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Carrars FRANK TOURLE THOMSON, R.N.

PREPARED UNDER THE SUPERINTENDENCE OF

THE LATE

Sie CW RE EO SONS Kintse Pek Ss swe,

KEGIUS PROFESSOR OF NATURAL HISTORY IN THE UNIVERSITY OF EDINBURGH
DIRECTOR OF THE CIVILIAN SCIENTIFIC STAFF ON BOARD

AND NOW OF

JOHN MURRAY

ONE OF THE NATURALISTS OF THE EXPEDITION

LIBRARIES 7

ZOOLOGY—VOL. XX.

PART LXII.—REPORT ON CEPHALODISCUS DODECALOPHUS
By WILLIAM C; M‘INTOSH, M.D., LL.D., F.R.S., &c.

Published bp @rder of ber Mayesty’s Government

PRINTED FOR HER MAJESTY'S STATIONERY OFFICE
AND SOLD BY
LONDON :—EYRE & SPOTTISWOODE, EAST HARDING STREET, FETTER LAN!
EDINBURGH :—ADAM & CHARLES BLACK
DUBLIN :—HODGES, FIGGIS, & CO.
1887

Price Four Shillings.

| PRINTED BY NEIL

t ‘s y id ¥ J ee
FOR HER MAJESTY’S ST. FICE

HOLT OR DAN OU.

Tats Report consists of a description by Professor William C. M‘Intosh,
F.R.S., of CepHaLopiscus popEcaLoputs, one of the most curious and interesting
-organisms dredged by the Expedition, with an Appendix on its affinities
by Sidney F. Harmer, B.A., B.Sc., Fellow of King’s College, Cambridge. It
contains forty-eight pages, and is accompanied by seven plates and woodcuts.

The Manuscript was received in instalments between 25th April 1887
and 19th May 1887.

Joun Murray.

CHALLENGER Orrick, 32 QUEEN STREET,
Episgeureu, 22nd July 1887.

159857

THE

VOYAGE OF H.M.S. CHALLENGER.-
ZOOLOGY.

REPORT on Cepuatopiscus poprcatornus, M‘Intosh, a new type of the
Potyzoa, procured on the Voyage of H.M.S. Challenger during the
Years 1873-76. By Wuitam C. M‘Inrosu, M.D., LL.D., F.R.S.,
- &c., Professor of Natural History in the University of St. Andrews.

Class POLYZOA, J. V. Thompson.

Section AsprpopHora, G. J. Allman.

Genus Cephalodiscus, M‘Intosh.
Cephalodiscus dodecalophus, M‘Intosh.

Cephalodiscus dodecalophus, M‘Intosh, Ann. and Mag. Nat. Hist., ser. 5, vol. x., 1882, p. 337,
et seq.

Among the collections made by the Challenger Expedition in the Strait of Magellan,
there was a structure which, from its external appearance, was in the first instance placed
among the Compound Ascidians. When it was found not to belong to this group
Mr. John Murray forwarded the specimen to various authorities for examination, and
my attention was drawn to the anomalous organism in the hope that it might be found
to have affinities with the Annelida. An examination of this remarkable type proved
that amongst its other affinities it was an ally of Rhabdopleura, a new type of the
Polyzoa which had been ably described and figured by Professor Allman in 1869 * from

1 Quart. Journ. Mier. Sct., vol. ix., N.S., 1869, pp. 57-68, pl. viii.
(ZOOL. CHALL, EXP.—PART .—1887 ) 1

2i THE VOYAGE OF H.M.S. CHALLENGER.

specimens procured at a depth of 90 fathoms in the Zetlandic Seas by Drs. Gwyn
Jeffreys and Merle Norman, which had received further elucidation at the skilled hands
of Professor G. O. Sars,’ as an inhabitant of the still waters in the deeps off the
Lofoten Islands. Though it thus fell within the department of Professor Allman, or that
of the late lamented Professor Busk (each of whom had arrived at a similar conclusion
in regard to its systematic position), yet both most disinterestedly desired that its descrip-
tion should remain in my hands. A preliminary account accordingly appeared in the
Annals and Magazine of Natural History for November 1882,’ having been previously
communicated to the Southampton meeting of the British Association.

The specimens of this remarkable form were trawled at Station 311 (in the Strait of
Magellan), January 11, 1876; lat. 52° 45’ 30” S., long. 73° 46’ 0” W.; at a depth of
245 fathoms; bottom, blue mud; temperature at the bottom 46°°0, surface 50°:0;
specific gravity at the bottom 1:02454, surface 101904. The bag of the trawl in this
region was filled, Mr. Murray tells me, with a vast mass of Hemuasters, numerous
examples of a Venus, and multitudes of Compound Ascidians, four species of which
have been described by Professor Herdman, who also noticed the distinction between
Cephalodiscus and the Ascidians. Further, in connection with the habitat of the new
form, it is interesting that several peculiar molluscoid rarities had previously been found
in the Strait of Magellan by Professor R. O. Cunningham, naturalist on board H.M.S.
“Nassau,” such as his Goodsiria coccinea, a long, lobed, rooted fibro-gelatinous mass of
a vivid scarlet colour, with the minute flask-shaped animals in circumferential cells, and
the equally curious Pywra molinx, of Blainville. Thus if the Strait be not the head
quarters of peculiar Molluscoida, it is certainly one of the centres round which many are
grouped, including the present new type—perhaps the most remarkable of them all.

Amongst the branches of the ccencecium of Cephalodiscus were a few minute
Arachnida, sessile-eyed Crustaceans, fragments of Annelids and sponges, besides many
Foraminifera of the Rotulate type, which were chiefly studded on the spines (or filaments)
and other parts.

1On some Remarkable Forms of Animal Life, &c., vol. i., 1872, pp. 1-18, Tab. i, ii.
? Ser. 5, vol. x. p. 337.

REPORT ON CEPHALODISCUS DODECALOPHUS. 3

DESCRIPTION.
The description of this peculiar type may be taken under the following heads :—

I. The House or Ceencecium ;
II. The Polypides, including—
a. Buccal disk.
b. Branchial plumes.
c. Digestive system.
Mouth.
Pharynx.
(Esophagus.
Stomach.
Pyloric chamber.
Intestine.
Food.
d. Body-wall and body-cavities.
e. Muscular system and pedicle.
J. Nervous system.
g. Reproductive organs.
h. Budding.
III. General Remarks and Homologies.

I. Ca@nectiom.

At first sight the flexible ccencecium might be mistaken for a sea-weed, since it is
composed of a much branched fucoid tissue, tinged of a pale brownish hue, and semi-
translucent. Moreover the whole surface of the thickish stems is hispid with long
tapering spinous processes or fimbriz of the same tough secretion, and perforated
here and there by somewhat large apertures with smoothly rounded edges. A more
minute inspection reveals various opaque bodies in groups in the interior of the branches;
and, the appearance of these suggested the relationship of the structure to the Polyzoa or
Ascidians. When first seen in the Strait of Magellan it was supposed, Mr. Murray
observes, to be a Compound Ascidian. After being subjected to more careful examina-
tion on the completion of the voyage, the late lamented Professor Busk, however, pointed
out its distinction from the ordinary Polyzoa; while Professor Herdman, as already
mentioned, was satisfied it did not fall under the Ascidians.

The house or cceencecium of Cephalodiscus dodecalophus* (Pl. I. fig. 1) consists of

1 xePaan, head; d/oxos, disk; dadexa, twelve; AcPes, plume.

4 THE VOYAGE OF H.M.S. CHALLENGER.

thickish, irregularly rounded or flattened stems of the consistency of soft sea-weed, and
having a slight lustre like the semitransparent tubes of many Annelids. The stems
have a diameter varying from four or five millimetres to double or treble that breadth in
the flattened expansions ; but the general size of many of the branches is nearly uniform.
They cover a considerable area with their network, the extreme length in one example
being about 9 inches, and the breadth 5 or 6 inches. The main trunks appear to
have sprung from submarine objects, such as stones or sponges, but instead of standing
erect as in a soft Gorgonian, to which the inosculations of the branches give it some
resemblance, they seem to have been more or less horizontal, since pillars of the

Fic. 1.—Fragment of Polyzoarium of Cephalodiscus dodecalophus, M‘Intosh.

cooncecium occasionally pass, like aérial roots, from the underside to the plane of attach-
ment. Various foreign bodies, such as tubes of Serpulz and portions of sponge, are,
moreover, occasionally enveloped by the ccencecium, the originally soft secretion having
insinuated itself into all the irregularities of their surfaces, and extended around and
beyond them. The surface of the branches is everywhere studded with elevations and
ridges, which terminate in long spines of the same tissue—simple, bifid, trifid or multifid—
and here and there bending downward to join the main stem, so as to form loops and
arches, or inosculating with adjacent spines or fimbriz (woodcut, fig. 1). Some of the

REPORT ON CEPHALODISCUS DODECALOPHUS. 5

“spinous processes are very large, and project far beyond the others, while occasionally
they occur in groups. They generally taper a little towards the tip, which is often
_ attenuate, and of a deeper brownish hue than the rest of the ecencecium (PI. VIL. fig. 1).
The free tips of the branches frequently show a somewhat palmate arrangement, with
longer spines variously divided. ‘The irregularity in regard to the distribution of the
spines recalls the processes on the peculiar sponge Chondrocladia, though this feature
is much more marked than in the latter. All the spines are hollow, and in connection
with the canals and cavities of the ccencecium.

The surface of the ccencecium, moreover, is dotted, especially at the bases of the
spines, with large rounded apertures, which lead into the interior of the stem, the latter
being honeycombed from end to end by an irregular system of wide canals and somewhat
rounded cavities, intersected by bridles and arches, which thus provide for the constant
ingress and egress of sea-water throughout the entire system. The inner wall of these
canals and chambers is as smooth and glistening as the outer surface of the ccencecium,
the secretion being perfectly homogeneous. It cuts with great readiness, and as cleanly
as a soft Fucus; while it is much less tough than the glistening tubes of the Annelids.
Microscopically it is composed of numerous layers of a translucent and very fine mem-
branous secretion, so that in the preparations there are endless lines and folds, while the
sheen or lustre is doubtless due to the same arrangement.’ The whole disposition of the
tissue clearly indicates that it is the work of the polypides, just as much as the tube of
an Annelid or Phoronis, the more regular and less bulky tube of Rhabdopleura, and in
some respects the shell of a Mollusk. Like the Annelidan tubes it most approaches, it
is little affected at first either by nitric acid or caustic potash, though the former after a
time somewhat softens and bleaches it.

