I

I

.2^

HARVARD UNIVERSITY

LIBRARY

OF THE

Museum of Comparative Zoology

mum d l^t Pttsatm ai (H^omparatifae ^aaloQis

at harvard college.
Vol. v. No. 2.

REPORT

HYDROIDA

COLLECTED DURING THE EXPLORATION OF THE GULF STREAM BY L. F. De POURTALES,
ASSISTANT UNITED STATES COAST SURVEY.

[PCBLISHED ET PERMISSION OF PkOFESSOE BENJAMIN PeIRCE, SUPERINTENDENT D. S. COAST SURVEY.)

BY

GEO. J. ALLMAN, M.D., LL.D., F.R.S., M.R.I.A., Cor.M.Z.S.L.,F.R.C.S.I.,

PKESIDEST OF THE LINN.EAN SOCIETY, MEMBER OF THE ROYAL DANISH ACADEMY OF SCIEN'CES,

EMERITUS REGIUS PROFESSOR OF NATURAL HISTORY IN THE

UNIVERSITY OF EDINBURGH,

ETC.

WITH THIRTY-FOUR PLATES.

CAMBRIDGE:

WELCH, BIGELOW, AND COMPANY,

2Snitoetsits IPttSjS.

1877.

INTRODUCTORY.

The collections of Hydroids obtained by Mr. de Pourtales during the ex-
ploration of the Gulf Stream between Florida and Cuba, while assistant
of the Coast Survey, were sent to me by Mr. Alexander Agassiz for deter-
mination. The collection, which had been put up in spirits and is, for the
most part, in an excellent state of preservation, proves to be a very large
one, and to contain a great number of undescribed sj^ecies. The determi-
nation of the specimens, and the drawing and description of the new
species, have occupied more time than I had anticipated, and with the
pressure of other avocations have caused more delay than I could have
wished in the publication of the results.

All the enlarged drawings and details of structure have been carefully
made by myself, while most of the drawings representing the natural size
of the hydroid, as well as the completion of some of my sketches and the
drawing of the whole on stone, have been executed by Mr. Hollick ; and
I must here bear testimony to the truthfulness of his work and the almost
photographic actuality with which he has reproduced the natural form of
the specimen.

One of the most striking features of the collection consists in the large
number of undescribed species, and the small percentage which can, with
probability, be referred to forms known to exist on the European side
of the Atlantic.

Leaving out of consideration a few specimens whose characters, in con-
sequence of their imperfect preservation, could not be ascertained, the
collection consists of seventy-one species. Sixty-four are here figured and
described for the first time, and none of these have as yet been known to
occur beyond the area to which the exploration was confined. There thus
remain only seven species which, so far as their identification is possible,

2 INTRODUCTORY.

are already known as European forms. These are Filellum immersum, Hale-
eimn muricutum, SerMarella polyzonias, Sertularella Gayi, Antemmlaria ramosa,
Plumnlaria cutJumna, and probably Tubuluria indivisa, whose identification is,
in consequence of the absence of all the soft parts, less certain than in the
others.

One of the specimens here described, Halecium, capilhris Pourtales, has
been already examined and named {Thna capillaris) by Mr. de Pourtales
in No. 6, Bull. M. C. Z., Vol. I. Mr. de Pourtales has also described Tubuluria
crinis, but this has not been received by me in a condition sufficiently
perfect to admit of further examination.

The Gymnoblastic genera sufficiently well preserved for satisfactory de-
termination consist of nine species, all new and referable to two genera,
Eudendrium and Bimeria. Species of Tubularia would also seem to exist
in the collection, and one of these, as just said, is probably the Tubularia
indivisa of the European seas ; but as in none of the specimens of apparent
Tubularia does anything remain beyond the tubular perisarc, the characters
needed for a reliable determination are entirely wanting.

Several of the specimens referred to Eudendrium have, on the contrary,
their soft parts well preserved, and leave no doubt of the correctness of
this determination; while others may, with a provisional reservation, be
referred without much hesitation to the same genus. In the little hydroid
referred to Bimeria the soft parts are well preserved both in the tropho-
some and the gonosome.

Of species referable to Calyptoblastic genera fifty-six are here described
and figured. Of these, fifty-five are now recorded for the first time, while
I have figiu'ed one form which occurs also on the eastern side of the At-
lantic, and has been elsewhere * described by myself as a variety of Sertu-
larella Gayi.

Of the fifty-five new Calyptoblastic species forty-five belong to the Ser-
tularinae and ten to the Campanularinae.

The collection is especially rich in the Plumularida; ; no less than twenty-
eight out of the seventy-one determinable species belong to this beautiful
family. Of these, twenty-six species are now described for the first time,
the remaining two, so far as it is possible to determine specimens in which
no gonosome is present, are identical with the Antemmlaria ramosa and the
Plumnlaria caihurina of the European shores.

• Reports on the Hydroids collected during the Expeditions of H. M. S. Porcupine, Trans. Zobl.
Soc, London, February, 1873.

INTEODUCTOEY.

3

It is thus obvious that the region from which the present collection has
been obtained, and which includes an area between the Florida Reef on
the north and west, and Cuba, the Salt Key, and Bahama Banks on the
south and east, is characterized by a very distinct hydroid fauna, and must
form part of a special province in the geographical distribution of the
Hydroida. How far the same forms will be found to extend beyond the
limits of the exploration must remain for future researches to decide.

The European species which was met with in greatest abundance over
this area is the SerhilarcUa Gai/i, which occurred chiefly in the condition of
the strong irregularly branched variety already referred to. It was among
the most widely distributed species of the area, and was obtained from no
less than nineteen different dredgings.

Among the specimens of Gymnoblastea the gonosome is present in a
considerable proportion of species. So also a large proportion of the
Plumularido3 is provided with the gonosome, and presents some interest-
ing and beautiful modifications of this part of the hydroid colony. From
the other Calyptoblastic forms, however, the gonosome is in almost every
instance absent. The very rare cases in which it is present are from some
of the deepest dredgings made.

Among the new species are many which must be regarded as representa-
tives of new generic groups. Indeed, throughout the whole collection we
meet with features many of which are of great interest and significance in
their general bearing on hydroid morphology.

Bathi/metrical Distribution. — With very few exceptions a careful record had
been kept of the depths from which the specimens had been dredged.
These depths varied from that of quite shallow water to four hundred and
seventy-one fathoms. The following table will show at a glance the relative
richness in hydroid life of the various depths explored: —

Species whose

depths have

been recorded,

10

2

5
13
10

6

Between

om which the species
been dredged.

have

Species whose
depths have
been recorded.

Deptlis from which the species have
been dredged.

1 and

10 fathoms.

Between

200

and

250 fathoms

10 "

20

6

«c

250

300 "

20 "

50

2

tt

300

350

50 "

100

it

350

400 "

100 "

150

2

(t

400

450

150 "

200

2

..

450

500

DEFINITIONS OF TERMS.

In the descriptions of the genera and species I have adopted the tei-minology which I have used
on other occasions, and these descriptions will perhaps be rendered more intelligible by giving here
definitions of the principal terms employed.

Hydrosoma. The entire hydroid colony.

Ectoderm. The more external of the two organized layers of which the body of every hydroid
is composed.

Endoderm. The more internal of the two organized layers of which the body of every hydroid
is composed.

Perisarc. The unorganized chitinous excretion by which the soft parts are to a greater or less ex-
tent invested.

Zooids. The more or less independent products of non-sexual reproduction, forming by their asso-
ciation the hydroid colony.

Trophosome. The entire assemblage of such zooids as are destined for the nutrition of the colony.

Gonosome. Tlie entire assemblage of such zooids as are destined for the sexual reproduction of
the colony.

Hydrantbs. The proper nutritive zooids, or those which carry the mouth and proper digestive
cavity, and which are almost always set with tentacles.

Hydrotheca. The cuplike chitinous receptacle which protects the hydranth in the Calyptoblastic
genera.

Intrathecal Ridge. An imperfect septum by which in many Plumularids the cavity of the hydrotheca
is transvcri^ely divided into a distal and a proximal portion.

Hydrophyton. The common basis of the hydrosoma by which its zooids are connected into a
single colony.

Hydrorhiza. The proximal end of the hydrophyton by which the colony fixes itself to other
bodies.

Hydrocaulus. All that portion of the hydrophyton which intervenes between the hydrorhiza and
the h\ilrantli. It is poli/nijilionic or fascicled when it is composed of several mutually adherent tubes ;
vwnn:<iph<mic, when consisting of a single tube. In some species the cavity of its perisarc may be divided
by annular ridges or imperfect septa, — septal riilges. The rachht is that portion of the hydrocaulus along
whicli in the I'lumularida; the hydrothecse are an-anged.

Ccenosarc. The common organized fleshy portion of the hydrophyton ; the living bond b)- which
the zooids are organically imited to one another.

Nematophores. Peculiar Ixidies developed in certain genera from definite points of the hydrosoma,
and consisting of a chitinous recejjtacle with sarcode contents in which thiead-cells are usually im-
mersed. They are eminently characteristic of the family of the Plumularidae. They are supracalycbie
when situated one on each side of the orifice of the hydrotheca ; mesial when situated on the mesial line
of the hydrotheca or rachis.

Gonophore. The ultimate generative zooid which gives origin directly to the generative elements,
— ova iir spcrnuitozoa.

Gonangium. An external chitinous receptacle within which in the Calyptoblastic genera the gono-
phores are developed.

Acrocyst. An external sac which in certain hydroids is formed on the summit of the gonangium,
where it constitutes a receptacle into which the ova are discharged in order to pass within it through
some of the earlier stages of their development.

Corbula. A basket-shaped receptacle which encloses groups of gonangia in certain plumularian hy-
droids.

Phylactogonia. Special branches intended for the j)rotection of the gonangia in certain plumularidans.

Gymnoblastic. The condition of a hydroid when no external protective receptacle (hydrotheca or
gonangium) invests either nutritive or generative buds. Gymnoblastea, the name of one of the sub-
orders of IIydroida.

Calyptoblastic. Tlie condition of a hydroid when an external protective receptacle (hydrotheca or
gonaniiuni) invests either the nutritive or generative buds. Calyptoblastea, the name of one of
the sulioi'dcrs of IIydkoida.

DESCRIPTIONS OF NEW GENERA AND SPECIES.

Suborder GYMNOBLASTEA.

Family EUDENDRIDiE.

Genus EUDENDRIUM Ehrenberg (in part).

Eudendrium eximium.

PI. I. Figs. 1, 2.

Trophosome. — Hydrocaulus attaining a height of about six inches, much
branched, with the main branches and subordinate ramuU alternate and
distichous ; main stem and origin of the principal branches fascicled ; ulti-
mate ramuli with nearly obsolete annulation at their origin. Hydrauths
with about twenty tentacula.

Gonosome. — Female sporosacs springing irregularly from the body of the
hydranth and from its supporting ramulus.

Dredged from a depth of 43 fathoms off the Florida Reef.

This is a fine species, rendered conspicuous by its size and by its profuse
ramification. All the branches, both the primary ones and the subordinate
ramuli, are in the same plane. The main stem is strongly fascicled, and
towards its base acquires a thickness of nearly two lines.

From E. ramosum o{ the Eui'opean coasts the present species differs in
the more extensive fascicuLition of its main stem, in the disposition of its
ultimate ramuli, which are not, as in E. rainosiim, confined to one side of
their supporting branch, and in the absence of very decided annulation at
the origin of the branches.

All the specimens preserved in the collection are female, and the hydranth
of the sporosac-bearing ramulus shows no tendency to atrophy.

6 EUDENDRIUM ATTENTJATUM.

Eudendrium exiguum.

PI I. Figs. 3, 4.

Trophosome. — Hydrocaulus attaining a height of about an inch, irregularly

branched, fascicled in- main stem ; principal branches and ultimate raniuli

slender, mostly annulated at their origin. Hydranths with about twenty

tentacula.

Gonosome not known.

Dredged from a depth of 98 fathoms off the Florida Reef.

This is a small species ; it is strongly fascicled towards the proximal end
of the main stem, but the branches are for the most part monosiphonic, very
slender, and with very thin perisarc.

Eudendrium fruticosum.
PL II. Figs. 1, 2.

Trophosome. — Hydrocaulus attaining a height of about two inches, much
and irregularly branched ; main stem and base of principal branches fasci-
cled. Hydranths with about twenty tentacles.

Gonosome. — Male gonophores bithalamic, springing in a verticil of about
ten from the body of the hydranth. Female gonophores oval, also spring-
ing in a verticil from the bodj^ of the hydranth.

Dredged off Key West from a depth of 135 fathoms.

This is a strong, confusedly branched form. The annulation of the peri-
sarc is either altogether obsolete or is at most represented by a few obscure
rings at the origin of the ultimate branches, or an occasional group of rings
near the middle of their length. The stem is thick and strongly fascicled
below, where it resolves itself into numerous hydrorhizal filaments.

In the hydranths which carried the gonophores there was no tendency to
atrophy in the male, and but little in the female.

The specimen was loaded with small spherical capsules, — probably a
moUuscan or annelidan nidus, — which adhered to the stem and branches
in dense clusters.

Eudendrium attenuatum.

PI. II. Figs. 3, 4.

Troplwsome. — Hydrocaulus attaining a height of about two inchis, not
fascicled, very slender, alternately branched ; ultimate ramuli short, given

EUDENDRIUM GRACILE. 7

off alternately at sliort and nearly equal intervals along the stem and
branches ; main branches and ramuli annulated at their origin ; stem with
a few annulations here and there.
Gonosome not known.

Dredged S. S. W. of Tortugas from a depth of 60 fathoms.

The specimen was destitute of both gonosome and hydranths, but its very
slender non-fascicled stem, and short regularly disposed hydranthal ramuli,
afford characters sufficiently diagnostic. In the absence, however, of hy-
dranths and gonosome, the species is only provisionally referred to Eu-
dendrium.

Eudendrium laxum.
PL III.

TropJiosome. — Hydrocaulus attaining a height of about two inches, irreg-
ularly branched, not fascicled ; ultimate ramuli alternate, rather long, and
with a few annulations at their origin.

Gonosome. — Sporosacs (male) bithalamic, springing in a verticil of about
ten from the body of the hydranth.

Dredged off Sand Key from a depth of 100 fathoms.

This is a loosely branched, somewhat straggling species, with unusually
long, flexile, hydranth-bearing ramuli.

Imbedded in the coenosarcal walls of the lower end of the hydrocaulus
and in those of the hydrorhiza, there occurred in the specimen clear
spherical bodies of whose nature I am unable to give any satisfactory
account. They showed no trace of a nucleus, but are too regular to be
mere lacunae. Their real nature can scarcely be determined without an
examination in the recent hydroid.

Eudendrium gracile.
PL IV. Figs. 1, 2.

Trophosome. — Hydrocaulus attaining a height of upwards of an inch,
slender, fascicled at extreme base, alternately branched ; ultimate ramuli
with nearly obsolete annulation at their origin.

Gonosome not known.

Dredged at Double-Headed Shot Key from a depth of from 3 to 4 fathoms.

This is a slender and delicate species. The hydranths were well pre-
served in the specimen, but no gonosome was present.

8 BIMEEIA HUMILIS.

liudendriuiu tenellum.
PI. IV. Figs. 3, 4.

Tro2)hosome. — Hydrocaulus attaining a height of about half an inch, very
slender, not fascicled, irregularly branched ; branches annulated at their
origin ; main stem and branches with groups of two or three annuli at
distant and irregular intervals.

Gonosome not known.

Dredged off Double- Headed Shot Key from a depth of 471 fathoms.

Endendnnm tenellum is a minute and very slender form, perhaps the most
slender species as yet referred to the genus Eudendrium. Its reference to
this genus is probably correct, but as neither hydranths nor gonophores
were present in the specimen, it may possibly have its true place in some
other.

The specimens were obtained along with Sertularella amphorifera from the
deepest dredgings made.

Eudendrium cochleatum.

PI V. Figs. 1, 2.

Trophosome. — Hydrocaulus attaining a height of between two and three
inches, not fascicled, alternately branched ; main branches and ultimate
ramuli with very distinct oblique annulation at their origin, and here and
there with groups of three or four ordinary transverse annuli.

Gonosome not known.

Dredged off Cape Fear River from a depth of 6 fathoms.

The strongly marked screw-like annulation at the origin of the branches
forms a characteristic feature of this species. Some of the hydranths were
well preserved in the specimen, but no gonophores were present.

Attached to it were numerous specimens of a little tube-dwelling crus-
tacean.

Family BIMERID^.

Genus BIMERIA Str. Wright.

Bimeria humilis.

PI. V. Figs. 3, 4.

Trophosome. — Hydrocaulus attaining a height of about a line and a half,

springing at intervals from a creeping and ramified stolon, sending off

OBELIA MARGINATA. 9

short, alternate liydranth-bearing ramuli which are marked at their origin
by spiral corrugations, and which, increasing in thickness towards their distal
ends, gradually pass into the piriform body of the hydranth; perisarc very
opaque. Hydranths large, assuming for the most part a drooping attitude.
Gonosome. — Gonophores (male ?) oviform, supported on short spirally
corrugated peduncles, scattered on the hydrocaulus.

Dredged at Tortugas in shallow water.

