nat. Hist. U. 8., IV. p. 355. 1862.
Sertularia rosacea LINN. Syst. 1306.

Sertularia rosacea JouNST. Brit. Zeoph., p. 64.

Sertularia rosacea Pack.; in Can. Nat. & Geol., Dec. 1863.

? Sertularia plumea Des.; in Proc. Bost. Soc. N. H., II. p. 66. 1848.

‘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. Acass.

Sertularia corniculata Murray; in Ann. & Mag. N. H., X. Pl. XI. Fig. 3. 1860.

Bay of San Francisco (Murray).

SERTULARIA Linn. (emend. Agass.).

Sertulara Lrxyn. Syst. Nat.
Sertularia AGAss. Cont. Nat. Hist. U. S., IV. p. 356. 1862.

Sertularia abietina Liny.

Sertularia abietina LINN. Syst. 1307.

Sertularia abietina Fas. Fauna Groenlandica. No. 453.

Sertularia abietina Jounst. Brit. Zooph., p. 75.

Sertularia abietina AGAss. Cont. Nat. Hist. U. S., IV. p. 356. 1862.

St. George’s Bank, Newfoundland ; Mingan Islands.

Cat. No
Cat. No
Cat. No

Cat.

. No

. 195, New Brighton, Eng., Oct. 1860, H. J. Clark. Hydrarium.
. 196, Liverpool, Eng., 1861, Thos. J. Moore.

. 197, St. George’s Bank, W. Stimpson.

. 419, Mingan Islands, 1861, Anticosti Expedition.

Sertularia cupressina Linn.

Sertularia cupressina LINN. Syst. 1308.

Sertularia cupressma Jounst. Brit. Zooph., p. 80.

Sertwaria cupressina Leipy. Inv. R. I. and N. J., p. 6.

Sertularia cupressma 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-

dromed
Cat.
Cat.
Cat.
Cat.
Cat.
Cat.
Cat.
Cat.
Cat.

No

usarium.
No.
No.
No.
No.
No.
No.
No.
No.

203, Beverly, July, 1861, A. Agassiz. Hydromedusarium.
204, Nahant, May, 1862, A. Agassiz. Hydromedusarium.
205, Chelsea, May, 1862, H. J. Clark. Hydromedusarium.
206, Eastport, Me., 1851, W. Stimpson. Hydromedusarium.
207, Mount Desert, Me., W. Stimpson. Hydromedusarium.
208, Suisconset, July, 1849, L. Agassiz. Hydromedusarium.
209, Suisconset, Mass., L. Agassiz. Hydrarium.

211, Lynn, Mass., Jan. 1861, H. J. Clark. Hydrarium.

. 212, Massachusetts Bay, L. Agassiz.

144

SERTULARIA ANGUINA.

Sertularia argentea Ext. & Sor.

Sertularia argentea Eruis & Sot. Zooph., p. 38.

Sertularia argentea Jounst. Brit. Zooph., p. 79, Pl. 15, Fig. 3; Pl. 14, Fig. 3.
Sertularia argentea AGAss. Cont. Nat. Hist. U. S., IV. p. 356. 1862.
Sertularia argentea Stimps. Mar. Iny. Grand Manan, p. 8. 1853.

Sertularia argentea Morcu.; in Besk. af Gronland, p. 97.

Sertularia fastigiata Fax. (teste Morch). Fauna Groénlandica, No. 458.

Grand Manan (W. Stimpson).
Cat. No. 215, New Brighton, Oct. 1860, H. J. Clark. Hydrarium.

Sertularia falcata Linn.

Sertularia falcata Linn. Syst. 1309.

Sertularia falcata AGAsSS. Cont. Nat. Hist. U. 8., IV. p. 356. 1862.
Plumularia falcata JounstT. Brit. Zooph., p. 90, Pl. 21, Figs. 1, 2.
Plumularia falcata Pack.; in Can. Nat. & Zool. Dec. 1863.
Plumularia falcata Strmps. 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., 1860, 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 Trasx.

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, Pl. XI. Fig. 2. 1860.

Bay of San Francisco (Trask, Murray); Monterey, Punta de los
Reyes, Tomales Point (Trask).

SERTULARIA TURGIDA. 145

Sertularia gracilis A. Acass.
Plumularia gracilis MURRAY ; in Ann. & Mag. N. H., V. p. 251, Pl. XI. Fig. 1. 1860.

Bay of San Francisco (Murray).

Sertularia myriophyllum Livy.

Sertularia myriophyllum Linn. Syst. 1309.
Plumularia myriophyllum JOHNST. 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 Srimes.
Sertularia latiuscula Strmps. Mar. Inv. Grand Manan, p. 8. 1853.

Grand Manan (W. Stimpson).

Sertularia filicula Ext. & Sot.
Sertularia filicula Etuis & Sou. Zooph., p. 57, Pl. 6, Figs. ¢, C.

Sertularia filicula Stimes. Mar. Inv. Grand Manan, p. 8. 1853.
Sertularia filicula Jounst. Brit. Zooph., p. 76, Pl. 14, Fig. 1.

Grand Manan (W. Stimpson).

Sertularia furcata Trask.
Sertularia furcata TRASK ; in Proce. Cal. Acad., March, 1857, p. 101, Pl. V. Fig. 2.

San Francisco (Trask).

Sertularia turgida Trasx.
Sertularia turgida Trask; in Proc. Cal. Acad., March, 1857, p. 101, Pl. IV. Fig. 1.

San Francisco (Trask).

Sertularia producta Srimes.

Sertularia producta Stimps. Mar. Inv. Grand Manan, p. 8. 1853.

Grand Manan (W. Stimpson).

NO. Il. 19

146 COTULINA.

AMPHITROCHA Agass.

‘Amphitrocha AGass. Cont. Nat. Hist. U. S., IV. p. 356. 1862.

Amphitrocha rugosa Acass.

Amphitrocha rugosa AGAss. Cont. Nat. Hist. U. S., IV. p. 356. 1862.
Sertularia rugosa LINN. Syst. 1308.

Sertularia rugosa Fas. Fauna Gronlandica. No. 454.

Sertularia rugosa JouNstT. Brit. Zooph., p. 63, Pl. X. Figs. 4—6.
Sertularia rugosa Strmps. Mar. Inv. Grand Manan, p. 9. 1853.
Sertularia rugosa Morcw ; in Besk. af Gronland, p. 97.

Amphitrocha cincta AGAss. Cont. Nat. Hist. U. 8., IV. p. 356. 1862.

Massachusetts Bay (L. Agassiz) ; Grand Manan (W. Stimpson).
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 Aaass.

Cotulina AcaAss. Cont. Nat. Hist. U. S., IV. p. 356. 1862.

Cotulina tricuspidata A. Acass.
Sertularia tricuspidata ALDER (non Murray). Cat. Zooph. Northumb. and Durham, p. 21, Pl. I.
Figs. 1, 2. 1857. :
Sertularia tricuspidata Pack.; in Can. Nat. & Geol. Dec. 1863.
Massachusetts Bay (L. Agassiz).
Cat. No. 233, Massachusetts Bay, L. Agassiz.
Cat. No. 234, Massachusetts Bay, L. Agassiz.
Cat. No. 255, Eastport, Me., July, 1851, W. Stimpson.
Cat. No. 236, Eastport, Me., July, 1852, W. Stimpson.

Cotulina polyzonias Acass.

Cotulina polyzonias AGass. Cont. Nat. Hist. U. S., IV. p. 356. 1862.
Sertularia polyzonias Linn. Syst. 813.

Sertularia polyzonias JOHNST. Brit. Zooph., p. 61, Pl. X. Figs. 1-3.
Sertularia polyzonias Mércu ; in Besk. af Gronland, p 97. 1857.
Sertularia polyzonias Strmps. Mar. Inv. Grand Manan, p. 9. 1853.
Sertularia polyzonias Pack.; in Can. Nat. & Geol. Dec. 1863.
Sertularia pinnata Goutp. Rep. Iny. 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, Mingan Islands, 1861, Anticosti Expedition.

Cotulina tamarisca A. Acass.

Sertularia tamarisca Linn. Syst. 1307.
Sertularia tamarisca JOHNST. Brit. Zooph., p. 74, Pl. XIII. Figs. 2-4.

Eastport, Me. (A. E. Verrill ; Sea-Coal Bay, N. 8. (Anticosti Expedi-
tion) ; Massachusetts Bay (Agassiz).

Cat. No. 231, Grand Manan, W. Stimpson. 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. Acass.

Sertularia tricuspidata Murray (non Alder). Ann. & 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 pumila. It is supported by a very
slender stem, which branches near the base; the branches rise verti-
cally, forming fan-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 hydre 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 bottle-shaped neck.

San Francisco, Cal.

Cat. No. 436, San Francisco, Cal., Normal School, Salem.

HALECIUM Okey.
Halecium OxEN. Lehrb. der Naturg. 1815.

Thoa Lamx. Pol. Cor. Flex. 1816.
Halecium AGass. Cont. Nat. Hist. U. S., IV. p. 357. 1862.

Halecium muricatum Josnst.

Halecium muricatum Jounst. Brit. Zooph., p. 40, Pl. IX. Figs. 3, 4
Sertularia muricata Evuis & Sou. Zooph., p. 59, Pl. VIL. Figs. 3, 4.

Cat. No. 421, Eastport, Me., 1863, A. E. Verrill.

148 . THUIARIA.

Halecium halecinum Jounsr.
Halecium halecinum Jounst. Brit. Zooph., p. 38, Pl. VII.
Halecium halecinum AGass. Cont. Nat. Hist. U. S., IV. p. 357. 1863.
Halecium halecinum Mércu ; in Beskriv. af Gronland, p. 97. 1857.
Sertularia halecina Linn. Syst. 1308.
Sertularia halecina Fas. 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.

GRAMMARIA. Strives.

Grammaria Stimrs. Mar. Inv. Grand Manan, p. 9. 1853.
Grammaria AGAss. Cont. Nat. Hist. U. 8., IV. p. 357. 1862.

Grammaria gracilis Srures.

Grammaria gracilis Strmps. Mar. Inv. Grand Manan, p. 9. 1853.

Grand Manan (W. Stimpson).

Grammaria robusta Stimps.
Grammaria robusta Stimes. Mar. Inv. Grand Manan, p. 9, Fig. 3. 1853.

Grand Manan (W. Stimpson).

THUIARIA Ftem.

Thuiaria FtEM. British Animals. 1828.

Thuiaria thuja Frem.

Thuiaria thuja Fuem. British Animals, p. 545. 1828.
Sertularia thuja Lrxyn. Syst. 1308.
Thuiaria thuja JouNstT. Brit. Zooph., p. 83.

Mingan Islands, N. §.
Cat. No. 240, Norway, M. Sars.

Cat. No. 420, Mingan Islands, N. 8., Anticosti Expedition, 1861.

drarium.

TUBULARIE. 149

SusorpER TUBULARI® Aaass.

Tubularie AGAss. Cont. Nat. Hist. U. S., IV. p. 338. 1862.
Tubularina EXRENB. Coral]. d. Rothen Meeres.
Tubularina and Hydrina Jounst. Brit. Zooph., p. 29.

Family NEMOPSIDA Agass.

Nemopside Acass. Cont. Nat. Hist. U.S., IV. p. 345. 1862.

NEMOPSIS Agass.

Nemopsis AGAss.; in Mem. Am. Acad., IV. p. 289. 1849.
Nemopsis McCr. Gymn. Charl. Harbor, p. 57.
Nemopsis Acass. Cont. Nat. Hist. U. S., IV. p. 345. 1862.

Nemopsis Bachei Aeass.

Nemopsis Bachei AGass.; in Mem. Am. Acad., IV. p. 289, Fig. 1849.

Nemopsis Bachei Acass. Cont. Nat. Hist. U. S., IV. p. 345. 1862.

Nemopsis Gibbesi McCr. Gymn. Charl. Harb., p. 58, Pl. 10, Figs. 1-7.

Nemopsis Bachei A. AGASS.; in Proc. Bost. Soc. Nat. Hist., UX. 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 Nemopsis Gibbesi of
McCrady, found at Charleston, whether he has not described again,
under a new name, the NV. Bachei found by Professor Agassiz in Vine-
yard Sound in 1848, and of which a wood-cut was published 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 Medusze
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 IA OB
of observing this Medusa, at the time when it had only
four tentacles to each marginal bulb (Fig. 227), no ova-
_ries, 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 NV. Gibbesi, that I am inclined to consider them as identical. The

ig. 227. Youngest Nemopsis observed, having four tentacles at the base of each chymiferous

150 NEMOPSIS BACHEI.

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
common 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,
are 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 . sie. SUB.
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. 250) 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 exception that the tentacles, which are carried erect upon their
ae base, are not contractile like the others, and
have a more clavate appearance (Figs. 227 —
230), they differ im 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 im
this genus the eyes were supported upon a
peduncle, like 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 more 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, Nemopsis somewhat more advanced than Fig. 227, having the second and third set
of tentacles developed.

Fig. 229. Maenified view of the sensitive bulb at the base of one of the chymiferous tubes, ec.

Fig. 230. Nemopsis in which the genital organs extend a considerable distance along the chy-
miferous tubes.

ACAULIS. 151

small portion of the upper part of the chymiferous tubes (Figs. 227,
228), but with advancing age extend farther down (Figs. 230, 231), and
in the adult they reach the circular tube. The genital organs remind
us, in their mode of growth, of what we find in Melicertum and Stau-
rophora. The outline of the bell is but little changed from the earliest
stages to the more advanced ; it simply grows Fig. 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-
Crady of the Hydroid of Nemopsis, and by
Stimpson of Acaulis, remind us very forcibly
of detached heads of Tubularians. The heads
of our Pennaria (Globiceps tiarella Ayres)
frequently drop off, and nothing is more common than to see, at the
time of breeding, several of these heads, covered with Medusz, floating
about in the jars where the Pennarie are kept, and to have the Me-
dusee buds come to maturity while 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 Medusz
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.

V Ae La ft

ACAULIS Srimes.

Acaulis Stimrs. Mar. Inv. Grand Manan, p. 10. 1853.
Acaulis AcAss. Cont. Nat. Hist. U. S., IV. p. 345. 1862.

Acaulis primarius Stuuves.

Acaulis primarius Stimes. Mar. Inv. Grand Manan, p. 10, Pl. 1, Fig. 1.
Acaulis primarius AGass. Cont. Nat. Hist. U. S., IV. p. 345. 1862.

Grand Manan (W. Stimpson).
Cat. No. 162, Grand Manan, W. Stimpson. Hydromedusarium.

Fig. 231. Magnified view of the genital organs, the actinostome, and the oral tentacles.

152 BOUGAINVILLEA.

Family BOUGAINVILLEA Liitk.

Bougainvillee LUrK.; in Vidensk. Med., p. 29. 1849-50.
Bougainvillide GEGENB. ; in Zeit. f. Wiss. Zool., p- 220. 1856.
Hippocrenide McCr. Gymn. Charl. Harbor, p. 56.

Bougainvillide AGass. Cont. Nat. Hist. U. S., IV. p. 344. 1862.
Eudendroide AGass. Cont. Nat. Hist. U. S., IV. pp. 282, 342. 1862.

BOUGAINVILLIA Less.

Bougainvillia Less.; in Ann. des Se. Nat., V. 1836.
Hippocrene Mert. ; (Preoce. Moll.) in Mém. Acad. St. Petersburg, p. 229. 1835.
Hippocrene AGASS.; in Mem. Am. Acad., p. 250. 1849.

Bougainvillia Mertensii Acass.

Bougainvillia Mertensiti AGAss. Cont. Nat. Hist. U. S., IV. p. 344. 1862.
Hippocrene Bougainvillei Br. (non Less.) ; n Mém. Acad. St. Petersburg, p. 293, Pl. 20. 1838.

If the Hydrarium, collected at San Francisco, is the Hydrarium of
Bougainvillia Mertensvi, there can be no doubt of the specific differ-
ence between it and Bougainvillia superciliaris Agass. It grows quite
luxuriously, attaming a height of nearly two and a half inches; the
stems are very stout, particularly the main branch, 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
branches 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-
villia superciliaris are circumpolar species, like the Zoxopneustes dro-
bachiensis.