This secretion of Cephalodiscus is paralleled by the curious investment or “house”
of Appendicularia, which by some has been held to be the homologue of the Ascidian
test, and which fills the tow-net with a semi-solid mass when the animals are abundant.
It differs considerably from the branched system of annulated tubes formed by Phab-
dopleura, each of these corresponding to a single polypide, while the rings of which it
is composed are successively produced at the termination of the tube by the secreting
powers of the great buccal shield or pre-oral disk. Professor Lankester, moreover, has
very clearly explained’ that the differences of the rings in the attached or recumbent part
of the tube and those of the erect portion—differences first pointed out and figured by
Professor Allman °—are due to the changes in the buccal disk which secretes them, this
disk being characteristically bifid in the young specimens which form the recumbent
portion of the tube. This symmetry and regularity are absent.in the house of Cephalo-

1 All these features are well seen in a series of skilful sections mounted by the dextrous hands of the late Professor

Busk. 2 Quart. Journ. Mier, Sci., vol. xxiv., N. S., p. 625.
5 Journ. Roy. Mier. Soc., vol. ix. pp. 61-62, pl. viii. figs. 4, 6, &c., 1869.

6 ‘THE VOYAGE OF H.M.S. CHALLENGER.

discus, apparently because the polypides are not restricted and regulated in their labours
by the contractile stalk, but are free to wander throughout the ccencecium, and to add
layer upon layer to strengthen their protective investment. The buccal shield is in all
probability the chief secreting organ, the great sheets of membrane, consisting of the
secretion hardened in sea-water, being formed by its agency, but the shape of the spinous
processes or fimbrize suggest some other assistance, such as might be obtained from the
enlarged and glandular tips of the plumose arms.

While there can be little question that the protective house of Cephalodiscus differs
materially from the thickened cuticle of the posterior region of the polypides in the
ordinary Polyzoa, and which collectively is termed zocecium, yet it seems unnecessary to
complicate the subject by the introduction of new nomenclature.’ The term ccencecium
as instituted by Professor Allman, and which was used in the preliminary description,
points to an obvious character, and gives that amount of significance which it is always
well to preserve if possible in scientific terms. The term tubarium, proposed by my
friend ‘Professor Lankester, is very appropriate in the case of Rhabdopleura, but does not
apply to the condition in Cephalodiscus, in which the common abode of the polypides is
more aptly indicated by the already existent term coencecium.

It is not a matter for surprise that creatures so minute should secrete so conspicuous
a home for themselves, or that it should assume the algoid or zoophytic outline, especially
when the productions of sponges and other forms are remembered, or when we reflect
that even a transparent structureless fluid inside a smooth capsule (as in the Nemertean
stylet-pouch) can produce, in countless examples of each species, precisely the same form
of solid crystalline stylet. The enlistment of numbers in the present- case supplies any
deficiency likely to arise from minute size. The secretions, indeed, both of this form
and Rhabdopleura, are most interesting, and indicate a degree of skill and persistence of
pattern quite as marked asin much more elevated types. The condition in Cephalodiscus
is perhaps the more striking of the two, on account of the perfect freedom of the polypides,
the spinous processes or fimbriz of the surface, and the numerous anastomoses of the
ccencecium. The peculiar shape of the latter, moreover, has probably been found to be
that best adapted for the preservation of the animals, by its resemblance to seaweeds or
allied structures in the neighbourhood, on the one hand, and on the other, by its affording
complete aeration, abundant supply of food, and security to the little architects and
their delicate plumes.

II. Potyprpes.

The rounded cavities and canals of the semitransparent ccencecium contain numerous
opaque masses (the polypides) and large ova slightly attached by their peduncles. The
former often occur in groups, each individual, however, except in the case of buds,

1 #.g., Edicularium.

REPORT ON CEPHALODISCUS DODECALOPHUS. 7

being perfectly free, and at liberty to wander anywhere along the chambers or externally
through the apertures. In some cases they are packed closely together in the cavity,
probably from external causes acting after immersion in spirit ; for thin partitions, bridles,
and pillars of the semitransparent ccencecium often separate the individuals. The
cavities are generally clean, though occasionally a little mud containing sponge and
other spicules, including peculiar reticulated fragments apparently of Radiolarians, occurs.
This would seem to show that currents of sea-water sweep through these chambers very
freely, probably assisted by the active movements of the cilia covering the tentacular
plumes. Moreover, in dissecting out the latter, an operation performed with ease, owing
to the friability of the ccencecium, at first sight it may almost be supposed than an
ovigerous envelope containing embryos is before us, so remarkable is the profusion of eggs
and animals, and apparently so active is the
reproductive function. The aspect of the
adults and their terminal buds, the proportion-
ally large size of the ova, and other features,
however, negative such a supposition.

Each adult polypide (and they are some-
what uniform in size) measures, from the extre-
mity of the cephalic plumes to the tip of the
pedicle, about two millimetres (woodcut, fig. 2);
and of this length the body-proper—that is from
the buccal disk to the posterior bulbous region
above the pedicle,—is rather more than one
millimetre. The body in most is bean- or
kidney-shaped (PI. Il. fig. 1), generally more
rounded and bulbous posteriorly, since there
is a tendency to a forward curve behind the
pedicle. The dorsal surface is smooth and

a Bois Fig. 2.—Ventral view of Cephalodiscus dodecavuphus,

convex, a distinct constriction, however, being M‘Intosh.

usually evident just behind the anterior region

bearing the brownish-red pigment-spots. The latter region is generally bulbous and
prominent, and in many a slightly elevated median ridge leading to the arms is present.
So far as the spirit preparations go, therefore, the external differentiation of the anterior
region, called “thoracic” by Lankester in Rhabdopleura, is indistinct in Cephalodiscus,
but internally the collar body-cavities are diagnostic. As the pedicle is often curved
forward or projected outward at a small angle to the body, the ventral surface is
thus rendered comparatively short (Pl. III. fig. 2); indeed, in those which are much
bent, the base of the pedicle touches the buccal disk. This contour of the body is
interesting in relation to the oblique direction of the cup-like body of Loxosoma. When

8 - THE VOYAGE OF H.M.S. CHALLENGER.

the pedicle is extended (PI. III. fig. 1) the ventral surface is nearly straight and con-
tinuous with the pedicle, which leaves the body posteriorly at the ventral edge, while the
kidney-shaped mass of the body projects dorsally. The pedicle in contraction is:shorter
than the body, is nearly cylindrical, and terminates in a rounded end; but in extreme
elongation its appearance is much more attenuate. It is marked ventrally by various
longitudinal striz from the muscular bands.

The anterior region of the body curves somewhat suddenly downwards and back-
wards, and forms a flattened surface on which the great buccal disk or pree-oral lobe
rests.

Buccal Disk.
The great buccal disk (Pl. II.; Pl. VI., fig. 2, bs) forms a thin plate with two

slight and generally bilaterally arranged elevations in the centre anteriorly, and is

divided into two regions by a notch at each side, the anterior moiety being the larger

and thicker. The surface of the latter is marked by an arch of brownish pigment-grains,

which are densest in the centre of the curve, and shade off gradually on each side; while
a very conspicuous and well-defined deep brownish-red band commences in the posterior.
division at the notch, and runs with a backward curve to the opposite side. Between
this and the posterior margin a brownish pigment-belt—less developed than in front—

occurs. The two bands just mentioned form, when completed, a somewhat flattened

ring. In many specimens, however, the brownish pigment has been entirely removed by

the spirit, leaving only the well-defined reddish band posteriorly.

In intimate structure (PI. VI. figs. 2, 3, bs)’ the disk is found to, consist of a ventral
plate, the superficial characters of which have been described, and a pedicle. In
section the former presents the features of a great hypodermic shield somewhat similar
in structure to the Nemertean or Annelidan skin, and the surface of which in life is
probably clothed with cilia, as indeed Professor G. O. Sars found in Rhabdopleura,
though no distinct cuticular layer is visible in the preparations. This hypodermic tissue
is marked in section by vertical strize, which in the thick anterior central region assume
a somewhat radiate aspect. The free parts of the shield present dorsally a firm basement-
tissue under the cuticle, while ventrally, that is, on the secreting surface, the granular
glandular tissue terminates in a translucent smooth edge. As the pedicle is approached,
a narrow reticulated region appears within the basement-tissue strengthening the dorsal
region of the disk, and the inner as well as the outer wall of this region assumes a firm
structure—so as to resemble the basement-tissue. In the centre of the pedicle this
region is traversed by a radiate series of muscular fibres, which spring from the firm tissue,
constituting a kind of skeleton strengthening the basal part with which the plumes are

1T am much indebted to my assistant, Mr. John Wilson, B.Sc., for making a series of finely stained sections of
Cephalodiscus. These have enabled me to determine features not fully seen in unstained sections made in cork by the
hand,

REPORT ON CEPHALODISCUS DODECALOPHUS. 9

connected. From this insertion they radiate into the thick central mass of the shield,
and some appear to reach the pale ventral region of the hypoderm. Somewhat behind
the former region the fibres also arise from the basement-tissue lining the hypodermic
investment of the pedicle. This fan-like arrangement of the muscular fibres must confer
great mobility on the disk, so that its broad scale-like surface can be applied either as a
sucker or in an undulatory or partial manner, indeed enabling it to act as a useful
locomotive organ. In this connection also it is probable that the basement-tissue may
be highly elastic, especially in the absence of any signs of horizontal or transverse
muscular fibres, and in connection with the entrance or exit of fluid by the proboscis
pores. The glandular nature of the disk, again, shows that it is a structure with
secerning powers of great activity, and in close relation with the remarkable ccencecium.
Superiorly the pedicle of the buccal disk runs into the region at the base of the arms,
and in sections a fine layer of longitudinal and oblique muscular fibres occurs on the
inner surface of the dorsal wall of the pedicle, though such have not yet been seen any-
where on the inner surface of the shield.