The massive-looking hydranths and the enlargement of the hydrocaulus
towards their base give a peculiar aspect to this little hydroid. The peri-
sarc, which is very opaque, is apparently continued for some distance over
the tentacles, as in li. vestita Wright, the only species of the genus hitherto
described. In the condition of the specimens of B. hiimilis, however, it was
not possible to make this out satisfactorily.

The massive hydranths and comparatively slight development of the
hydrocaulus distinguish this species from B. vestita. In both species the
hydranths exhibit a tendency to assume a drooping attitude.

It occurred in considerable profusion, creeping over the surface of a sea-
weed which it covered with a low but rather dense growth.

Suborder CALYPTOBLASTEA.

Tribe CAMPANULIN.S:.

Family CAMPANULARID^.

Genus OBELIA Peron & Lesueur.

Obelia marginata.
PI. VI. Figs. 1, 2.

Trophosome. — Stem attaining a height of nine inches, monosiphonic, pin-
nately branched ; pinnae alternate ; stem and pinnte gently zigzag, with a
strong short process given off from the salient angle of each geniculation,
and with a joint at the distal side of the process. Hydrothecaj supported
on short stout peduncles which rest on the processes of the stem and
pinnae, large, nearly cylindrical, slightly oblique at the inner side of the
base, and with a circular even orifice which is margined by a narrow, more
transparent rim.

Gonosome not known.

Dredged off Logger-Head Key from a depth of 9 fathoms.
2

10 THYROSCYPHUS.

This is a very large, strong form, rendered striking by its regularly pin-
nate hydrocaulus, and its large, nearly cylindrical hydrothecse, with perfectly
even orifice margined by a narrow clear band.

Without a knowledge of the gonosome its reference to Obella must be
regarded as purely provisional.

The beautiful little Lafoea venusta crept over the stem and pinnae of one
of the specimens.

Obelia longicyatha.

PI. VII. Figs. 4, 5.

Trophosome. — Hydrocaulus attaining a height of nearly an inch, fascicled
below, alternately branched ; main stem annulated for a short distance above
each ramulus; ramuli annulated at their origin; hydrothecal peduncles of
moderate length, more or less annulated. Hydrothecaa narrow, deep, nearly
cylindrical above, and then tapering towards the base; the orifice cut into
about twenty acute, deep, narrow teeth.

Gonosome not known.

Dredged from a depth of 90 fathoms off the Florida Reef.

The specimens were found attached to Halecium macrocephahmi. It is a
delicate species with the hydrothecae very thin and compressible. No gono-
some was present, and its reference to Obelia is therefore only provisional.

THYROSCYPHUS Allman nov. gen.

Geneeic Character. Trophosome. — Hydrocaulus divided into internodes,
each internode carrying a hydrotheca. HydrothecEe pedunculate ; orifice
closed by an operculum which is formed by four converging valves.

Gonosome not known.

The small and definite number (4) of valve-like segments composing the
operculum of the large and strong hydrothecse, combined with the very
definite division of the hydrocaulus into distinct and equal internodes, dis-
tinguishes the genus Thyroscyphus from the other operculate genera of the
Campanularida;. It is highly probable that if we were acquainted with
the gonosome other and still more important characters would be foimd.

LAOFEA VENUSTA. H

Thyroscyphus ramosus.

PL VI. Figs. 5, 6.

Trophosome. — Hydrocaulus attaining a height of about two inches, much
and rather irregularly branched. Hydrothecas alternate, large and deep,
oblique at the inner side of the base, supported each on a short peduncle
which consists of two oblique rings and which springs from the summit of
a short thick process given off from the distal end of the internode ; orifice
with a narrow border ; opercular valves broadly triangular.

Gonosome not known.

Dredged south of Sand Key from a depth of 10 fathoms.

Thyroscyphus ramosus is a large and strong species, rendered striking by
its large valvular and bordered hydrothecae. It contrasts markedly with
the other operculate Campanularin^e, which are all, so far as is known, small
and delicate forms.

Genus CAMPANULARIA Lamarck (in part).
Campanularia macroscypha.
PL VIII. Figs. 1, 2.
Trophosome. — Peduncles short, rising from a creeping stolon, marked with
a few distant annulations, and having a discoid internode just below the
hydrotheca. Hydrothecae large, cylindrical from above downwards for the
greater part of their length, and then tapering rapidly to the base ; orifice
cut into about twelve conspicuous, rather blunt teeth.
Gonosome not known.

Dredged off Sand Key from a depth of 120 fathoms.

This is a simple creeping species, and though of humble growth is re-
markable for the large size of its hydrothecae.

Family LAFOEID^ Lamouroux.

Genus LAFOEA.*
Lafo'ea venusta.

PL VI Figs. 3, 4.
Trophosome. — Hydrophyton minute, creeping. Hydrothecae borne on
moderately long, slightly corrugated peduncles, which spring at short in-

* It is difficult to find characters for the definition of the genus Lafoea. I regard, however, as an
essential character of the genus the absence of any definite floor to the hydrotheca, a character which

12 LAFOEA CONVALLARIA.

tervals from the creeping filament, cylindrical, deep, slightly curved in one
aspect, regularly annulated ; orifice circular with everted lip.
Gonosome not known.

Dredged along with Ohelia marginata at Logger-Head Key from a depth of 9 fathoms.

This elegant little campanularian was found creeping over the branches
of Obeliu marginata.

Lafo'ea tenellula.

PI. VIIL Mgs. 3, 4.

Trophosome. — Hydrothecae very minute, slightly curved, contracted below
into a short thick peduncle, springing at intervals from a creeping tubular
filament.

Gonosome not known.

Dredged south of Marquesas from a depth of 140 fathoms.

This is a very minute species. The form of the hydrothecoe resembles
that of the hydrothecoe of L. dumosa, but the whole hydroid is more minute
and delicate. The hydrothecte are usually marked by rings of elongation
behind the orifice.

Lafoea convallaria.

PI. IX.

Trophosome. — Stem attaining a height of about an inch, simple, fascicled
below, sending off simple, non-fascicled, alternate pinna?. Hydrothecoe
stalked, alternately disposed along the main stem and pinnoe, tumid towards
the base and contracted towards the orifice, which is turned towards one side.

Gonosome not known.

Dredged from a depth of 152 fathoms off tlie Florida Reef.

Lafoea convallaria is a beautiful little hydroid. Its cornucopia-like hydro-
thecoe on their short stalks, with their regular symmetrical disposition along
the main stem and pinnoe, give to the entire hydrophyton a remarkable and
very elegant aspect.

The form of the hydrotheca appears to change somewhat by age, for
while in some the distal end is turned only slightly to one side, in others

it possesses in common with the operculate genus Cuspidella. The cavity of the hydrotheca thus passes
uninterruptedly into tliat of the supporting peduncle, or if the hydrotheca bo sessile, into the cavity
of the stem or branch which carries it. Admitting the correctness of tliis view, it appears to nie
verj doubtful -whether many of the species referred to Lafoea are rightly so placed.

CUSPIDELLA PEDUNCULATE. 13

the orifice is tui-ned quite downwards by a curving of this part of the
hydrotheca. In many of the hydrothecoo annular indications of growth
show themselves just behind the orifice. The peduncles are nearly equal
in length to that of the hydrotheca3 which they support.

The pinnie of one side are not given off from the middle point of the
interval between two pinnas of the opposite side, but rather nearer to
one of these than to the other.

The species is probably correctly referred to the genus Lafoea, but in
the absence of all knowledge of the hydranths this determination must be
taken as only provisional.

Lafoea coalescens.

PI. X.

Trophosome. — Hydrocaulus attaining a height of about half an inch, alter-
nately branched, fascicled below, springing from a network of tubular fila-
ments. Hydrothecfe borne on the summit of peduncles which are for the
most part given off from the sides of a common tube to which they become
immediately adnate until within a short distance of their extremities. Hy-
drothecae very deep, tubular, tapering towards the base, and again slightly
narrowing towards the margin, which is itself slightly everted.

Gonosome not known.

Dredged south of Marquesas^ from a depth of 140 fathoms.

The adnate condition of the hydrothecal peduncles gives to this elegant
little hydroid a remarkable character. This must, however, be regarded as
a continuation of the fascicled state of the lower part of the stem. Occa-
sionally hydrothecae occur which are borne on shorter peduncles springing
from the main stem, but free in their entire course, while there are also
some which are borne on free peduncles springing "from the hydrorhiza.

The hydrothecoe in every case pass gradually into the supporting pedun-
cle without any basal diaphragm.

Genus CUSPIDELLA* Hincks.

Cuspidella pedunculata.
PL VIII. Figs. 5, 6.
Trophosome. — Hydrosoma very minute. Hydrothecae springing by

* The genus Cuspidella was instituted by Hincks for certain minute operculate Campanularlna; which
he separated from Calycella {Cumpanularia syrinyia of authors) on the ground of the sessile condition

14 OPLORHIZA.

rather long peduncles from a creeping filament, very delicate and filmy,
deep, tapering toward the base, where they gradually pass into the peduncle
without any definite line of demarcation.
Gonosome not known.

Dredged south of Tortugas from a depth of 260 fathoms.

OPLORHIZA Allman nov. gen.

Generic Character. Trophosome. — Hydrotheca3 tubular, provided with
a floor and having the orifice cut into thin collapsible segments ; borne by
peduncles which spring from a creeping network of tubes. Hydrorhizal
network carrying peculiar appendages which are in the form of tubular re-
ceptacles with an orifice in the summit, and which enclose a granular, fleshy
column, supporting a cluster of thread-cells.

Gonosome not known.

The genus Oplorhiza is nearly allied to Lafoeina Sars. In Lafoeina,
however, the hydrothecae are absolutely sessile on the hydrorhiza, and their
cavity passes directly into that of the hydrorhiza without the intervention
of an infrathecal diaphragm or floor.

The genus Lafoeina was established by Michael Sars for a little Lafoea
like hydroid [Lafotina tenuis) obtained off the Norwegian coast, and essen-
tially distinguished from Lafoea by the presence of peculiar urticating
appendages which are borne by the hydrorhiza.* These appendages in
Lafoeina are long, filiform, and flexuous, while in Oplorhiza they are short
and cup-shaped. In both genera they remind us strongly of the nemato-
phores of the Plumularidse. Like these they consist of a chitinous receptacle
with fleshy contents which are probably of a simply sarcodic nature, and in
which thread-cells are immersed. In the species on which the genus Oplo-
rhiza is founded, these contents extend through the proximal part of the
appendage in the form of a cylindrical column, which towards the summit
becomes enlarged into a bulb in which numerous very long, curved thread-
cells are imbedded. A very similar condition exists in Lafoeina tenuis.

of the hydrothecK. A more important character, however, will be found in the absence of any defi-
nite floor or basal diaphragm in the hydrothecse. It is the only known operculate form of the Cam-
panulinffi in which the cavity of the hydrotheca thus passes uninterruptedly into that of the supporting
tube as in the non-operculate genus Lafoea. The sessile or pedunculate condition must be regarded
as of merely secondary or specific value.

* G. O. Sars, Bidrag til Kundskaben om Norges Hydroider. Forhandlinger i Videnskabs-selskabet i

ChrMania, 1873, p. H9.

HALECIUM FILICULA. 15

Lafoeina and Oplorhiza afford the only known instances in which organs
resembling true nematophores occur outside of the family of the Plumularidae.

Oplorhiza parvula.
PI. VII. Figs. 1-3.

Trophosome. — Hydrosoma very minute, scarcely attaining a line in height.
Hydrothecge deep, narrowing towards the summit and towards the base ;
peduncles with about two rings just below the hydrotheca, and several less
distinct ones at their origin from the hydrorhiza. Hydrorhizal appendages
very minute, clavate, scattered over the upper side of the hydrorhiza.

Gonosome not known.

Dredged south of Marquesas from a depth of 296 fathoms.

Family HALEOID^.

Genus HALECIUM Oken.

Halecium filicula.

PI XL Figs. 1-4.

Trophosome. — Hydrocaulus attaining a height of about three inches, alter-
nately branched; branches pinnately disposed; internodes rather long; main
stem and principal branches fascicled, but becoming monosiphonic toward
their distal ends. Hydrophores* with one or more usually oblique and
irregular annulations at their base, then gradually widening from the most
distal annulation to the summit, where they terminate in a circular and
abruptly everted margin.

Goiwsome not known.

Dredged south of Marquesas from a depth of 140 fathoms.

This species is rendered striking by the graceful trumpet-shaped form of
its hydrophores. Many of these are provided with a double or even triple
margin, caused by the hydranth in its growth leaving behind it the old
dilated extremity of the hydrophore, and becoming encircled by a new one,
— a common occurrence among the various species of Halecium.

* The genus Halecium is destitute of true hydrothecje, and the term hydrophore is here used for
the appendages of the stem which take the place of the hydrothecse in giving support to the hydranths.

16 HALECIUM MACROCEPHALITM.

Just within the everted margin of the hydrophore is the circle of minute
brilliant points which is scarcely ever absent in any species of Halecium.

Halecium capillare.

Thoa capillaris Pouktales. Bull. M. C. Z., I. No. 6.

PI. XL Figs. 5, 6.

Trophosome. — Hydrocaulus attains a heiglit of about an inch and a half,
slender, irregularly branched, fascicled at the origin of the main stem and
principal branches ; internodes rather long. Hydrophores short, nearly
cylindrical.

Gonosome not known.

Dredged five miles S. S. W. of Sand Key from a depth of from 90 to 100 fathoms.

This is a small and delicate species. The circle of brilliant points which
in almost every species of Halecium occurs just within the margin of the
hydrophore is not here obvious.

This is one of the specimens examined by Mr. de Pourtales, who has
assigned to it the specific name here adopted.

Halecium macrocephalum.
PI. XII. Figs. 1-5.

Trophosome. — Hydrocaulus attaining a height of about two inches, rigid,
stout, and very irregularly branched in all directions; main stem and
principal branches fascicled, becoming monosiphonic distally; internodes of
moderate length. Hydrophores suppressed. Hydranths very large, sup-
ported directly on the fixed lateral processes of the stem.

Gonosome. — Gonangia springing from the sides of the lateral processes
which support the hydranths ; female slipper-shaped, with the orifice situ-
ated near the middle of one side ; male smaller than female, cylindrical,
with truncated summit.

Dredged off Sand Key from a depth of 120 fathoms.

Halecium viacroceplmlum is remarkable for the suppression of the hydro-
phore, whose sole representative is found in the narrow membranous lip,
which is here quite sessile on the fixed bracket-like process of the stem.

In some of the specimens the form of the hydranths was well retained.
These were very large, reaching when fully extended the height of about
two internodes of the stem.

CEYPTOLAEIA CONFERTA. 17

In their slipper-shaped form the female gonangia come very near to those
of H. Beanii. The orifice, however, in the latter is more exserted than in
the present species.

Halecium macroceplmlum, in the suppression of its hydrophores, and in the
great size of its hydranths, comes very near to H. sessile Nordman. It is,
however, a much stouter form than H. sessile, which, moreover, judging from
the figures and descriptions of that species, has a monosiphonic instead of a
fascicled stem.

As a rule, the hydranths are relatively large in the various species of
Halecium, and this fact, taken in connection with the absence of a true
hydrotheca, is not without significance.

Tribe SERTULARIN^.

Family GRAMMAR IDiE.

Genus CRYPTOLARIA Busk.

Cryptolaria conferta.
PL XII. Figs. 6-10.

Trophosome. — Hydrocaulus attaining a height of about two inches, much
and irregularly or subdichotoraously branched, fascicled except towards the
terminations of the branches. Hydrothecae adnate for somewhat more than
half their height, and in the fascicled portion of their stem deeply immersed,
then becoming free and arching outwards ; adnate portion slightly narrowing
downwards , free portion cylindrical, with circular and entire orifice behind
which the walls are marked by several annular striae.

Gonosome ?

Dredged o£E Cojima, Cuba, from a depth of 450 fathoms.

Cryptolaria conferta forms crowded entangled tufts. The proximal portions
are strongly fascicled, but towards the extremities the fascicled condition dis-
appears. Here the whole form of the hydrotheciB is frequently visible, but
farther down the greater part of every hydrotheca is immersed and con-
cealed in the fascicled portion.

The hydrotheca where fully seen in the non-fascicled portion of the hy-
droid is found to have a distinct floor perforated by an offset from the coeno-

j^g CEYPTULARIA COXFERTA.

sarc of the branch. It is possible that this floor disappears with age, and
that the older hydrothecaj, where they are immersed in the fascicled stem,
are without it. In Cryptolaria longitheca, another species occurring in the pres-
ent collection, the hydrothecae appear to pass continuously into the tubes of
the hydrocaulus without the intervention of a perforated floor. I have had
no opportunity of examining the nearly allied genus Grammaria, but accord-
ing to Sars the hydrothecjB in this genus form continuous tubes passing un-
interruptedly into the tubes of the fascicled stem and allowing of the entire
retraction of the hydranth from the hydrothecae into the tubes of the stem.

On the branches of the specimen here described there occurred here and
there certain very remarkable bodies, the real nature of which I have not
succeeded in placing beyond doubt. They are of an irregularly fusiform
shape, and at the spots where they occur surround the branch like minute
sponges. A closer examination shows them to consist of a multitude of flask-
shaped, apparently chitinous receptacles (Figs. 9, 10), adnate to one another
by their sides, and springing by a narrow base from an irregular network of
tubes which encircles the branch. The distal extremity of each is prolonged
into a free neck-like extension which terminates in an even circular orifice.