This species is undoubtedly the Hippocrene Bougainvillei 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. HU. The ramifications of the tentacles surrounding the actinos-
tome are very numerous, and the eye-specks at the base of the mar-
ginal tentacles small. The spherosome 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 Bougainvillia 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.
Behring’s Strait (Brandt) ; Gulf of Georgia, W. T. (A. Agassiz).
Cat. No. 33, San Francisco, Cal., March, 1859, A. Agassiz. Hydrarium.
Cat. No. 49, Gulf of Georgia, W. T., May, 1859, A. Agassiz. Medusa.

Bougainvillia superciliaris Acass.

Bougainvillia superciliaris Acass. Cont. Nat. Hist. U. S., IV. pp. 289, 291, Figs. 37-39; p. 344,
Pl. 27, Figs. 1-7. 1862.

Hippocrene superciliaris AGAss.; in Mem. Am. Acad., IV. p. 250, Pls. 1-3.

Hippocrene superciliaris Stimes. Mar. Inv. Grand Manan, p. 11. 1853.

Bougainvillia superciliaris A. AGASS.; in Proc. Bost. Soc. Nat. Hist., IX. Figs. 24, 25.

Hippocrene Bougainvillei GOULD (nec Br., nec Less.). Rep. Inv. Mass., p. 348. 1841.

2 Tubularia ramosa GouLp. Rep. Inv. Mass., p. 350. 1841.

2 Eudendrium cingulatum Stimps. Mar. Inv. Grand Manan, p. 9. 1853.

The development of the young Medusz 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 superciliaris (Fig. 232), of which a

Fig. 232.

complete description has already been given by Professor Agassiz, in
the Memoirs of the American Academy for 1849, is one of our most
common Medusz, 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 Medusz buds are found along the stem below the heads ;
Figs. 234, 235 are early stages, when the bell is elongated, and inca-

232. Magnified profile view of adult Bougainvillia superciliaris.
NO. IL. 20

154 BOUGAINVILLIA SUPERCILIARIS.

pable of expansion and contraction. In Figs. 236, 237, which are some-
what older Meduse in different attitudes, the digestive cavity is well

Fig. 233. Fig. 235.

developed, and from the four corners of the actinostome bulge out four
club-shaped appendages, the first traces of the oral tentacles. There

Fig. 238.

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. Hydromedusarium 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 Hydromedusarium.

MARGELIS. 155

of uniform thickness, the veil large and powerful ; Fig. 239.
the abactinal portion of the bell becomes somewhat
more thickened, and when it has separated from
the Hydrarium (Fig. 258), 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 sounen quadrangular, filled with
dark pigment cells, p, and at the base of each amine a bright eye-
speck, e, is formed; the club-shaped oral appendages soon gig. oi,
begin to branch, poeonal tentacles appear in pairs on each
side of the original pair (Fig. 240), and the young Medusa
soon assumes all the principal features of thé 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.

waa

MARGELIS Sreenst.

Margelis StmENstT.; in Vidensk. Medel. for 1849-50, p. 43.

Margelis AGass. Cont. Nat. Hist. U. S., IV. p. 344. 1862.
Bougainvillia Less.; in Ann. Se. Nat., V. 1836.

Hippocrene McCr. (nec Mert. nec Agass.). Gymn. Charl. Harb., p. 61.

The structural differences observed in the European Bougainvillia
britannica Forbes, and the Hippocrene carolinensis 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. 239. Maenified view of sensitive bulb. p, 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.

Hippocrene superciliaris of the northeast coast, and the Hippocrene
Mertensvi of the northwest coast, which are differences in the propor-
tion of the digestive cavity, its position, the thickness of the bell, and
the mode of branching of the oral tentacles.

Margelis carolinensis Acass.

Margelis carolinensis AGass. Cont. Nat. Hist. U. S., IV. p. 344. 1862.
Hippocrene carolinensis McCr. Gymn. Charl. Harbor, p. 62, Pl. 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

Fig. 241. ¢ Fig. 243.

branches twice, and each of these branches twice (Fig. 242); the cay-
ity of the bell is small and globular; the marginal bulbs are large and

Fig. 242. 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 base 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 proportion, 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, cylindrical, and not yet divided by four longitudinal furrows
into genital pouches. These small Meduse 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 branch only in somewhat more advanced stages.
The generic identity of Bougainvillia britannica with our Margelis
carolinensis is perhaps not better shown than by the agreement of the
young Medusz in all their essential features, while the Hydrarium shows
that the specific difference between the English and American represen-
tatives is not to be questioned. See the observations of Dalyell on the
development of his Tubularia ramosa, Pl. XI. 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 Meduse (Fig. 244), small,

Fig. 244. Young Mareelis, 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.

simple tentacles, terminating with a cluster of lasso-cells ; in somewhat
older Medusz the oral tentacles have two branches, as in Fig. 246,
when there are six tentacles to each marginal bulb, with a small bundle
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 Hudendrium ramosum. The
main stem is stout, and tapers gradually; the main branches begin
close to the root, and thus form clusters of stems, from which branch
off irregularly secondary branches, which are quite slender, and ramify
but little. The Hydre are very large, and quite closely packed to-
gether, growing with equal profusion on the main stem and on the

Fig. 246.

Fig. 247. Fig. 248.

branches. The Hydrarium is found growing attached to Fucus vesicu-
losus in great abundance. The general color of the main stem is some-
what grayish green, the Hydre are of a delicate rosy tint. The Me-
dusze buds are developed, somewhat as in our Bougainvillia supercil-
aris, along the stem (Fig. 248), without, however, being limited to the
proximity of the Hydra head, as the Meduse 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 Meduse buds of Margelis carolinensis.

EUDENDRIUM. 159

all over the stem, resembling in this 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.

ay ey
Wire wt Bhy
f \

EUDENDRIUM HEnzresns.

Eudendrium EXRENB. Corall. d. Roth. Meeres. 1834.
Eudendrium Acass. Cont. Nat. Hist. U. 8., IV. p. 342. 1862.
Calamella Oxen. Lehrb. der Naturg. Gesch. 1815.

Thoa LAMx. Pol. Cor. Flex. 1816.

Eudendrium dispar Acass.

Eudendrium dispar Acass. Cont. Nat. Hist. U. S., IV. pp. 285, 289, 342, Fig. 36; Pl. 27, Figs.
10-21. 1862.
Thoa dispar AGAss. Cont. Nat. Hist. U. S., TV. Pl. 27, Figs. 10-16. 1862.

This Hydroid (Fig. 249) is closely allied to the Doe
Tubularia ramea of Dalyell and the Coryne pu-
silla var. muscoides of Johnston. The male and
female communities are readily recognized by the
different color of the Medusz buds ; the male Me-
dusze 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. 249. Female Medusz buds in different stages of development.

160 EUDENDRIUM RAMOSUM.

Eudendrium tenue A. Acass.

This species (Fig. 250) can at
once be distinguished from the
E. dispar Agass. (Fig. 249) by
its large clusters of Medusz,
while in the /. dispar the Me-
dus buds are always somewhat
scattered, and never clustered to-
gether, as in 7, tenue. This is
quite a small species, the tallest
specimens hardly rising more than
an inch to an inch and a half,
while the #. dispar is a large
Hydroid, growing in tall stems,
branching but little; the Z. 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.,

A
VAV Ved ee

Eudendrium ramosum McCr.

Eudendrium ramosum McCr. Gymn. Charleston Harbor, p. 64.
2 Eudendrium ramosum JouNST, Brit. Zooph., p. 46.

McCrady has identified this species with the English £. 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 Fores.

Lizzia Forses. Brit. Naked-eyed Meduse, p. 64. 1848.
Lizzia Acass. Cont. Nat. Hist. U. S., IV. p. 345. 1862.
Cyteis SARS (non Esch.). Beskriv., p. 28. 1835.

Lizzia grata A. Acass.

Lizzia grata A. AGAss.; in Proc. Bost. Soc. Nat. Hist., p. 100, Figs. 28, 29. 1862.

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 pairs of

Fig. 251.

Fig. 252.

tentacles (Fig. ‘253), while in the Bougainvillia we have, for the first
set, as well as for the subsequent cycles, 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 cluster 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
(p, 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. 251. 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. Il. 21

162 LIZZIA GRATA.

extends ; the genital pouches are on the sides of the digestive cavity,
extending nearly to its extremity. The actinostome terminates in four
large lobes, edged with short oral tentacles, surmounted by a knob of

Fig. 255.

lasso-cells ; these lips are quite expansive and contractile. (¢ ¢, ¢’, ¢”,
Fig. 255.) In the young Medusez the digestive cavity terminates with
only four club-shaped tentacles (¢, Fig. 256); this soon branches in

Fig. 258.

somewhat older stages, as that of Fig. 252, and assumes the shape of
Figs. 257, 258, ¢, 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.

254. Proboscis of male Lizzia; magnified. 4 ‘
255. One of the four lobes of the actinostome, seen from above. 4, ¢, t/, t,t”, tentacles
of actinostome.
256. Actinal view of the proboscis of a young Lizzia. 1, oral tentacle; d, digestive cavity.
257. Actinal view of proboscis of an older specimen. a, actinostome; g, genital pouches;
t, tentacles of actinostome.

Fig. 258. Abactinal view of Fig. 257, somewhat less magnified, with the oral tentacles in a
different attitude ; lettering as above.

1

DYSMORPHOSA. 163

DYSMORPHOSA Patt.

Dysmorphosa Putu.; in Archiv f. Nat., p. 37. 1842.
Podocoryne Sars. Fauna Lit., p. 4. 1846.

Sars has traced the development of a Medusa from Podocoryne
carnea which is very closely allied to Dysmorphosa fulgurans 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
number, arrangement, and order of appearance of the tentacles, so com-
pletely, that I have referred it to the genus Dysmorphosa 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 Medusze, and traced the budding from the proboscis in exactly
the same manner as it is here given. The Lizzia figured by Claparéde
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. Aa@ass.

This Medusa (Fig. 259) is sometimes so abundant that the whole sea,
when disturbed, is brilliantly lighted by the peculiar bluish phosphores-
cent color which they give out. Their great number is easily accounted
for by their mode of reproduction and by its rapidity. Young Medusz
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. 260.

four days; from three to four Medusxz develop at the same time ; the
Medusx 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. 259. Adult Dysmorphosa; magnified.
Fig. 260. Magnified proboscis, showing young Medusz of the second and third generations.

164 NUCLEIFERZ.

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
Turritopsis nutricula, and could readily be mistaken for it. It would
be most natural, therefore, to place this genus in the family of Nuclei-
ferse ; 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 Bougainvillide.

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 Bougainvillidee ?

Massachusetts Bay, Nahant (A. Agassiz); Buzzard’s Bay, Naushon
(A. Agassiz).

Family NUCLEIFERA: Less. :

Nucleifere Less. Prod. Mon. Méd. 1837.

Nucleifere AGAss. Cont. Nat. Hist. U. 8., IV. p. 346. 1862.
Oceanide Escu. (p. p. non Agass.). Syst. der Acal., p. 96. 1829
Occanide GEGENB.; in Zeitschrift f. Wiss. Zool., p. 219. 1856.
Oceanide McCr. Gymn. Charleston Harbor, p. 21.

Clavide McCr. Gymn. Charleston Harbor, p. 37.

Clavide AGAss. Cont. Nat. Hist. U. S., IV. p. 338. 1862.

TURRIS Less.

Turris Luss. Prod. Mon. Méd. 1837.

Turris AGAss. Cont. Nat. Hist. U. S., IV. p. 346. 1862.
Oceania Aucr. (p. p. non Agass.). Medusa.

Clavula Wrieut. Hydra.

Turris vesicaria A. Acass.

Turris vesicaria A. AGAss.; in Proc. Bost. Soc. Nat. Hist., IX. p. 97.

This Medusa I formerly supposed to be the Medusa digitalis of
Fabricius ; it certainly is not that of Forbes. Since that time I have
ascertained that the Medusa digitalis of Fabricius belongs to a dif
ferent family, the Trachynemide. (See page 57.) It has been found
but once at Nahant, in the early part of the spring, and probably

TURRIS 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. 261

Nel
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,

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. 262. The same, with the bell contracted.

Fig. 263. A portion of the disk, seen from the abactinal pole. a, opening of actinostome ; ,
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. J, lips of actinostome ;
g', convoluted genital organs, extending from one side of the bell to the other ; g, part of the geni-
tal organ on the other side of the chymiferous tube; c!, as in Fig. 263; v, base of bladder sur-
mounting the bell.

166 TURRIS VESICARIA.

deep festoons (Fig. 263) from one chymiferous tube to another; they
form a compact mass, and fill the 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 tube communicate five tentacles placed between the chy-
miferous tubes, and one opposite 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.

ND PALIN I I

Fig. 268.

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; 0, 268.)
In the genera Turris, Ptychogena, Olindias of Miiller, 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 tubes; 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. 265. Magnified view of a part of a chymiferous tube.

Fig. 266. Base of one of the chymiferous tubes, and part of the circular tube. ¢, chymiferous
tube; ¢', circular tube; b, sensitive bulb of tentacle; e, eye-speck ; /, lash of the tentacles coy-
ered with lasso-cells.

Fig. 267. One of the tentacles in a semi-profile view.

Fig. 268. One of the tentacles, seen from the abactinal pole. 0, 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.

Turritopsis McCr. Gymnoph. Charleston Harbor, p. 24. 1857.
Turritopsis McCr. On Turritopsis, new species,....p. 2. 1
Turritopsis AGass. Cont. Nat. Hist. U. S., IV. p. 347. 1862.

Turritopsis nutricula McCr.

Turritopsis nutricula McCr. Gymn. Charleston Harbor, p. 25, Pls. 4, 5, 8, Fig. 1.
Turritopsis nutricula AGAss. Cont. Nat. Hist. U. S., IV. p. 347. 1862.
Turritopsis nutricula A. AGAss.; in Proc. Boston Spe Nat. Hist., IX. Figs. 22, 23.

The young Medusz have only four stiff tentacles, with a long bottle-
shaped digestive trunk (Fig. 269), fastened by its base to the lower
part of a short prolongation of the 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 Medusx 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 Fig. 270.
advancing size the gelatinous mass loses its
bell shape, and becomes more globular, the
tentacles (then sixteen In number) losing
somewhat their stiffMess; 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 were 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 Tuwrritopsis, 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 limes 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 Medusz of many of the
Tubularians.

There is found at Nahant the young of a species of Turritopsis which
differs from the Zurritopsis nutricula 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 Meduse a totally different aspect from the
young of the 7. nutricula. I might mention here that the trace of its
connection with a Hydroid stock was very distinct in young Meduse ;
the adult Medusa was not observed.

Charleston, 8. 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.

As, /
Mir Jeal—CLAY ,
'

STOMOTOCA Aaass.

Stomotoca AGAss. Cont. Nat. Hist. U. S., IV. p. 347. 1862.
Saphenia ForBEs (non Esch.). British Naked-eyed Medusze, p. 25. 1848.

Stomotoca apicata Acass.

Stomotoca apicata AGAss. Cont. Nat. Hist. U. 8., IV. p. 347. 1862.
Saphenia apicata McCr. Gymn. Charleston Harbor, p. 27, Pl. 8, Figs. 2, 3.
Charleston, S. C. (McCrady) ; Newport (A. Agassiz).
Cat. No. 454, Newport, A. Agassiz. Medusa.

Stomotoca atra Acass.

Stomotoca atra A. AGAss.; in Agassiz’s Cont. Nat. Hist. U. S., IV. p. 847. 1862.

This Medusa (Fig. 271) is much larger than the one Forbes has de-
scribed as S. dinema (Naked-eyed Meduse, PI. IL. 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-

STOMOTOCA ATRA. 169

eter almost immediately above the circular tube, where it curves in
slightly, and then bends uniformly towards the abactinal pole; the
upper part is almost hemispherical, being very blunt at the abactinal
pole; the peduncle tapers gradually from the base to the ovaries;
the ovaries are barrel-shaped, extending to the digestive cavity, which
is small at the pomt where the chymiferous tubes empty into it, but
gradually bulges ont, 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 chymiferous tubes 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-

Fig. 271. Fig. 273. Fig. 272.