In the centre of the buccal shield is a large mesoblastic cavity through which
the radiate muscular fibres before mentioned pass, and which communicates with the
anterior by two well-marked pores situated dorsally on each side of the middle line at
the great central nervous system. In oblique sections (e.g. Pl. VI. fig. 3, bp) these pores
lie closely together in their progress inwards. What relation the ciliated “sense” organ
of Rhabdopleura, as described by Sars, and also figured by Lankester, may have to the
proboscis-pores of Cephalodiscus is a feature of moment for future consideration. In
Cephalodiscus these pores seem to be formed by invaginations of the hypoderm of the
region, but their function is as uncertain as the single pore perforating the nervous system
in the proboscis of Balanoglossus. The organ in the latter is much more muscular and
has an evident proboscis-gland.

While therefore the buccal disk of Cephalodiscus is in all probability the main organ
of locomotion, just as in Rhabdopleura, which was seen by Professor G. O. Sars drawing
itself up to the aperture of its tube, it differs from the shield of the latter by its much
greater size.

In the form just mentioned the organ somewhat resembles the truncated and
thickened opercular process of certain Annelids, while in Cephalodiscus it overlaps
the neighbouring parts to a great extent. The intimate structure of the shield in
Rhabdopleura has only been alluded to by Sars, and he does not appear to have clearly
made it out. He says—‘ On examining more closely this buccal shield we observe in
the middle of it an opaque part which seems to contain an interior glandular organ.
Continuing the investigation and slightly pressing the animal, we notice, however, that
this opaque appearance is not produced by any such internal organ, but by a peculiar
and seemingly muscular structure of the shield itself. It exhibits, seen from below, in

(ZOOL. CHALL. EXP. —PART Sh Qqq 2

10 THE VOYAGE OF H.M.S. CHALLENGER.

the middle numerous ‘small bubbles situated rather far from each other, or somewhat
irregularly formed smail cells, which, however, when more closely examined (and this
is particularly evident’ in those which lie nearer: to the periphery of the disc), show
themselves to be external rounded extremities of small inwardly prolonged cylinders,
which together appear to form a thick fascicle of incompletely differenced muscular fibres
penetrating into the stalk of the buccal shield.” He thus does not refer to the structure
of the hypoderm of the disk, and yet this is one of its most important features, especially
in connection with its functions. In all probability, however, it closely agrees with the
hypoderm in the disk of Cephalodiscus, and the muscular fibies described by Sars no
doubt arise from the basement-tissue connected with the lophophoral arms, and radiate
in a fan-like manner into the hypoderm of the pre-oral shield. Further examination of
Rhabdopleura would also appear to be necessary in regard to the presence or absence of
a pre-oral cavity and proboscidian pores as seen in Cephalodiscus and Balanoglossus.

The buccal disk is apparently the homologue of the epistome in the ordinary Polyzoa,
as Mr. Harmer affirms in the case of Rhabdopleura. It is also interesting to find
paired spaces in the epistome of Loxosoma.'

The hypoderm of the buccal disk folds evenly over anteriorly to pass backwards and
upwards’ to the pedicle, and as the latter is connected with the basal framework of the
arms, this region forms the common ground for the origin of the twelve plumes.? On
removing the disk, some of the plumes often remain attached to the pedicle, while others
in the lateral regions are fixed to the basal tissue in front of the broad apron-like post-oral
lamella on each side.

, In transverse section the centre of the disk, even in early buds, presents a large
‘median chamber, traversed by the radiate fibres of its muscular system, and communi-
“eating with the exterior through the pair of pores occurring in the region of the nervous
system. It would thus seem that sea-water could be admitted into the interior, though,
perhaps, this is by no means indispensable for the performance of its functions. Mr.
Harmer has drawn my attention to the great similarity between the proboscis of Balano-
glosst.s and this organ (buccal shield) in Cephalodiscus, though, it is.trie, only a single
proboscis-pore leading through the nerve-ring of the stalk exists in the former, which
I:kewise has a proboscis-gland ‘and the so-called “heart.” The functions of the organs
differ very considerably, but there can be little doubt as to the nature of the interesting
homologies between the two forms.

Bronchial Plumes.

From the dorsal edge of the basal region just described, twelve plumes arise almost in
linear series, six on the one side of the median line and six on the other. A thickened
1. Harmer, Quart. Journ. Micr. Sci., vol. xxv., N.S., pl. xx. fig. 18. 2 Hence the name dodecalophus.

!

REPORT ON CEPHALODISCUS DODECALOPHUS. 1 oh

hypodermic area, with a median fissure, is visible in sections, and the pale region underlying
this indicates the central nervous system. The hypoderm of the basal.region contains
numerous granular masses (gland-cells and pigment) which have a brownish hye by trans-
mitted light. The plumes (Pl. II.) are nearly of uniform size, and consist of # thickish
central stem, occasionally slightly crenate, and furnished with a series of longitudinal
fibres ; while distally each is terminated by a peculiar bulbous enlargement, which at first
sight resembles the tip of certain hydroid tentacles (e.g., Coryne or Syncoryne) bristling
with dart-cells and pigment. The rugose appearance, however, is due to large gland-cells
containing granules and globules (PI. V. fig. 1), which are arranged in a somewhat regular
manner round a central cavity, and which present a deep yellowish tint in the preparations.
This structure may perhaps be a further and special development of the somewhat large
hypodermic granules of the tips of the pmnz. The appearance of these bulbous enlarge-
ments in section is shown in Pl. IV. fig. 3, part of the upper wall of the stem in this
ease being formed of the ordinary hypoderm below the tip. When the latter is cut
longitudinally, the space in the centre of the bulbous extremity is found to be continuous
with a similar space at the end of the arm. Very soon, however, transverse bridles and
fibres occupy the central region of the latter, so that a kind of meshwork takes the place of
acanal. In transverse section the terminal region of the stem is formed of a thick coating
of hypoderm (probably in life covered by a ciliated cuticular layer) somewhat regularly
marked (PI. IV. fig. 4) by strize so that the cell-like divisions are frequently wedge-shaped.
The hypoderm abuts on a basement-tissue, apparently continuous with that which belongs
to the basal apparatus next the disk, and which is in relation laterally with the axes of
the pine on each side. The wall of the canal of the arm, even in this region, presents
a series of fibres which render it hirsute in section, but they do not in every case meet
across tbe Iumen. As we proceed downward, however, the sections of the arms are
flattened and the margins prominent, so as to form ventral grooves, and the two sides are
bound together by transverse fibres, a median junction especially being conspicuous.
This meshwork of fibres is better seen in good horizontal and longitudinal sections of the
plumes, in which the transverse fibres pass from side to side in almost parallel series,
minute nuclei or corpuscles being everywhere abundant, apparently adhering to the fibres,
or perhaps indicating their origin from cells of the connective tissue. As in the basal
region, therefore, the centre of the arm is composed of a series of reticulations or meshes.
The hypoderm also of the arm below the terminal region is considerably thinner, showing
that this system of lacune reaches its culminating point in the terminal enlargement.
The longitudinal fibres inside the basement-tissue are probably those observed in the
external views of the arms.

The sides of the stem (Pl. IV. fig. 1) are rendered plumose by a large number of long
slender filaments having rounded or slightly bulbous extremities, which present a linear
streak from base to apex, due to the axis or skeleton. The latter was first clearly

Di THE VOYAGE OF H.M:S. CHALLENGER.

discriminated as a “skeleton” in Cephalodiscus by Professor Ray Lankester, for 1t had
only been indicated as a septum in my preliminary account in the Annals of Natural
History. The examination of fresh specimens of Rhabdopleura off the Norwegian
coast had enabled him to detect the existence of a ‘‘ consistent mesoblastic skeleton” in
the lophophoral arms, as in Phoronis, and thus forewarned he had comparatively little
difficulty in making out “a precisely similar skeleton” in Cephalodiscus. In the latter
the so-called “skeleton” of the arms is fixed to the basal apparatus formerly described,
and seems to consist of a somewhat firm basement-tissue with longitudinal fibres and
reticulations in certain parts. It differs considerably from the condition as figured in
Rhabdopleura, in which twisted filaments and particles are described by Lankester.
The pinne which pass out from the main stem do not taper, and are composed for the
most part of granular hypoderm with a few brownish pigment-cells, and the central axis
or skeleton. The pigment gives in some a light pinkish or pale violet blush to the
feathery plumes, which in life must have been finely tinted ; and it is further interesting
that the same pigment occurs in the lophophore of Rhabdopleura, as shown in Professor
Lankester’s excellent figures.' The skeleton (PI. IV. figs. 1, 2a) runs from base to apex
and terminates within the cellular tip. It is somewhat dilated where it joins the main
stem (Pl. V. fig. 2, sk) and the exact mode of its junction with the axial channel of the
latter is difficult to trace, so gradually is it merged into the tissues of the region.
No definite ending of these axial structures occurs as in Rhabdopleura, where Professor
Lankester figures them as if articulated to the skeleton of the arm, the base of the
pinnules dilating, and the central region abruptly terminating, as it reaches the main
stem. The dilated bases of the skeletal rods of the filaments in Cephalodiscus join the
sides of the reticulated main channel, but no evidence of a continuous central lumen is
observed in transverse sections of the free portions, though the double outline, and the
appearance of sections of their bases (Pl. V. fig. 2), would indicate the possibility of such.
Endosmosis at least would thus readily occur. In the transverse sections of the bases of the
processes just alluded to a series of apertures appears in the tissue of the arm. The
condition as described in Rhabdopleura therefore differs from that in Cephalodiscus,
especially in regard to the skeleton of the arm, though the general plan of structure is
similar. It would also appear to be more readily made out in the former than in the
latter, though perhaps this may be partly owing to the examination of fresh examples.
Professor Lankester describes the skeleton in Rhabdoplewra as cartilaginous, but so far
as appearances go in Cephalodiscus it more resembles a structureless translucent basement-
substance, probably of a chitinous nature. It was best followed in the preparations
immersed in a weak solution of caustic potash.