Each receptacle gives exit after a time to a single spherical body, which
is retained for a period in an external membranous sac connected by a nar-
row neck to the orifice of the flask-shaped receptacle (Fig. 9, a, a).

It is scarcely possible not to recognize in these bodies an assemblage of
true hydroid gonangia, each giving origin within it to a single ovum, which
is subsequently expelled from its cavity and lodged in an acrocyst in which
it continues to be for some time retained.

With the exception, indeed, of there being no apparent hydrothecae in-
tercalated among, the gonangia, the bodies in question resemble in all
essential points a colony of Coppinia. For, just as in Coppinia, we have
here a colony of mutually adherent gonangia, each containing a sporosac
with a single large ovum, which after a time is carried out and retained
within an acrocyst. The absence of apparent hydrothecae, however, will
not allow us to make too close a comparison with Coppinia or to regard
these enigmatical bodies as constituting a hydroid colony complete in itself.

Another view, however, suggests itself. May they not represent the
gonosome of the hydroid with which they are associated ? In favor of this
interpretation it may be urged that nothing else which can be regarded
as a gonosome occurs in the specimen, and that if we look upon them as

CRYPTOLARIA LONGITHECA. 19

merely a parasitic hydroid we should have in these bodies a gonosome
without its correlative trophosome. Further, the tubular base from which
the gonangia spring forms a close irregular plexus which embraces the fas-
cicled stem of the supporting hydroid, and 1 believe I have traced a com-
munication between this plexus and the cavities of the outermost tubes of
the stem.

If we admit the reasonableness of this view, we may compare the entire
hydroid to a Coppinia in which the trophosome, instead of consisting of
a number of sessile hydrothecse intercalated among the gonangia of the
gonosome, as in the only known species of Coppinia, is further differentiated,
and assumes the form of a branching hydrocaulus with the hydrothecte
distributed along its length.

I do not wish, however, to lay too much stress on this view. I do not
feel that I have been able to place beyond all doubt the reality of a com-
munication between the tubular base of the incrusting body and the tubes
of the stem, while the fascicled condition of the stem increases the difficulty.
Against its constituting the proper gonosome of the supporting hydroid,
may also be urged the facts of its irregular form and of its sometimes ex-
tending in such a way as to embrace a portion of more than one branch,
exactly as a foreign incrusting growth might do. The question, however,
of its exact relation to its associated hydroid must await for its solution
the examination of recent specimens.

Cryptolaria longitheca.

PI. .XIII Figs. 4, 5.

Trophosome. — Hydrocaulus attaining a height of about two inches, pin-
nately but not profusely branched; fasciculation disappearing towards the
ends of the branches. Hydrothecfe cylindrical, adnate in the non-fascicled
portion for about half their height, then becoming free and bending out-
wards ; margin circular and even, surrounded by annular striae.

Gonosome not known.

Dredged off Double-Headed Shot Key from a depth of 315 fathoms.

Cryptohria longilheca is a fiir less profusely branched species than C. conferta,
and from this species it further differs in the pinnate disposition of its
branches and in being a stronger form with larger hydrothecaj. The hy-
drothecJB, moreover, where a complete view of them can be obtained, as in

20 CRYPTOLAPJA ELEGANS.

the unfascicled portion of the hydrocaulus, are cylindrical throughout, pre-
senting no diminution of their diameter towards the base as in C. conferta.
They appear also to pass continuously into the tubes of the hydrocaulus,
no distinct floor being apparent in the hydrothecte of any part of the
specimen.

The circular striae which surround the margin of the hydrothecse are here
as in other species most probably indications of successive elongations occur-
ring during the growth of the hydroid.

Cryptolaria abies.
PI. XIII. Fi(/s. 1-3.
Troj)hosome. — Hydrocaulus attaining a height of about two inches, irreg-
ularly branched, with a pinnate disposition of the ultimate ramuli. Hydro-
thecae, where completely visible, near the ends of the branches where the
fasciculation ceases, flask-shaped, adnate by somewhat more than half their
height, and then bending outwards; mai'gin circular, even, and without
obvious annular striation.
Gonosome not known.

The hydrothecfe of this species are considerably smaller than those of
either C. conferta or C. longitheca. They can be seen, too, in the distal,
non-fascicled portions of the hydrocaulus, Avhere they are fully exposed, to
be of a very different shape from those of the two former species, being here
of an elongated flask-shape, tumid below and gradually narrowing towards
the orifice. Here also they are plainly provided with a distinct floor, and
in all respects resemble a typical sertularian hydro theca. In the fascicled
portion of the stem, where they are in great part immersed and concealed,
their form cannot be satisfactorily determined.*

Cryptolaria elegans.
PI. XIV. Figs. I, 2.

Trophosmiie. — Hydrocaulus attaining a height of about an inch, delicate,
pinnately and very regularly branched; pinnte alternate fascicled only at
their base or entirely monosiphonic. Hydrothecae alternate, tubular, nearly
cylindrical, narrow, adnate for somewhat more than half their height on
the distal portions of the hydrocaulus, with the free part bending outwards

* Tlie label placed with the specimens of this species had become effaced, so that neither their exact
station in the area explored nor the de[)th frnm which thcv were dredged could be ascertained.

SEETULAEELLA CONICA. 21

at nearly a right angle to the adnate part. Margin circular, even, frequently
surrounded by annular striae.
Gonosome not known.

Dredged from a depth of 152 fathoms ofT the Florida Reef.

This is a much smaller and more delicate form than any of the other
species of Cryptolaria in the collection, its hydrothecae having only about
half the diameter of those of C. ahies, the species which in this respect
approaches it most nearly. The fasciculation is not carried to the same
extent as in the other species, for it usually disappears from the pinnce at
a short distance from their origin, and those pinnae which are given off
near the summit of the stem are generally quite monosiphonic.

In the monosiphonic portions the hydrothecaj are seen to arise from the
sides of a common tube to which they are generally adnate for more than
half their height; they are here provided with a distinct floor, and are
entirely differentiated from the supporting tube. In the fascicled portion
they are, as in all the other species, deeply immersed and in great part
concealed.

The pinnse are so disposed that those of one side do not arise from the
middle point of the space opposite to the interval between two pinnse of
the opposite side, but from a point quite near to one end of this space.

Family SERTULARIDiE.
Genus SERTULARELLA Gray.

Sertularella conica.

PL XV. Figs. 6, 7.

Trophosomc. — Hydrocaulus attaining a height of about an inch and a
half, simple or with an occasional short branch, not fascicled. Hydrothecae
distant, each springing from a point close to the distal end of an internode,
tumid towards the base, much narrowed towards the orifice, slightly marked
with transverse corrugations on its upper side.

Gonosome not known.

Dredged southwest of Tortugas from a depth of CO fathoms.

Sertularella conica is a rather rigid species. It is distinguished from S.
poli/zonias by its nearly simple habit, by the greater distance of the hydro-
thec« from* one another, and by their more conical form, resulting from
their rapid narrowing towaids the orifice.

22 SERTULAliELLA GAYT.

Sertularella amphorifera.
PI XV. Figs. 8-10.

Trophosome. — Hydrocaiilus very slender, dichotomously branched; inter-
nodes long, attenuated, each carrying a hydrotheca near its distal end. Hy-
drothecae nearly cylindrical, deep, adnate to the internode for about their
proximal third, then becoming free and bending outwards ; margin with
three teeth, one internal and two lateral.

Gonosome. — Gonangia springing each from a point near the base of a
hydrotheca ; obovate, strongly annulated, rapidly narrowing to its point of
attachment, and terminating distally in a conical neck, which carries on its
summit a small circular orifice with everted margin.

Dredged off Double-Headed Shot Key from a depth of 471 fathoms.

Sertularella ampharifera is very closely allied to the S. tricuspidata of Alder.
It is destitute, however, of the two or three oblique annulations which at
intervals give to the stem in S. tricuspidata a twisted appearance, while
the disposition of the teeth of the hydrotheca is also different, there being
an anterior but no posterior tooth in Alder's species. Further, the gonangia
of the present species become much more rapidly narrow towards their
point of attachment, a condition which makes them closely resemble in
form the old Roman amphora.

The specimens in the collection were mere fragments, so that the full size
to which the sjjecies grows could not be ascertained. They were obtained
from the deepest dredgings of the exploration

Sertularella G-ayi viir. robusta.
PI. XV. Figs. 3-5.

I have assigned to the well-known species Sertidarella Gai/i the hydroid
here figured, which I regard as one of the many variations of that species,
from the typical form of which it differs in its more irregular ramification
and stouter habit. The specimens examined had attained a height of two
or three inches, and sprung from a hydrorhiza composed of a dense tow-
like mass of fine tubular filaments, formed by the disunion, free exten-
sion, and repeated division of the tubes which constitute the fascicled stem.

The valvular apparatus by which the orifice of the hydrotheca is closed
was well seen in some of the specimens, and the four bands by which the
valves are connected with the body of the hydranth were in some cases
visible (Fig. 4).

SERTULAEIA TUMIDA. 23

These bands, so far as I am aware, have not been hitherto described.
I have found them in many other Sertularidans, and they are especially
obvious in young hydrothecse. They are destitute of fibrillation, and appear
to consist of a cord of protoplasm enclosing nucleus-like bodies, and are
plainly intended to close the valves forming the operculum of the hydro-
theca during the retreat of the hydranth.

Specimens of the same variety, but in which the strong, robust habit
was still better marked, were dredged by the " Porcupine," in the eastern
parts of the North Atlantic*

Genus SERTULARIA Linn^us (in part).

Sertularia marginata.
PI XVI. Fi(/s. 1, 2.
Tropliosome. — Hydrocaulus attaining a height of about an inch, simple;
internodes elongated, attenuated below every pair of hydrothecoe. Hydro-
thecae opposite, deep, tubular, free, and divergent above for about three
fifths of their height, slightly tumid below ; orifice entire, with a broad rim
formed by close strias, which run in a circular direction round the distal
end of the hydrotheca.
Gonosome not known.

Dredged from a depth of 324 fathoms, off Florida Reef.

The species is remarkable for its distant pairs of long tubular hydro-
thecfe, with the orifice surrounded by a band of delicate circular striae.
The specimen is destitute of gonangia ; it is possibly immature, and may
become ramified before attaining its adult condition.

Sertularia tumida.

PI XVI. Figs. 3, 4.

Trophosome. — Hydrocaulus attaining a height of | of an inch simple ;
internodes of moderate length, thinning away for some distance below
each pair of hydrothecae. Hydrothecoe opposite, short, tumid below, adnate
to the stem for about half their length, and with the distal half free and
diverging at nearly a right angle.

Gonosome not known.

Tortugas, shallow water.

• See Report of the Hj droids collected during the Expeditions of H. M. S. Porcupine, Trans. Zobl. Soc.
London, 1873.

24 SERTULAPJA EXIGUA.

The present species resembles in its general habit Sertularia pumila,
and might, without examination, be mistaken for it. It is, however, dis-
tinguished from that species by its tumid hydrothecae, and by the wide
angle at which their distal portion diverges from the stem ; as well as
by the greater length of the internodes and consequent separation of the
pairs of hydrothecae.

No gonangia were present, and the specimen may not have attained
its full growth. In some of the hydrothecse the hydranths were fairly
preserved, and the opercular bands were recognizable.

Sertularia tubitheca.
PL XVI. Figs. 5, 6.

Trophosome. — Hydrocaulus attaining a height of upwards of an inch,
branched ; branches opposite ; internodes of moderate length, thinning away
below every pair of hydrothecae. Hydrothecje long, tubular, cylindrical,
free, and divergent for a little more than their distal half, with the orifice
circular, abruptly but slightly everted, and having close behind it an
annular ridge resembling the margin of a former orifice.

Gonosome not known.

Dredged from a depth of 16 fathoms at the Tortugas.

Sertularia tuhitheca is a small but elegant species. The double-lipped
condition of the hydrothecEe was constant in the specimens examined, and
seems due to the existence of an earlier orifice, to Avhich the present one
has succeeded. It is possible that indications of more than one such earlier
orifice would be found in older specimens.

Sertularia exigua.

Pi. XVI. Figs. 7, 8.

Trophosome. — Hydrocaulus minute, simple, attaining the height of about
^ of an inch ; internodes very short, not prolonged by an attenuated con-
tinuation below the pairs of hydrothecae. Hydrothecae opposite, not tumid
below ; free and divergent on their distal half, and with the opposed sides
of each pair parallel to one another.

Gonosome unknown.

Dredged off Cape Fear from a depth of 9 fathoms.

This little Sertularia might be mistaken for S. pumila ; unless, however,

DESMOSCYPHUS. • 25

the specimens are immature, and would have acquired a greater develop-
ment in their adult state, it is a much smaller form than S. pmnila. Fur-
ther, in S. pumila the opposed sides of the hydrotheca3 composing each
pair converge from above downwards, while in S. exigua they are parallel.

Sertularia distans.
PL XVI. Figs. 9, 10.
Trophosome. — Hydrocaulus attaining a height of about an inch, simple
or with an occasional branch ; internodes rather long and prolonged by an
attenuated extension below each pair of hydrotheca^. Hydrothecaj tubular,
with the distal half free and divergent, and the opposed sides of the proxi-
mal halves parallel.
Gonosome not known.

Dredged off Tennessee Reef from a depth of 21 fathoms.

This species bears considerable resemblance to ^S*. inanila, from which,
however, it differs in the much greater length of its internodes and con-
sequent distance of its pairs of hydrothecfe. The orifice of the hydrotheca
is cut off' obliquely above and below, so as to present two broad lateral
teeth, and the intervals between these are closed by two thin membra-
nous valves. Each of these valves is composed of delicate superimposed
lamina?, which may be usually seen partially separated from one another, as
thin exfoliating films.

The species resembles also S. gracilis Hassall in the length of its inter-
nodes, but it is a larger form.

In the absence of gonosome it is imj)ossible to approximate it closer
to any European form.

" DESMOSCYPHUS Allman nov. gen.

Generic Character. Trophosome. — Hydrocaulus jointed, each internode
corresponding to one or more pairs of hydrothecfe. Hydrothecfe adnate to
one another in pairs, each pair adnate to the side of the hydrocaulus.

Gonosome. — Gonangia simple, borne along the front of the hydrocaulus.

The genus Desmoscyphus was originally constituted for a hydroid from
the New Zealand shores.* It resembles most of the species of Thuiaria in
the extent to which the hydrothecse are adnate to the hydrocaulus, but it

* Allman on New (Jenera and Species of Hydroida, Journ. Linn. Soc. Zoology, Vol. XII.
4

26 DESMOSCYPHUS LONGITHECA.

differs from this genus in the fact that the hydrothecae are also adnate
to one another in pairs, and thus brought all to one side of the hydro-
caulus ; while a still further difference is found in the fact that the inter-
nodes may in some cases carry each a single pair of hydrothecffi, as in Ser-
tularia.

In the New Zealand species, Desmosci/phts BiisHi, the main stem is divided
into internodes of variable length, canying each a variable number of pairs
of hydrothecfB, while the branches are regularly divided into equal internodes
each with one pair of hydrothecae. In the species here described from the
Gulf Stream (Z>. longitheca), the entire hydrocaulus is regularly divided into
internodes, each carrying a single pair of hydrothecae.

Desmoscyphus longitheca.
PI. XIV. Figs. 3-6.

Trophosome. — Hydrocaulus attaining a height of about an inch, pinnately
branched ; pinnae alternate, much contracted at their origin ; main stem and
pinnsB divided into regular internodes, each internode carrying a single pair
of hydrothecaj. Hydrothecae long, tubular, with semicircular orifice, which
is closed by a valve-like lid ; along the branches and the greater part of
the main stem adnate to one another in pairs for nearly their entire height,
but becoming free and diverging from one another close to their distal ends;
towards the basal end of the stem the hydrothecae of each pair receding
from one another and ultimately disposed on two diametrically opposite
sides of the internode.

Gonosome not known.

Key West, shallow water.

Desmoscyphus longitheca constitutes an interesting transition form by which
the genus Desmoscyphus becomes connected with Sertularia. For while in
D. Buskii the branches alone are divided into equal internodes, each carry-
ing a single pair of hydrothecfe, the main stem being composed of internodes
of variable length, each with a variable number of hydrothecae, in the present
species both stem and branches possess the Sertularian character of division
into equal internodes, with a single pair of hydrothecfe upon each.

Further, in D. longitheca the hydrothecfB composing each pair, where they
approach the base of the main stem, begin to recede from one another, the
separation gradually increasing, until just above the hydrorhiza they are
situated upon opposite sides of their supporting internode exactly as in a

THUIAEIA PLUMULIFEEA. 27

true Sertularia ; while the resemblance of this part of the hydroid to a Ser-
tularia is further increased by the occurrence of a deep constriction be-
tween each internode.

Genus THUIAEIA Fleming.

Thuiaria distans.

PI. XVII. Figs. 1, 2.

Trophosome. — Stem attaining a height of about four inches, simple, non-
fascicled, sending off alternate pinna?, whicli extend from its distal end to
within a short distance of the base ; pinna? with transverse joints at distant
but uncertain intervals ; main stem with an oblique joint just above the
origin of each pinna. HydrothecfB distant, alternate, borne upon the stem
and pinna?, to each of which thej' are adnate for very nearly their entire
height; short, tubular, slightly enlarging upwards and bending outward,
with a somewhat wavy margin destitute of teeth, and with a narrow, though
distinct border.