C0. 7? a
Woy
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mn

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NX
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AO

/

ing with an actinostome divided into four lips. While swimming, these
Medusz 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 bemg deeply lobed (Fig. 273), the
intermediate portions of the periphery not seeming to be so highly
contractile as that which immediately adjoims 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. Il. 22

170

RHIZOGETON.

RHIZOGETON Aaass.

Rhizogeton AGass. Cont. Nat. Hist. U. S., IV. p. 347. 1862.

Rhizogeton fusiformis Acass.

Rhizogeton fusiformis AGASS.

Massachusetts Bay

Cont. Nat. Hist. U. S., IV. pp. 224, 347, Pl. 20, Figs. 17-23. 1862.

(Agassiz).

Cat. No. 52, Nahant, Mass., July, 1861, A. Agassiz. Hydrarium.

CLAVA Gwe.

Clava GMELIN ; in Beschiift. d. Berlin. Ges. Naturf. Freunde. 1775.

Fig. 274.

Clava leptostyla Acass.

Clava leptostyla AGAss. Cont. Nat. Hist. U. S., IV. pp. 218, 222,
Fig. 32; 338, Pl. 20, Figs. 11-16%; Pl. 21. 1862.

Clava multicornis Strmps. Mar. Inv. Grand Manan, p. 11. 18538.

Clava multicornis Lerpy. Mar. Inv. Rhode Island and New Jersey,
p- 8, Pl. XL Figs. 33, 34. 1855.

Clava multicornis Pack.; in Can. Nat. & Geol. Dee. 1863.

The Clava leptostyla (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.

WILLIADUE. 171

Family WILLIADZ: Forbes.

Williade Fores. British Naked-eyed Medusm, p. 19. 1848.
Berenicida AGAss. (p. p. non Esch.). Cont. Nat. Hist. U. S., TV. p. 345. 1862.

WILLIA. Forbes.

Wilsia Fores. British Naked-eyed Meduse, 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, Pl. 9, Figs. 9-11.
Willia ornata AGAss. Cont. Nat. Hist. U. S8., TV. p. 846. 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 im 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-
dusxe (Laomedea diaphana, Clytia bicophora, etc.). In very young
Williz, 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 adjoming 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 slightly 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 turned 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 far 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 Willa 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 (/, Fig. 279), running in the thickness

Fig. 277. 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 circle. 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 young Willia; magnified.

Fig. 277. Part of the cireular tube. J, 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 abactinal pole.

PROBOSCIDACTYLA. 173

both sides of the cross-shaped edges of the digestive cavity, giving it a
quadrangular appearance, when seen from above. (Fig. 279.) Found
at Naushon the last part of September, one tenth to one eighth of an
inch in diameter.

Charleston Harbor (McCrady) ; Buzzard’s Bay, Naushon (A. Agassiz).

PROBOSCIDACTYLA Branpt.

Proboscidactyla BRANDT ; in Mém. Acad. St. Petersburg, II. p. 228. 1835.
Proboscidactyla 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 genus 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.

Proboscidactyla flavicirrata Br.; in Mém. Acad. St. Petersb., p. 390, Pl. 19. 1838.
Proboscidactyla flavicirrata AGAss. Cont. Nat. Hist. U. S., 1V. p. 346. 1864.

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-like 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 Fig. 281.
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 (0, Fig.
282); at the pomt 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.

174 PROBOSCIDACTYLA FLAVICIRRATA.

chymiferous tube dividing into two main branches, and each branch
Fig. 282. subdividing again into eight, making in all sixty-
four branching tubes, and as many tentacles and
eye-specks. Between each of the ocelli 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 bemg probably some-
thing similar to what we find on the disk of Aw-
relia flavidula, made up of large lasso-cells, only
much more densely crowded together. The shape
of the bell is almost perfectly thimble-shaped,
there being neither bulgmg 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. 8, first fork; /, tubes containing
lasso-cells, as in Willia.

SARSIADZ.

Family SARSIADA Forbes.

Sarsiade Forsss (restr. Agass.). Brit. Naked-eyed Medusz, p. 54.
Sarsiade AGass. Cont. Nat. Hist. U. S., LV. pp. 184, 217, 339.

CORYNE Girt.

Coryne GART.; in Pall. Elen. Zooph. 1774. Hydra.

Syncoryna EMRENB. (p.p-). Corall. des Rothen Meeres. 1834. Hydra.

Stipula Sars. Bidrag til Sdedyr. Nat. 1829. Hydra.
Hermia Jounxst. British Zoophytes, p. 111. 1838. Hydra.

Coryne AGass. Cont. Nat. Hist. U. S., IV. p. 339. 1862. Hydra.

Sarsia Less. Zooph. Acal., p. 333. 1843. Medusa.
Sthenio Dus.; in Ann. Se. Nat. 1845. Medusa.
Sarsia AGASS.; in Mem. Am. Acad., p. 224. 1849. Medusa.

Coryne mirabilis Acass.

Coryne mirabilis AGass. Cont. Nat. Hist. U. S., IV. pp. 185-217, Figs.
9-31; Pl. 20, Figs. 1-9; Pl. 235, Fig. 12; III. Pl. 11°, Figs. 14,
15; Pls. 17-19. 1860-62.
Sarsia mirabilis AGAsS.; in Mem. Am. Acad., IV. p. 224, Pls. 4, 5.
Sarsia mirabilis-‘Strmes. Mar. Inv. Grand Manan, p. 11. 1853.
Oceania tubulosa GOULD (non Sars). Iny. of Mass., p. 348. 1841.
Sarsia glacialis Morcu ; in Beskriv. af Groenland, p. 95. 1857.
Tubularia stellifera CouTu.; in Bost. Journ. Nat. Hist., I. p. 56.
Tubularia stellifera Goutp. Inv. Mass., p. 350. 1841.

This Medusa (Figs. 283, 284, 285) is one of the
earliest visitants of our wharves. The ice has

Fig. 284. Fig.28. scarcely gone from the shores
when numbers of young Me-
dus, just freed from the
Hydrarium, swarm near the
surface on any sunny day.
Captain Couthouy has de-
scribed, under the name of
Tubularia stellifera, 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. ¢, tentacles ;
e, veil; c, circular tube ; 0, actinostome.

Fig. 285. Coryne mirabilis, with expanded proboscis. d, proboscis ;
a, b, thickness of the bell.

175

176 . CORYNE ROSARIA.

served, I am unable to state this positively. It seems to make but
little difference to the Hydrarium (Figs. 286, 287, 288) or to the

Fig. 286.

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. Hydrarium.

Cat. No. 268, Boston, April, 1862, A. Agassiz. Young Meduse.

Cat. No. 269, Boston, May, 1862, A. Agassiz. Young Medusa.

Museum Diagrams, No. 20, 21, after L. Agassiz.

Coryne rosaria A. Acass.

Coryne rosaria A. AGAss.; in Agassiz’s Cont. Nat. Hist. U. S., IV. p. 340. 1862.

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 differences between this Medusa, and the European or American
representatives on the two sides of the Atlantic. The Hydrarium re-
sembles somewhat Coryne stipula 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 ; im Coryne
rosaria the heads, which are quite slender, are supported by remark-
ably 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. Meduse buds were

Fig. 286. Cluster of Hydraria of Coryne mirabilis.
Fig. 287. Young Hydrarium.
Fig. 288. Magnified view of a head with Medusa bud, d, attached.

SYNDICTYON. 77

observed on the Hydrarium in March; no young Meduse have been
observed; the adults attain an enormous size, meas-
uring more than an inch in polar diameter, as in Fie.
289, which is drawn the natural size.

The spherosome bulges very rapidly from the abacti-
nal pole (Fig. 289) 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 bemg somewhat darker. It resembles Sarsia
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.

Fig. 289.

SYNDICTYON A. Agass.

Syndictyon A. AGASS.; in Agassiz’s Cont. Nat. Hist. U. 8., IV. p. 340. 1862.

Syndictyon reticulatum A. Aeass.

Syndictyon reticulatum 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 Meduse 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.
NO. II. 23

178 SYNDICTYON RETICULATUM.

diameter. The young Meduse 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
Medusz 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; the sensitive bulb is large, the

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 Dipurena; the whole surface of the sphero-
some is covered with clusters of large lasso-cells (Fig. 296), giving
it a granulated appearance ; the ground-work consists of mmute gran-
ulation, which appears under a low magnifying power to be arranged

Fig. 293. Fig. 294. Fig. 295.

Fig. 290. Hydromedusarium of Syndictyon reticulatum, greatly magnified.

Fig. 291. Syndictyon reticulatum, immediately after it has become freed from the Hydrome-
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 RETICULATUM. 179

in rows parallel to the circular tube, upon which are scattered large
lasso-cells. The actinal and polar 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 immer 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 chymiferous tubes
are narrow (Fig. 296), of uniform diameter through-
out ; the sensitive bulb is ovoid, with a well-defined
lenticular-shaped concentration of black pigment-
cells (Fig. 293); the bulb itself is colored light-
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-cells begin at some distance from the base of the tentacle (one
fourth 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, Fig. 297.
dividing into smaller granules, which are small, un-
developed lasso-cells, forming a net-work 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 Medusx, similar to those developed from
the Hydroid, are found swimming freely about durmg June and
July.

The young Medusa described above gradually loses the characters
which distinguished it from Sarsia, and as it becomes more advanced,
it resembles so closely Sarsia, that were it not for the invariable

Fig. 296. Fig. 291, from the abactinal pole.
Fig. 297. Part of net-work of the surface of the spherosome. , 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 those 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 different; the lips (four in number) are quite
prominent (a, Fig. 300), though often carried in trumpet fashion, at

Fig 298.

the extremity of the digestive cavity (a, Fig. 300), and the spherosome
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. Cont. Nat. Hist. U. S., IV. p. 341. 1862.

McCrady established this genus from an investigation of two species
of Medusee, 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

Fig. 298. Adult Medusa, in a natural attitude.

Fig. 299. The same Medusa as Fig. 298, with the tentacles contracted.

Fig. 300. Actinostome of adult Medusa. a, when protruded, trumpet-shape ; a’, showing the
lips of actinostome.

DIPURENA CONICA. 181

chymiferous tubes. This is so contrary to what we have thus far found
to be uniformly the position of these organs among Tubularian Medusz,
that there is probably some mistake in Forbes’s drawing. .

Dipurena strangulata McCr.

Dipurena strangulata McCr. Gymnoph. of Charleston Harbor, p. 33, Pl. 9, Fig. 1.
Dipurena strangulata Acass. Cont. Nat. Hist. U. S., IV. p. 341. 1862.

Charleston, S. C. (McCrady).

Dipurena cervicata McCr.

Dipurena cervicata McCr. Gymn. Charleston Harbor, p. 34.
Dipurena cervicata AGAsS. Cont. Nat. Hist. U. S. IV. p. 341. 1862.

Charleston Harbor (McCrady).

Dipurena conica A. Agass.
Dipurena conica A. AGASS.; in Agassiz’s Cont. Nat. Hist. U. S., IV. p. 341. 1862.

In the young Medusa the shape of the bell is nearly sugar-loaf (Fig.
301); the cavity of the bell is formed by a Fig. 301.
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 (wv, Fig. 302) being about half the
size of the lower one (/, 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- Fig. 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; magnified.
Fig. 302. Digestive cavity of a young Dipurena conica. uw, the upper part; /, the lower.

182 DIPURENA CONICA.

shaped row of large elliptical cells surrounding the upper end of the

Fig. 303. terminal cavity, these cells bemg 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 are pig-
ment-cells, 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 strangulata 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- Fig. 304.
tive bulbs ; according to McCrady, they are exceedingly
pointed in D. strangulata, while the sensitive bulb of D.
conica widens as it approaches the circular tube. The
largest specimens 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-shaped, 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,

Fig. 205. separated by a constriction,
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 specimens. 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 are widely separated ;
greatly magnified.

ORTHOCORYNIDZ. 183

two parts are simply connected by a narrow tube as long as the diges-
tive cavities themselves ; 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, 9 ~“/« =

Museum Diagram, No. 20, after A. Agassiz.

Family ORTHOCORYNIDZ: A. Agass.

I have ventured to separate the genus Zanclea from the Pennaride,
with which it had been associated by McCrady and Professor Agassiz,
and to form a new family, on account of the observations of Allman on
the development of Zanclea from its Hydroid, Coryne impressa Ald.
The peculiar form of the Hydrarium, and the still more remarkable
characters of the Medusz, with their tentacles bearing pedunculated
knobs of lasso-cells, separate them from the square Medusx of the
Pennaridze, 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
family, the Orthocorynide. Does not also the Heterocordyle Cony-
bearei belong to this family? The great difference between the repro-
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.
Corynitis AGAss. Cont. Nat. Hist. U. S., IV. p. 340. 1862.
Halocharis Acass. Cont. Nat. Hist. U. S., IV. p. 239. 1862. Hydrarium.

Corynitis Agassizii McCr.

Corynitis Agassizii McCr. Gymn. Charl. Harbor, p. 30, Pl. 9, Figs. 3-8.
Corynitis Agassizii AGAss. Cont. Nat. Hist. U. S., IV. p. 340. 1862.
Halocharis spiralis AGAss. Cont. Nat. Hist. U. S., IV. p. 239, Pl. 20, Figs. 10, 10°. 1862.

Charleston, 8. C. (McCrady).

184 GEMMARIA.

GEMMARIA McCr.

Gemmaria McCr. Gymn. Charl. Harbor, p. 49.

Zanclea McCr. (non Geg.). Gymn. Charl. Harbor, p. 48.

Zanclea AGASS. (p. p.). Cont. Nat. Hist. U. S., IV. p. 344. 1862.
Acrochordium Mry.; in Noy. Ac. N. Aur XVI. 1834. Hydrarium ?

Gemmaria gemmosa McCr.

Gemmaria gemmosa McCr. Gymn. Charl. Harbor, p. 49, Pl. 8, Figs. 4, 5.
Zanclea gemmosa McCr. Gymn. Charl. Harbor, p. 49.
Zanclea gemmosa AGass. Cont. Nat. Hist. U. S., IV. p. 344. 1862.

McCrady has distinguished with reason the genus Gemmaria from
Fig. 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 cladophora 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-shaped ; 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, 8. C. (McCrady); Buzzard’s Bay, Naushon (A. Agassiz).

ere, Wee Oo)

Gemmaria cladophora A. Acass.

The shape of the inner bell of the adult Medusa of this species is
peculiar ; the outline does not follow that of the outer bell (Fig. 307),

Fig. 307.

Fig. 306. Profile view of half of a young Gemmaria gemmosa ; magnified.
Fig. 307. Profile view of Gemmaria cladophora ; magnified.

GEMMARIA CLADOPHORA. 185

but is curved in the opposite direction ; near the upper bend of the
chymiferous tubes, it runs up mto a pomt, making a sharp and deep
groove round the projection of the
spherosome; the chymiferous tubes
(c’, Fig. 308), as well as the circu-
lar tube, are very 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 cay-
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

Fai OE. 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 halfway up the sphero-
some. (Fig. 308.)

The tentacles are broad and thick, two of them
being more developed than the others (Fig. 507) ;
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 gig suo.
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 Medusez are quite rapid in their movements. (Fig. 307.)

Professor Clark discovered at Nahant a Hydroid closely resembling
the Coryne implexa 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 implexa.

Massachusetts Bay, Nahant (A. Agassiz).

Cat. No. 363, Nahant, 1862, A. Agassiz. Medusa.

? Cat. No. 63, Nahant, May, 1862, H. J. Clark. Hydrarium.

Museum Diagram, No. 20, after A. Agassiz.

Fig. 308. Quarter of the disk of © Gaingion, seen from the abactinal pole. c, circular
tube ; c’, chymiferous tube ; 6, sensitive bulb, having a great accumulation of pigment and lasso
cells extending along the chymiferous tubes ; c’, opening leading into the chymiferous tubes from
the digestive cavity, 0; g, g, genital organs; g!, fatty globules at base of proboscis.

Fig. 309. Actinostome of Gemmaria, enlarged.