The skeleton of the arms and their pinnules gives a definite character to the processes,
as observed in the sketches. Though perfectly mobile, the pinnules stand out from the

1 Quart. Journ. Micr. Scz., vol. xxiv., N.S., p. 621.

REPORT ON CEPHALODISCUS DODECALOPHUS. 15

stem somewhat stiffly, the curves being for the most part terminal, and thus they do not
mix with each other in an inextricable manner. In the same way the beautiful plumes of
the Sabellidee and Phoronis have a certain amount of rigidity from their internal skeleton,
while their graceful motions and their branchial functions are in no way interfered with.

No special muscular apparatus can be made out in the pinnules, the covering of the
central axis consisting of hypodermic cells and granules. Nor would such be necessary
in regard to the physiology of the organs, the elasticity of the skeletal axis and its con-
nection with that of the main stem being sufficient to keep the parts in a position suitable
for their functions without any effort on the part of the animal. The main stem hasa series
of longitudinal fibres, but their muscularity is doubtful. In any case the motions of the
disk would influence that of the entire lophophoral apparatus, especially as its great
fan-like muscles arise from the skeleton of the basal apparatus of the arms.

The bases of the arms are hollow and in communication with the two great cavities
(one on each side) of the region (Pl. VII. fig. 3, cv) which Mr. Harmer, on good grounds,
identifies with the collar-spaces of Balanoglossus. In section the basal spaces are
generally filled with fibres detached from the walls, but in some views definite corpuscles
in groups are visible. The latter consist of minute rounded bodies with a central
nucleus. From the structure of the parts it will thus be apparent that though probably
pervious none of the arms show a clear median channel except at base and apex. The
paired cavities connected with the lophophoral apparatus communicate with the exterior
by a well-marked and comparatively large pore on each side in ‘front of the gill-slits.
These pores present a radiate arrangement of the hypodermic wall in transverse section
and thus are readily recognised; while in certain longitudinal sections a more or Jess
urceolate aspect is produced.

Tho tentacles of Zowosoma are stated by Professor Vogt and others to be devoid of a
central chamber, and the central axis of the same organs in Pedicellina' is only
cellular (and translucent). Even in habdopleura careful examination under most
favourable circumstances by Professor Lankester gave no indication of a median canal,
even in the main stems. He was unable to detect any definite cell-structure in the
skeletal tissue, but observed that it had a refringency indicating a certain density, and
presented small twisted filaments and particles within its substance at intervals. The
relation of the twisted filaments to the fibres described in the main stem of each plume
in Cephalodiscus is a subject that requires further investigation, and the same may be
said of the “particles” which occurred at intervals—in relation to the nuclei already
described. Whether Rhabdoplewra shows any indication of the lacune at the base of
the lophophore is a question also requiring determination, though if such had existed it
could hardly have escaped, in the living animal, two observers of such experience as Sars
and Lankester.

1 Wide Nitsche, Zeitschr. f. wiss. Zool., Bd. xx. p. 22, Taf. iii. fige. 1, 2.

14 THE VOYAGE OF H.M.s. EU aS TR BI:

The arrangement of these numerous Heneonlve arte differs ee ae from that in
Rhabdopleura, in which only two symmetrical tentacular arms with their pinne occur.
In certain young buds, however, in which the first pair of plumes far surpass the others
in length, a striking résemblance is temporarily produced to the condition in Rhabdo-
pleura. The latter and Cephalodiscus diverge from the ordinary Polyzoa in this
respect, both having mobile plumes that curve gracefully in various directions, instead of
the somewhat stiffish corona and straight tentacles of the other forms. In Cephalodiscus,
besides in all probability branchial functions, they are apparently of great tactile service,
and if covered with cilia, as in all likelihood they are, they must aid in providing currents
in the cavities of the ccenceecium, and, as Sars and Lankester suggest, may indirectly
cause food-currents, that is, bring the minute particles which constitute the nourishment
of the species within reach of the currents between the buccal shield and the post-oral
collar. The efferent currents again would readily find exit by the gill-slits behind the latter
lamella. Both Rhabdopleura and Cephalodiscus differ from the ordinary Polyzoa in the
absence of the tentacular web at the base. Both have very long pinne; but Cephalo-
discus excels the other in this respect, and is further characterised by the remarkable
glandular tips to the arms. The plumes are wholly absent as such in Balanoglossus, and
this constitutes a marked distinction externally. As formerly stated in regard to
Phoronis, however, there are certain evident homologies between the several forms.

Post-oral Lamella.

In Rhabdopleura Sars described “‘a strongly projecting, nearly semilunar border of
skin, ciliated on its edges,” and extending from the base of the-tentacular arms down-
wards on each side, thus forming with the buccal shield a narrow half-tube or channel ~
leading to the mouth, through which the nourishment is probably conveyed to the mouth ©
by the ciliated tentacles. The condition in Cephalodiscus, however, considerably
diverges, since the post-oral lamella (Pl. II. fig. 1) forms a flattened apron-like process,
fixed anteriorly to the ventral surface behind the eyes, and sloping along this margin
backwards to the mouth, the surface gently merging into the mucous membrane of the
oral cavity. Moreover, a central space—more or less distinct according to the line of
section—oceurs between its layers. Laterally and posteriorly it forms a somewhat free |
lamella. In minute structure this lamella presents two layers of hypoderm, each with a.
fine basement-layer, and having intermediate fibres, chiefly muscular. A strong series’
of these passes out from the basement-tissue of the post-oral mucous membrane, and
radiates to the outer (ventral) layer of the lamella, for the posterior or dorsal has
merged into the mucous membrane at the sides. The hypoderm of the two surfaces just
mentioned offers certain differences, especially in the free part of the lamella (PI. VI.

1 Proc. Roy. Soc. Edin., 1880-81, vol. xi. p. 217.

REPORT ON CEPHALODISCUS DODECALOPHUS. “45

fig. 2, pl; Pl. VIL fig. 5, pl), that covering the ventral surface being denser and more
finely granular, and with a more definite margin, which is probably richly ciliated. This
denser and somewhat regularly streaked hypoderm (which also stains more readily) shows
several prominent frills or rugze where it joins the oral region, and it just turns the
outer edge:of the lamella‘ all round and then ceases. The dorsal layer of hypoderm on
the other hand is more; lax, and is thrown into a series of frills or crenations in the
preparations,'the streaks in it being more conspicuous than the granules. It resembles,
indeed, the somewhat lax hypoderm observed on the pedicle, and like the latter contains
numerous pigment-corpuscles which do not readily stain. So far as the structure can
form a guide, the ventral surface would seem to be more important functionally than the
dorsal.

The oral region therefore has a different environment from that in Rhabdopleura,
though the plan of structure follows parallel lines. Thus in the excellent figures of
Lankester,! a well-marked plate situated behind the mouth, and running into the buccal
disk in front of it, is apparently the homologue of this lamella. When the disk is
folded backwards (op. cit., fig. 2) the two surfaces come more or less,into contact, and
would thus send currents more surely into the mouth. Lankester does not allude to
this region, which lies just in front of his thoracic division in Rhabdopleura. In the
flattened surface of the post-oral lamella the buccal shield is closely applied in the
preparations, though in life they can of course be separated at will, thus permitting the
currents caused by the cilia of the opposed surfaces to reach the oral aperture. As its
posterior face has perhaps only to ‘perform the function of separating the currents
connected with the mouth from those of the gill-slits, the differences in structure are thus
explained.

The post-oral lamella may have some relation to the Molluscan foot, and also to
the post-oral ring of cilia in Polygordius, especially as a ciliated groove in the latter
runs between it and the mouth. Harmer’s view that it is homologous with the oper-
culum of Balanoglossus, as described in Bateson’s valuable and suggestive papers * on this
form, appears to be well founded.

,

Digestive System.

Mouth.—The margin of the oral lamella leads on each side (PI. IIL fig. 3; Pl. VL.
fig. 2, m) into the mouth, and in some ventral views it passes straight inwards to the
sides of the latter, and. forms a transverse margin anteriorly. The edges of the mouth
are slightly raised or frilled laterally and posteriorly, the latter often being spout-shaped.

1 Op cit., pl. xxxviii. figs. 1, 2.

2 Quart. Journ. Micr. Sci., April 1884, Studies from the Morph. Lab. Univ. Camb., vol. ii. part i., and vol. iii. part 1.
The author has overlooked some remarks previously published in this country on Balanoglossus. Vide Nemerteans,
Ray. Soc., 1873, p. 144.

16 THE. VOYAGE OF H.M.S. CHALLENGER.

Anteriorly it is devoid of any well-defined boundary other than the attachment of
the pillar of the great buccal shield, and leads directly upwards into the alimentary canal.
(Pl. III. fig. 1, m). Moreover, as Mr. Harmer first noticed im his sections, a solid
diverticulum proceeds upwards dorsally into the stalk of the buccal shield, and this may
- fairly be held to be the homologue of the notochord of Balanoglossus. In transverse
section it is nearly circular and presents a somewhat regular arrangement of its cells, so
that a concentric appearance is frequently present. In longitudinal section, on the other
hand, the process, which is small, has a slightly bent clavate outline, a dotted axis
indicating the lumen continued from the alimentary canal. The mucous membrane of
the buccal chamber and gullet are thrown into many prominent ruge, from the dense
glandular nature of the tissue. The latter is especially thick on the ventral side of the
mouth (the region lying in front of the post-oral lamella), and a strong layer of muscular
fibres passes to the basement-tissue of this region, which must thus possess considerable
mobility. The surface of the mucous membrane is apparently richly ciliated, the
cylindrical epithelium of which it is composed being so closely arranged as to give a
finely striated character to the tissue. In some preparations a thin film occurs on the
surface of this glandular tissue, but this is evidently due to mucus, and not to the
separation of a superficial or cuticular coat.