Gonosome not known.

Tortiigas, shallow water.

Thuiaria distans is remarkable for the length of the intervals by which
the hydrothec* of each side are separated from one another. The inter-
nodes of the stem are regular in length, and support each three hydrothecae ;
those of the pinnse are irregular in length, and vary in the number of hydro-
thecae to which they give support.

The coenosarc of the stem is canaliculated.

Thuiaria plumulifera.

PL XVII Figs. 3-6.

Trop/iosome. — Stem attaining a height of about six inches, slender, flexile,
emitting numerous pinnate branches which are disposed from distance to
distance rather irregularly on all sides of the stem, and which carry the
hydrothecae both upon their axis and pinnse ; pinnse alternate, much con-
tracted at their origin. Hydrotheca? alternate, deep, adnate for nearly their
entire length ; orifice with two strong, broad teeth, beyond which the walls
of the hydrothecae are continued as a thin, membranous, collapsible tube.

Gonosome not known.

Dredged off Cape Fear from a depth of 9 fathoms.

28 THUIARIA SERTULAEIOIDES.

Thtiiaria phtmiilifei-a has a good deal of the habit of Hi/dralhnania falcata.
The pinna-bearing branches are regularly divided into equal internodes,
each internode carrying three hydrothecte and giving off a pinna from
alternate sides just above its proximal end. The pinnae are much contracted
at their origin, and united to the branch which carries them by a very short,
nearly globular internode. The- joints of the pinnae are at distant and
uncertain intervals.

The hydrothecaa at their distal ends are thin and collapsible, so that it
was very difficult to determine the true form of the orifice. In some cases,
however, where the parts were well preserved, it could be seen that the
thin collapsible portion was a tubular prolongation of the walls beyond
the true orifice, which was provided with two strong, broad lateral teeth.

The gonangia had all fallen, but the indications of their attachment
were visible just below many of the hydrothecae.

Thuiaria pinnata.
PI. XV. Figs. 1, 2.

Trophosome. — Stem attaining a height of nearly three inches, sparingly
branched, fascicled below, alternately pinnate ; pinnjB given off at nearly
right angles to the stem, jointed at distant and imcertain intervals.
Hydrothecaj borne both by stem and pinnte, deep cylindrical with
obscurely 4-toothed mai'gin, adnate to the axis in their whole length.

Gonosome not known.

Double-headed Sliot Key from a depth of 3 to 4 fathoms.

Thuiaria pimiaia is a strong, rather rigid form, rendered somewhat
striking by the very open angle at which the pinna? are given off from
the stem. Some of the hydranths were well preserved in the speci-
men, and it would appear that they are capable of extending them-
selves far beyond the orifice of the hydrotheca.

Thuiaria sertularioides.

PI. XVI. Figs. 11, 12.

Trophosome. — Hydrocaulus attaining a height of three inches, slender
cylindrical, sending off short, simple branches which spring from the
anterior aspect of the axis. Hydrotheca? opposite, with the distal half
free and divergent, gradually narrowing from the base to the orifice,

PLUMULAEIA FILICULA. 29

which is obliquely cut above and below so as to present two broad
lateral teeth.

Gonosome not known.

In its opposite hjdrothecte adnate to the axis for only half their
height, and disposed in distant pairs, this hydroid has so much of the
aspect of a Sertularia that it might at first sight be easily referred
to that genus. The fact, however, that the pairs of hydrotheca? are not
separated from one another by a joint removes it from Sertularia, and
notwithstanding the freedom of the hydrothecse for so considerable a
portion of their height, brings it into the genus Thuiaria.*

It is a slender form, with a somewhat rigid habit which it would seem
to owe to the non-jointed condition of the axis.

Family PLUMULARIDiE.

Genus PLUMULARIA, Lamarck (in part).

Plumularia filicula.
PL XV III. Figs. 1, 2.

Trophosome. — Hydrocaulus attaining a height of about two inches, simple
or with an occasional branch close to the root, not fascicled ; pinna) alter-
nate, one borne by each internode of the stem, immediately below a joint,
where it is supported on a long process of the internode ; proximal inter-
node of thepinnsB short and destitute of hydrotheca; following internodes
elongate, every alternate one carrying a hydrotheca, the hydrotheca-bearing
internodes slightly longer than the intervening ones. Hydrotheca3 small,
each borne near the middle of its supporting internode. Supracalycine
nematophores large ; a single mesial nematophore borne by the hydrothecal
internode at the proximal side of the hydrotheca, two by each of the inter-
vening internodes, and a single one by the short proximal internode.

Gonosome. — Gonangia elongate, oval, smooth, narrowed below into a

* I regard the presence of a joint at regular, intervals between every two or every two pairs of hydro-
thecEe as an essential character of the true Sertularidans (_ Sertularia, Sertularella, Diphasia) quite irrespec-
tively of the extent to which the hydrothecae are adnate to the hydrocaulus. In Thuiaria, on the other
hand, the joints occur at distant, and for the most part irregular intervals, thus allowing numerous hy-
drotheca to follow one another without any intervening joint. See Journ. Linn. Soc. Zoology, Vol. XII.
p. 267.

30 PLUMULARIA ATTENUATA.

short peduncle, by which they sprnig from the axils of the pinnte, open-
ing on the summit by a wide oblique aperture.

Off Alligator Reef, from a depth of 88 fathoms.

This species grows in tufts, numerous undivided stems springing from
a common base. It is of a rather rigid habit; the pinnre are close set;
besides the nematophores of the pinnae we find on each internode of the
stem two large, alternately placed, solitary nematophores, and two pairs
of nematophores which are borne by the lateral process on which the
hydrothecal ramulus is supported.

Plumularia macrotheca.
PI. XVIII. Figs. 3, 4.

Trophosomc. — Hydrocaidus attaining a height of about two inches, simple,
fascicled, springing from an entangled mass of fine tubular filaments; pinnae
very slender, alternate, composed each of a succession of long internodes
alternating with short ones, each of the long internodes bearing a hydro-
theca. Hydrothecte deep, tubular, with very slightly everted margin.
Supracalycine nematophores springing each from a short process which pro-
jects from the long internode, just below the margin of the hydrotheca,
one mesial nematophore carried by the same internode at the proximal
side of the hydrotheca, and another on each of the short internodes.

Gonosome not known.

Off Cojima, Cuba, from a depth of 450 fathoms.

Phmmlaria macrotheca is remarkable for its long narrow hydrotheca}.
Its very slender pinnae are rather widely set upon the stem, which is fas-
cicled, and, like other fascicled stems, resolves itself below by the separation
of its comjjonent tubes into a loose plexus of hydrorhizal filaments.

Plumularia attenuata.
PI. XVIII Figs. 5, 6.

Trophosome. — Hydrocaulus branched, fascicled below ; piiuite alternate,
each arising from a point of the stem close to the distal end of an inter-
node; internodes of pinnae elongated, becoming abruptly slender in the
distal two thirds of their length. HydrothecJB small, borne by the thicker
basal portion.

Supracalycine nematophoi'es springing from tooth-like processes which

PLUMULARIA MEGALOCEPHALA. 31

flank the hy(]i'otheca on each side ; mesial nematophores, one at the distal
and one at the proximal side of each hydrotheca.
Gonosome not known.

Off Boca Grande, from a depth of 105 fathoms.

The abruptly attenuated distal portion of the internodes of the pinnae
is sufficient to distinguish this species. The internodes of the stem are
short, and the pinnae are in consequence close set, resembling in this respect
those of P. filicvla. In the stem each internode carries two nematophores
which are placed laterally and alternately, and one pair of nematophores
which is borne by the lateral process.

Plumularia megalocephala.
PL XIX. Figs. 1, 2.

Tropliosome. — Hydrocaulus irregularly branched, not fascicled ; pinnte
alternate, each borne close to the distal end of an internode of the stem,
where it is supported on a long stout process of the internode ; proximal
internode of pinna short and destitute of hydrotheca; following inter-
nodes longer, every alternate one carrying a hydrotheca, and slightly
longer than the others. Hydrothecae small and shallow, each borne near
the middle of its internode, and supporting a very large hydranth. Besides
the supracalycine pair of nematophores, each hydrotheca-bearing internode
carrying a single mesial nematophore at the proximal side of the hydro-
theca ; intervening internode carrying two mesial nematophores, and short
basal internode carrying one.

Gonosome not known.

Off Alligator Reef, from a depth of 14 fatliouis.

The specimens from which the description has been written were im-
perfect, and the height to which they had attained could not be determined
with certainty, but it was probably about two inches. The internode
intercalated between the hydrotheca-bearing internodes was sometimes
present, sometimes absent, and was of variable length. The internodes
of the stem carry two nematophores placed laterally and alternately, and
one or two pairs on its lateral process.

Some of the hydranths in the specimens were sufficiently well preserved
to afford a sketch of their outline. They are of enormous size in com-
parison with the hydrothecas, into which they could never have been
retracted. The very large pear-shaped body was supported on a slender
stalk, the only part which lay within shelter of the hydrotheca.

32 HALOPTETtlS.

Flumularia geminata.
PL XX. Fiffs. 1-4.

Troj)hosome. — Stem attaining a height of about one inch, dichotomously
branched ; internodes towards the distal extremity of the branch alternately
longer and shorter ; each shorter internode carrying near its middle a
hj'drotheca, on each side of which springs an ultimate ramulus, also com-
posed of alternately longer and shorter internodes ; each shorter one
carrying a hydrotheca. Hydrothecte campanulate with slightly everted
niai'gin, free for about its distal half Lateral nematophores borne each
on a strong tooth-like process of the internode ; mesial nematophores
carried upon both the hydrothecal and the intervening internodes.

Gonosome. — Gonangia pyriform, borne on short two-jointed peduncles
which sj^ring from the mesial line immediately below the hydrotheca, the
narrow proximal end of the gonangia carrying a nematophore on each
side.

Off' Sand Key, from a depth of 120 fathoms.

Plmmtlaria geminata is a very remarkable form ; the ultimate ramuli given
off in regular pairs from the principal branches confer upon it a very
striking aspect. All these pairs of I'amuli are directed towards one side
of the branch from which they spring. The proximal joint of each hydro-
theca-bearing internode in the ultimate ramuli is very oblique, the distal
one transverse. This internode carries a single mesial nematophore, which
is situated at the proximal side of the hydrotheca, while each intervening
internode of the ramulus carries three. In the main branches each hydro-
theca-bearing internode carries also a nematophore at the distal side of
the hydrotheca, while four nematophores are borne on every intervening
internode.*

HALOPTERIS Allman nov. gen.

Generic Character. Tropho.wme. — Hydrosoma pinnate plumose; stem
and pinna3 divided into internodes. H^'drothecEe adnate to side of pinnte,
imilatei-al. A pair of nematophores flanking the hydrotheca, one on
each side, and adnate to it. Mesial nematophores two (or more), not
adnate to the hydrotheca, fixed, monothalamic, with an oblique aperture
continued into a lateral slit.

Gonosome not known.

* See Addenda, p. 56.

HALOPTERIS CARINATA. 33

The genus Halopteris constitutes an intermediate form between Aglao-
phenia and Plumularia. To Aglaophenia it shows an affinity by its
paired nematophores being adnate to the hydrothecte, and by its fixed
monothalamic mesial nematophores with slit-like aperture. To Plumularia
it is connected by having more than one azygous nematophore seated
on each internode of the pinnae, and all at a distance from the hydro-
theca, by the wide separation of the hydrothecje from one another, and
by their even margin.

Halopteris carinata.

PL XIX. Figs. 3-7.

Trophosome. — Hydrocaulus attaining a height of about two inches,
simple, non-fascicled ; pinnae alternate, springing one from each internode
of the stem, near its proximal end ; internodes of pinna3 separated from
one another by oblique joints, each carrying a hydrotheca near its mid-
dle. Hydrothecse very large, adnate to internode for about two thirds of
their height, and then becoming free, deep, nearly cylindrical in lateral
aspect, infundibuliform in front aspect, margin even, with a slightly
prominent cusp in front, from which a slight keel is continued for some
distance along the front of the hydrotheca. Lateral nematophores in
the form of a long tubular stalk which springs from the internode at
a point near its middle, and thence passing obliquely across the side of
the hydrotheca, reaches the margin, where it terminates in a cup-like
dilatation. Mesial nematophores free, fixed by a narrow base, two on
each internode, one being just below the hydrotheca, and one at a
little distance above it.

Gonosome not known.

Off Carysfort Reef, from a depth of 35 fathoms.

This is a remarkable hydroid, rendered striking by its long tubular lat-
eral nematophores, and by the peculiar form and large size of its hy-
drothecae. The stem carries between the pinnae longitudinal rows of
short fixed nematophores whose oblique aperture is continued into a
lateral slit. Though the mesial nematophores of the pinnae are attached
by a narrow base, they are firmly fixed, thus, along with the nemato-
phores of the stem, contrasting with the movable and easily detached
nematophores of the true Pluuuilaria\ In this respect, and in their
oblique and slit orifice, they resemble the nematophores of Aglaophenia.

34 AKTENNOPSIS.

Genus ANTENNULARIA Lamarck.

Antennnlaria simplex.

PL XXI. Figs. 1, 2.

Trophosome. — Hydrocaulus attaining a height of about three inches,
simple ; verticils closely set, each composed of about five ramuli ; ramuli
borne each on a stout process from the stem, and composed of long,
nearly equal internodes, every internode carrying a hydrotheca near its
proximal end. Hydrothecfe small, campanulate, flanked on each side by
a short tooth-like process from the internode. Supracalycine nemato-
phores borne on the tooth-like processes ; two mesial nematophores on
each internode, one at the proximal and another at the distal side of
the hydrothecre ; a pair of nematophores borne on the basal process and
single nematophores scattered over the common stem.

Gonosome not known.

Off Alligator Reef, from a depth of 86 fathoms.

The present species comes very near to Anteimularia ramosa, from
which, however, it difiers in its simple habit, and iu the position of
the hydrothecoe, which are here situated further towards the proximal
end of each internode.

ANTENNOPSIS Allman nov. gen.

Genekic Character. Trophosome. — Stem jointed, sending off scattered
jointed ramuli which carry the hydrothecfe. HydrothecsB with entire
margin, unilateral, associated with a pair of movable supracalycine nemato-
phores and Avith movable azygous nematophores borne along the hydrothecal
side of the ramuli.

Gonosome. — Gonangia not protected by corbulae or other appendages.

The genus Anteniiopsis differs from Antennularia, to which it is closely
allied, by the scattered disposition of its ramuli, which in Antennularia
are verticillate.

In all the species of Antennularia which I have examined, the coeno-
sarc is canaliculated in the stem, the hydrosomal cavity being there
represented by a network of intercommunicating canals. In Antennopsis
hippiiris the hydrosomal cavity is of the ordinary simple type, but we do
not yet know enough of the species which may compose the genus
Antennopsis to enable us to regard this as a true generic character.

HIPPURELLA. 35

Another feature in which Antennopsis hippuris differs from the species
of Antennularia consists in the absence of the tow-like mass of fila-
ments which forms the hydrorhiza of the various species hitherto referred
to the latter genus, the place of these entangled filaments being here
taken by a small knot of free tubular fibres.

Antennopsis hippuris.
PL XXL Figs. 3, 6.

Trophosome. — Hydrocaulus attaining a height of about two inches, spring-
ing from a cluster of distinct tubular fibres ; stem simple, non-fascicled,
divided into rather short internodes ; ramuli slender, supported each by
a thick process of the rachis which is given off" from all sides irreg-
ularly, every alternate internode of the ramulus supporting a hydrotheca.
Hydrothecae small, cup-shaped. Hydrothecal internodes carrying besides
the supracalycine nematophores two mesial nematophores, one at the
proximal and one at the distal side of the hydrothecte ; intervening
internodes with two mesial nematophores.

Gonosome. — Gonangia shortly pedunculate, borne singly in the axils
of the ramuli ; male ? elongated oval, with an oblique terminal orifice ;
female ? slipper-shaped with the distal end curved over to one side,
and with a sub-terminal orifice.

09' Double-Headed Shot Key, from a depth of 195 fathoms.

Antennopsis hippuris is a small and rather delicate species. Like almost
every other hydroid, it is dioecious, and the collection contains specimens
of each sex, which differ from one another considerably in the form of
the gonangia. The contents of the gonangia were not well enough pre-
served to enable their nature to be determined, and it is therefore with
hesitation that, guided by the analogy of some other forms, I have
regarded the long oval gonangia as male, and the shorter slipper-shaped
ones as female.

HIPPURELLA Allman nov. gen.

Generic Character. Trophosome. — Hydrocaulus branched, ultimate
ramuli pinnate on the proximal portion of the branches, but distributed
on all sides towards their distal extremities. Hydrothecae borne on the
ultimate ramuli, unilateral, with entire margin, associated with a pair of

36 MONOST^CHAS.

supracaljcine nematophores, and with azygous nematopbores along the
hydrothecal side of the ramulus.
Gonosome not known.

The genus Hippurella unites in itself the characters of a Plumularia
and of an Antennularia or Antennopsis. Indeed, the genera Plumularia,
Antennularia, Antennopsis, and Hippurella differ from one another mainly
in the disposition of the ultimate ramuli. The characters thus afforded
have long been recognized as of generic value in the separation of
Antennularia from Plumularia, and the application of the same principle
to other forms necessitates the construction of Antennopsis and Hippurella
as legitimate genera.