Fig. 310. Cluster of lasso-cells of the marginal tentacles.
NO. II. 24

a? dy A ty

186 PENNARIDA.

CANDELABRUM Buarnv.

Candelabrum Buainy. Man. d’Actin., p. 307. 1834.
Candelabrum AGass. Cont. Nat. Hist. U. S., IV. p- 340. 1862,
Myriothela Sars. Reise i Lof. og Fin., p. 14.

Spadiz GossE; in Ann. & Mag. N. HL, p. 125. 1855.

Candelabrum phrygium Braryv.

Candelabrum phrygium Buaryy. Man. d’Actin., p. 317. 1834.
Lucernaria phrygia Fas. Fauna Gronlandica. No. 333.
Lucernaria phrygia AGAss. Cont. Nat. Hist. U. S., IV. p. 341. 1862.
Corymorpha phrygia Morcu.; in Besk. af Gronland, p. 96.

Greenland (Fabricius) ; Grand Manan (W. Stimpson).

Cat. No. 161, Grand Manan, W. Stimpson. Hydromedusarium.

Family PENNARIDA: McCr.

Pennaride McCr. (restr. A. Agass.). Gymn. Charl. Harbor, p. 46. :
Pennaride AGASS. (p. p.). Cont. Nat. Hist. U. 8., [V. 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 Hydrarium by Allman.

PENNARIA Gotopr.

Pennaria Goupr. (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.
Globiceps AYRES ; in Proc. Bost. Soc. Nat. Hist., IV. p. 198. 1852.
Globiceps AGAss. Cont. Nat. Hist. U. 8., IV. p. 344. 1862.
Eucoryne Lerpy. Iny. N. J. and R.1., p. 4. 1855.

I have not given to the Gilobiceps tiarella of Ayres a new generic
name, although it is probable that it does not belong to the same

genus as the Pennaria gibbosa Agass., as the development of the latter
species requires renewed examination to decide the question.

Pennaria gibbosa Acass.

Pennaria gibbosa Acass. Cont. Nat. Hist. U. S., IV. pp. 278, 344; II. Pl. 15, Figs. 1, 2.

Florida (L. Agassiz).
Cat. No. 19, Key West, Florida, March, 1853, L. Agassiz. Hydrome-
dusarium.

Cat. No. 20, Jéremie, Hayti, Dr. Weinland.

PENNARIA TIARELLA. 187

Pennaria tiarella McCr.

Pennaria tiarella McCr. Gymn. Charleston Harbor, p. 51.

Globiceps tiarella AYRES ; in Proc. Bost. Soc. Nat. Hist., p. 193, Pl. X. Figs. 1-5. 1852.
Eucoryne elegans Lerpy. Mar. Iny. N. J. and R.1., p. 4. 1855.

Globiceps tiarella AGAss. Cont. Nat. Hist. U. S., IV. p. 344. 1862.

Fig. 311.

The Medusa of Globiceps tiarella is
one of the most remarkable of our
naked-eyed Medusee. As in the Sarsi-
adze, the Medusa bud is formed among
the tentacles (Fig. 511), 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 white eggs are developed from the pro-
boscis, fillimg the whole cavity of the bell as
they increase in size, and giving the Medusa an
opaque milky appearance; the walls of the
spherosome 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 Medusz Fig. 313,
are almost always distorted, either on one side
or the other, by the eggs or bunches of sper-
maries 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 large eggs
happens to be placed (e, Fig. 312); two or
three of the eggs generally escape before the
Medusa bud 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 egos have escaped,

Fig. 311. A fertile Hydra of Pennaria tiarella, showing the mode of budding ; magnified.

Fig. 312. A Medusa distended by an ege, e; magnified.

Fig. 313. Profile view of Medusa of Pennaria tiarella; magnified. f, folds produced by the
distension of spherosome.

188 PENNARIA TIARELLA.

owing to their distension (f,; Fig. 315); as soon as the eggs have all
escaped, and the Medusze have become detached, they move about with
great activity, their motions resembling 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. 514), with deep indentations
between the chymiferous tubes (Fig. 315); the digestive trunk is short,
bottle-shaped, not extendmg 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 bell m such a way that when seen in profile 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 Sarsiade, Bougainville, 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. 315),
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, 8. C. (McCrady).

Vig. 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. Hydromedu-
sarium.

Cat. No. 22, Naushon, Sept. 1861, A. Agassiz. Hydromedusarium.

Cat. No. 23, Newport, R. 1, Prof. J. Leidy. Hydromedusarium.

Cat. No. 24, Newport, R. I, S. Powell. Hydromedusarium. MY

Cat. No. 25, Beverly, Mass., T. Lyman. Hydrarium.

Cat. No. 26, West Yarmouth, Mass., Aug. 1860, T. Lyman. Hydrarium.

Cat. No. 407, Nahant, September, 1862, A. Agassiz. Hydrarium,

Family TUBULARIADA Johnst.

Tubwariade Jounst. (restr. Agass.) ; in Trans. Berwick Club, p. 107.
Tubulariade Acass. Cont. Nat. Hist. U. S., IV. p. 342. 1862.

EUPHYSA Forsss.

Euphysa Forses. British Naked-eyed Meduse, 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 spherosome 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. Acass.

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 (¢, ¢,
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 (p, 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.

190 ECTOPLEURA.

The Medusa is exceedingly active, moving very rapidly and inces-
santly. Found at Nahant in the latter part of August.

Fig. 319.

Fig. 316.

Fig. 317.

Euphysa is not, as Professor Agassiz has stated, the generation of
Medusz which become separated from the base of the reproducing
tentacle in Hybocodon. That generation of Meduse are identical with
the parent Medusa, as well as the second generation which bud from
the large tentacle of this first set of Meduse.

Massachusetts Bay, Nahant (A. Agassiz).

Cat. No. 452, Nahant, A. Agassiz.

ECTOPLEURA Aaass.
Ectopleura AGAss. Cont. Nat. Hist. U. 8., IV. p. 342. 1862.

In this genus I would include those species of the genus Sarsia (like
Oceania telostyla Geg., Sarsia turricula McCrady, and Sarsia gemma-
Jfera 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. 316. Euphysa vireulata, seen in profile ; magnified.

Fig. 317. Proboscis of Euphysa. a, actinostome ; 0, ovaries ; g, fatty globules; magnified.

Fig. 318. Actinal view of Euphysa, to show the character of the veil. 7, the odd long tenta-
cle; t', one of the pair of tentacles ; 1", the odd small tentacle.

Fig. 319. One of the tentacles seen in profile, to show the character of the band of pigment:
cells, p, extending along the base of the chymiferous tube from the origin of the tentacle, ¢’.

x

ECTOPLEURA OCHRACEA. 191

Ectopleura turricula Acass.

Ectopleura turricula AGAss. Cont. Nat. Hist. U. S., IV. p. 343. 1862.
Sarsia turricula McCr. Gymn. Charleston Harbor, p. 36, Pl. 8, Figs. 6-8.

Charleston, S$. C. (McCrady).

Ectopleura ochracea A. AGass.

Ectopleura ochracea A. AGASS.; in Agassiz’s Cont. Nat. Hist. U. S., IV. p. 343. 1862.

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,
contracting again 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 appendages 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. twrricula 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 abactinal pole (Figs.
321, 322) a thread of bunches of lasso-cells (/, Fig. 320), like that of
Turritopsis. The bunches are 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 agere-
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 attachment of the digestive trunk; the digestive cavity itself
is of a delicate rose color, with whitish bunches 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 ochracea, magnified. 4, 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 eae
Fig. 321. Fig. 322.

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
Fig. 323. 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 med than in older specimens. The
Hydroid of this Medusa probably resembles the Tubularia Dumortier
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.

wa 4 1

Rat

CORYMORPHA Sars.

Corymorpha Sars. Beskriv., p. 6. 1835.
Corymorpha AGass. Cont. Nat. Hist. U. S., IV. p. 343. 1862.

Corymorpha pendula Aéass.

Corymorpha pendula AGass. Cont. Nat. Hist. U. S., IV. pp. 276, 343, Pl. 26, Figs. 7-17.
Corymorpha nutans Stimes. Mar. Iny, Grand Manan, p. 9. 1853.
Corymorpha pendula A. AGASS.; in Proc. 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 each side
of the base of the tentacles.

Fig. 323. The base of one of the tentacles, magnified. p, cluster of pigment-cells.

HYBOCODON. 193

developed, the long tentacle (Fig. 524) 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. 524) are
capable of great contraction and expansion; the lasso- Fig. 324.
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 pigment-cells 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 Medusz 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 Aaass.

Hybocodon Acass. Cont. Nat. Hist. U. S., IV. p. 343. 1862.

Hybocodon prolifer Acass.

Hybocodon prolifer AGAss. Cont. Nat. Hist. U. S., IV. pp. 243, 343, Pl. 23°, Figs. 10,11; Pl. 25.
1862.

This is one of the few known Tubularians
found growing singly. (Fig. 325.) The char-
acter of the Medusx 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 Medusee (Fig. 328), similar to the parent

Fig. 324. Medusa of Corymorpha, seen in profile. 1, long odd tentacle ; 2, pair of tentacles ,
3, short odd tentacle.

Fig. 325. Single Hydra of Hybocodon. 0, mouth surrounded with tentacles ; ¢, ¢, marginal
tentacles; d, d, advanced Meduse buds ; a, stem.

NO. Il. 25

194 PARYPHA.

Medusa, from the base of the single largely-developed tentacle, is a
feature it has in common with other Medusze 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-

bocodon. Should the Diplonema of Greene prove to be one of these
asymmetrical Medusze, the name Hybocodon 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. 1862.
Pyzxidium Lrvck.; in Archiv f. Nat., I. p. 31. 1856.

Parypha cristata Acass.

Parypha cristala AGAss. Cont. Nat. Hist. U. 8., IV. p. 342. 1862.
Tubularia cristata McCr. Gymn. Charleston Harbor, p. 54.

Charleston, 8. C. (McCrady).
Cat. No. 14, Sullivan’s Islands, 8. C., December, 1851, L. Agassiz.

? Cat. No. 16, Florida, 1850, L. Agassiz.

Fig. 326. Hybocodon prolifer Agass., seen from the broad side. v, proboscis; 7, 0, radiating
tubes; s, circular tube ; m, buds of Meduse at base of long tentacle, ¢.

Fig. 327. Hybocodon prolifer, seen facing the long tentacle. a, point of attachment to Hy-
drarium ; 0, c, radiating tubes; e, rows of lasso-cells extending from base of tentacle to abactinal
pole; 0, proboscis ; 7, Medusz budding from base of long tentacle, ¢.

Fig. 328. Medusa bud of Hybocodon. a, base of attachment; 0, proboscis; 6, c, chymiferous
tubes; d and near c, Medusz buds at base of tentacle, t.

THAMNOCNIDIA. 195

Parypha crocea Acass.

Parypha crocea AGAss. Cont. Nat. Hist. U. S., IV. pp. 249, 342, Pls. 23, 23°, Figs. 1-7. 1862.

Boston Bay (L. Agassiz).
Cat. No. 13, Warren Bridge, Boston, June, 1858, H. J. Clark. Hy-

dromedusarium.

Parypha microcephala A. Acass.

Resembles in its general aspect the Parypha 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
floating logs 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-

medusarium.

THAMNOCNIDIA Agass.

Thamnocnidia AGass. Cont. Nat. Hist. U. S., TV p. 342. 1862.

Thamnocnidia spectabilis Acass.
Thamnoenidia spectabilis AGass. Cont. Nat. Hist. U. 8., IV. pp. 271, 342, Pl. 22, Figs. 1-20. 1862.

Massachusetts Bay, Boston (L. Agassiz).
Cat. No. 6, Boston, August, 1851, H. J. Clark. Hydromedusarium.

Thamnocnidia tenella Acass.
Thamnocnidia tenella Acass. Cont. Nat. Hist. U. S., IV. pp. 275, 342, Pl. 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. Acass.

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 genume 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 specimens. 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 Livy.

Tubularia Linn. (restr. Agass.). Syst. Nat. 1756.
Tubularia AGAss. Cont. Nat. Hist. U. S., 1V. p. 342. 1862.

Tubularia larynx Livy.

Tubularia larynx E.uis. Cor., Pl. 16, Fig. 6.
Tubularia larynz Jounst. Brit. Zooph., p. 50, Pl. 8, Fig. 3; Pl. 5, Figs. 3, 4.
Tubularia larynz Straps. Mar. Iny. Grand Manan, p. 9. 1853.

Grand Manan (W. Stimpson).

Tubularia Couthouyi Acass.

Tubularia Couthouyi AGass. Cont. Nat. Hist. U. S., IV. pp. 266, 342, Pl. 23%, Figs. 8, 9; Pls.
24, 26, Figs. 1-6. 1862.

Tubularia indivisa Straps. Mar. Inv. Grand Manan, p. 9. 1853.

Tubularia indivisa Goutp. Rep. Inv. Mass., p. 350. 1841.

Tubularia indivisa Morcu ; 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 HYDRAIDA Gray.

Hydraide Gray. Syn. Brit. Mus., p. 76. 1840.
Hydrina ENRENB. (p. p.). Corall. d. Roth. Meeres, p. 67.
Hydraide Jounst. Brit. Zooph., p. 120, Second Edition.

HYDRA Loy.

Hydra Linn. Syst. Nat. 1756.

Hydra gracilis Acass.

Hydra gracilis AGAss.; in Proc. Bost. Soc. Nat. Hist., TM. p. 354.
Hydra gracilis AYRES ; in Proc. Bost. Soc. Nat. Hist., V. p. 103.

Our fresh-water Hydra has as yet been studied so insufficiently,
that I am unable to add anything respecting the development of the
Medusze, 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 Medusz of the Hydra, it seems to me that it finds
its natural place among the true Hydroids, and not among the Dis-
cophore, 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 Aaass.

Hydra carnea AGASs.; in Proc. Bost. Soc. Nat. Hist., IIL. 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 HYDRACTINIDZ.

Family HYDRACTINIDA Agass.

Hydractinide AGass. Cont. Nat. Hist. U. S., IV. p. 339. 1862.

HYDRACTINIA Van BeEnepen.

Hydractinia VAN BENEDEN ; in Bull. Acad. Bel., VIII. 1841.
lydractinia AGAsSS. Cont. Nat. Hist. U. 8., IV. p. 839. 1862.
Synhydra Quat.; in Ann. des Scien. Nat., XX. p. 280. 1843.

Hydractinia polyclina Acass.

Hydractinia polyclina AGAss. Cont. Nat. Hist. U. S., I. Pl. 16; IV. pp. 227-239, 339, Figs.
38-35; Pl. 26, Fig. 18. 1862.

Hydra squamata Fas. Fauna Grénlandica. No. 338.

Alcyonium echinatum GouLp. Rep. Inv. Mass., p. 351.

Hydractinia echinata Letpy. Mar. Inv. New Jersey and Rhode Island, p. 3, Pl. X. Fig. 35. 1855.

Hydractinia echinata Stimps. Mar. Inv. Grand Manan, p. 11. 1853.

Hydractinia echinata McCr. Gymn. Charleston Harbor, p. 66.

Clava squamata Mércu ; in Beskriv. af Gronland, p. 96.

Hydractinia polyclina Pack.; in Can. Nat. & Geol. Dec. 1863.

As such constant reference is made to Hydractinia in the comparison
of the free colonies of Nanomia to the fixed Hydroids, figures of male

Fig. 330.
Fig. 329.

(Fig. 329) and female (Fig. 330) colonies of this species are here intro-
duced to facilitate the comparison.

Point Judith (Leidy) ; Atlantic coast of North America (L. Agassiz).

Cat. No. 55, Grand Manan, 1859, A. E. Verrill.

Cat. No. 56, Grand Manan, October, 1857, J. EH. 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, 1862, A. Agassiz.

Museum Diagram, No. 25, after L. Agassiz.

Fig. 329. Part of male community of Hydractinia. a, a, sterile individuals; }, fertile indi-
vidual; d, male Medusz ; 9, 0, proboscis ; t, elongated tentacle of sterile individuals.

Fig. 330. Part of female community. a, sterile individual; 6, fertile individual, producing
female Medusz, d, e, f, g, h, i; 0, peduncle of mouth ; c, individual with globular tentacles.