Pharyngeal Region.—Beneath the post-oral lamella and immediately behind the
pores of the second region are a pair of gill-slits, which were first clearly recognised as such
by Mr. Harmer, who has kindly interested himself in the structure of this form, and
whose very thin sections enabled him to unravel certain pomts which would otherwise
have been obscure. The folds leading to these in transverse section are shown in
Pl. VI. fig. 2, gs. Immediately behind the collar-pores the ordinary hypodermic coating
of the body becomes continuous with the translucent wall of the slits, which seems to be
a modified continuation of the pharyngeal mucous membrane. The granules are finer,
and the whole tissue is more translucent. It also does not stain so well as either the
collar-pores or the pharyngeal lining proper. In connection with this structure it is
interesting to note that Bateson’ mentions that the gill-slits in Balanoglossus arise as
dorso-.ateral evaginations. As soon as the posterior boundary of the mouth is completed,
und this is easily recognised in the preparations by the appearance of the pigment-cells in
the dorsal layer of the hypoderm of the post-oral lamella as it now stretches right across the
ventral surface, the spacious pharynx presents a thickly folded wall of the same kind of
minutely glandular tissue. The projection of some of these thick folds of glandular
tissue under the post-oral lamella, sometimes causes peculiar appearances in transverse
section, as if special diverticula existed. Bounding this thick glandular wall externally
is a firm basement-layer, probably of a highly elastic nature, and it is to this coat that
the muscular fibres formerly alluded to are attached.

1 Op. ctt., p. 14.

REPORT ON CEPHALODISCUS. DODECALOPHUS. . 177-

(Esophagus.—tThe firm and finely glandular cesophageal region (PI. III. fig. 3, a little
behind @), which is characterised by the paucity of its folds, is comparatively short, for it
merges into the gastric chamber a little behind the termination of the buccal shield
(Pl. III. fig. 3).

Stomach.—The stomach forms a large cavity, which in some instances fills the whole
of the body-space, with the exception of the dorsal area occupied by the intestine. In
certain longitudinal sections the cesophagus forms a comparatively limited tube, while the
stomach fills the entire body-cavity. (Pl. III. fig. 3), but dorso-ventral flattening of the
former may have occurred in such cases. The wall of this region is also somewhat thick,
and when fully formed, is distinguished from the cesophageal region by its more numerous
and often symmetrical folds, and sometimes by a differentiation into three pseudo-strata,
viz., a deeply stained, granular, epithelial, superficial layer marked by close parallel striz,
a pale intermediate region with granular glands, and externally another deeply stained
stratum of granular glands. It is not implied that there is separation in continuity
between the three regions indicated, but rather that either from preparation or otherwise
such a condition appears in the stomach. The colour of this region in life is probably as
characteristic as in Rhabdoplewra, where it is yellowish, but this feature could not be
made out in the spirit-specimens, for all are bleached. In the preparations it not
unfrequently happens that rupture of the alimentary wall occurs along the middle region,
so that the complexity of the folds in the body-cavity is imereased. Externally the
whole organ is surrounded by a firm. basement-layer continued from the cesophageal
region, and from its elasticity this probably subserves certain of the functions of a more
elaborate contractile apparatus, for muscular fibres have not been clearly determined.
The chamber narrows posteriorly towards the pedicle, and terminates in the intestine,
the glandular wall, however, undergoing no change of note.

In ?habdopleura, Sars‘ mentions that the stomach has tolerably thin walls, but in
all probability he speaks comparatively, as from the nature of the glandular tissue such
organs have proportionally thick walls.

Intestine.—As in Rhabdopleura, the stomach terminates at the posterior end of the
body-cavity at the base of the pedicle by a wide aperture in the intestine. In favourable
sections (Pl. IIL. fig. 3), the intestine is observed to leave the ventral side of the fundus
of the stomach, and passing under it, curve forwards along the dorsal wall. The glandular
lining of the ventral wall of the stomach passes evenly into the intestine and gradually
diminishes in thickness, whereas the lining of the posterior wall shows a characteristic
bend at the pylorus, and again a fold in the anterior wall of the intestine behind the
fundus (Pl. III. fig. 3, near vtd). This peculiar fold in the wall of the canal probably
indicates a tendency to the formation of a second or pyloric stomach, as in
Phoronis, and is therefore of considerable morphological significance. The intestine

1 Op. cit., p. 5.
(zooL. CHALL. EXP.—PART LXu.—1887.) Qaq 3

18 THE VOYAGE OF H.M.S. ‘CHALLENGER.

acquires its narrow firm texture even before the appearance of the forward curve
along the dorsal wall. The latter forms a somewhat large canal, which proceeds
along the dorsal wall above the stomach to terminate on the anterior promi-
nence of the body in the anus, which lies considerably above the region of the
plumes, and, indeed, the area in which the large pigment-spots are situated intervenes
There is thus a decided difference when the anal region is contrasted with that
in Rhapdopleura, in which the anus is situated close to the base of the tentacular
arms on the dorsal side of the animal, that is, on what Sars terms the posterior region.
Lankester, however, in his figure’ shows the anus elevated on a rectal cone, with a
depression between it and the base of the lophophoral region ; and, moreover, on the
lateral and ventral faces of this cone isolated blackish pigment-corpuscles are present.
No rectal cone is present in Cephalodiscus, for the prominent anterior end of the body
carries the anus on its summit. It has the form of a more or less elliptical aperture,
often of considerable size. The minute structure of the wall of the intestine differs
considerably from that of either gullet or stomach by its well-defined boundary
line—both externally and internally. The external consists of the firm basement-
layer, which ventrally bounds the stomach, and which at each side of the usually
elliptical or transversely elongated gut (in section) runs into a thinner basement
layer bounding the canal dorsally within the proper wall of the body. The granular
glandular coat which follows is narrow, and is limited internally by a remarkably
definite margin in section, so that the canal is at once distinguished in the prepara-
tions. In Professor Lankester’s section” of the intestine in Rhabdopleura, no such
compact and definite wall is observable, the gut apparently being enclosed by a
somewhat moniliform layer of cells. This divergence in structure doubtless indicates
difference in function, probably in relation to the free and the fixed conditions of
the respective animals. The terminal region of the gut (or rectum) frequently shows
considerable dilatation, the indigestible debris being probably sent out at intervals in
a stream, and it is this deposit which is occasionally found in certain crevices of the
ccencecium.

Food.—A survey of the fine muddy debris found in the alimentary canal, and
especially in the intestine, shows that the currents—set up in the surrounding water by
the plumes, and conveyed towards the oral aperture by the ciliated surface of the post-
oral lamella and the great buccal disk—carry inward, amongst indigestible sponge-
spicules and sand-particles, many Diatoms, bodies resembling minute Thalassicollide and
other Radiolarians, as well as organic particles of various kinds. When large forms like
the Ascidians flourish on a diet composed largely of Diatoms, it is evident that this minute
type is amply cared for in this respect. The honeycombed condition of the ccencecium,

1 Op. cit., pl. xxxviii. fig. 2, b, and pl. xl. fig. 11, e.
2 Op. cit., pl. xli, fig. 13, A.

REPORT ON CEPHALODISCUS DODECALOPHUS. 19

and the multitude of external apertures, thus suffice to place the little ciliated animals in
favourable circumstances as regards food, especially when the nature of their surroundings
is taken into account.

Body-waill.

In Rhabdopleura two layers of the body-wall were clearly distinguished by Professor
Allman, who had not the material aid which sections give the younger inquirers.
He called them ectocyst and endocyst, the latter “a very delicate membrane.”
Professor Sars, again, with fresh specimens at his disposal, denied that there was any
endocyst “(unless we consider the glassy skin, which closely surrounds the digestive
apparatus, to be an endocyst), consequently also no perigastric fluid.” Professor Ray
Lankester again, from the examination of living examples, recently observes of Rhabdo-
pleura that “the tissue which bounds the body-cavity consists of fusiform cells tapering
into fine fibres, sometimes brauched.” He further figures the structure of the body-wall
in optical and in transverse section, the coat formerly mentioned having within it
apparently a basement-membrane with ciliated enteric cells projecting from its inner
surface. In whatever way this form is considered, the structure of its body-wall very
much differs from that of Cephalodiscus.

I am unable from the mode of preparation of the examples (in spirit) to say much
about the pigment of the surface of the skin, but in some numerous specks of a reddish-
brown colour are still visible over the entire surface (PI. II. fig. 1); while, as already
mentioned, the buccal disk almost always presents the dull reddish band. In all
probability it is brightly tinted in life. In this respect it approaches the condition in
Balanoglosus, e.g., Balanoglossus kowalevskii has a white proboscis, a brilliant red-orange
collar with a whitish line round the operculum, while the rest of the body is orange-yellow.

Externally the surface is probably covered in life by a delicate ciliated cuticle, but
this cannot be differentiated in the preparations. The same difficulty is met with in the
euticular tissues of the Nemerteans. A decided difference is thus apparent between
Cephalodiscus and Loxosoma, in which the cuticle is considerably developed. What
remains is a well-marked layer of hypoderm (PI. VI. fig. 2, hp) of the usual granular,
glandular structure. The coat just mentioned attains its greatest thickness at the base
and on the pedicle, but this may be partially due to corrugation from contraction. In
this layer are the numerous pigment-corpuscles and gland-cells, which latter do not readily
stain with carmine. It is bounded internally by a basement-layer, which is thin dorsally,
but better marked ventrally, especially behind the mouth, for the layer of longitudinal
muscular fibres now forms an additional coat in this region, and rests against the base-
ment-layer. Like the hypoderm the latter passes over the pedicle at the posterior end
of the body, and both are often thrown into wrinkles from contraction. The body-wall

' 20 " THE VOYAGE OF H.M.S. CHALLENGER.

is: further strengthened ventrally by a muscular layer, but this will be described under

its special head. The preparations showed traces of what might be an. epithelial

layer on the inner surface of the before-mentioned basement-tissue, but such were far
from being distinct. In the living Riiabdopleura, on the other hand, such an epithelial
layer is described by Professor Lankester, under the name of “ enteric epithelium,” and its

“ distinctness in this form suggested its presence in Cephalodiscus.