Hippurella annulata.

PI XXL Fiffs. 7, 8.

Tropkosome. — Hydrocaulus attaining a height of about three inches,
springing from a dense bundle of tubular filaments, fascicled throughout
the main stem, which sends off numerous non-fascicled branches, which
are pinnately disposed below, but given off irregularly towards the distal
end of the hydrocaulus; ultimate ramuli alternate and pinnate towards
the proximal ends of the branches, but towards the distal ends surround-
ing the branch on all sides, and hei'e either scattered or regularly verticil-
late ; each composed of alternate long and short internodes with inter-
vening groups of A'ery short ring-like internodes, each of the long internodes
carrying a hydrotheca. Hydrothecaj deep, thimble-shaped, with slightly
everted margin. Besides the supracalyciue pair of nematophores, there
are two mesial nematoj)hores, borne by the ramulus, between every two
hydrothecae.

Gonosome not known.

Off Pacific Keef from a dfpth of 283 fathoms.

The species is rendered striking by the large size and deep thimble-
shaped form of its hydrothecae, and by the annulation, at intervals, of its
ultiuiate ramuli.

MONOST^CHAS Allman nov. gen.

Generic Character. Trophosome. — Stem branched ; hydrothecal ramuli
confined to one side of their supporting branches. Hydrothecse unilateral

MONOSTiECHAS DICHOTOMA. 37

with entire margin, associated with a pair of supracalycine nematophores,
and with free mesial neinatophores.

Gonosome. — Gonangia not contained in corbuljB, or connected with special
branches.

The unilateral disposition of the hydi'othecal or ultimate ramuli on the
main branches is very remarkable, and, being absolutely constant, becomes
a character of generic value.

Monostaechas dichotoma.
PL XXII. Figs. 1-5.

Tropkosome. — Hydrocaulus attaining a height of about an inch and a half,
pellucid, dichotomously branched ; every alternate internode of the hydro-
thecal ramuli carrying a hydrotheca and separated from the others by a
transverse distal joint, and a very oblique and more strongly marked
proximal one. Hydrothecte rather large cup-shaped, flanked on each
side by a prominent tooth-like process of the internode. Supracalycine
neniatojjhores borne by the tooth-like processes, one mesial nematophore
borne by the hydrotheca-bearing internode at the proximal side of the
hydrotheca, and two by the intervening internode ; numerous nemato-
phores borne in a single series along the opposed sides of the bifurcate
ing branches.

Gonosome. — Gonangia pyriform, contracted below into a short stalk, Avhich
springs from a slightly prominent process of the internode, just below the
base of the hydrotheca, and carries a nematophore on each side of it.

Off Pacific Reef, from a depth of 283 fathoms.

The present species closely resembles, in several important characters,
the Plmmlaria catharina of Johnston. In the form and position of the
hydrothecae, in the internodes and nematophores of the ultimate ramuli,
and in the form and position of the gonangia, the resemblance is so close,
even in minute details, that it is impossible to find in these parts any
characters by which the one hydroid can be distinguished from the other.

It is entirely different, however, with the ramification of the species for
which I have here founded the genus Monost^chas. This ramification is
of a very remarkable kind, so much- so, indeed, that I regard it as affording
a character of generic value. It has not only no resemblance to that of
Plumularia catharina, but belongs to a type which has no representative
in any other known Plumularidan.

38 ANTENNELLA GRACILIS.

ANTENELLA Allman nov. gen.

Gekeric Character. — Trophosome. — Hydrocaulus consi.sting of simple
steins, which spring from a congeries of tubular filaments ; stems divided
into internodes, destitute of pinnae, and directly bearing the hydrothecse.
HydrothecjB with entire margin. Neraatophores free and movable.

Gonosome not known.

If in a true Plumularia the rachis had never been developed, and the
pinnae had thus come to stand immediately on the hydrorhiza, we should
have a form with the essential characters of Antennella.

Antennella gracilis.
PI. XXII. Fiffs. 6, 7.

Trophosome. — Hydrocaulus attaining a height of about an inch, simple
or with an occasional divisiou near its base, springing in dense tufts from
a mass of creeping, tortuous, inosculating, and entangled filaments, divided
into internodes by very oblique joints, and with an intervening obscure hori-
zontal joint, also generally apparent. Hydrothecne borne along the hydro-
caulus from its distal end to within a short distance of its base, rather large,
cylindrical, deep, with a circular margin, free for about half their height.
Supracalycine nematophores borne each on the extremity of a long hollow
process which flanks the hydrotheca on each side ; mesial nematophores
usually four between every two hydrothecos.

Gonosome not known.

Dredged off Caiysfort Reef from a depth of GO fathoms.

A form nearly allied to the Antennella gracilis of the present Report has
been dredged off the British coast by Hincks, who regards it as a variety
of Plumulana cidharina Johnston, and believes it to be identical with the
Antemmlaria cijathifera of Dana, and with the Sertularia secundaria of Cavolini.
That all these belong to the form for which I have constituted the genus
Antennella, there can, I think, be little doubt.

Throughout that section of the Plumularidae which is characterized by
its movable nematophores, and of which Plumularia setacea may be taken
as the type, the modifications of ramification as expressed in the disposition
of the hydrothecal or ultimate ramuli admit of being thrown into a series
whose members present a definite relation to one another.

Taking as our point of departure such forms as Plumularia setacea of

AGLAOPHENIA RAMOSA. 39

the European shores or P. filicula, etc. of the present Report, we find that
the hydrothecal ramuli are given off on two opposite sides of the simple or
branching stem from which they spring with a regularly alternate arrange-
ment. In P. catharina the hydrotliecal ramuli, instead of being alternate,
are exactly opposite. In P. geminata, while the points of origin of these
ramuli are opposite to one another, as in P. catharina, the ramuli themselves
are all directed to one side, and thus lie in unilateral pairs along the sup-
porting branch. In the genus Monostsechas, as represented by the single
species M. dichotoma, the main stem is dichotomously branched, and every al-
ternate prong of the forks gives off — from one side only — the hydrothecal
ramuli. In Antennella the whole of the main stem has disappeared, and the
hydrothecal ramuli come to be borne directly on the hydrorhiza.

Again, in Antennularia the hydrothecal ramuli are disposed in regard-
verticils along the stem. In Antennopsis they also surround the stem,
but instead of being disposed in verticils they are scattered. What An-
tennularia is to P. catharina with its opposite distichous ramuli, Anten-
nopsis is to P. setacea with its alternate distichous ramuli. Finally, in
Hippurella we have a transition between the alternate and distichous
ramuli of P. setacea and the scattered ramuli of Antennopsis or verticillate
ramuli of Antennularia ; the proximal parts of the branches having their
hydrothecal ramuli disposed as in P. setacea, while towards the distal
extremity these ramuli become scattered as in Antennopsis or verticillate
as in Antennularia.

Each of these modifications is in itself so well marked that it may be
justly taken as characterizing a distinct specific form, or, in some cases, even
a generic group. Any one of them, however, may be regarded as an easily
understood derivation from others, while all may obviously have descended
from a single ancestral form

Genus AGLAOPHENIA Lamourotjx (in part).

Aglaophenia ramosa.

PL XXIII. Figs. 1-4.

Trophosome. — Hydrocaulus attaining a height of about six inches, sub-

dichotomously branched, fascicled in main stem and branches, and becoming

monosiphonic only near the distal ends ; pinniB given off at an acute angle

from the anterior aspect of the branches ; internodes of rachis with a

40 AGLAOPHEXIA RHYNCHOCARPA.

strongly marked septal ridge on a level with the intrathecal ridge, and
with a less distinct one at the base of the snpracalycine nematophores.
HydrothecaB deep, with strongly dentate oblique margin, and with the
intrathecal ridge extending obliquely upwards across the entire width of
the hydrotheca. Snpracalycine nematophores strong, overtopping the
hydrotheca ; mesial nematophore attaining nearly the level of the margin
of the hydrotheca, and adnate to it for nearly its entire height ; cauline
nematophores forming a longitudinal series on front of the stem.
Gonosome not known.

Florida Reef, from a depth of from 2 to 3 fathoms.

This is a tall-growing species, with a loose, somewhat straggling habit.
In the absence of all knowledge of the gonosome, its reference to Aglao-
phenia is only provisional.

Aglaophenia rhynchocarpa.
PL XXIII. Figs. 5-8.

Trophosome. — Hydrocaulus attaining a height of about two inches,
non-fascicled, simple, springing in dense plumose tufts from a network
of tubular fibres; internodes of pinnae divided transversely by three or four
strongly marked imperfect septa. Hydrothecre incurved in front, margin
deeply dentate with the anterior tooth strong and bifid ; intrathecal ridge
well marked, stretching obliquely upwards across the entire width of the
hydrotheca. Snpracalycine nematophores slightly overtopping tlie margin
of the hydrotheca; mesial nematophore adnate for nearly its entire length
to somewhat less than the proximal half of the hydrotheca.

Gonosome. — Corbula"! closed, with the rachis continued beyond the distal
end in the form of a beak ; leaflets each with a strong process at its base
directed outwards and . iwards the distal end of the corbula; nematophoral
ridges not rising in p.'ominent crests.

Key West, Triangle Shoal, 3 to 4 fathoms.

This is a very beautiful species, and presents several well-marked char-
acters. The hydrothecje are rendered striking by their rather prominent
base giving rise to a sinus-like depression of the anterior wall, and by
the bifid anterior tooth of the margin. It is, however, in the corbula that
the most marked characters are to be found. The prominent beak-like
distal exten.sion of the rachis forms a striking feature, while the processes

AGLAOPHENIA APOCARPA. 41

which the leaflets of the corbula give oflF at their base form a series of
pinna? upon each side of the rachis, very obvious when the corbula is viewed
either from above or below. These pinnte-like processes carry nemato-
phores along their upper side, and when viewed from below are seen to
send off a somewhat triangular, flat, wing-like expansion from the lower.
The beak-like extension of the rachis carries also on its upper surface
nematophores which are disposed in two pairs. The peduncle of the cor-
bula carries a single hydrotheca.

Aglaophenia lophocarpa.
PI XXI r. Figs. 1-4.

Trophosome. — Hydrocaulus attaining a height of between two and three
inches, simple, not fascicled ; pinna? alternate, springing from a point near
the distal end of each internode. Hydrotheca? deep, somewhat tumid below,
margin slightly everted, with nine equal very distinct teeth ; intrathecal
ridge transverse. Siipracalycine nematophores slightly overtopping the
hydrothecie ; mesial neraatophore adnate to within a very short distance
of its summit, and attaining nearly half the height of the hydrothecas ;
cauline nematophores two on each internode of main stem, one close to the
axil of the pinna and the other near the proximal end of the internode.

Gonosome. — Corbula with about ten pairs of leaflets ; leaflets broad,
united into a completely closed corbula, the distal margin of each carry-
ing numerous well-developed denticles, and projecting from the sides of
the corbula in the form of a pectinated ridge which is continued as a
free serrated crest beyond the roof; a spur-like denticle at the base of
each leaflet ; peduncle of corbula carrying a single hydrotheca.

Off Tortugas, from a depth of 68 fathoms.

The corbula of this species, with its pectinated ridges and crests, is a very
beautiful object, and affords a well-marked specific character.

Aglaophenia apocarpa.
PI XXIV. Figs. 5-9.
TropJiosome. — Hydrocaulus attaining a height of about two inches,
simple, not fascicled ; pinnse alternate ; internodes of pinnae somewhat
bent backwards at their proximal end so as to give rise to a slight
angular bend at the point of junction of every two internodes. Hydro-
thecas deep ; margin with about nine deeply cut teeth, slightly everted ;

42 AGLAOPHENIA GRACILIS.

intrathecal ridge transverse. Supracalycine nematophores stout, slightly
overtopping the hydrotheca ; mesial nematophore attaining nearly half
the height of the hydrotheca, adnate for nearly its entire length ; two
canline nematophores on each internode of stem, one of which is situated
close to the axil of the pinna, and the other near the distal end of
the internode.

Gonosome. — Corbula with about ten pairs of leaflets ; leaflets quite free,
narrow, with denticles nearly equally developed on each edge and with
a spur-like denticle at its base ; peduncle of corbula carrying a single
hydrotheca.

Off Sand Key, from a depth of 1 00 fatlioms.

In its trophosome this species comes very near to Aglaophenin lophocarpa.
It diflers from it, however, in the occurrence of a slight angular bend be-
tween every two internodes of the pinnae, and more especially by its open
corbula3.

There can be little doubt that the open condition of the corbute is
not here the result of an immature state of these bodies. Like a similar
condition of the corbulas of other species, it is of considerable morpho-
logical interest as a persistent state of a condition elsewhere transitory.

The nature of the denticles along the edges of the leaflets is very
obvious in this species. They are plainly seen to be nematophores of
the ordinary Aglaophenian type. Their cavity communicates by an apei'-
ture in the base with the interior of the leaflet, and through this
aperture their contents become united with the coenosarc of the leaflet.
The coenosarc does not uniformly fill the leaflet, but is disposed in the
form of a loose, irregular network of intercommunicating channels.

Aglaophenia gracilis.
PL XXV. Figs. 1-4.

Trophosome. — Hydrocaulus attaining a height of about three inches,
sparingly branched, not fascicled ; pinna3 alternate, springing from a point
near the distal end of each internode ; internodes of pinnae with two
strong but short septal I'idges, one on a level with the short, strong
intrathecal ridge, the other on a level with the base of the supracaly-
cine nematophore. Hydrothecae deep, slightly widening towards the
orifice, with strongly toothed margin ; intrathecal ridge strong and short.

AGLAOPHENIA RIGIDA. 43

situated near the bottom of the hydrotheca. Supracalycuie nemato-
phores scarcely overtopping the hydrotlieca ; mesial nematophore adnate
to less than half the height of the hydrotheca, and with a short, free
extremity ; cauline nematophores two on front of each internode of the
stem, one of these close to the axil of the pinna, and the other near to
the proximal end of the internode.
Gonosome not known.

Off Carysfort Reef, from a depth of 52 fathoms.

This species comes very near to Aglaophenia rigida in the form of
its hydrothecte. The hydrothecal internodes, however, are longer and
narrower than in that species. A. rigida, moreover, is a much more
I'amified and a taller form.

Aglaopbenia rigida.
PL XXV. Figs. 5-9.

Trophosome. — Hydrocaulus attaining a height of about nine inches,
springing from a mass of tortuous filaments, non-fascicled, slender, wiry,
much branched towards the distal ends of the stems ; branches given
off from a point on the anterior side of the stem, from which they
frequently spring in pairs ; plnniB alternate, springing from a point
a little below the distal end of each internode ; hydrothecal inter-
nodes short, each with two short septal ridges. Hydrothecae closely set,
deep, slightly widening towards the orifice, and with strongly toothed
margin. Supracalycine nematophores slightly overtopping the hj^dro-
theca ; mesial nematophore adnate to about half the height of the
hydrotheca and terminating in a short, free extremity.

Gonosome. — Corbulte completely closed, long, nearly cylindrical, with
about fourteen ridges rising into slightly prominent crests ; denticles of
ridges cup-shaped, with the basal one in the form of a tubular diver-
gent spur.

Off Cape Fear, from a depth of 9 fathoms.

The pinnae appear to be easily detached in this species, for most of
the specimens were nearly destitute of them, and presented little more
than a cluster of long, naked, wiry stems.

The ramification is peculiar, the branches springing from the anterior
side of the stem, where each is usually accompanied by a second from

44 AGLAOPHENIA DISTAIS^S.

the same point of origin, the twin branches then directing themselves
forwards and remaining nearly parallel to one another.

The hydrothecas are so closely set that the summit of each is on a
level with the base of the next above it.

This species closely resembles the preceding, A. gracilis, of which it
may possibly be regarded as a variety.

Aglaophenia distans.
PL XXVI. Figs. 1-8.

Trophosome. — Hydrocaulus attaining a height of about four inches, sim-
ple, rooted by an entangled bunch of tubular filaments, fascicled below,
becoming non-fascicled above, and here divided into equal internodes,
each of which carries a pinna on alternate sides ; pinnae distant, attain-
ing the length of nearly an inch. Hydrothecce deep, nearly cylindrical
above, narrowed below ; margin crenate, with a single long tooth-like process
in front ; intrathecal ridge not conspicuous. Supracalycine nematophores
not overtopping the hydrotheca ; mesial nematophore attaining about a
third of the height of the hydrotheca, to which it is adnate for its entire
length.

Gonosome. — Corbulje composed of niunerous pairs of ribs, which are
quite free from one another, each carrying a small hydrotheca near its
origin, and having numerous tooth-like nematophores along its distal
edge ; peduncle of corbula rather long, cai'rying three hydrothecre.

Dredged oif Pacific Reef, from a depth of 283 fathoms.

The present species is rendered very distinct by the long tooth-like
process on the front margin of the hydrotheca, and by its remarkable
open corbula?. The form of the hydrotheca is not absolutely constant,
and occasionally there may be seen on the same pinna with the ordi-
nary form others in which the narrowing of the hydrotheca towards
the base is much less marked. (Fig. 4.)