DIPHY &. 199

SuporpER DIPHY Cvv.

Diphye Cuy. Reéegne Animal, TV. 1817.
Calycophoride LEwck. (p. p.) ; in Archiv f. Nat., I. p. 256.
Diphye Acass. Cont. Nat. Hist. U. S., IV. p. 370. 1862.

1854.

For the reasons which 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 DIPHYIDA Esch.

Syst. der Acal., p. 122. 1829.

Diphyide Escu. (restr. Agass.).
1862.

Diphyide Acass. Cont. Nat. Hist. U. S., IV. p. 371.

EUDOXIA Escu.

Eudoxia Escu. Syst. der Acal., p. 125. 1829.
Eudoxia Less. Zooph. Acal., p. 460. 1843.

Eudoxia alata McCx.

Eudoxia alata McCr. Gymnoph. Charleston Harbor, p. 70, Pl. 8, Figs. 9, 10.

Charleston Harbor (McCrady).

DIPHYES Cov.
Diphyes Cuv. Regne Animal, TV. 1817.
Ersea Escu. Syst. der Acal., p. 127. 1829.

Cucullus Q. & G.; in Ann. des Se. Nat., X. 1829.
Diphyes Less. Zooph. Acal., p. 438. 1843.

Diphyes pusilla McCr.

Diphyes pusilla McCr. Gymn. Charleston Harbor, p. 72.

Charleston, 8. C. (McCrady).

200 PHYSOPHOR/.

SuBORDER PHYSOPHORZ Go.pr.

Physophore Gotpr. Handb. d. Zool. 1820.
Physophore AGAss. Cont. Nat. Hist. U. S., IV. p. 367. 1862.

Family AGALMIDA Brandt.

Agalmide BRanpT ; in Mém. Acad. St. Petersburg, p. 234. 1838.
Agalme Less. Zooph. Acal., p. 509. 1843.

Stephanomie Less. Zooph. Acal., p. 475. 1843.

Stephanomide Lrvck.; in Archiv f. Nat., I. p. 312. 1854.
Stephanomide Huxu. Ocean. Hyd., p. 72. 1858.

Agalmide Acass. Cont. Nat. Hist. U. §., IV. p. 368. 1862.

NANOMIA A. Aaass.

Nanomia A. Acass.; in Proc. Boston Soe. Nat. Hist., IX. p. 181. 1863.

Nanomia cara A. Acass.

Nanomia cara A. AGAss.; in Proc. Bost. Soc. Nat. Hist., IX. p. 181. 1863.

This Siphonophore is closely allied to the genus Agalmopsis of Sars,
but the nature of the tentacles of the feeding polyps, and the mode of
arrangement of the swimming-bells, show undoubtedly that it cannot
be placed in the same genus as Agalmopsis, 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 substance ; the na-
ture of the contents of the float varies in different families
of Siphonophoree, 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-bubble 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 different 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 obliquely, in such a way

Fig. 332.

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 Medusex, and capable, like it, of beating up and

Fig. 332. Nanomia cara; natural size.
NO. Il. 26

202 NANOMIA CARA.

down, and forecmg 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. 354) ; two of these
tubes, ¢’, ¢, are straight, and run directly from the point of junction of

Fig. 833. the four tubes (7, Fig. 334) to the circular tube,
while the other tubes, ¢, 4 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 passmg through the abactinal pole of the spherosome ;
while in Fig. 356, 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 (j’, Fig. 335) of the connecting tube (¢’, Fig. 335) is some-
what to one side of the point of junction of the chymiferous tubes

Fig. 334.
t!

t! j
(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 the actinal pole, somewhat more magnified. 7, t, bent chy-
miferous tubes; ¢/, t', straight chymiferous tubes; c, circular tube round veil; j, point of junction
of the four chymiferous tubes.

Fig. 335. A portion of the same bell, seen from the abactinal pole; lettering as in Fig. 334.
j'; opening of tube, ¢, leading into the main axis connecting with one of the straight chymiferous
tubes.

NANOMIA CARA. 203

the shape of the swimming-bell is rectangular. There can be but little
doubt that these swimming-bells, as I have called them, are genuine
Meduse ; they have all the characters of Medusz, 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, Fig, 336.

the cavity of which opens directly into the
chymiferous 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
Medusz 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 fillmg 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 eight swimmine-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
young bells are formed, as the Medusee 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- Fig. 337.

ming-bells resemble still more the <
Meduse 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. 336. The same bell as Fig. 333, 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 different stages of development. a, the chymiferous
tubes are simple sacs; 0, the tubes, having united, make a circuit ; ¢, first signs of bending of the
tubes, ¢, of the preceding figures. ;

204 NANOMIA CARA.

the different phases in which the chymiferous tubes are mere pouches
(a, Fig. 337), then large tubes connected by a circular tube (6, Fig. 337),
till finally the bell becomes somewhat expanded at one pole, and the
tubes have a tendency to bend, as in ¢, 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 Medusz buds, and we find no trace as yet of
the wing-shaped appendages, and of the difference of outline of older
Medusx, 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 part 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
polyps (Medusz) 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 polyps ;
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 tenta-
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 flaring
trumpet-shaped ; they are exceedingly contractile, and sometimes ex-
pand far beyond the axis in search of food; they communicate by.
- means of a somewhat narrow neck with the main 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 Medusz (feeding polyps) of the first kind formed, in the younger stages,
with tentacular knob and scale. In the upper part of the figure a closed bud, with an oil-bubble,
is seen ; this bud is ready to be liberated and become an embryonic community, like Fig. 346.

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 (Medusx) (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. 340. : Fig. 341.

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, until,
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 adjoiming them ready to develop and take their place
if any accident should happen to the longer meshes.

The third kind of polyp (Medusze), which is found along the axis, are
polyps with closed extremities (Fig. 341), differing besides from the

others in 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 Meduse.

Fig. 340. The second kind of Medusz, having cork-shaped tentacles. The scales in this and
following figure are omitted ; they differ in no respect from those 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 irregularly over its surface ; the walls of this polyp
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 simply men-
tion here, and shall return to them hereafter.

The new polyps 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. polyps, though they remain
aes closed at their distal extremity
after they have attained a con-
siderable size (p, p’, p’, Fig.
342) ; the scarlet pigment-cells
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
polyp 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 (Medusze) these different
buds will give rise ; the peculiar sole-shaped knobs of one of the kinds
of tentacles are nothing but an expansion 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. 538. (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 more
marked, and the lasso-cells‘are now arranged in a row along the ex-
tremity (d, Fig. 343); the walls become thicker as the lasso-cells

Fig. 342. Cluster of Meduse (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. 344); there is then formed a still larger row of lasso-cells,
extending along the edge, and concealing the others (f, 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 being the
greater size of the outer row of lasso-cells, and their closer packing,
which 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 community, 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 (Medusz) cannot circulate into its
very extremity ; even the scales, which seem in their full-grown state

Fig. 344.

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, b, c, Fig. 345). In
the view from above, a, the triangular shape is already apparent; a
profile view, 6, shows its greater thickness than in a fully-developed
scale, while in an end view, ¢, it is still quite pentagonal.

Besides these different kinds of appendages, we find the sexual
individuals scattered in small clusters of abortive Medusz near the
lower extremity of the axis, generally in the third nearest the terminal

Fig. 343. a, b, c, d, tentacular knobs like those of Fig. 339, in different stages of development.

Fig. 344. e, f, g, the same tentacular knobs, still further developed.

In Figs. 343 and 344 all the figures are seen in profile, except ) of Fig. 343, and g of Fig. 344,
which are seen from the flat side, to show the arrangement of the lasso-cells.

Fig. 345. Young scale ; seen from above, a; in profile, 6; 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 Medusz of
which are either males or females. There is no great difference be-
tween the appearance of the male and female Medusx ; they do not
(as is the case in Agalmopsis, accordmg to Sars) separate from the com-
munity, and lead an independent existence ; they wither on the stem,
after having discharged their contents. The Medusz form bunches,
the single Medusz of which are directly attached to the main axis;
they are somewhat pointed in outline, with four tolerably well defined
riz ais, Chymiferous tubes, resembling quite closely the sessile Me-
dus 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 Nanomie (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. 538 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 m 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 resembling in every respect Fig. 346, which 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 fishing 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 early 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

Fig. 346. Youngest Nanomia found swimming on surface.
Fig. 847. Somewhat 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 rudimentary 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. 348.

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 im different stages of
development, such as are figured in Fig. 342; the buds immediately
under the float, the nature of which seemed still doubtful in the last
stage (Fig. 548), 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 small
swimming-bells, like those of Fig. 337, and of Medusz (feeding polyps), like those of Fig. 342.

Fig. 349. Still more advanced Nanomia.

Fig. 350. Young Nanomia, where we find several Meduse (feeding polyps) of the first kind,
having all the characters of those found in the adult (Fig. 332), and embryonic swimming-bells.

NO. IL. 27

210 NANOMIA CARA.

different kinds of individuals taking the place we find them occupying
in the adult; 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 termimal 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 young Nanomia is that it is entirely composed of the
polyp element, and of the polyps with knobbed 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 Hydrocysts (Fig. 541), as Huxley
has called the closed polyps, make their appearance. The remaining
swimmine-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. 532.)

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, Velella,
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, Agalma, Nanomia, Halistem-
ma, Stephanomia, and Forskalia; while in the third and highest sub-
order we find the greatest development of the swimming-bells, accom-
panied by a reduction in the number of individuals forming a smgle
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 community, and not a single animal, as maintained by
the former. The solution of this question has been considered in
various ways by Agassiz, Koélliker, Vogt, Leuckart, Gegenbaur, 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 Hydroids 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 imdependently
by Vogt, and also developed further, from Professor Agassiz’s lectures,
by McCrady, a Siphonophore is neither a single animal, and its different
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 different 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 simply different suborders of the
order of Hydroids ; 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 Renilla, 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 Medusz differing from the Hydroid
Medusz 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 Medusz 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 intrusted 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 floatmg Hydroid, and the other individuals, developed
as the axis or original Hydroid becomes larger, are not Polyps like the
original one, but Medusze in various stages of development, having a
different appearance from those we are accustomed to consider as such.
We have, in the suborders of Siphonophorz, communities of different
kinds of Medusz, instead of having communities of different kinds of

ple NANOMIA CARA.

Hydroids, as in Hydractinia, only these Medusze never separate from
the original parent-stock from which they are produced. The float
corresponds to the part of the stem of the fixed Hydroids by which
they are attached, and the different individuals arismg from this single
-Polyp are Medusx. ‘To show the Medusa character of these individ-
uals, I must preface by saying that the tentacles, the Polyp, 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 with
our notion of Medusa a regularly-shaped bell, chymiferous tubes, and
a proboscis. But this is not the universal character of Meduse ; the
abortive sessile Medusz of Sertularians, Campanularians, and Tubula-
rians are as much Medusz, 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 differ-
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 Polyp; let us take
one of these Hybocodon Meduse, cut away the two lateral spheromeres
of the bell, and at the same time reduce the spheromere which bears
the lone 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 respect to those of
our community. The cluster of tentacles corresponds to the single
tentacle, the scale with its tube corresponds to the remaining sphero-
mere and its chymiferous tube, while the proboscis and the Polyp 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 Medusz are exceedingly rudimentary, and in that case
it would only be carrying out for free Hydroids what has become
perfectly familiar to us among the fixed Hydroids.

By reducing this proposition to a mathematical form, I may perhaps
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 different spheromeres ; they all become imaginary in our Nanomia,

NANOMIA CARA. 213

with the exception of one root, which is positive, and this would repre-
sent the only remaining spheromere, that of the Deckstiick.

If this view is correct, it is evident that the opinion of Huxley, who
considers the scale as homologous to the um of Campanularians, can-
not be sustained. I have already hinted at the similarity of the em-
bryonic Nanomia, in the stage of Fig. 547, 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 remaim 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 Medusz 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
when we find that there are genuine Meduse (Dysmorphosa) which
for four generations reproduce themselves by budding from the pro-
boscis, exactly im the same way in which we find additional individuals
arising along the walls of the original Polyp among Physophoride, we
are at a loss to find any distinctions to separate the Siphonophores
from the true Hydroids, and we cannot consider them as anything
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.

PORPITA.

SusorDER PORPITA Gotpr.

Porpite Goutpr. Handb. der-Zool. 1820.
Porpite and Physalie Acass. Cont. Nat. Hist. U. S., IV. p. 366. 1862.
Chondrophore Cuam. et Eys. Acta Nova, X.

From a comparison of the young stages of Nanomia with the known
Siphonophore, I have been induced to extend the limits of this sub-
order so as to include Physalia, forming thus three suborders among
Hydroids of the old order of Siphonophorx, the Diphyx, the Physo-
phore, and the Porpite.

Family PHYSALIDA Brandt.

Physalide Br. ; in Mém. Acad. St. Petersb., p. 236. 1835.
Physalide AGAss. Cont. Nat. Hist. U. S., IV. p. 366. 1862.

PHYSALIA Lame.

Physalia LaAmK. An. s. Vert., II. p. 89. Second Edition.

Arethusa Brown. Nat. Hist. Jam.
Arethusa Less. Zooph. Acal., p. 530. 1843.

Physalia AGAss. Cont. Nat. Hist. U. S., IV. pp. 335, 366.

Fig. 361. Physalia Arethusa Tr.

dg
yj
vie
43
Y)
43

Physalia Arethusa Tiu.; in Krusenst. Reise, Pl. 23, Figs. 1-6. 1813.

Physalia Arethusa OL¥.; in Mem. Berl. Acad., Pl. 1. 1832.

Physalia Arethusa AGAss. Cont. Nat. Hist. U. 8., IV. pp. 335, 367,
Pl. 35. 1862.

Physalia pelasgica Bosc. Hist. Nat. d. Vers, II. p. 168.

Physalia aurigera McCr. Gymn. 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 Physalia
azoricum, which may be only the young of Phy-
salia Arethusa. (See Voyage de la Coquille, Plate
5, Fig. 4.) To facilitate the comparison of the
different 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. a, blunt end of air-sac supporting
the community ; b, open end of air-sac ; c, crest of air-sac ; ™, bunches
of single individuals ; n, tentacle contracted ; 1, t, tentacles of the lar-
gest kind expanded.

PHYSALIA ARETHUSA. 215

of Hydra and of Meduse (Figs. 352, 353, 354) are introduced

here.

Charleston (McCrady); Gulf of Mexico (Brown, Sloane) ; Florida
(L. Agassiz); Cape Cod (A. Agassiz); Martha's Vineyard (W. H.
Forbes). rev 1 ie

Cat.
Cat.
Cat.
Cat.
Cat.
Cat.
Cat.
Cat.
Cat.
Cat.
Cat.
Cat.
Cat.

No.
No.
No.
No.
No.
No.
No.
No.
No.
No.
No.
No.
No.

305, Florida, 1850, L. Agassiz.

306, Florida, 1850, L. Agassiz.

307, Florida, 1850, L. Agassiz.

308, Key West, Fla., February, 1858, L. Agassiz.

309, Key West, Fla., March, 1858, L. Agassiz.

310, Tortugas, Fla., February, 1858, L. Agassiz.

311, New Providence, Bahamas, April, 1861, F. G. Shaw.
312, Mobile, Alabama, L. Agassiz.

315, 40° N. Lat., 60° W. Long., Captain W. H. A. Putnam.
314, Naushon, Mass., 1861, W. H. Forbes.

325, Tortugas, Fla., March, 1858, L. Agassiz.

385, Beaufort, N. C., May, 1863, A. 8. Bickmore.

386, Bermudas, A. S. Bickmore.

Museum Diagram, No. 28, after L. Agassiz.

Fig. 352. Bunch of single Hydre, and clusters of Meduse, of Physalia Arethusa Til. 3, 0,
Hydrz, with their tentacles, c, c; d, d, bunches of tentacles.

Fig. 353.
single Hydre ; ¢, c, tentacles.

Fig. 354. Bunch of Medusz in various stages of development. a, hollow base of attachment ;
b, Hydra; d, d, Meduse buds.

Bunch of Hydre. a, hollow base of attachment communicating with air-sac; 8, b, b,

216 VELELLID&.

Family VELELLIDA Esch.