. Body-cavity.—The foregoing layers enclose the body-cavity (co in sections of buds),
which. is generally filled more or less completely by the alimentary canal. In the
preliminary account’ it was pointed out that this investment was probably homologous
with the “thin glassy skin” of Sars surrounding the digestive canal*in Rhabdopleura,
and that the preparations gave no evidence of perigastric fluid. Though the existence of
a body-cavity was not specially noticed, the preparations did not warrant a denial of
its presence in Cephalodiscus, as Professor Lankester states in a recent paper,’ for thus
the hypoderm and basement-tissue must have been amalgamated with the coat of the
alimentary canal, which was not the case. This statement does not in any way detract
from the credit which Lankester has in clearly describing for'the first time the chamber
m the living Rhabdopleura. Small nucleated corpuscles “were occasionally seen in

‘groups in the cavity of Cephalodiscus in the sections, but they may have been intro-

duced from other sources. Neither Sars nor Lankester observed such in the living
Rhabdopleura. In sections the continuation of the body-cavities in front are seen a
little behind the paired cavities connected with the lophophoral apparatus, and are
likewise surrounded by basement-tissue.

Muscular System and Pedicle.

As previously mentioned, the short ventral surface of the body is continued
into the cylindrical pedicle, which is invested by the hypoderm and basement-tissue,
the former being thrown into numerous and_ rather regular transverse wrinkles
in contraction, and being thicker dorsally than ventrally. At the terminal region
of the foot (Pl VI. fig. 1, hps) the hypoderm’is much increased in thickness,
but has the same structure. It is free from the wrinkles which characterise
other parts of the region; and appears indeed in favourable preparations to form a
flattened sucker-hke disk. The basement-layer within the terminal hypoderm is thick,
and has attached to it the longitudinal muscular bands, so that it is possible it may be
occasionally used as a sucker like that of Loaosoma, or like the larval organ in
Balanoglossus. The entire pedicle: within ‘the basement-tissue is filled with the longi-
tudinal fibres, which arise on the ventral wall of the body in the region of the mouth,
where they present the form of a thinner lateral region and a denser central, the latter in

1 Op cit., p. 344. 2’Polyzoa, Ency. Brit., vol. xix. p. 436.

REPORT ON CEPHALODISCUS DODECALOPHUS. 21

the preparations being somewhat semicircular and of considerable thickness. These fibres
pass backwards (causing the ridge on the ventral surface in contraction) towards the
pedicle, which they enter, filling the central space. In transverse section the’ appearance
of the latter varies, but in the best preparations a certain uniformity is observable
(Pl. IV. fig. 5), viz., beneath the uniformly rounded hypoderm a median fold occurs
in the basement-tissue dorsally, while a much larger and wider one occurs ventrally,
and at each side of this an inner longer and an outer shorter process exist. The whole
has a symmetrical appearance. Such an outline would indicate that the basement-tissue
was elastic and that no circular muscular fibres existed, and indeed from the descriptions
of Vogt and other authors similar elastic tissues subserve the function of circular fibres
in Loaxosoma. In some sections of unstained examples the thick basement-tissue had
a somewhat different aspect (Pl. VII. fig. 2), probably from the condition after
immersion in spirit ; this, however, was exceptional. A layer of fine longitudinal fibres
hes on the inner surface of this coat, and from it numerous transparent and somewhat
gelatinous fibres of connective-tissue pass to the central area, which contains large
structures deeply stained and almost resembling gland-cells, but which appear to ‘be
sections of the long mobile muscular fibres continued from the fundus of the body into
the pedicle. The close approach made by these to the ‘‘muscular band of closely-set
fusiform cells” described by Lankester in the stalk of Rhabdopleura is noteworthy ;
they probably represent a further development of that tissuae—in which the cells have
disappeared. A similar series of muscle-cells in the axis of the stalk is described by
Harmer in his valuable paper on Loxosoma.' In contraction the transverse wrinkles of
the basement-tissue are so close that they resemble a circular muscular coat.

No distinct canal is thus observed in the centre of the pedicle throughout its length.
Towards the tip, however, certain spaces containing what appears to be a coagulable fluid
occur, and also globules and granules, as explained in connection with the buds.

The pedicle in Cephalodiscus is thus evidently a development of the body-cavity,
which in the young bud freely opens into its upper region. It differs, therefore, from
the soft stalk of Rhabdopleura, first so clearly described by Professor Allman, for that
has no connection with the body-cavity in the adult; yet as the development of both
forms is unknown a little reservation is necessary, especially as it also contains muscular
fibres in Rhabdopleura, and gives rise to the buds and branches. ‘The fibres of the stalk
in Rhabdopleura, according to Professor Sars, proceed “rather high up on the ventral
side,” and “over the skin which encloses the digestive apparatus. [ts ventral fibrous
part may still be traced (see fig. 15) a considerable distance forward in the form of a
rather wide, clear, skin-border which gradually disappears in front of the cardia. In
this skin-border the fine longitudinal fibres may still be distinctly observed diverging like
radii, but I was not able to trace their course further.”* The arrangement of the parts

1 Op. cit., p. 19. 2 Op. cit., p. 10.

22 THE VOYAGE OF H.M.S. CHALLENGER.

in Fhabdopleura has also been carefully figured on a larger scale from life by Professor.
Lankester,| There are thus interesting points in analogy between the two forms in
regard to the polypide-stalk, but at the same time important structural differences.

Professor Lankester again holds that the chitinous covering (his Caulotheca) of
certain parts of this region is the true homologue of the ccencecium of an ordinary
Polyzoon, and there is something to be said in favour of such a view. As already
explained, however, I prefer to adhere to the term already in use, especially in the
present uncertainty in regard to the development of the types under consideration.
Nor do I fully share my friend’s views concerning the “serious error” of confounding
the pedicle in the forms just mentioned with the funiculus of the Eupolyzoa. The
structural relations of the organ in the several forms no doubt differ, but the remarkable
analogy in regard to the budding shows that from the “vagrant protean funiculus” of
the Gymnolematous Ectoprocta to the pedicle and soft stalk of Cephalodiscus and
Rhabdopleura there is at least one striking function carried out often on very similar
lines. Variations it is true occur, in which the endocyst is associated with the funiculus
in producing the buds in the marine Ectoprocta, but this does not affect the main point
at issue, but rather brings the analogy closer with such forms as Cephalodiscus.

The pedicle on the other hand nearly resembles the stalk in Loxosoma. ‘There is no
pedal gland, however, in Cephalodiscus.

One of the most remarkable points of resemblance between Cephalodiscus and
Balanoglossus is the occurrence of a pedicellate structure in the young of the latter
(Balanoglossus kowalevskir) as described by Mr. Bateson.” This organ presents itself on
the disappearance of the cilia as a small papilla, and is situated at the central part of the
posterior surface. Moreover, it is directed ventrally, just as the pedicle of Cephalodiscus
is, and, indeed, the general contour of the young form at this stage simulates the
condition in Cephalodiscus. This conical process serves as a sucker by which “ the
animal can attach itself to foreign bodies sufficiently firmly to prevent being washed off
by a stream of water from a pipette. The anterior surface of the proboscis is also shghtly
suctorial, and by thus fixing itself posteriorly, and extending the proboscis, it is able to
creep slowly about, somewhat in the manner of a leech.” The organ “subsequently
attains a considerable size and is traversed by several wrinkles. It afterwards entirely
disappears, but as to its mode of disappearance I have no certain observations. It would
appear to occur very suddenly at the stage when the animal possesses seven to eight gill-
slits. I have found animals with eight gill-slits which possess this sucker, and also
animals of apparently the same age without it; hence it may be inferred that it under-
goes a rapid atrophy at this point.” Mr. Bateson further observes that similar suckers
occur as larval organs in Tunicata, Ganoids and Amphibia, but these fall far short, of the

1 Op. cit., pl. xl. fig. 12.
2 Quart. Journ. Micr. Sci., Stud. Morph. Lak. Univ. Camb., vol. iii. part 1. p. 3, pl. 1. figs. 1-4, 1886.

REPORT ON CEPHALODISCUS DODECALOPHUS. 23

interest connected with the condition of the permanent pedicle in Cephalodiscus. This
is a truly homologous process of the posterior body-cavities, and in sections at the base,
as already explained, the septum is visible (vide Pl. V. fig. 4). It is further placed
ventrally in regard to the intestine, and its tip, so far as structure shows, is in all
probability also used as a sucker; indeed, the buccal shield and the tip of the pedicle
form far more efficient and permanent sucking disks than ever occur at any stage in
Balanoglossus. It is the disappearance of the “tail” in the latter which alters the
character of its reproduction, and confines it so far as known to the sexual process. The
presence of this organ in Cephalodiscus, again, and its striking activity in bud-formation,
open up new fields in homology and assist in bridging over the gaps which formerly
existed between apparently isolated groups.

Nervous System.

In the preliminary account of Cephalodiscus' no distinct nervous system was
observed. In Rhabdopleura all that the careful observations of Sars could distinguish
in regard to a nervous system was that “immediately behind the anal aperture, between
the terminal part of the intestine and the dorsal wail of the gullet, which here forms a
little concavity, there appeared a clear vellular body (fig. 15, 7) in which several evident
nuclei were visible. I cannot, however, pronounce any decided opinion as to the
significance of this object ; it can scarcely be a nervous ganglion, as it does not lie in the
substance of the body itself, but only in the thin external skin which encloses the body.”
Lankester, again, considers that it is probable that the ‘clear cellular body” just
mentioned by Sars may be a gonad. It is doubtful, however, whether the latter interpre-
tation can be maintained, especially when the condition now known in Cephalodiscus is
cousidercd. At the base of the plumes in the latter, and situated over the median space
existing there—above the mouth—is in section a region (Pl. VI. fig. 3, ne; Pl. VII.
fig. 8, nc), which appears to me to contain the central nervous system of the animal.