The corbula?, which closely resemble those of Aglaophenia bispinosa, are
in the highest degree instructive, and afford a beautiful example of
morphological transformation. Like the corbul^e of other species they
are metamorphosed pinnie, but the change here undergone is of such a
character as to bring out very distinctly their true morphology. The
pinna (Fig.) 7, which is here to become a corbula, retains nearly its ordi-

AGLAOPHENIA SIGMA. 45

nary form for some distance from its origin. It is, however, somewhat
more attenuated, while its hydrothecte are sHghtly smaller than in the
ordinary pinna?. In the specimens examined these hydrothecaj were three
in number, and the first and third internode carried each a small accessory
mesial nematophore (not represented in the figure) at the proximal side of
the principal one. After the third internode the pi'incipal transformation
of the pinna suddenly commences and continues to its distal end.

This transformation consists in the liydrothecae ceasing to be adnate
to the rachis of the pinna?, and becoming elevated on short stalks while
they become at the same time approximated and thrown alternately to
the right and left, so that the pinna carries now two alternate rows
of short processes, each bearing a little cup similar to that of the ordi-
nary hydrotheca except in being somewhat smaller.

With the elevation of the hydrotheca above the level of the rachis
the supracalycine and mesial nematophores are carried up with it (Fig. 8).
The former (b) retain nearly their ordinary shape and size, but the mesial
nematophore (c) becomes enoi'mously developed, being not only greatly
increased in length, but becoming broad, flattened, and somewhat sabre-
shaped, while a row of small tubular nematophores is developed along
the distal edge of each, as well as along the proximal edge of the stalks
(a) which cany them.

It is the mesial nematophores thus singularly transformed which
mainly constitute the ribs which form the sides of the corbula. Be-
tween these and the mesial nematophores of the proximal portion of
the pinna, which remains nearly unaltered, there is no gradual transition,
but it is interesting to note that the internodes of tliis part of the
pinna differ from those of the ordinary pinnte in carrying a small acces-
sory mesial nematophore, which is repeated and multiplied on the short
stalks which form the bases of the ribs in the corbula.

The joints, which are very distinct in the proximal portion of the
pinna, become obsolete in the corbula.

Aglaophenia sigma.

Fl. XXVI. Figs. 9, 10.

Trophosome. — Hydrocaulus attaining a height of about six(?) inches,
simple, fascicled almost to the tip ; pinnae alternate, with their origin
from the front aspect of the stem. Hydrothecag deep, nearly cylindrical,

46 AGLAOPHENIA BISPINOSA.

with the margin cut into rather shallow teeth, and with the cavity dividecl
into a distal and proximal portion by a distinct intrathecal ridge of a
sigmoid form. Supracalycine nematophores not overtopping the hydro-
tlieca ; mesial nematophore adnate to the proximal fourth of the hydro-
theca, becoming free only close to its point.
Gonosome not known.

Dredged off Alligator Reef, from a depth of 110 fathoms.

The remarkable sigmoid form of the intrathecal ridge constitutes a
very distinctive character of this species. Another striking feature is
found in the numerous well-marked septal ridges by which the inter-
nodes of the jjinme have their cavity divided into intercommunicating
chambers. It is a strong, rather rigid species, and attains a considerable
size ; but as the specimen had lost its hydrorhizal extremity, the entire
length attained by it could not be determined with certainty.

In the absence of the gonosome its reference to the genus Aglao-
phenia is of course only provisional.

Aglaophenia bispinosa.
Ph. XXVII. and XXVIII

Trophosome. — Stem attaining a height of eight inches, stout, simple,
rising from an entangled mass of branching tubular filaments, fascicled
below, and presenting from distance to distance knot^like projections ;
pinnae alternate, attaining a length of nearly an inch and a half Hy-
drothec£B deep, widening upwards; margin with a single, strong tooth-like
process in front, and Avith short, blunt teeth in the rest of its extent ;
intrathecal ridge not conspicuous. Supracalycine nematophores stout,
not overtopping the hydrotheca ; mesial nematophores two in number,
the distal one adnate to the hydrotheca, along which it extends for
about one third of the height of the hydrotheca, the proximal one forming
a short, stout spine-like process just below the distal.

Gonosome. — Corbulte open, formed by two alternate or sub-opposite
series of free, rib-like processes, each of which carries near its base a
small hydrothecal cup, and along its distal margin a series of numerous
tooth-like nematophores ; the rachis of the corbula continued towards
the common stem as a long peduncle carrying about five unchanged
hydrothecae.

Die<lgcd off Alligator Reef, from a depth of 156 fathoms, and off Tennessee Ri-ef, from a depth
of 2ii0 fathoms.

AGLAOPHENIA CONSTEICTA. 47

Aghophenia bispinosa is a beautiful species, and is surpassed in size by
very few hydroids. The proximal part of the stem is composed of a
congeries of tubes (PI. XXVII.), which at rather regular intervals become
curiously contorted into knot-like projections, and which, at the extreme
proximal end, become separated from one another, and here form a large
entangled mass of hydrorhizal filaments. Knot-like projections of quite a
similar kind occur in the European Aghophenia myriophglla. Towards its
distal extremity the stem loses its polysiphonic or fascicled condition and
becomes monosiphonic. In the specimens examined the pinnse were borne
along somewhat less than the distal half of the stem.

The hydro thecae are remarkable for the long, strong tooth which
projects from the front of the margin ; but a still more remarkable
character is found in the presence of a second mesial nematophore
situated on the internode, just behind the normal one and unconnected
with the hydrotheca. (PI. XXVIII.)

The corbulce (Fig. 3) are very beautiful. They closely resemble those of
A. distans, present the same elements in their formation, and, like these,
afford a most instructive illustration of the essential morphology of the
organ. The peduncle which connects them with the common stem, and
which consists of the proximal portion of the pinna, which, in its ter-
minal portion, becomes transformed into the corbula, is vinusually long
(Fig. 4), and consists of five scarcely altered internodes with their hy-
drothecas; an additional mesial nematophore, however, is developed near
the proximal end of each of these internodes.

Aglaophenia constricta.

PI. XXIX. Figs. 1-4.

Trophosomc. — Stem attaining a height of about eight inches, thick,
fiiscicled, springing from an entangled mass of wiry filaments, and send-
ing off numerous, irregularly disposed, simple branches, which carry
alternately disposed pinnte, three pinnte springing from every internode.
Hydrothecas with the distal half expanded and separated from the proxi-
mal part by a deep constriction ; margin with four broad teeth. Supra-
calycine nematophores slightly overtopping the margin of the hydro-
theca ; mesial nematophore nearly equalling in length the height of
the hydrotheca, to which it is alinost entirely adnate ; cauline nema-

48 AGLAOPHENIA PERPUSILLA.

tophores two on the axil of each pinna, and one immediately below
the pinna in front.
Gonosome not known.

Off Conch Reef, from a depth of 30 fathoms.

This is a well-marked species. The expanded summit of the hydro-
theca and the deep constriction between this and the proximal poi-
tion are striking features. No gonosome was present in the specimen)
arid it is quite possible that if this were known we should find it
necessary to remove the species from Aglaophenia.

Aglaophenia perpusilla.

PI XXIX. Figs. 5-7.

Trophosome. — Hydrocaulus attaining a height of about one fourth of an
inch ; stem simple, non-fascicled ; pinnae alternate, each springing from
the anterior aspect of an internode in the axil of a strong tooth-like pro-
cess, which carries on its proximal side a fixed nematophore, and just below
which another strong fixed nematophore also springs from the internode.
Hydrothecae deep, slightly Avidening upwards ; margin with about nine
strong and deeply cut teeth, the anterior tooth continued into a narrow
keel, which runs down the front of the hydrotheca ; intrathecal ridge dis-
tinct, horizontal, situated at the junction of the lower and middle third
of the hydrotheca. Supracalycine nematophores strong, overtopping the
hydrotheca ; mesial nematophore scarcely reaching the intrathecal ridge,
adnate as far as its oblique terminal orifice.

Gonosome not known.

Dredged off the Quicksands from a depth of 34 fathoms.

Ar/laophenia perpusilla is the most minute of all the hitherto described
species of Aglaophenia, and is further rendered very distinct by certain
special characters. The tooth-like processes given off from the anterior
side of each internode of the stem have not been found in any other
Aglaophenia. These processes appear bifid from the fact of their carrying
in front a strong nematophore, while just below this another similar nemato-
phore is also borne by the internode. A peculiar feature in the mesial
nematophore of the hydrotheca consists in the constriction of its cavity
by a process which projects transversely into it from its anterior wall.

The species occurred sparingly, growing over a seaweed. No gonosome

CLADOCARPUS. 49

had been developed in the specimens obtained, which were possibly ex-
amples of young individuals ; but though the entire colony might increase
in size with age, it is not probable that older specimens would present
any important change of form.

In the absence of a gonosome the reference of the species to Aglaophenia
is provisional.*

CLADOCARPUS Allman nov. gen.

Generic Character. Trophasome. — Hydrosoma pinnate, plumose. Ne-
matophores fixed ; supracalycine neraatophores one on each side of the
orifice of the hydrotheca ; mesial nematophores either adnate to the front
of the hydrotheca or free.

Gonosome. — Gonangia not included in corbulai, but borne on the sides
or at the base of special protective branches (phylactogonia), which are
appendages of the pinnae.

The genus Cladocarpus was originally defined by me for the reception
of a remarkable Plumularidan obtained in tbe eastern parts of the North
Atlantic during one of the expeditions of the " Porcupine." t Its most
important character is found in the possession of peculiar branching ap-
pendages, which are destined to support the gonangia, or in some other
way to afford protection to them. It is convenient to have a special name
for these appendages, and that of " phylactogonium " is suggested by the
function which devolves upon them.

The phylactogonia differ essentially from the corbulse, whether open or
closed, of the Aglaophenite ; for they are not, like corbulie, metamorphosed
pinnge, but appendages superadded to the normal pinnae.

In Kirchenpauer's subgenus Macroryuchia the gonangia are also borne
on special appendages, but the pinnae which in Cladocarpus retain their
normal form, and support the phylactogonia, are here suppressed, and are
represented only by short stunted processes destitute of hydrothecaj.

The macrorychial Aglaopheniae of Kirchenpauer are further distinguished
from Cladocarpus by the fomn of the mesial nematophores, which are very
long, usually fiir surpassing the height of the hydrotheca3, and which, as
Kirchenpauer first pointed out, are always provided with a lateral as well
as a terminal orifice after they cease to be adnate to the hydrotheca.

* See Note on p. 56.

t Report o;i the Hydroida collected during the Expeditions of H. M. S Porcupine, Trans. Zool.
Soc. Lond., Vul. VIII. Part VIII.
7

50 CLADOCAEPUS DOLICHOTHECA.

To the genus Cladocarpus I must also refer a Plumularidan dredged by
Oscar Sars in the North Atlantic, and described by him under the name
of Acjlaophenia bicuspis*

In the Cladocarpus paradisea of the present Report the gonangia are borne
exclusively on the sides of the phylactogonia ; while in C. doUcJiotheca and in
C. ventricosus they are borne only on the main stem, the phylactogonia
arching over them so as to afford them protection in the manner of the
leaflets of a corbula. In C. formosa of the Porcupine Report, the gonangia
are borne both by the phylactogonia and by the main stem.

Cladocarpus dolichotheca.
PL XXX.

Trophosnmc. — Stem attaining a height of about an inch and a half, carry-
ing alternate pinnae for a short distance from its distal end, and with three
four or very oblique internodes just below the pinnate portion. Hydrothecos
widely separated from each other, deep, tubulai", with the margin carrying
a single long tooth in front, crenate in the rest of its extent; each hydro-
theca overarched by the portion of the pinna which intervenes between
it and the next above it; intrathecal ridge obsolete. Supracalycine ne-
matophores tubular, overtopping the hydrotheca; mesial nematophore not
adnate to the hydrotheca, but springing from a point just below its base,
where it forms a free tubular spine-like process with a long oblique slit-like
orifice.

Gonosome. — Gonangia ovate, with a latero-terrainal orifice, borne on the
front of the stem, each one singly, close to the axil of one of the distal five
or six pinnfB, which become here more or less diminished in length, and
carry each near its origin a dichotomously divided branch (phylactogonium)
which forms three bifurcations, and arches over the front of the stem, and
the gonangium there situated.

Dredged off racific Reef from .a depth of 283 fathoms.

This is a remarkable and beautiful species. It is i-endered very striking
by its deep and widely separated hydrothecae, each overarched by that
portion of tlie rachis which intervenes between it and the next above it ;
the freedom of the mesial nematophore from the hydrotheca is also a well-

* G. Oscar Sars, Bidrag til Kundskaben om Norges Hydroider. Forhandlinger i Videnskabs-Selskabet
i Christiania, 1873, p. 98, Tab. II., figs. 7 - 10.

CLADOCAEPUS DOLICHOTHECA. 51

marked character. The parts of the rachis to which the backs of the hydro-
thecfB are appUed are divided, by imperfect septa (septal ridges), into
numerous very distinct chambers, while a few similar ridges also project
into the cavity of the intervening portion.

Where the stem ceases to give off pinna?, it becomes divided into three
or four internodes by very oblique joints, so as to assume, for some way
down, the appearance of being twisted, and then continues towards the
hydrorhiza as a simple continuous tube (Fig. 5). Along nearly the whole of
its course from the termination of the pinnate portion to the base, the stem
carries a longitudinal series of tubular nematophores, which are situated
at short and equal intervals from one another, and give to this part of the
hydrosoma a close resemblance to certain forms of graptolites.*

The phylactogonia, or protective appendages of the reproductive cap-
sules, resemble in form the antlers of a stag. Their branches are set with
large tubular nematophores. They arch over the front of the stem, their
branches crossing one another from opposite sides, and forming a cage-like
roof over the gonangia. They occiu- only on some of the pinn;v, which are
situated close to the distal end of the stem, one springing from each pinna
close to its origin. Though the pinnaa which carry them retain their normal
form, they are all more or less shortened, most of them supporting only
a single hydrotheca.

It is difficult to form any well-founded opinion as to the exact homology
of these appendages. The nature of the changes which have resulted in the
formation of a corbula in certain species of Aglaophenia might lead us to
suspect that in Cladocarpus dolichotheca the phylactogonium represents the
mesial nematophore of the proximal hydrotheca of its supporting pinna.
The fact, however, that this nematophore is at the same time present in its
normal state renders such an explanation untenable. The phylactogonium
probably represents, in a greatly modified condition, the mesial nematophore
of a hydrotheca, which had itself been totally suppressed.

The sex of the gonophores could not be determined in the specimen.

* I have elsewhere (Gymnoblastie Hydroiils, p. 17!!) endeavored to show the probability ihat the den-
ticles of graptolites represent the nematophores of the Plnmularidaa, the hydrotheeie beinj^ entirely sup-
pressed ; and I have attempted to support this view on both anatomical and embryological grounds. As
the nematophores of the PluraularidEe are filled with sarcode capable of a rich development of pseudopodia,
the graptolites would by this comparison be brought into close relation with the Rhizopoda. They would
thus represent an ancestral form in which the affinities looked on one side to the Hydroida, and on the
other to the Rhizopoda. No hydranths were developed in them, for the hydroid characters had not yet
gained that ascendency over the rhizopodal which we see in the existing Plunudarida!, which, according to
this hypothesis, have iidierited their nematophores from the extinct graptolites.

52 CLADOCAEPrs ye>;teicosus.

Cladocai-pus ventricosus.

PI XXXI.

Trophosome. — Stem attaining a height of about an inch and a half,
not fascicled, simple : pinnae alternate, each spi-inging from a rather long,
lateral process of the stem, somewhat waved. Hjdrothecae distant ; front
wall with a depression just below the margin, then greatly inflated ;
margin with a long, strong tooth in front, and with shallow ci'enations
in the rest of its extent; intrathecal ridge strong, transverse, springing
from a projection of the posterior wall of the hydrotheca near its fun-
dus, and reaching a point about midway between this and the anterior
wall. Supracalycine nematophores scarcely overtopping the hydrotheca ;
mesial nematophore quite detached from the hydrotheca.

Gonosome. — Phylactogonia springing from the proximal internodes of
a certain number of the pinnae, which are situated near the distal end
of the stem, twice bifurcating ; gonangia springing from the stem in
groups, each group close to the axil of a pinna, obovate, with the sum-
mit curved over the termino-lateral orifice.

Dredged oft' Sand Key from a depth of 100 fathoms.

This is a well-marked form ; its singular ventricose hydrotheca?, and
the complete removal of the mesial nematophore from the hydrotheca, at
once distinguish it. In Cludocarpus dolichoihecu the mesial nematophore,
while equally free from the hydrotheca, originates close to its base, but
in the present species its point of origin is removed much farther back,
and the entire nematophore is adherent to the front of the internode.
The septal ridges of the hydrothecal internodes are very distinct.

Where the stem towards its proximal end ceases to carry pinnte, it is
provided with two or three very oblique joints, each of which carries a
fixed nematophore, and similar nematophores are continued down the
stem in a longitudinal series, at short and equal intervals (Fig. 5) ; here,
again, as in Cladocarpiis dolicJwtheca, strongly suggesting the disposition of
the denticles in one of the single-sided graptolites. Near the base of the
stem the nematophores may become biserial and opposite. Cauline nema-
tophores are also situated, one on the axil of each pinna and one on
the stem in the intervals between the pinnte. The sex of the gonan-
gia could not be determined. The phylactogonium has a single bifur-
cation close to its origin, and one of its branches again bifurcates.