Velellide Escu. (restr. Agass.). Syst. d. Acal., p. 165. 1829.
Velelle Less. Zooph. Acal., p. 560. 1843.
Velelide AGass. Cont. Nat. Hist. U. S., 1V. p. 366. 1862.

VELELLA Lam«.

Velella Lam. Anim.s. Vert., I. 1819.

Velella Luss. Zooph. Acal., p. 562. 1843.

Velella AGass. Cont. Nat. Hist. U. S., IV. p. 366. 1862.

Rataria Escu. Syst der Acal., p. 166. 1829.

Chrysomitra GEGENB.; in Zeit. f. Wiss. Zool., p. 231. 1856. Medusa.
Linuche Escu. Syst. der Acal., p. 91. 1829. Medusa.

? Rataria PaGenst. ; in Zeit. f. Wiss. Zool., XII. p. 496. 1863.

Velella mutica Bosc.

Velella mutica Bosc. Hist. Nat. d. Vers, II. p. 158.

Velella mutica Less. Voyage de la Coquille, Pl. 6. 1829.
Velella mutica Less. Zooph. Acal., p. 571. 1843.

Velella mutica AGass. Cont. Nat. Hist. U. S.,1V. p. 366. 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 Meduse among
Tubularians, as McCrady has done; but the polymorphism of the

Fig. 355.

Fig. 357

Hydre (Fig. 855) and the presence of the float (Fig. 356) associate
the Hydrarium with the Porpita. 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 Hydre of Velella. a, base of attachment of
Hydra; 6, end of Hydra; d, d, clusters of Medusze. All these figures are copied from Professor
Agassiz’s Contributions, Vol. III.

Fig. 356. Velella, seen from below, to show the Hydrx. m, opening, so-called mouth ; a, fer-
tile Hydr situated between the mouth and the outer tentacles, the sterile Hydra.

Fig. 357. Magnified view of a free Medusa of Velella mutica Bosc. 0, proboscis ; b, chymif-
erous tube; c, circular tube.

VELELLA SEPTENTRIONALIS. Oy

brilliant ochre 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. 296, Florida, 1850, L. Agassiz.

Cat. No. 297, 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 Escu.
Velella septentrionalis Escu. Syst. der Acal., p. 171, Pl. 15, Fig. 1. 1829.

Numerous specimens were collected at the entrance of the Straits
of Fuca. The proportions of this species are quite different 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. I. 28

18 PORPITID&.

Family PORPITID Guild.

Porpitide Guixv.; in Zool. Journ., XI. p. 403.

Velellide Escu. (p. p.). Syst. der Acal., p. 165. 1829.
Porpitide Acass. Cont. Nat. Hist. U. S., IV. p. 366. 1862.
Porpite Less. Voyage de la Coquille, II. p. 55. 1829.

PORPITA Lame.

Porpita LAMK. Anim. s. Vert., I 1819.

Porpita Less. Zooph. Acal., p. 583. 1843.

Porpita Acass. Cont. Nat. Hist. U. S., IV. p. 366. 1862.
Polybrachiona Guixv. ; in Zool. Journ., XI.

Ratis Less. Zool. de la Coquille. 1829.

Acies Less. Zool. de la Coquille. 1829.

? Armenistarium Costa. Faune de Naples.

Porpita linneana Less.

Porpita linneana Less. Zooph. Acal., p. 588. 1843.

Polybrachionia linneana GuiLD.; in Zool. Journ., XI. Fig.

Porpita linneana McCr. Gymn. Charleston Harbor, p. 42.

Porpita linneana AcGass. Cont. Nat. Hist. U. S., IV. p. 366. 1862.
? Porpita atlantica Less. Voy. de la Coquille, Pl. 7, Fig. 2.

West Indies (Guilding); Florida (L. Agassiz); Charleston, S. C.
(McCrady).

Cat. No. 289, Fort Jefferson, Fla., April, 1859, Dr. Whitehurst.

Cat. No. 290, Pensacola, Fla.

Cat. No. 291, Key West, Fla., L. Agassiz.

Museum Diagram, No. 27, after L. Agassiz.

TABULATA. 219

SuporpER TABULAT AGassiz.

Tabulate Acass. Sill. Journ., XXVI. p. 140. 1858.

Corallaria Tabulata Epw. & Haims. Archiv du Mus., V.

Madreporaria Tabulata Epw. & Hare. Hist. Corall., I. p. 228. 1860.
Tabulate AGAss. Cont. Nat. Hist. U. S., IV. p. 292. 1862.

Family MILLEPORIDA Agass.

MILLEPORA Lavy.

Millepora Lixn. Syst. Nat.

Millepora alcicornis Liv.

Millepora alcicornis Lin. Syst. Nat., X. 1758.

Millepora alcicornis DANA. U.S. Ex. Exp. Zoophytes, p. 543.

Millepora alcicornis Epw. & Haime. Hist. Corall., II. p. 228.

Millepora aleicornis AGAss. Cont. Nat. Hist. U. S., III. p. 292, Pl. 15, Figs. 3-13. 1860.
Millepora alcicornis VERRILL ; in Bull. Mus. Comp. Zodl., p. 59, No. 3. 1864.

The absence of radiating partitions in the Tabulate seems to show,
without much doubt, that their true place is among the Hydroids. It
is true that Professor Agassiz has not observed the Meduse buds on
the specimens he has figured (Fig. 358), yet the Hydroid character
of the animal, and their similarity to Halocharis-like Hydroids, is very

Fig. 358. Fig. 359. Fig. 360.

striking. It certainly is not more wonderful to have among Acalephs
Hydroids which should deposit hard limestone parts (Figs. 359, 360),
as Millepora and the like, than it is to find among the Polyps animals
im 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. Magnified view of extended Hydroids of Millepora. a, a, small Hydroids; 0, larger
ones ; m, mouth; ¢, tentacles.

Fig. 359. Branch of Millepora alcicornis ; natural size.

Fig. 360. ‘Transverse section of branch. a, 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 showimg more strikingly the character of the dif
ferent Acalephian Faunz 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 forthcoming number of the Museum Catalogue the limits and
nomenclature of our Marine Faunz 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 Acalephs. 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-
lima. 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 third series of species 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 distribution of the different species overlap and enclose
one another so as to give us for the character of the Fauna of any par-
ticular locality three different elements of distribution ; first, the cos-
mopolitan species, spreading over wide 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 faunal 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-

220 _. .. GEOGRAPHICAL DISTRIBUTION.

teras, presents features of its own; the coast of the Carolinas and
Georgia has likewise 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 Medusz are found. 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 fauna
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 locality.

NORTH PACIFIC.

SITKA, ALEUTIAN ISLANDS, BEHRING’S STRAITS, KAMTSCHATKA.

Bolina septentrionalis Mert. Behring’s Straits. Mertens.
Janira cucumis Less. Sitka. Mertens.
Dryodora glandiformis Ag. Behring’s Straits. Mertens.
Phacellophora camtschatica Br. Kamtschatka. Mertens.
Cyanea Postelsii Br. Sitka. Mertens.
Cyanea ferruginea Esch. Aleutian Islands ; Kamtschatka. Eschscholtz.
Pelagia Brandtii Ag. Aleutian Islands. Mertens.
Polybostricha helvola Br. Aleutian Islands. Mertens.
Melanaster Mertensii Ag. Kamtschatka. Mertens.
Aginopsis Laurentii Br. Behring’s Straits. Mertens.
Trachynema camtschaticum A. Ag: Kamtschatka. Mertens.
Staurophora Mertensit Br. Aleutian Islands. Mertens.
Diphasia (nigra-like) Behring’s Straits. W. Stimpson.
Sertularia (abietina-like) Behring’s Straits. W. Stimpson.
Cotulina Greenei A. Ag. Behring’s Straits. W. Stimpson.
Thuiaria (thuja-like) Behring’s Straits. W. Stimpson.
Bougainvillia Mertensii Ac. Behring’s Straits Mertens.
Proboscidactyla flavicirrata Br. Kamtschatka. Mertens.

GULF OF GEORGIA, W. T.

Bolina microptera A. Ag. A. Agassiz. Polyorchis penicillata A. Ag. A. Agassiz.
Pleurobrachia Bachei A. Ag. A. Agassiz. Laodicea cellularia A. Ag. A. Agassiz.
Idyia cyathina A. Ag. A. Agassiz. Gonionemus vertens A. Ag. A. Agassiz.
Heccedecomma ambiguum Br. A. Agassiz. Melicertum georgicum A. Ag. A, Agassiz.
Cyanea Postelsti Br. : A. Agassiz Bougainvillia Mertensii Ag. A. Agassiz.
Trachynema camtschaticum A. Ag. A. Agassiz. Stomotoca atra A. Ag. A. Agassiz.
Oceania gregaria A. Ag. A. Agassiz. Proboscidactyla flavicirrata Br. A. Agassiz.
Crematostoma flava A. Ag. A. Agassiz. Coryne rosaria A. Ag. A. Agassiz.
Zygodactyla cerulescens Br. A. Agassiz. Physalia sp. A. Agassiz.
Aquorea ciliata Esch. A. Agassiz. 7elella septentrionalis Esch. A. Agassiz.
Laomedea pacifica A. Ag. A. Agassiz. Porpita sp. A. Agassiz.

GEOGRAPHICAL DISTRIBUTION.

SAN FRANCISCO, CALIFORNIA.

Aurelia labiata Cham. & Eys.
Phacellophora camtschatica Br.
Polybostricha helvola Br.
Melanaster Mertensti Ag.
Laomedea rigida A. Ag.
Laomedea pacifica A. Ag.
Polyorchis penicillata A. Ag.

Aglaophenia franciscana A. Ag.

Diphasia corniculata A. Ag.
Sertularia anguina Trask.

Ocyroe maculata Rang.
Idyia ovata Less:

Polyclonia frondosa Ag.
Pelagia cyanella Pér. et Les.
Clytia (volubilis-hke).
Laomedea (antipathes-like).
Laomedea (gracilis-like).
Aglaophenia pelasgica McCr.
Aglaophenia trifida Ag.
Aglaophenia acinaria Duch.
Aglaophenia atlantica Duch.

Bolina vitrea Ag.

Idyopsis affinis Ag.
Polyclonia frondosa Ag.
Aurelia marginalis Ag.
Pelagia cyanella Pér. et Les.
Liriope tenuirostris Ag.
Clytia (intermedia-like).
Clytia (volubilis-like).
Orthopyxis (poterium-like).
Laomedea (amphora-like).
Laomedea (dichotoma-like).
Rhegmatodes floridanus Ag.
Zygodactyla cyanea Ag.
Eirene cerulea Ag.

A. Agassiz.
A. Agassiz.
A. Agassiz.
A. Agassiz.
A. Agassiz.
A. Agassiz.
A. Agassiz.
A. Agassiz.
Murray.
Trask.

WEST

Rang.
Brown.
Poey.
Swartz.
Duchassaing.
Duchassaing.
Weinland.
Weinland.
Weinland.
Duchassaing.
Duchassaing.

Sertularia gracilis A. Ag.
Sertularia furcata Trask.
Sertularia turgida Trask.
Cotulina Greenei A. Ag.
Bougainvilia Mertensii Ag.
Coryne rosaria A. Ag.
Paripha microcephala A. Ag.

223

Trask.
Trask.
Trask.
Murray.
A. Agassiz.
A. Agassiz.
A. Agassiz.

Thamnoenidia tubularoides A. Ag. A. Agassiz.

Hydra tenuis Ayres.
Physalia sp.

INDIES.

Dynamena ostrearum Duch.
Dynamena (disticha-like).
Zelleria simplex Duch.
Tubularia Ehrenbergit Duch.
Tubularia Lamourouxii Duch.
Tubularia glandulosa Duch.
Tubularia pinnata Duch.
Physalia Arethusa Til.
Velella mutica Bose.

Porpita linneana Less.
Millepora alcicornis Lin.

FLORIDA REEF.

. Agassiz.

. Agassiz.
. Agassiz.
Agassiz.

Agassiz.

Agassiz.

Agassiz.

Agassiz.

Agassiz.

Agassiz.

. Agassiz.

. Agassiz.

. Agassiz.

. Agassiz.

Sisigisiislislslslslslslsisls

Eutima pyramidalis Ag.
Dynamena sp.

Pasithea sp.

Aglaophenia pelasgica McCr.
Aglaophenia trifida Ag.
Plumularia quadridens McCr.
Plumularia sp.

Nigelastrum sp.

Pennaria gibbosa Ag.
Paripha cristata Ag.
Physalia Arethusa Til.
Velella mutica Bose.

Porpita linneeana Less.
Millepora alcicornis Linn.

CHARLESTON, SOUTH CAROLINA.

Bolina littoralis MeCr.
Mnemiopsis Gardeni Ag.
Beroe punctata Esch.
Idyopsis Clarkii Ag.
Stomolophus meleagris Ag.
Cyanea versicolor Ag.
Foveolia octonaria A. Ac.
Persa incolorata McCr.
Liriope scutigera McCr.

McCrady.
L. Agassiz.
McCrady.
L. Agassiz.
L. Agassiz.
L. Agassiz.
McCrady.
McCrady.
McCrady.

Oceania folleata Ag. u
Eucheilota ventricularis McCr.
Clytia bicophora Ag.
Platypyxis cylindrica Ag.
Eucope divaricata A. Ag.
Obelia commissuralis McCr.
Ejiirene gibbosa Ag.

Eutima mira McCr.

Eutima variabilis McCr.

Ayres.
A. Agassiz.

Duchassaing.
Duchassaing.
Duchassaing.
Duchassaing.
Duchassaing.
Duchassaing.
Duchassaing.
Brown.
Brown.
Guilding.
Linnzeus.

. Agassiz.

. Agassiz.

. Agassiz.

. Agassiz.

Agassiz.

. Agassiz.

. Agassiz.

Agassiz.

Agassiz.

Agassiz.
Agassiz.

. Agassiz.

. Agassiz.

. Agassiz.

alll ail sil all ail ail all all silallollall«

McCrady.
McCrady.
McCrady.
L. Agassiz.
L. Agassiz.
McCrady.
McCrady.
McCrady.
McCrady.

224

Aglaophenia pelasgica McCr.
Aglaophenia triida Ag.
Aglaophenia tricuspis McCr.
Plumularia quadridens McCr.
Plumularia (Catharina-like).
Dynamena cornicina McCr.
Diphasia (nigra-like).
Nemopsis Bachei Ag.
Margelis carolinensis Ag.
Eudendrium ramosum McCr.
Turritopsis nutricula McCr.
Stomotoca apicata Ag.

Willia ornata MecCyr.

BUZZARD’S BAY AND LONG ISLAND SOUND.

Mnemiopsis Leidyi A. Ag.
Lesueuria hyboptera A. Ag.
Pleurobrachia rhododactyla Ag.
Cyanea arctica Pér. et Les.
Cyanea fulva Ag.
Dactylometra quinquecirra Ag.
Trachynema digitale A. Ag.
Oceania languida A. Ag.
Eucheilota ventricularis McCr.
Eucheilota duodecimalis A. Ag.
Clytia volubilis A. Ag.

Clytia bicophora Ag.
Platypyxis cylindrica Ag.
Evucope diaphana Ag.

Obelia commissuralis McCr.
Laomedea amphora Ag.
Rhegmatodes tenuis A. Ag.
Zygodactyla groenlandica Ag. |
Aiquorea albida A. Ag.
Eutima limpida A. Ag.

Lafea calearata A. Ag.
Dynamena pumila Lamx.

McCrady.

L. Agassiz.

McCrady.
McCrady.

L. Agassiz.
L. Agassiz.

L. Agassiz.
McCrady.
McCrady.
McCrady.
McCrady.
McCrady.
MeCrady.

. Agassiz.
. Agassiz.
. Agassiz.
. Agassiz.

. Agassiz.

Agassiz.

Agassiz.

Agassiz.

. Agassiz.

Agassiz.

Agassiz.

Agassiz.

Agassiz.

Agassiz.

Agassiz.

Agassiz.

. Agassiz.

Agassiz.
. Agassiz.
. Agassiz.
. Agassiz.