The area is of considerable proportional size, and is minutely cellular and granular, while
fibrous bands stretching from it occur in other views. Its inner face rests on the thick
basement-layer bounding the collar-spaces at the base of the arms, and to the opposite
wall of which the muscular fibres of the great buccal disk are attached ; while its outer
covering is formed by a thick layer of hypoderm. This region forms an elevation dorsally
between the bases of the arms (Pl. VI. fig. 3, nc), and thus is in close communication
with these organs, while it is also within a short distance of the pigment of the oviducts,
though no branches have been traced to these organs. It extends a considerable distance
laterally on each side along the basal region, whence the plumes spring, and for some
distance on the dorsal surface of the buccal disk. The relations of the nervous system to

1 Ann. and Mag. Nat. Hist, ser. 5, vol. x. p. 337, 1882.

24 THE VOYAGE OF H.M.S. CHALLENGER.

the rudimentary.notochord will be specially referred to by Mr. Harmer in a note appended
to this paper. The view of Professor Sars that this structure cannot be a nervous ganglion,
because it does not lie in the substance of the body, would not seem to merit the
importance he attaches to it, when the condition of the great nerve-cords and ganglia of
Annelids, for instance, are considered. These are purely hypodermic in position, lying
between the latter and the basement-layer beneath.

In Phorons, again, a somewhat similar condition to that in Cephalodiscus is present,
the nervous concentration taking the form of a rmg round the mouth at the bases of the
tentacles, and which, like the cord running along the foot, is epidermic (hypodermic) in
position. The same position (hypodermic) of the nervous system is found in Balano-
glossus, so that the relations of the nerve-centre are by no means exceptional.

The position of this nervous centre would not appear to correspond with the larval
brain of Loxosoma as described by Mr. S. Harmer. In the stalked or adult Loxosoma,
again, the organ is absent, a condition due, Mr. Harmer thinks, to the fact that the larval
form dies after giving off buds. A very different condition, however, occurs in Cephalo-
discus, in which the young buds soon present this and all the other organs of the adult,
although it is true the development and perhaps metamorphoses of the species from the
egg are unknown. It has also to be borne in mind that certain parts of the central
nervous system may have been suppressed, and that we may have only a much modified
peripheral system remaining,

Sense-Organs.

In the prelimmary account of Cephalodiscus, the close relation of -the so-called eye-
spots to the ovaries was duly pointed out, and recently the examination of more
satisfactory sections made with a microtome demonstrated at once their true nature ; viz.,
that they are oviducts with thick pigmented walls. The resemblance of these structures,
both externally and in section, to a modified organ of sight, is one of the most remarkable
features in the animal. Their description will be given subsequently.

In Rhabdopleura, Lankester mentions the occurrence .of five spherical pigment-
corpuscles at the superior dorsal margin of the buccal disk, and regards them as rudi- ,
mentary sense-organs for the perception of light. The position of such is certainly peculiar
for organs of vision, but if Rhabdopleura has a trace of the central nervous organ
observed in Cephalodiscus, these would readily be within reach of its communications.

It is interesting that eyes occur in most larval Loxosome# ; indeed, they .-make their
appearance when the larva is still in the egg. They are situated under the hypoderm,
and resemble pigment-masses. In Loxosoma leptoclini, for instance, Harmer describes a
pigment-spot on each side of the larval brain (even when the lumen is still ‘present,..after
involution), They consist of crescentric reddish-brown masses of pigment, with a

1 Caldwell, Proc. Roy. Soc., vol. xxxiv. p. 372.

t
Or

REPORT ON CEPHALODISCUS DODECALOPHUS. 2

prominent lens, but whether the latter is a solid body, a cuticular formation, or only
fluid in the centre of the mass, is not explained. Mr. Harmer bases one of his arguments
for the interpretation he has’ given of the “‘ dorsal organ” (brain) on the constant relation
to each other of ganglion-cells, a fibrous layer and the eyes, and he seems to have facts
in his favour.

In Rhabdopleura a ciliated tubercle (considered by Lankester and others to be a
sense-organ) was discovered by Sars on the dorsal surface at the base of each arm of the
lophophore. In Loxosoma also Vogt' describes a tactile papilla on each side near the
arms, and Salensky ° traced nerves from the ganglion to these posterior sense-organs in
Loxosoma crassicauda. No such organs, however, can be observed in the preparations
of Cephalodiscus, though it is possible the search im the living animal might be more
successful. The oral folds of glandular tissue and the parts connected with the gill-
fissures are probably highly sensitive and ciliated, but no other sense-organs could be
observed.

Reproductive Organs.

No differentiation was noticed in regard to the sexes, and no dimorphism of the
zoids, as in Professor Ehler’s remarkable burrowing form (Hypophorella expansa’).
Nothing is more striking, however, than the profusion of buds and the abundance of
ova, apparently one of the chief ends of the species being propagation. The chambers
of the coencecium present many of the large ova, and they are occasionally found amongst
the plumes, as in Phoronis, with its swarms of minute eggs; but such in the former is
probably accidental ; and almost every adult bears one or more buds attached near the
tip of the pedicle.

Ovary.—In most specimens a pair of large ova are observed projecting anteriorly
(Pl. III. fig. 2, ov), so that their pure white colour is recognised through the attenuated
integument above and behind the eye-like oviducts, which, as it were, mark the anterior
boundary of the ovary. In section it is found that a septum passes from the median
wall of the rectum to the opposite wall of the body, thus dividing the body-cavity in
that region into two spaces, in which are the ova supported on a pair of lateral
mesenteries. As soon as the glandular tissue forming the dorsal wall of the buccal
cavity appears, the mesenterial septum just indicated is attached to its basement-layer
externally, and also more or less in the median line. The septum disappears on the approach
of the stomach, or about the posterior termination of the great buccal disk, and any
product remaining towards the end of the latter is generally pushed to one side. As a

1 Sur les Loxosoma des Phascolosomes (sep. copy), p. 8, pl. xii. fig. 1.

2 Ann. d. Sci. Nat. (Zool:), sér. 6, t. v. p. 12 (art. 3), pl. xii. figs. 2, 3.
3 Abhandl. d. k. Gesellsch. d. wiss. Gottingen, 1876.

(ZOOL, CHALL. EXP,—PART LXU.—1887.) Qaq 4

26 THE VOYAGE OF H.M.S. CHALLENGER.

rule anteriorly one of the spaces contains a group of small ova (Pl. VI. fig. 2, ov), with
nucleus and nucleolus. In the smallest ova observed the nucleus is very distinct, and of
a more or less rounded form and with a large nucleolus. The yolk outside the former is
minutely granular, and sometimes, to judge from the preparations, does not quite fill the
egg-capsule. As the eggs increase in size the yolk-granules become somewhat more
distinct, the nucleus being large and rounded, and the nucleolus a highly refracting
circular body of considerable size. Moreover, as\ they increase they tend to move away
from the smaller ova, and indeed bulge outwards on the opposite side. The largest ova,
of which, as a rule, there is only one, are much more coarsely granular, and present only
a nucleus with minutely granular contents, the nucleolus having disappeared or having
become very indistinct. The capsule surrounding each of the eggs is definite and
tough, and the eggs are further enveloped by a common layer, which in all probability
is allied to the follicular layer in fishes and other types, and this dips between each,
apparently enclosing the ova in separate chambers. The ova are probably extruded
through the oviducts with the pigment in their walls, and it is noteworthy that, as Mr.
Harmer has specially pointed out to me, no pigment is visible in young individuals in
which the ovaries are not yet functional. There is thus an approach to the condition in
Loxosoma in this respect, for the latter has oviducts for conveying the ova into the
vestibule. The same may be said with regard to Phoronis, though in this the so-called
nephridia lie on the other side of the intestine.

The comparatively large size of these ova recalls the condition in the Aegan in
which the great ova produce embryos about a third the size of the adult.

Oviducts and Pigment.—On the ventral surface are two large and conspicuous
pigment-spots, which as already mentioned closely resemble eyes: they indeed give a
most peculiar and characteristic aspect to the animal when viewed from the ventral
surface. These are placed a little in front of the anterior margin of the post-oral
lamella, and in ordinary preparations are more or less covered by the buccal disk.
They are circular or irregularly rounded, and of various shades of brown or
reddish-brown, with occasionally a tinge of violet. In ordinary views from the exterior
these organs show a pale centre surrounded by a broad margin of pigment, so
that the former assumes the aspect of a lens (Pl. VI. fig. 2, od). In section the
hypoderm in the central region is hollowed more or less deeply, and its wall
presents a finer, columnar arrangement of its cells, and, in addition, it is almost, if not
quite, transparent. Moreover, an aperture exists in the centre, as already mentioned.
In shape the ducts have the form of a blunt cone, the apex of which abuts on the _
modified hypoderm, while its base rests on the small anterior ova. The pigment-cells
form a thick layer; their inner pale portions projecting internally, so that their
resemblance to an optical apparatus is remarkable. Nothing intervenes between their
cavity and the ovigerus envelope, and indeed, as formerly stated, they are so closely

REPORT ON CEPHALODISCUS DODECALOPHUS. 27

related that they are generally removed together in dissection. No nerve-fibres could be
traced from the central organ to these organs, though appearances were favourable to
such a view. Mr. Harmer, who independently arrived at a similar conclusion with
regard to the function of these organs, thinks the pigment of an excretory nature.

On extrusion the ova (PI. V. figs. 5, 6) are pure white, and either pyriform or rounded
in shape. Each is provided with a well-formed pedicle of the transparent investment,
truncated at the extremity for attachment. The diameter of the circular kind is about
z's inch, or including the short stalk 75 inch. In the more pyriform or longer forms the
total length (including the stalk) is about 3% inch, and the transverse about 345 inch.
The diameter of the contained yolk is about 7 inch in the former kind, and in the latter
is nearly of the same proportional size, though more ovoid in outline. A large space
(perivitelline) existed around these eggs, but whether endosmose had occurred after
deposition, or otherwise, is at present unknown. The capsule is hyaline and structure-
less, presenting only a few wrinkles at the base of the stalk, which is hollow and
truncated at the tip. The opaque white central region is coarsely granular, as in the
intra-ovarian eggs. ach is attached to the wall of the chamber of the ccencecium by the
pedicle, though as now seen, that is after the action of spirit, many have become
detached.