CLADOCAEPUS PARADISEA. 53

There are thus two bifurcations in this species, while in Cladocarjnis doli-
chotheca there are three. This difTerence appears constant.

The branches of the phylactogonia are all provided with well-devel-
oped tubular nematophores, which are arranged along each branch in
a single longitudinal series.

Cladocarpus paradisea.
Pk. XXXII. and XXXIII

Trophomme. — Stem attaining a height of fourteen inches, irregularly
branched, fascicled, and thick below, gradually losing its fascicled condi-
tion, and becoming monosiphonic towards the distal ends of the main
stem and branches ; pinnse alternate, rather distant, attaining a length
of about one inch and a quarter. HydrothecJB large, deep, widening up-
wards ; margin with two strong teeth in front ; rest of the margin des-
titute of teeth ; intrathecal ridge faintly marked, forming a waved line
which stretches across the middle of the hydrotheca. Supracalycine nema-
tophores bracket-shaped, not overtopping the margin of the hydrotheca ;
mesial nematophore attaining about one third the height of the hydro-
theca, to which it is adnate to within a short distance of its extremity.

Gonosome. — Gonangia-bearing appendages (iDhylactogonia) in the form
of pinnately branched offshoots, which spring each from a pinna of the
trophosome close to its origin, and is set with cup-shaped nematophores
along its stem and branches ; branches of phylactogonia alternate ; female
phylactogonium larger than male, aiid carrying a single gonangium in front
of the axil of each of its branches ; male with a cluster of gonangia
at the base of each branch ; female gonangia obovate, with a latero-
terminal transversely elongated orifice over which the summit of the
gonangium bends in the manner of a hood ; male gonangia smaller
than female, obovate, with a sub-terminal orifice not arched over by the
summit.

Dredged off Tennessee Reef, from a depth of 174 fathoms, and off Samboes, from 123 fathoms.

Cladocarpus paradisea is a magnificent species. I take for granted that
the difference presented by the gonosomes in the specimens examined
is a sexual one, for there is no difference in the trophosomes ; but
though I believe I am right in regarding the larger gonosome (PI.
XXXIII. Fig. 3.) as the female, I could not from the specimens determine
this point with certainty.

54 HALICOItXAEIA SPECIOSA.

The two strong teeth on the front margin of the hydrotheca are so
situated, that with the slightly everted intervening portion of the mar-
gin they give to this part the appearance of the lip of a jug, and con-
stitute a striking character. The pinnae arise somewhat from the anterior
aspect of the stem, and their internodes exhibit four well-marked septal
ridges.

There are usually thi-ee or four male gonangia (Fig. 5) in a cluster, and
of these one is always placed in front of the axil between the stem of
the phylactogonium and its branch ; towards the distal end of the phy-
lactogonium the clusters are often reduced to a single gonangium.

The branches of the female phylactogonium carry two longitudinal
series of large cup-shaped neraatophores. (Figs. 3, G.) These are situated
exactly opposite to one another, one on the front, the other on the back
of the branch, each series extending from the base to the apex of the
branch, and formed by about three equally distant nematophores. Along
the stem of the phylactogonium two series of similarly shaped nema-
tophores also occur. These are confined to the front of the stem, and
are disposed alternately. There is farther on the back of the phylacto-
gonium in each axil a somewhat bracket-shaped nematophore. (Fig. 4.)

In the male (Fig. 6) the phylactogonia as well as the gonangia are much
smaller than in the female. Both stem and branches carry cup-shaped
nematophores as in the female, but in the male these are all confined
to the front. A bracket-shaped nematophore is carried on the back of
the phylactogonium over the axil of each branch, as in the female.

Genus HALICORNARIA Busk (modified).*

Halicornaria speciosa.

PI. XXXIV.

Trophosomc. — Stem strong, attaining a height of about five inches,
simple, monosiphonic pinnate almost to the base ; internodes of stem
each giving off two pinn*, which are opposite, or nearly so, towards
the base of the stem, but more alternately disposed towards the distal end,
where the internodes become longer and more oblique. Hydrotheca3 wide ;

* The "'■enus Halicornaria fuuiuU'd liy Busk, who used it in a ividt-r sensu, is here intended to include
only those PlumularidiE which, with a trophosome formed on the general type of Aglaophenia, have gonan-
gia which are never imluded in corljidiv or proteeled by phylactogonia.

HALICOENAEIA SPECIOSA. 55

margin Avith wide, rather shallow creiiatioii ; intrathecal ridge springing from
the anterior side of the hydrotheca about midway between the margin
and base, and extending transversely to about the middle of its lateral
walls. Supracalycine nematophores stout, overtopping the margin of the
hydrotheca ; mesial nematophore reaching the margin of the hydrotheca,
and adnate to it in nearly its entire length.

Gonosome. — Gonangia cylindrical, with a broad, truncated summit, con-
tracted below into a short, stout latero-basal peduncle, which springs
from the front of the stem close to the origin of a pinna.

Double-Headed Shot Key, from a depth of from 4 to 5 fathoms.

Halicornaria speciosa is a strong, handsome species. The pinnfe are abso-
lutely lateral, showing no disposition to arise from the anterior aspect
of the stem. The stem is unusually thick for a monosiphonic or non-
fascicled form, and each of its internodes carries four nematophores, one
just above and one just below the point of origin of the pinna at each
side.

The gonangia in the specimen are small in proportion to the size
of the trophosome, and are possibly immature.

ADDENDA.

See Text, Page 32.
Plumularia geminata.

Between the present species and the Pliimula)ia catharina Johnston there
is a close relation. The form of the hydrotheca, of the gonangia with
their basal nematophores, and of the internodes in the ultimate ramuli, is
very similar in the two species, while between the same parts in Plumu-
laria catharina and Ilonostcechas dichotoma (see p. 37) a corresponding identity
of form will be found.

Foot-note to Page 49.

I am indebted to Miss Gatty for an opportunity of examining a second species of tlie same remarkable
form, which may well constitute a subgenus of Aglaophenia. From Aglaophenia perpusilla this differs
chiefly in the width of the keel which runs down the front of the hydrotheca, and in the presence of a
shallow constriction between that portion of the hydrotheca which lies at the proximal side of the
strong intrathecal ridge and that which lies at the distal side. A decided bithalamic character is
thus given to the hydrotheca. The specimens scarcely surpass A. perpusilla in size. They are from
the Gulf of Mexico, are attached to Gulf Weed, and are destitute of gonosome. I have assigned to
the species the name of A. late-carinala.

\

DESCRIPTION OF THE PLATES.

PLATE I.

Figs. 1, 2. Eudendrium eximium.
Fig. 1. Natural size.
Fig. 2. Portion of a colony with female gonophores, magnified.

Figs. 3, 4. Eudendrium exiguum.
Fig. 3. Natural size.
Fig. 4. Portion, magnified.

PLATE II.

Figs. 1 - 2'. Eudendrium fruticosum.

Fig. 1. Natural size. A cluster of capsular bodies ; probably a molluscan or annelidan nidus has become

attached to the stem and branches.
Fig. 2. A portion with hydranths and male gonophores, magnified.
Fig. 2*. A ramulus with hydranth and female gonophores, magnified.

Figs. 3, 4. Eudendrium attenuatum.
Fig. 3. Natural size.
Fig. 4. A portion, magnified.

PLATE III.

Figs. 1-4. Eudendrium laxum.
Fig. 1. Natural size.

Fig. 2. A portion with hydranths and male gonophores, magnified.

Ficr. 3. A portion of the hydrorhiza magnified, showing the clear spherical bodies in the coenosarc.
Fig. 4. A portion of the stem with similar bodies, still further magnified.

PLATE IV.

Figs. 1, 2. Eudendrium gracile.
Fig. 1. Natural size.
Fig. 2. A portion with hydranths, magnified.

Figs, 3, 4. Eudendrium tenellum.

Fig. 3. Natural size.

Fio-. 4. A portion, magnified.

PLATE V.

Figs. 1, 2. Eudendrium cochleatum.

Fig. 1. Natural size. The tubes of a little tubicolous crustacean are seen attached to some of the

branches.
Fig. 2. A portion with hydranths, magnified.

Figs. 3, 4. Bimeria humilis.

Fig. 3. A colony growing over the surface of a seaweed, natural size.
Fig. 4. A portion magnified, with hydranths and male (?) gonophores.

58 DESCRIPTION OF THE PLATES.

PLATE XI.

Figs I, 2. Obelia marginata.
Fig. 1. Natural size. Drawn from a small specimen.
Fig. 2. A branch, magnified. Creeping over it is a colony of Lafoea venusta.

Figs. 3, 4. Lafoea venusta.

Fig. 3. Natural size. It is seen creeping over a branch of Obelia marginata.
Fig. 4. A portion, magnified, creeping over Obelia rnarginala.

Fig 5, 6. Thyroscyphus ramosus.
Fig. 5. Natural size.

Fig. 6. A portion of a branch, magnified.

PLATE VII.

Figs. 1-3. Oplorbiza parvula.

Fig. 1. Natural size.

Fig. 2. Portion of a colony, magnified.

(a, a) Hydrorhizal appendages.
Fig. 3. One of the hydrorhizal appendages, still further magnified.

Figs. 4, 5. Obelia longicyatha.

Fig. 4. Natural size.

Fig. 5. Portion of a colony, magnified.

PLATE VIII.

Figs. 1, 2. Campanularia raacroscypha.
Fig. 1. Natural size.

Fig. 2. Portion of a colony, magnified.

Figs. 3, 4. Lafoea tenellula.
Fig. 3. Natural size.
Fig. 4. Portion of a colony, magnified.

Figs. 5, 6. Cuspidella pedunculata.
Fig. 5. Natural size.
Fig. 6. Portion of a colony, magnified.

PLATE IX.

Figs. 1, 2. Lafoea convallaria.

Fig. 1. Entire colony, natural size.

Fig. 2. Distal portion of a colony, magnified.

PLATE X.

Figs. 1, 2. Lafoea coalescens.

Fig. 1. Entire colony, natural size.
Fig. 2. The same, magnified.

PLATE XI.

Figs. 1-4. Halecium filicula.
Fig. 1. Natural size.

Fig. 2. Portion of a pinna with hydranth, magnified.

Fig. 3. Portion of main stem near its distal extremity, carrying hydrophores and a pinna; magnified.

Fig. 4. Distal extremity of a hydrophore with double margin, still further magnified.

Figs. 5, 6. Halecium capillare.
Fig. 6. Natural size.
Fig. 6. Portion of a branch, magnified.

Fig.

1.

Fig.

2.

Fig.

3.

Fig.

4.

Fig.

5.

DESCRIPTION OF THE PLATES. 59

PLATE XII.

Figs. 1-5. Halecium macrocephalum.

Entire colony, natural size.

Portion of a branch with hydrophores and hydranths, magnified.

Portion with two hydrophores, still farther enlarged.

An internode carrying a male gonangium.

An internode with a female gonangium.

Figs. 6-10. Cryptolaria conferta.

Fig. 6. An entire colony, natural size.

(a) One of the clusters of flask-shaped bodies associated with it.
Fig. 7. A portion taken from a point near the proximal end where the stem is still fascicled ; magnified.
Fig. 8. A portion taken from a point near tlie distal end where the stem is monosiphonic ; maguified.
Fig. 9. A portion of one of the associated clusters of flask-shaped bodies as seen in section, parallel to
the axis of the cryj>tolaria stem; magnified.

(a, a) Acrocysts (?) into which the contents of the capsule have escaped.
Fig. 10. A portion of the same as seen in section transverse to the axis of the stem,
(a) Flask-shaped capsules with their contents still included.

(b, h) The basal tubes seen in tranverse section and surrounding the larger and thioker-walled
tubes (c, c) which form the fascicled stem of the cryptolaria, and are here also seen
in transverse section.

PLATE XIII.

Figs. 1-3. Cryptolaria abies.

Fig. 1. Natural size.

Fig. 2. Portion of a branch taken from a point near its distal end, where it has lost its fascicled condi-
tion ; magnified.

Fig. 3. Portion of stem with the proximal parts of two branches showing the fascicled condition of the
hydrocaulus; magnified.

4, 5. Cryptolciria longitbeca.

Fig. 4. Natural size.

Fig. 5. Portion of a colony, magnified.

PLATE XIV.

Figs. 1, 2. Cryptolaria elegans.

Fig. 1. Entire colony, natural size.

Fig. 2. Portion taken from the distal extremity of the colony, magnified.

Figs. 3-6. Desmoscyphus longitheca.

Fig. 3. Several stems attached to some foreign body, natural size.

Fig. 4. Front aspect of a portion of a colony from a point near the basal end of the stem ; magnified.

The lowest hydrothecae have begun to recede from one another.
Fig. 5. Portion of stem viewed laterally, magnified.
Fig. 6. Proximal extremity of stem, magnified. The hydrothecse of each pair have receded fjom one

another, and now occupy opposite sides of the stem.

PLATE XV.

Figs. 1, 2. Thuiaria plnnata.

Fig. 1. Entire colony, natural size.

Fig. 2. Portion of a pinna with hydranths, magnified.

3-5. Sertulcirella Gayi var. robusta.
Fig. 3. Natural size.
Fig. 4. Portion of a branch with hydrothecse and gonangium, magnified. In the uppermost hydrotheca

60 DESCEIPTIOX OF THE PLATES.

contractile (?) bands are seen passing from the inner side of the hydrothecal valves to the body of
the hydranth.
Fig. 5. Portion of branch with front view of the hydrothecse ; magnified.

Figs. 6, 7. Sertularella couica.

Fig. 6. Natural size.
Fis. 7. Portion magnified.

o o

Fifs. 8-10. Sertularella amphorifera.
Fig. 8. Natural size.

Fig. 9. Portion of a colony with gonangium ; magnified.
Fig. 10. Ilydrotheca stiU further enlarged.

PLATE XVI.

Figs. 1, 2. Sertularia marginata.
Fig. 1. Natural size.
Fig. 2. Distal end of colony, magnified.

Figs. 3, 4. Sertularia tumida.
Fig. 3. Natural size.
Fig. 4. A portion, magnified. In one of the hydrotheca; the hydranth and two opercular bands are still

visible.

Figs. 5, 6. Sertularia tubitheca.

Fig. 5. Entire colony, natural size.
Fig. 6. A portion, magnified.

Figs. 7, 8. Sertularia ezigua.

Fif. 7. Colony growing on a seaweed ; natural size.
Fig. 8. A portion, magnified.

Figs. 9, 10. Sertularia distans.
Fig. 9. Natural size.
Fig. 10. A portion, magnified.

Fics. 11, 12. Thuiaria sertularioides.
Fig. 1 1 . Natural size.
Fio-. 12. A portion, magnified.

PLATE XVII.

Fics. 1, 2. Thuiaria distans.

Fio-. 1. Entire colony, natural size.
Fio-. 2. A portion, magnified.

Figs. 3-6. Thuiaria plumulifera.

Fig. 3. Entire colony, natural size.

Fig. 4. Portion of a branch with pinnae, magnified.

Fig. 5. Hydrotheca more enlarged, lateral view.

Fig. 6. Same, front view.

PLATE XVIII.

Fig. 1. Natural size.

Fio. 2. A portion with gonangia, magnified.

Figs. 3, 4. Plumularia macrotheca.

Fig. 3. Entire colony, natural size.
Fig. 4. A portion of a pinna, magnified.

Figs. 5, 6. Plumularia attenuata.
Fig. 5. Natural size.
Fi". 6. Portion of stem with pinna, magnified.

DESCRIPTION OF THE PLATES. 61

PLATE XIX.
Figs. 1, 2. Plumularia megalocephala.

Fig. 1. Natural size.

Fig. 2. A portion of a brancli with pinna-, magnified.

Figs. 3-7. Halopteris carinata.

Fi": 3. Entire colony, natural size.

Fif. 4. Portion of stem with pinna;, magnified.

Fig. 5. Portion of a pinna, still further magnified ; lateral view.

Fig. 6. Same, front view.

Fig. 7. Same, back view.

PLATE XX.

Figs. 1-4. Plumularia geminata.

Fig. 1. Natural size.

Fig. 2. A portion, magnified.

Fig. 3. A portion, still further magnified ; front and back view of pinnae.

Fig. 4. Lateral view of pinna.

PLATE XXI.

Figs. 1, 2. Antennularia simplex.
Fig. 1. Natural size.
Fig. 2. A portion, magnified.

Figs. 3-6. Antennopsis hippuris.

Fig. 3. Natural size.

Fig. 4. A portion, magnified ; with male (?) gonangia.
Fig. 5. Portion of a pinna, still further magnified.
Fig. 6. Portion of a colony with female (?) gonangia.

Figs. 7, 8. Hippurella annulata.

Fig. 7. Entire colony, natural size.

Fig. 8. Portion of a branch with pinnae, magnified.

PLATE XXII.

Figs. 1-5. Mouostaechas dichotoma.

Fig. 1. Entire colony, natural size.
Fig. 2. A portion, magnified.

Portion of a pinna, still further magnified; front view.

Same, lateral view.

Young gonangium.

Figs. 6, 7. Anteunella gracilis.

Entire colony, natural size.

One of the pinna-like stems, magnified.

PLATE XXIII.