PEE >> >> E> EE bE EEE Eb Pb bP

. Agassiz.

GEOGRAPHICAL DISTRIBUTION.

Dipurena strangulata McCr.
Dipurena cervicata McCr.
Corynitis Agassizii MeCr.
Gemmaria gemmosa McCr.
Pennaria tiarella McCr.
Ectopleura turricula Ag.
Paripha cristata Ag.
Hydractinia polyclina Ag.
Eudoxia alata McCr.
Diphyes pusilla McCr.
Physalia Arethusa Til.
Velella mutica Bose.
Porpita linnceana Less.

Sertularia cupressina Lin.
Nemopsis Bachei Ag.
Bougainvillia superciliaris Ag.
Margelis carolinensis Ag.
Eudendrium dispar Ag.
Ewdendrium tenue A. Ag.
Dysmorphosa fulgurans A. Ag.
Modceria sp.

Turritopsis nutricula McCr.
Stomdtoca apicata Ag.
Clava leptostyla Ag.

Willia ornata McCr.
Dipurena conica A. Ag.
Gemmaria gemmosa McCr.
Pennaria tiarella McCyr.
Cordylophora sp.
Ectoplewra ochracea A. Ag.
HHybocodon prolifer Ag.
Hydra carnea Ag. (Conn.)
Hydractinia polyclina Ag.
Nanomia cara A. Ag.
Physalia Arethusa Vil.

MASSACHUSETTS BAY.

Bolina alata Ag.

Lesueuria hyboptera A. Ag.
Mertensia ovum Morch.
Pleurobrachia rhododactyla Ag.
Idyia roseola Ag.

Aurelia flavidula Pér. et Les.
Cyanea arctica Pér. et Les.
Campanella pachyderma A. Ag.
Trachynema digitale A. Ag.
Halimocyathus platypus FH. J. C.
Manania auricula H. J. C.
Lucernaria quadricornis Mill.
Haliclystus auricula H. J. C.
Tiaropsis diademata Ag.

. Agassiz.

J. Clark.
. Agassiz.
. Agassiz.

an

L. Ag

A. Agassiz.
A. Agassiz.
L. Agassiz
L. Agassiz
L. Agassiz
L. Agassiz
A. Agassiz
A. Agassiz
H. J. Clark
18

L

L

L

. Agassiz.

Oceania languida A. Ag.
Wrightia sp.

Clytia intermedia Ag.
Clytia bicophora Ag.
Clytia volubilis A. Ag.
Platypyxis cylindrica Ag.
Orthopyxis poterium Ag.
Eucope diaphana Ag.
Eucope alternata A. Ag.
Eucope parasitica A. Ag.
Eucope polygena A. Ag.
Eucope pyriformis A. Ag.
Eucope articulata A. Ag.
Eucope fusiformis A. Ag.

McCrady.
McCrady.
McCrady.
McCrady.
McCrady.
McCrady.
L. Agassiz.
McCrady.
McCrady.
McCrady.
McCrady.
McCrady.
McCrady.

Leidy.

L. Agassiz.
Leidy.

. Agassiz.
. Agassiz.
. Agassiz.
. Agassiz.
. Agassiz.
. Agassiz.
. Agassiz.
Leidy.

A. Agassiz.
A. Agassiz.

A. Agassiz.

Perr > > >

A. Agassiz.
L. Agassiz.
A. Agassiz.
A
A

. Agassiz.

. Agassiz.

. Agassiz.

. Agassiz.

. Agassiz.

Agassiz.

Agassiz.

Agassiz.

Agassiz.

Agassiz.
Agassiz.
Agassiz.
Agassiz.

. Agassiz.
. Agassiz.

PRP >> RR OEE oop

. Agassiz.

GEOGRAPHICAL DISTRIBUTION.

Obelia commissuralis McCr.
Laomedea amphora Ag.
Laomedea gigantea A. Ag.
Laomedea reptans Lamx.
Laomedea sp.

Stomobrachium tentaculatum Ag.

Falopsis ocellata A. Ag.
Halopsis cruciata A. Ag.
Zygodactyla groenlandica Ag.
Zygodactyla crassa A. Ag.
Tima formosa Ag.

Lafea cornuta Lamx.

Lafoa dumosa Sars.

Melicertum campanula Pér. et Les.

Staurophora laciniata Ag.
Ptychogena lactea A. Ag.
Plumularia arborea Des.
Dynamena pumila Lamx.
Dyphasia fallax Ag.
Dyphasia rosacea Ag.
Sertularia cupressina L.
Sertylaria argentea Ell. & Sol.
Sertularia falcata L.
Sertularia myriophyllum L.
Amphitrocha rugosa Ag.
Cotulina tricuspidata A. Ag.

NORTHERN COAST

Bolina alata Ag.
Mertensia ovum Morch.

Pleurobrachia rhododactyla Ag.

Idyia roseola Ag.

Aurelia flavidula Pér. et Les.
Cyanea arctica Pér. et Les.
Manania auricula H. J. C.
Lucernaria quadricornis Miill.
Haliclystus auricula H. J. C.
Haliclystus salpine H. J. C.
Oceania languida A. Ac.
Clytia volubilis A. Ag.

Clytia bicophora Ag.
Orthopyxis poterium Ag.
Eucope diaphana Ag.
Eucope pyriformis A. Ag.
Obelia commissuralis McCr.
Laomedea amphora Ag.

Melicertum campanula P. et Les.

Staurophora laciniata Ac.
Dynamena pumila Lamx.
Diphasia fallaz Ag.
Sertularia abictina L.
Sertularia cupressina WL.

NO. Il.

. Agassiz.
. Agassiz.

Agassiz.

Agassiz.

Desor.

POU PPO Pe Pp ee eo
>
2
S

Agassiz.
Agassiz.
. Agassiz.
. Agassiz.
. Agassiz.
Agassiz.
Agassiz.
Agassiz.

Agassiz.

Pe See eee

OF MAINE,

W. Stimpson.

A. Agassiz.

W. Stimpson.
W. Stimpson.
W. Stimpson.
W. Stimpson.
W. Stimpson.
W. Stimpson.
W. Stimpson.
W. Stimpson.

L. Agassiz.

A. E. Verrill.
W. Stimpson.

W. Stimpson.

J. E. Mills.

W. Stimpson.

29

Cotulina tamarisca A. Ag.
Halecium halecinum Jobust.
Bougainvillia superciliaris Ag.
Eudendrium dispar Ag.
Eudendrium tenue A. Ag
Eudendrium sp.

Lizzia grata A. Ac.

Dysmorphosa fulgurans A. Ac.

Turris vesicaria A. Ag.
Turritopsis sp.

Rhizogeton fusiformis Ag.
Clava leptostyla Ag.

Coryne mirabilis Ag.
Syndictyon reticulatum A. Ag.
Gemmaria cladophora A. Ag.
Pennaria tiarella McCr.
Euphysa virgulata A. Ag.
Hybocodon prolifer Ag.
Corymorpha pendula Ag.
Paripha crocea Ag.
Thamnocnidia spectabilis Ag.
Thamnocnidia tenella Ag.
Tubularia Couthouyi Ag.
Hydra gracilis Ag. (Mass.)
Hydractinia polyclina Ag.
Nanomia cara A. Ag. ©

Sertularia argentea L.
Sertularia falcata Ag.
Sertularia latiuscula Stimps.
Sertularia myriophyllum L.
Sertularia filicula Ell. & Sol.
Sertularia producta Stimps.
Amphitrocha rugosa Ag.
Cotulina tricuspidata A. Ag.
Cotulina polyzonias Ag.
Cotulina tamarisca A. Ag.
Halecium halecinum Johnst.
Halecium muricatum Johnst.
Grammaria gracilis Stimps.
Grammaria robusta Stimps.
Acaulis primarius Stimps.
Eudendrium dispar Ag.
Coryne mirabilis Ag.

Clava leptostyla Ag.
Candelabrum phrygium Bl.
Corymorpha pendula Ag.
Thamnocnidia tenella Ag.
Tubularia larynx Ellis.
Tubularia Couthouyi Ag.
Hydractinia polyclina Ag.

225

. Agassiz.

Agassiz.

Agassiz.

Agassiz.

Agassiz.

Agassiz.

Agassiz.
Agassiz.
Agassiz.

Agassiz.

Agassiz.

Agassiz.

Agassiz.
. Agassiz.
. Agassiz.

. Agassiz.

Agassiz.

Agassiz.

Agassiz.

Agassiz.
Agassiz.

. Agassiz.

Agassiz.

Agassiz.

Agassiz.

Agassiz.

col call call ll call call coll coll =U lok ak Sol al “oc cal cal cl

GRAND MANAN, AND EASTPORT.

J. E. Mills.
W. Stimpson.
W. Stimpson. -
A. E. Verrill.
W. Stimpson.
W. Stimpson.
W. Stimpson.
W. Stimpson.
A. E. Verrill.
W. Stimpson.
A. E. Verrill.
A. E. Verrill.
W. Stimpson.
W. Stimpson.
W. Stimpson.
A. E. Verrill.
W. Stimpson.
W. Stimpson.
W. Stimpson.
W. Stimpson.
A. E. Verrill.
W. Stimpson.
W. Stimpson.
A. E. Verrill.

Bolina alata Ag.
Pleurobrachia rhododactyla Ag.
Idyia roseola Ag.

Aurelia flavidula Pér. et Les.
Cyanea arctica Pér. et Les.
Haliclystus auricula H. J. C.
Clytia volubilis A. Ag.

Clytia bicophora Ag.
Orthopyxis poterium Ag.
Laomedea (dichotoma-like).
Laomedea (gelatinosa-like).
Laomedea (geniculata-like).
Lafea cornuta Lamx.

Lafea dumosa Sars.
Cosmetira sp.

Mertensia ovum Morch.
Pleurobrachia rhododactyla Ag.
Idyia cucumis Less.

Idyia borealis Less.

Aurelia flavidula Pér. et Les.
Cyanea arctica Pér. et Les.
Chrysaora hepteena Pér. et Les.
Trachynema digitale A. Ag.
Manania auricula H. J. C.
Lucernaria quadricornis Mill.
Haliclystus auricula H. J. C.
Medusa bimorpha Fab.
Tiaropsis diademata Ag.
Campanularia volubilis Morch.
Campanularia olivacea Lamx.
Eucope diaphana Ag.

GEOGRAPHICAL DISTRIBUTION.

NOVA SCOTIA.

Anticosti Exp.
Anticosti Exp.
Anticosti Exp.
Anticosti Exp.
Anticosti Exp.
Anticosti Exp.
Anticosti Exp.
Anticosti Exp.
Anticosti Exp.

Dawson.
Dawson.
Dawson.

Anticosti Exp.
Anticosti Exp.
Anticosti Exp.

GREENLAND.
Fabricius.
Fabricius.
Fabricius. Dynamena pumila Lamx.
Scoresby. Sertularia abictina L.
Fabricius. Sertularia argentea L.
Fabricius. Amphitrocha rugosa Ag.
Martens. Cotulina polyzonias Ag.
Fabricius. Halecium halecinum Johnst.
Fabricius. Bougainvillia superciliaris Ag.
Fabricius. Coryne mirabilis Ag.
Steenstrup. Coryne pusilla Girt.
Fabricius. Coryne muscoides Johnst.
Morch. Candelabrum phrygium Bl.
Morch. Tubularia indivisa Linn.
Morch. Hydractinia polyclina Ag.
Morch.

Dynamena pumila Lamx.
Sertularia abietina L.
Sertularia argentea L.
Sertularia plumea Dawson.
Sertularia falcata L.
Sertularia myriophyllum L.
Sertularia latiuscula Stimps.
Cotulina tricuspidata A. Ag.
Cotulina polyzonias Ag.
Cotulina tamarisca A. Ag.

Halecium muricatum Johnst.

Thuiaria thuja Flem.

Eudendrium (ramosum-like).

Tubularia larynx Ellis.
Tubularia Couthouyi Ag.

Dawson.
Anticosti Exp.
Dawson.
Dawson.
Anticosti Exp.
Anticosti Exp.
Dawson.
Anticosti Exp.
Anticosti Exp.
Anticosti Exp.
Anticosti Exp.
Anticosti Exp.
Dawson.
Dawson.
Dawson.

Zygodactyla groenlandica P. et Les. Fabricius.
Melicertum campanula Pér. et Les. Fabricius.

Fabricius.
Fabricius.
Fabricius.
Fabricius.
Fabricius.
Fabricius.
Morch.
Sabine.
Morch.
Morch.
Fabricius.
Morch.
Fabricius.

SYSTEMATIC TABLE

OF THE ORDERS AND FAMILIES OF NORTH AMERICAN ACALEPHZ
DESCRIBED IN THIS VOLUME.

PAGE

Order CTENOPHORZ Esch. . Fe eH
Suborder Lopatx Esch. . 9 14
Family Bolinide Ag. A ; > wel
Family Ocyroee Less. . : ‘ 25
Suborder Saccatz dg. . 5 > 2B
Family Mertenside Ag. : : 26
Family Cydippide Geg. . ‘ 5 BB
Suborder Eurystom Leuck. 5 35

Family Beroide Esch, . . - 35

Order DISCOPHORZ Esch. . é 40
Suborder RuizostToME& Ag. . - 40
Family Rhizostomide Esch. . : 40
Family Polyclonide Ag. . ‘ . 41
Suborder SEMEZOSTOMEE Ag. - 41
Family Aureliade Ag. . < 3 41
Family Sthenoniz 44g. . : : 43
Family Cyaneide 4g. . 5 . 44
Family Pelagide Geg. . 3 5 47

Suborder HapLostoMEm® Ag. . - Ol
Family Thalassanthez Less. . a 51

Suborder TRACHYNEMIDE A. Ag. - 54
Family Trachynemide Geqg. . ° 55
Family Leuckartide Ag. . : - 60

Suborder LucERNARLE Johnst. - 61
Family Cleistocarpide H. J. C. 5 Gil

Family Eleutherocarpide H. J. C. 62

Order HYDROIDZ Johnst. .

Suborder SERTULARIZ Ag.
Family Oceanide Esch.
Family Eucopide Geg.
Family 2iquoride Esch. .

Family Geryonopside Ag. .

Family Polyorchide A. Ag.
Family Laodiceide Ag.
Family Melicertide Ag. .
Family Plumularide dg.

Family Sertulariade Johnst.

Suborder TuBuLARIZ Ag.
Family Nemopside Ag. .
Family Bougainvillee Liitk.
Family Nucleiferz Less. .
Family Williade Forbes
Family Sarsiadee Forbes .

Family Orthocorynide A. Ag.

Family Pennaride MeCr.
Family Tubulariade Johnst.
Family Hydraide Gray .

Family Hydractinide Ag. .

Suborder DipHym Cuv.
Family Diphyide Esch.

Suborder PoysopHorx Goldf. .

Family Agalmide Brandt
Suborder Porpirxz Goldf..
Family Physalide Brandt
Family Velellidee Esch. -
Family Porpitide Guild.
Suborder TABULATE Ag. .
Family Milleporide Ag.

PAGE

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INDEX OF GENERA AND SPECIES.

Acaulis Strmps.. . ;
primarius STIMPS.. .
Acies Less. . é : :
Acrochordium Mery. . : 3
Eginopsis J. MULu. . 2
ffginopsis Br. . . :
Laurentii Br. . >
Z@quorea Psr. et Les. . 3
albida A. AGass. :
ciliata Esc. . 5
globularis Morcu :

groenlandica Pir. et LEs.

Aglaophenia Lamx. . :
cristata McCr.
franciscana A. AGASs.
pelasgica McCr. .
trifida AGAss. . .
tricuspis McCr. . 0

Aglaura penicillata Bu. .

Alcinoe Less. . 5 ; 5
vermicularis GOULD .

Aleyonium echinatum GovuLD .

Amphitrocha AGass. 0

cincta AGASS.. 2 5

rugosa AGASS. . 2
Anais Less. . 5 : :
Arethusa BROWN . : A
Armenistarium COSTA 5 6

Atractylis WRIGHT - :

Aurelia Pér.et Les. . 5
aurita GOULD . a
flavidula PEr. et Les.
labiata CHAm. et Eys.
marginalis AGASs. . é
sea-ovartis MorcH

Beroe Brown. 3 5
cucullus Mop. . C
cucumis FAB. . : 6
cucumis MERT. .
glandiformis MERT. .

ovata Escu. ; 2
ovum Fas. . 6 :
pileus Fas. . ° 2

PAGE
151
151
218
184

[Synonymes are in Italics.]

Beroe (continued)
pileus Scor. .
punctata CHaAm. et Eys.
Biblis Lxss. C : é °
Bolina Merr. ©. 3 :
alata AGASS. . 5 3
littoralis McCr. . 5
microptera A. AGASS. .
septentrionalis AGASS. .
septentrionalis MERT.
vitrea AGASS.
Bougainvillia LEss.
Bougainvillia Less. .
Mertensii AGAsS. . 8
superciliaris AGASS.

Calamella OKEN ° :
Calicella Hincks .«
Candelabrum Bt. .

phrygium BL.
Campanella Less. . 0
Campanella Bt.

campanula Morc# .

Fabricii Luss.

pachyderma A. AGASS. .
Campanularia LAMX.

dumosa JOHNST.

dumosa LEIDY

noliformis McCr. .

syringa STIMPS. .

volubilis ALDER.

volubilis LEIDY .
Campanulina VAN BEN. .
Cassiopea 'Tr1.

frondosa Escu. .

Pallas PkEr. et LEs.
Cephea rhizostoma GIBBES .
Chrysaora Escu. c ¢ 2

helvola Lxss.

melanaster BR.
Chrysomitra GEG. . : 5
Circe Mert. . :

camtschatica BR. . :

digitalis Monch. .

230 INDEX

Circe impatiens AGASs. .
Clava GMELIN. ‘
leptostyla AGAss. 0
multicornis STIMPS. .
squamata Morcr
Clavula WriGHt 0
Claustra Less. 5 : :
Clytia Lamx. . ¢ c
bicophora AGass.
cylindrica AGASS. .
cylindrica AGAss.
intermedia AGASs. .
volubilis A. AGass.
Corymorpha Sars ‘
nutans STIMPS. . 5
pendula AGass. .
phrygia Moren .
Coryne GArt. , °
i mirabilis AGASS.. :
rosaria A. AGASS. . .
Corynitis McCr. : 5
Agassizii McCr. . 6
Cosmetira FORBES. 3
Cosmetira sp.
Cotulina AGass..
Greenei A. AGAss..
polyzonias AGAss.
tamarisca A. AGASS. 6
tricuspidata A. AGASS.
Crematostoma A. AGAss. .
flava A. AGAss. .
Cucullus Q.&G. . é ;

Cunina Escu. 5 6 :
octonaria McCr. .
Cyanea Perr. et Les. . c
ambigua LEss. . °
arctica- Pir. et Lis. .
JSerruginea ESCH. -. 5
fulva AGASS. c E
Postelsii Br. . , :
Postelsii GOULD . 3
versicolor AGASS. . C
Cyancopsis behringiana Br.
Cydalisia Lxss. . ° ° 0

punctata Less. . 5
Cydippe Escn. . - c
cucullus Escu.

cucumis LESS. . : 2

ovum Escu. 6 .

pileus GOULD . : °
Cyteis Sars . 0 0

Dactylometra AGAss.

quinquecirra AGASS. .
Dianea DELLE CHIAJE . ‘
Dianea Q.& GG . é 5
Dianea LAMK. .

OF GENERA AND SPECIES.

. 113

Diancea

cyanella LAMK. . 5
denticulata LAMK. .

Diphasia AGAss.

corniculata AGASS..
fallax AGAss. . .
rosacea AGASS.

Diphyes Cuy. . ; *

pusilla McCr.

Diplocraspedon Br.
Dipurena McCr.

cervicata McCr..
conica A. AGASs.
strangulata McCr. .

Dryodora AGass.

glandiformis AGAss. .

Dynamena Lamx.. :

cornicina McCr. -
pelasgica Bu. .
pumila Lamx. .

Dysmorphosa Putt.

fulgurans A. AGASS. .

Ectopleura Acass. F

turricula AGASS..
ochracea A. AGASS.

Hirene Escu. . 5 ei

cerulea AGAsS. .
digitale Escu.
gibbosa AGAss.

Epenthesis McCr. .

folleata McCr.

Ephyra Pér. et Les. . :

octolabata GOULD

Ersea Escu..
Eschscholizia LxEss.

glandiformis LEss.

Eucheilota McCr. . é
duodecimalis A. AGASS.

ventricularis McCr.

Eucope Gre.

alternata A. AGAss.
articulata A. AGASS. .
diaphana AGass.
diaphana AGASS.
divaricata A. AGass.
fusiformis A. AGAssS. .
parasitica A. AGAss.
polygena A. Acass.
pyriformis A. AGAss.

Eucoryne Lery . : .

elegans LEIDy :

Eudendrium Enrens. .

cingulatum STIMps.

dispar AGAss. . ;
ramosum JOHNST. .
ramosum McCr.. C

112,

142

142
142
199)

180
181
181
181

34

34
141
142
139
141
163
163

190

191
113

199

INDEX

Eudendrium (continued)
tenue A. AGAss. .
Eudoxia Escu. .
alata McCr. . 6
Euphysa Forbes 5
virgulata A. AGAss.
Eurybia Escu. a 5
Eurybiopsis GEG. . :
Eutima McCr. . 6
limpida A. AGASS. .
mira McCr.
pyramidalis AGAss.
variabilis McCr..
Evagora PER. et Lus. 0

Foveolia Pir. et Les.
octonaria A. AGASS.

Gemmaria McCr. .
cladophora A. AGASs.
gemmosa McCr..

Geryonia Escu.. 5 c

Geryonopsis FORBES.

Globiceps AYRES 2 5
tiarella AYRES .

Gonionemus A. AGAss.
vertens A. AGASs.

Grammaria Srimes.
gracilis STrmMps. .
robusta STIMPs.

Halecium OKen.
halecinum JOHNST.
muricatum JOHNST.

Haliclystus H. J. Clark
auricula H. J. CLark
salpinx H. J. CLark

Halimocyathus H. J. CLark

platypus H. J. CLark
Halocharis AGASS. é
spiralis AGASS.
Halopsis A. Acass. .
cruciata A. AGASs.
ocellata A. AGASS.
Hecczedecomma Br. .
ambiguum Br. .

Hermia JOUNST. 0 0
Tippocrene McCr. C
Hippocrene MERT. . :

Bougainvillei BR.

Bougainvillei Goutp

carolinensis McCr.

superciliaris AGASS.
Hybocodon AGass. .

prolifer AGass.
Hydra Linn.

carnea AGASS.

.

OF

GENERA AND SPECIES.

160
- 199
199
o ILS)
189

60
- 116
116
- 116
118
- 116
41

51

184
184
- 184
60
- 112
186
- 187
128

148
- 148
148

- 147
148

- 147
62

Hydra (continued)
gracilis AGass.
tenuis AYRES .
squamata Fas. ’

Hydractinia Van Ben.
echinata Lriby 5
polyclina AGass.

Idyia Frem. . : :
borealis Less. .
cucumis Lxss. 0
cyathina A. AGASs.
ovata Less. . C
roseola AGASS. .

Idyopsis Acass. . é
affnis AGAsS. .
Clarkii AGass. 0

Janira OKkEN : :
cucumis LEss. 3

Lafoea Lamx. . -
calearata A. AGASsS.
cornuta AGASS. .
cornuta LAMx. :
dumosa Sars

Laodicea AGass. é

Laodicea Lrss. .
calcarata A. AGASS.
cellularia A. AGAss.

Laomedea Lamx. .
amphora AGASS.
dichotoma LEIDY
divaricata McCr.
gelatinosa Leipy
gelatinosa GOULD
gigantea A. AGass.
pacifica A. AGASs.
rigida A. AGAss. .

Lesueuria Epw..

hyboptera A. AGass.

Linuche Escu. 0 a
Liriope Gre. . 5 :
scutigera McCr. .
tenuirostris AGASS..
Lizzia ForBrs
grata A. AGASS. .
Lucernaria Miu. .
auricula Fas. . E
auricula MULL. .
Fabrictti AGAss. .
fascicularis FLEM.
octoradiata LAMX. .
phrygia Fas.
quadricornis MUL.
typica GREENE

231

197
197
198
198
198

232 INDEX

Manania H. J. Cuarx .
auricula H. J. CLARK.

Margelis STEEnstT.
carolinensis AGASS. .
Medea Escu. . ‘ :

fulgens Escu. . 0
Medusa Lixn.. . : 0

cequorea Fas. . .
aurita Fas...

beroe LINN. . c 0
bimorpha Fas. .

campanula Fax. .
campanulata Bosc .
capillata Fas. . 9
digitalis Fas. .

Jrondosa PALL. . 0

labiata Escu. .

pelagia LINN. . :
Melanaster AGass. :

Mertensii AGASS.
Melicerta PER. et Lus. 6

campanula Pir. et Les.

Melicertum Escu.
Melicertum OKEN
campanula Escu.
georgicum A. AGASS. .
penicillata Less.
penicillatum Escu.
Mertensia GEG. . :
Mertensia Less. . 0 0

cucullus AGASS.
glandifornis GEG. 6
ovum Moreh . :

Scoresbyi Less. . :
Mesonema cerulescens Br.
Millepora Linn..

aleicornis LINN. .
Mnemia Sars 0
Mnemiopsis Acass. .

Gardeni AGASS. . 0

Leidyi A. AGAss. .
Monocraspedon Br. : :
Myriothela Sars 0 0

Nanomia A. AGAss. .
cara A. AGASS. 0

WNemopsis AGAss. .
Bachei AGAss.
Gibbesi McCr. . :

Obelia PxEr. et LEs. 3
commissuralis McCr. .
Oceania AUCT. . :

Oceania Pr. et Les. . :
folleata AGAss. :

gregaria A. AGASS. .
languida A. AGAss.

OF GENERA AND SPECIES.

130

. 119
130

. 1385

. 119
119

C 108

. - 219

219

Oceania (continued)
tubulosa GOULD . 0
Ocyroe PER. et Lxs. .
Ocyroe Rane
labiata Bu.
maculata RANG .
Orthopyxis AGass.
poterium AGAss.. 0

Parypha Acass. . és
cristata AGASS. . f
crocea AGASS.

microcephala A. AGAss.

Pelagia Prr. et Les.
americana PER. et Lxs.
Brandtii AGAss.
cyanella Pr. et LEs. .
denticulata Br.
denticulata PER. et Lus.
noctiluca CHAM.
quinquecirra Dus. E

Pennaria Go.pr.
gibbosa AGASS. . =
tiarella McCr.

Persa McCr. j 9
incolorata McCr.

Phacellophora Br. .
camtschatica Br. .

Phialidium. Leuck.

Phortis McCr. :
gibbosa McCr. . 0

Physalia Lamx. .
Arethusa Tm. . ‘
aurigera McCr.
pelasgica Bosc . 5

Platypyxis AGASS.

Platypyxis AGass..
cylindrica AGASS. .

Pleurobrachia Fem.
Bachei A. AGASS. .
rhododactyla AGAss. .
Scoresbyi Morcu .

Plumularia LAMX.. 3 .
Plumularia Lamx.. 5
arborea Dus. : ;

falcata JOHNST.
franciscana TRASK.
gracilis Murr.
myriophyllum JOUNST. .
pelasgica LAMX.
quadridens McCr. .
struthionides Murr..
Podocoryne SARs . : 0
Polybostricha Br.. 5
helvola Br. . 0
Polybrachiona Guiip.
linneeana GUILD. Q

175
41
25
43

_ 25

81
81

194
194
195
195

186
186
187

139

140
144
140
145
145
139
140
140
163

50

50
218
218

INDEX

Polyclonia Br. . ‘ ‘
frondosa AGASS. .
Polyorchis A. Acass. ;
penicillata A. AGass.
Porpita Lamx.
atlantica LEss.
linneana Less.
Proboscidactyla Br.
flavicirrata Br.
Ptychogena A. Acass. .
lactea A. AGAss.
Pyxidium Levck.

Rataria Escu.
Ratis Less. is 5
Rhacostoma AGAss.
atlanticum AGASS.
Rhegmatodes A. Acass.
floridanus AGASS. . 6
tenuis A. AGAss.
Rhizogeton AGcass.
fusiformis AGASs.
Rhizostoma Escu.

Saphenia ForRxs . a
apicata McCr. : 0
Sarsia Less. . 0
mirabilis AGASS. .
glacialis Morcu . 0
turricula McCr. . 0
Scyphistoma SARs .
Sertularia Linn.
abietina LINN.
anguina TRASK.
argentea ELL. et SOL.
corniculata Murr. .
cupressina LINN...
faleata LINN. .
fallax Jounst.
Sastigiata Fas.
filicula Ext. et Sot.
furcata TRASK
gracilis A. AGAss.
Greenei Murr.
halecina Lin.
labrata Murr.
latiuseula Stmes.
muricata ELL. et SOL.
myriophyllum Linn.
pelasgica Bose
pinnata GOULD
plumea Drs.
polyzonias LINN. .
producta Srimes.
pumila Morcn
rosacea LINN. .
rugosa LINN.

OF GENERA AND SPECIES.

Sertularia (continued)
tamarisca LINN. .«
tenerissima STIMPS. . ‘
thuja FAB. .
thuja Linn.
tricuspidata ALD.
tricuspidata Murr. . ;
turgida TRAsK

Stlicularia Mny.

Spadiz GOssE = 0

Staurophora Br. .

A laciniata AGASS. .
Mertensi Br. .

Sthenio Dus. .

Stipula Sars

Stomobrachium ForBES .

Stomobrachium Br.
lenticulare GOULD
tentaculatum AGAss.

Stomolophus AGass. .
meleagris AGASS. .

Stomotoca AGass.
apicata AGAss. 6 0
atra AGASS. 6

Strobila Sars

Syncoryna EHRENB. 0

Syndictyon A. AGAss. . :
reticulatum A. AGAss.

Thamnocnidia AGASs. .
spectabilis AGAss.
tenella AGAss. 5
tubularoides A. AGass.

Thaumantias Escu.

Thaumantias GEG.. i :
diaphana AGASS. . 3

Thoa LAMX. .
dispar AGASS.

Thuiaria FLem. .
thuja Frem. ..

Tiaropsis AGass.
diademata AGAss. .

Tima Escu..
formosa AGASS.

Trachynema GEG.

camtschaticum A. AGASs.

digitale A. AGAss.
Trochopyzis AGASS. .
Tubularia Linn.
Couthouyi AGAss. .
cristata McCr.
indivisa GOULD
larynx ELxis
ramosa GUILD.
stellifera COUTH. .
Turris Less.
digitalis Morcr .

147,

234 INDEX OF GENERA AND SPECIES.

Turris (continued) Wrightia AGASS. . . : : aed)
vesicaria A. AGASS. . 1 . 164
Turritopsis McCr. : , A 167 Zanclea McCr.. 3 é : 184
nutricula McCr.. : ° o 16% gemmosa McCr. . a+) ee ee
Velella Lamx.* . : c d 216 Zygodactyla Br. . 6 f 6 103
mutica Bosc 0 5 5 . 216 cerulescens Br. . r 2 - 108
septentrionalis Escu. . . 217 crassa A. AGASS. . . . 106
cyanea AGASS. . 0 . - 107
Willia Forzrs . > 4 5 orl groenlandica AGASS. . : 103

ornata McCr.. 5 z c 171

THE END.

Cambridge : Electrotyped and Printed by Welch, Bigelow, & Co.

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MUSEUM OF COMPARATIVE ZOOLOGY.

\

ANNUAL REPORT of the Trustees, together with the Report of the Director for 1859,
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DIRECTIONS FOR COLLECTING objects of Natural History.

BULLETIN.

No. 1. List of the FISHES sent by the Museum to different Institutions, in Exchange
for other Specimens, with Annotations by F. W. Putnam. pp.16. April, 1863.

No. 2. List of the ECHINODERMS, by Atex. Acassiz. pp.12. August, 1863.

No. 3. List of the POLYPS and CORALS, by A. E. Verritu. pp. 32. January,

1864. -

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June, 1865. :

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