Figs. 1-4. Aglaophenia ramosa.

Fig. 1. Natural size.

Fig. 2. Portion of a branch with pinna;, magnified.
Fig. 3. Hydrotheca, still further magnified ; front view.
Fig. 4. Same, lateral view.

Figs. 5-8. Aglaophenia rhynchocarpa.

Fig. 5. An entire colony, natural size.

Fig. 6. Portion of a pinna, magnified ; lateral view.

Fig. 7. Hydrotheca of same ; front view.

Fig. 8. Corbula, magnified.

Fig.

3.

Fig.

4.

Fig-

5.

Fig.

6.

Fig.

7.

62 DESCRIPTIOISr OF THE PLATES.

PLATE XX I V.

Figs. 1-4. Aglaopbenia lophocarpa.
Fig. 1. Natural size.

Fig. 2. Portion of pinna, magnified ; lateral view.
Fig. 3. Portion of stem with pinn^, magnified ; front view.
Fig. 4. Corbula, magnified.

Figs. 5-9. Aglaopbenia apocarpa.

Fig. 5. Natural size.

Fig. 6. Portion of a pinna, magnified ; lateral view.

Fig. 7. Portion of stem with pinnae, magnified ; front view.

Fig. 8. Corbula, magnified.

Fig. 9. Part of a' leaflet of a corbula showing the lateral nematophores ; still further magnified.

PLATE XXV.

Figs. 1-4. Aglaopbenia gracilis.
Fig. 1. Natural size.

Fig. 2. Portion of a pinna, magnified ; lateral view.
Fig. 3. Same, front view.
Fig. 4. Portion of stem with pinna, magnified ; oblique view of pinna.

Figs. 5 -9. Aglaopbenia rigida.

Fig. 5. Entire colony, natural size.

Fig. 6. Portion of pinna, magnified ; lateral view.

Fig. 7. Same, front view.

Fig. 8. Corbula, magnified.

Fig. 9. Part of one of the ridges of the corbula, still further magnified.

PLATE XXVI.

Figs. 1-8. Aglaopbenia distans.

Fig. 1. Entire colony, natural size.

Fig. 2. A portion, magnified.

Fig. 3. Portion of the hydrotlieca, still further enlarged to show the anterior tooth-like process.

Fig. 4. A hydrotheca differing somewhat in form from the normal hydrothecae, but associated with these

in the same colony ; magnified.
Fig. 5. Orifice of hydrotheca viewed from above.

Fig. 6. Portion of a pinna with two hydrotheca; viewed in front ; magnified.
Fig. 7. Corbula, magnified.
Fig. 8. One of the leaflets of a corbula, still further magnified.

(a) Peduncle of leaflet.

(b) Supracahcine nematophores but slightly altered.

(c) Mesial nematophore greatly enlarged and altered in form. The slightly altered hydrotheca

is seen included between the supracalycine and mesial nematophores.

Figs. 9, 10. Aglaopbenia sigma.
Fig. 9. Natural size.
Fig. 10. Portion of a pinna, magnified.

PLATE XXVII.

Figs. 1-3. Aglaopbenia bispinosa.

Fig. 1. An entire colony, natural size; front view.

Fig. 2. The same, lateral view.

Fig. 3. Distal portion of the stem, magnified.

Fig.

1.

Fig.

2.

Fig.

3.

Fig.

4.

Fig.

5,

Fig.

6.

Fig.

7.

DESCEIPTION OF THE PLATES. 63

PLATE XXVIII.

Figs. 1-5. Aglaophenia bispinosa.

Fig. I. Portion of stem and pinna, magnified ; front view.
Fig. 2. Portion of pinna, magnified ; lateral view.
Fig. 3. Corbula, magnified ; viewed from above.
Fig. 4. Peduncle of corbula, more magnified.

(a, «) Internodes of peduncle showing the three mesial nematophores borne by each internode.
Fig. 5. Base of proximal rib of corbula, still further magnified.

(a) Supracalycine nematophores slightly altered.

(b) Base of mesial nematophore which has become transformed into a rib of the corbula.

Between a and b is seen the slightly altered hydrotheca with a hydranth still visible
in it.

PLATE XXIX.

Figs. 1-4. Aglaophenia constricta.

A specimen, natural size, with some sponges growing over its stem.
Portion of stem with the proximal ends of the pinnie ; magnified.
Portion of a pinna, still further magnified ; viewed laterally.
Same, viewed in front.

Figs. 5-7. Aglaophenia perpusilla.

Entire colony, natural size. '

Portion of a pinna, viewed laterally ; magnified.

Portion of stem with the proximal ends of two pinnae, magnified.

PLATE XXX.

Figs. 1-5. Cladocarpus dolichotheca.

Fig. 1. Entire colony, natural size.

Fig. 2. Distal end of a colony, magnified.

(a, a) Phylactogonia.
Fig. 3. Portion of a pinna with hydrotheca, magnified ; viewed laterally.
Fig. 4. Same, front view.

Fig. 5. Portion of stem near proximal end, showing nematophores disposed like the denticles of a grapto-
lite.

PLATE XXXI.

Figs. 1-7. Cladocarpus ventricosus.

Fig. ] . A colony, natural size.

Fig. 2. Distal end of a colony, magnified.

(a, a) Phylactogonia.

Fig. 3. Portion of a pinna, still further magnified ; viewed laterally.

Fig. 4. Same, front view.

Fig. 5. Portion of stem near the proximal end, with a longitudinal series of nematophores ; magnified.

Fig. 6. Gonangium, magnified ; lateral view.

Fig. 7. Same, front view.

PLATE XXXII.
Cladocarpus paradisea ; an entire colony, natiu'al size.

PLATE XXXIII.
Figs. 1-6. Cladocarpus paradisea.
Fig. 1. Portion of a pinna, magnified ; lateral view.
Fig. 2. Portion of stem with proximal end of pinna, not so highly magnified ; front view.

64 DESCEIPTIOIir OF THE PLATES.

Fig. 3. Proximal end of a pinna carrjing a phylactogonium ; magnified.

(a) Pinna.

(b) Phylactogonium with gonangia ; female (?) ; front view.

Fig. 4. Portion of a phylactogonium from a point near its distal end, carrying a single young gonangium ;

female (?) ; back view.
Fig. 5. Portion of a pinna with a phylactogonium, magnified.

(a) Pinna.

(b) Phylactogonium with gonangia ; male (?).

Fig. 6. Portion of one of the branches of a phylactogonium with two of its nematophores ; still further
magnified.

PLATE XXXIV.

Figs. 1-5. Halicornaria speciosa.
Fig. 1. Natural size.

Fig. 2. A portion taken from a point towards the proximal end ; magnified.
Fig. 3. Same, from a point near the distal end.
Fig. 4. Portion of a pinna, still further magnified ; front view.
Fig. 5. Same, lateral view.

ALPHABETICAL INDEX.

Aglaopheiiia
Ajilanjilieiiia apocarpa
Aghmphenia bictispis
Aglacipheiiia bispinosa
Aglaophenia constricta
Ai^laophenia distaiis
Aglaophenia gracilis
Aglanphenia late-carinata .
Aglaopheiiia lopbocarpa
Aglaophenia mgrmphylla .
Aglaophenia perpusilla
Aglaophenia ramosa . .
Aglaophenia rhynchocai'iia
Aglaophenia i-igida .
Aglaophenia sigma
Antenella
Antenella gracilis
Anteiinopsis
Antennopsis hippnris .
Antennularia .
Anfennalaria cyathifera
Antennularia ramosa
Antennularia simplex

Bat hy metrical distribution
Binieria ....

Binieria liumilis

Bimeria vestita . . . .
Bimeridoe ....

Calycella
Calyptoblastea .
Campanularia
Campanularia macroscypha
Campaiudaria syringa
Campanularidaj
Campanulinae
Cladocarpus

Clailocarpus dolichotheca
Cladocarpus formosa .
Cladocarpus paradisea .

PAGB

39

Cladocarpus ventricosus

41

Coppinia ....

50

Cryptolaria .

44,

46

Cryptolaria abies

47

Cryptolaria cnnferta

44,

47

Cryptolaria elegans .

42

Cryptolaria longitheca

56

Cuspidella

41

42

Cuspidella pedunculata

47

Definition of terms .

48

56

Desmoscyphus

39

Desmoscyphus Bmhii

40

Desmoscyphus longitheca

43

45

EudcndridiB

38

Eudendrium

38

Eudendriuni attenuatiim .

34

Eudendrium cochleatuni

35

Eudendriuni esiguuni

34

Eudendrinni exiniiuni .

38

Eudendriuni fruticosum .

2

34

Eudendrium gracile

34

Eudendrium laxum .
Eudendrium raniosum .

3

8
8
9
8

Eudendrium tenellum

Fildlum immersum

Grammaridse .

Graptolites

13

9
11

Gymnoblastea .

Halecidse

11

Halecinm .

13

Halecium Bcanii

9

Haleciiun capUlare .

9

Halecium filicula

49

Halecium macrocephal uni

50

,52

Halecium miiricatum .

50

Halecium sessile

5(

,33

Halicornaria

PAOE

. 50,52

18

. 17

. 20, 21

17, 19, 20

20

.18,19

13

13

4

25

26

26

5
5
6

8
6
5
6

7
7
5
8

17

51, note

5

15
15
17
2, 16
15
10, 16
2
. 17
54

66

ALPHABETICAL INDEX.

Halicomaria speciosa
Halopteris
Halopteris carinata
Hippurella
Hippurella annulata
Hydraltmania falcata

Lafoea. 11

Latbea coalRscens 13

Lafoea convallaria . . . . .12

Lafoea diimosa ...... 12

Lafoea tenellula 12

Lafoea venusta 10, 11

LafoeidjE 11

Lafoeiiia, tenuis ..... 14

Macrorynchia ...... 49

MonostjEchas ...... 36

Monostaechas dichotoma . . . 37, 56

Obelia 9

Obelia longicyatha 10

Obelia marginata 9, 12

Oplorhiza ....... 14

Oplorhiza parvula 15

Plumularia 29

Plumularia attenuata .... 30

Plumularia catharina ... 2, 37, 38, 56

Plumularia filicula 29

Plumularia geminata . . . .32, 39, 56
Plumularia macrotheea .... 30

Plumularia megalocephala ... .31

PAOE

54

Plumularia setacea

32

Plumularidse .

33

Rhizopoda

35

36

Sertularella

Sertularella amphorifera
Sertularella conica .
Sertularella Gayi .
Sertularella Gayi var. robusta .
Sertularella polyzonias
Sertularella tricuspidata.
Sertularia
Sertularia distans
Sertularia exigua
" Sertularia gracilis
Sertularia marginata
Sertularia pumila
Sertularia secundaria
Sertularia tubitheca .
Sertularia tumida
Sertularidae
Sertularinae

Tlioa capillaris
Thuiaria
Thuiaria distans
Thuiaria piiinata
Thuiaria plumulifera
Thuiaria sertularioides
Thyroscyphus .
Thyrosc.yphus ramosus
Tubularia crinis
TubulaHa indivisa

PAGE

38

29

51, note

21

. 8, 22
21

2, 3, 22
22

. 2,21
22
23
25
24
25
23
24, 25
. 38
24

. 23
21
17

2, 16
27
27
28
27
28
10
11
2
2

Al.LMAN, HyBHOIDS OF GuLF StREaM

Plate

' ill,,

'I y?

/

Auctor3oAKHoiliclt.3.dnB:t iel

M&. N HanKarfc imp

j4LiMAu,ftmKomi5 o? Gulf Stream.

Plate II.

Auclor iAFHollickadnat del ,

MStN.Haniiari/ imp

Allman" , Hydroid s OF Gulf Stream.

Plate ill.

V/

Auctor & A F HoUick, ad nat del.

M.ilN.Hanlia-rt imp

ALLMAN,IlYDROroS OT GuLP STRbJlM.

Tlm'k 1Y,

^J^

7

7

■h

Auctor % A FHolhck,a/J ,ia.L df.l .

M8iNH.^,:-.-„.rt

Allman , HTORoros of Gulf Stream ,

Platk V.

^^4fci2i,

^■aj^Safei

AucLor&.A-F.HonicXadliat del-

MA.l'l Hariiart imf

ALLMANllYDROn^S CF 'jUI.T StR¥,AM .

I.A'I'K

iDctcrr & A.F.HoUick, ad nat del

M&M Hajilmrl in.

Au.MAN.HnmoiDS of Qwh Strkam.

Plate Vlt

Auctot i AF Honici, .ad nat . d el .

U ,N UinlMiT imp

Almot.Hydroids of Cjui-v Strmm

Pl.ATE VIII

A/

Autior SiATHollkt, aiiimt, dpi.

M&ll Haiihart ittid.

ALlJ€AN,H^n)R01Di3 OF CDLF STREAM,

Y'tjct. ly

. ^\

A^--

r-

^1 //:^"^.^

.-:_<:

^

.. ^>

-Anctor JAEHoBick, ad Tia*, . ild .

M&.U Hsnhan nup

.;Ai.i,iv;A!>i,Bv);RrajiK OF Ciui.b' Stheam.

Aiiclrjr8cAFHonitt,adna.t del

MtNlliiihirl imp.

MAi^.HyDKoiDE OP Gulp Stet-avt.

PlatkaI.

1

^.

^

Aucbr &AEHollick, axL-nai..de

M i( f! a iuihai'l, Ito

KOt)

At,i.mam, HyDRoiDS OF Gulf S'CBEam

Pj.atk XII.

Auctor i A J. HolHc k, ad nat , del

MO Bin hart imp.

Auman.Htoboids Of Gul? Stke.am

RjiTEinr.

',!i;AF.HQllLck,al-tial del.

..\1?.1.'Hmi1.oji mil.

Platk XIV .

AviXa^lkAi jIoUick: , ainal. del.

IV) Ml lUli;;i,'l imn

AllmaNj-Rvbroids or Gulp Stream .

Platf; TV.

Aucter & A,F Hoilici, ad nat del .

MANHaohart imp.

OF Gulf Stream.

Plate

-aict/jr(5.ArH.ci:i;c>. adjiat del

MAKHari'hait y

inw

Allmaii.Hydroids 0"f Gulf Stream.

Plate X/H.

AuctOT & AF HolUck.ad nat del.

M.ciN Hanhart imp

?RO!DS OF Gulp Stream.

Plat

Auotor k A.7KoL1ick,iRiiai.^ei

MAN Haiihar'. imp

Allman, Hydrolds of Gulf Stream

RjATiJIK,

AuctorA A F HoUick.ad nst del

MSiNHanhsrt imp

/\Uii/CAi-r l-fyDRamB of Cuii* Stheat*.

Plai'i; IX.

Auctor A A.FHDlli!:k,3 3 nat del.

MAN.Hanhari. imp

;\Ll,MAH,IfoH01De OF GULF Stheam .

Plate ^XXI

hdllicX-aiinai. dvC

AljUvlAN/tiYDROIDS OF GuUl? StRIIAM ,

PuateXXH.

Auctor &. AP-Hollicli. ad tat del .

M &N Hanhart itnp

Allman.Hydroids of Gulf Stream.

ri,ATir,-)oni{.

>oU>p Xr A.F Hollick ad nai.del

M&NJiaJiJiarb imp.

^LLMAK, HyDROIDS OF GuLF StREAM

Aiidt<i-ftAFKollK*,axi)iitde] .

M * N Hsniiart

imp.

Allman.Hxdroids of Gulf Stbeam.

Pi.AT7.IW,

if .#^

r

■<;^

y

'y^

's ll

^ » ^ '^ A

^ ^ -f i ^

vi '

\ 'I

Avictor & AFHollick ed nat del.

M.&N.Hmhart imp .

^TiliMAN. HyDROTIiS OF GuLF STREAM.

PlateXj(V;

AuctM & A F. HoUiclt.ad nat del.

MAWHanhart imp

ALLMfiN. HYDB,MDS OS GrULT Stm.am .

PlateII3/I!

^ VV^

.actor lAl''.lioUick,ad imL . dsl.

MX^S Hatihart xatp

ALLMAil.HYDROIDS OF GuLF STRBAM,

PlaieBS/IIL

a

W i«

a

i : (!

>/: ■/ b

Auctor S.AT Hollick.ad nat dd ,

Miiitiaunariiiiip.

Aliman,Hyiiroids of Gulf Stream

Plate]

Au.cloT&AFllol]jd! ad-nat del.

M&NflanVarL imp

Auu/(an,I-!yi)roi))s of Giju S'I'RE/^-

P^teIXX .

Aijctor A A F. HoUick , ad nat del .

M& N.Hanhai-L itn-

Allman.Hyprqido of Gulf Streaj«i

I-'l;

'r-i

4, X

A\.1jMan,Bydroiiis of Gulp Strf.&m.

PbATKHxn

Auctor & A F.HoUick, ai n3t dd. .

M &N Hanhart imp

AujMAN, Hydboids of Gulf Strkam

Elate XXnir.

JsaAov ^AV.HoUiok.admb.ael.

M iiii iiaiiiart . iraw

ALLMAIf.HYTKOIDS OF GuLF StREAM\

?i.A-reIXXIV

'y

\ ■:#

Sf^^

r^ui

Auctor 4A.F Hollick adnat del

MS''NJlan}iarb.imp.

SE^

\97A

Harvard MCZ Llbrar

3 2044 066 300 732

Date Due