The products of the foregoing ova are yet undiscovered, though in all probability
they are motive embryos which carry the species to fresh sites on which to construct the
eoencecium. Such embryos had all been swept out of the chambers either before or after
capture, as no trace of such could be found in the preparations.

The reproductive organs seem to be more largely developed in this genus than in
Rhabdopleura, none indeed having been found in the latter by its discoverer, Professor
Allman, or subsequently in the living examples by Professor Sars. Professor Lankester,
however, was successful in finding a testis in “the form of a much elongated sae ending
blindly at one end and opening by the other to the exterior by a special pore.” The
latter occurs near the anus. The position of the aperture of the male generative system
thus probably indicates what will be found in the living Cephalodiscus, and it is possible
that the male organs are developed at a different period from the female in the same
animals, or that the males exist in different colonies. In some of the sections of the
reproductive organs minutely granular masses like sperm sacs were occasionally seen, but
further examination gave no grounds for supposing that they were anything but im-
perfectly preserved contents of the ovaries.

Budding.

No feature is more striking in this species than the great abundance of buds throughout
the entire series of adults inhabiting the coencecium. Very few exist without them, most

28 THE VOYAGE OF H.M.S. CHALLENGER.

presenting from one to three or more buds at various stages, and in all cases these.
proceed from the terminal region of the pedicle.

The early buds consist of minute and, in the preparations, somewhat pale clavate, or
pyriform bodies attached by the narrow end to the pedicle. They are situated round or
near the tip (which has the thickened investment), and are observed as little processes
projecting from the hypoderm. They appear to rise close above the terminal disk, and,
in their earlier stages at least, seem to have a channel of communication with the pedicle
of the adult (Pl. VI. fig. 1, ch). This channel runs upwards along the stalk of the bud
as far as the downward bend of the hypoderm (shield) where it is lost. In the earlier
buds longitudinal sections, for an examination of the best of which I am indebted to Mr.
Harmer, show, very clearly the three regions of the body, viz., shield, nuchal region and
body-proper, and each has its special spaces. Thus the shield presents its single cavity,
the nuchal or collar-region its paired spaces, and the third region contains the body-
cavity divided by the mesenteries (dorsal and ventral).

Very soon the pedicle is differentiated from the disk; the young animal consisting of
a large, flat, and somewhat thick disk, and a short, broad and somewhat crenate pedicle
attached to the parent. Two ovoid opaque thickenings are observed about this stage
dorsally (Pl. V. fig. 3, dp), and these are the earliest indications of the lophophoral
plumes. In cross section from above downwards the shield consists of a thick layer of
hypoderm which attains its greatest development ventrally, for this coat is in the form.
of a flattened ring round the central chamber. The latter is bounded by a firm investment.
of basement-tissue having fibres internally. It is this chamber in the younger forms that
communicates with the pedicle of the adult. The two dorsal bosses are simply hypodermic
growths of the upper layer of the shield, and present an elevation between them.

At a somewhat lower level the elongated cavity in the centre of the shield gives place
to a rounded median chamber (Pl. V. fig. 3, ve), with the dorsal hypodermic mass above
it; while the great bosses of the plumes lie on each side. ‘The latter still present the
same structure as the hypoderm of the broad disk, though there is a faint indication
of a linear streak in the centre. In the next slice the two nuchal or collar-spaces appear,
with the alimentary canal in the centre. In the septum, between the collar-spaces, the
tip of the notochord is observed, and it appears to be larger proportionally in the young
than in the adult. The basement-tissue bounding the nervous centre is now defined,
and the shield and bosses are diminishing. Behind this the folds of the alimentary
canal fill the central region of the body, the intestine being especially distinct as a
median canal, the longest axis of which is directed ventrally instead of being transverse
as in the adult. Posteriorly the body presents, firstly, two lateral chambers with fibres
internal to the basement-layer, and secondly, a median (dorsal), with a process of
basement-tissue running to the ventral line, and forming the septum between the two
former. ‘The pedicle seems to be filled with muscle-cells.

REPORT ON CEPHALODISCUS DODECALOPHUS. 29

In the terminal region of the pedicle of the adult certain areas containing a coagulable
fluid with globules and granules are present, and occasionally in the elevation caused by
a developing bud one or two of them are observed; and they are also seen in the buds
here and there in the course of the central muscles of the pedicle. Some appear to be
nucleated. The origin of these bodies is unknown, but they may be connected with the
mesoblastic or hypoblastic elements for the buds, though this is only a conjecture. In
regard to the presence of the three primary embryonic elements, as a rule, in such buds,
the remarks of Professor Haddon * seem to me to be very interesting, but they have yet
to be proved. The doubt remaining in the present case, for instance, relates to the precise
nature of the hypoblastic elements. In connection with this subject it is well to state
that some observers, as Mr. Harmer, demur to the connection of the latter layer with the
origin of the buds.

As development proceeds, the anterior or disk-bearing region of the body increases
much more in proportion than the posterior or pedicellate part. The buccal disk is
rapidly enlarged, and shows traces of the broad arch of pigment anteriorly and the
reddish band posteriorly, as well as the two median elevations on the surface. The
posterior moiety of the disk is especially large. Moreover, the body begins to project
outward superiorly, and the papillee of the plumes increase in number. These papillz
form a slightly curved row in front of the dorsal projection of the body (woodcut,
fig. 2).

In the next stage the disk is almost completely formed, though of smaller size and
more massive than in the adult. It is thickest anteriorly, much thinner posteriorly.
In the former region it presents in transverse section the elongated central chamber,
bounded ventrally by the massive hypoderm of the shield, which has the two median
prominences observed in the adult. This hypoderm folds over at each side, and is
continued as a thinner stratum dorsally, with a basement-layer next the chamber. Two
additional structures HEE ON appeared, viz., a dense (narrow) layer outside the basement-
tissue just alluded to, and fan-like fibres from the middle of the dorsal wall of the
chamber. ‘Two of the most ventral plumes (the first to appear) have now attained some
size, the tip being furnished with the radiate terminal glands, with the central chamber,
and the sides with short papille representing the filaments. Both the latter and the
axis of the plumes are composed of hypodermic tissue, and are apparently solid. Longi-
tudinal striz are visible along the centre of the axis, and they run into the lining of the
cavity in the terminal enlargement. Then the central chamber appears dorsally
in the middle line (PI. V. fig. 3, ve), and the fibres to the ventral wall of the shield radiate
out from the basement-tissue. Dorsally several less developed plumes also make their
appearance (Pl. VI. fig. 4), and the pale (nervous) area lies under the hypoderm. Next
the two nuchal chambers take the place of the former, and the hypoderm over the median

1 Op. cit., p. 34, Ke.

30 THE VOYAGE OF H.M.S. CHALLENGER.

nerve-area increases much in thickness, the whole forming a somewhat triangular region
between the bases of the plumes, which are thus carried outwards. None of these plumes
are so well developed as the first pair. While the nerve-area retains a large size, with the
two chambers and the fan-like fibres ventrally (Pl. VI. fig. 5), the knife now severs the
anus, which at this stage hes close behind the massive dorsal hypoderm of the nerve-area.
Then the glandular wall of the buccal chamber and the post-oral lamella appears, while
the body-cavity on one side of the rectum presents a granular mass (Pl. VII. fig. 4, ov),
the rudiment of the ovary. The great buccal disk becomes much broader as well as
thinner, and is solid, while a central chamber appears in the post-oral lamella. The
body-cavity is much better marked in the young forms than in the adults, and
just behind the mouth (Pl. VII. fig. 5, r, vt, oe) has in section a symmetrical arrangement
of the gullet, stomach and intestine, the body-wall showing the basement-layer beneath
the hypoderm. The pharynx, gullet and stomach are rounded or ovoid in transverse
section, but the intestine is triangular. The longitudinal muscular fibres appear along
the ventral wall immediately behind the mouth, and soon form the marked pattern so
characteristic of the region (Pl. V. fig. 4, co). The body-cavity thus shows from above
downwards the comparatively small intestine, now rounded, and the massive glandular
wall of the stomach in the middle, both being surrounded by a firm investment which
leaves what may be called the keel of the stomach to be attached to a pointed incurvation
of the ventral wall. On each side of the latter is the thick central mass of the longi-
tudinal muscles, which externally also present another increase before being lost on the
body-wall. A considerable perivisceral cavity exists on each side of the digestive organs.

Behind the foregoing the body-wall becomes thicker and the central chamber less,
especially as the stomach ends in the intestine. The ventral muscles have considerably
increased in bulk, and the double inflection for the longitudinal muscles on each side of
the median line more marked. At the curvature of the alimentary system in the body-
eavity, the pedicle proper commences, the external wall having a proportionally thicker
coating of hypoderm than the body-proper, and supported internally by the basement-
layer, rthich forms the W-shaped pattern inferiorly with a secondary curve on each outer
leg. The ventral half of the space is filled with the muscular fibres, while the rest is
split into two divisions by the median septum continued from the alimentary canal. The
sides of the septum and the inner surface of the wall are covered with fibres. The
buccal shield extends backwards to this region in the form of a broad, thin lamella, having
a median line of basement-tissue separating the ventral and dorsal layers of hypoderm,
and so little has the pedicle increased in length, that in some cases the free posterior
margin of the disk almost touches the pedicle of the parent to which the bud is attached.
The pigment inthe disk now approaches the condition in the adult.

The body-cavity of the buds at this stage thus glides insensibly into the first part of
the pedicle, but the brevity of the latter organ gives rise to rapid changes in section.

REPORT ON CEPHALODISCUS DODECALOPHUS. 31

The next slice, indeed, shows the muscular fibres filling up the entire central area of the
pedicle, while the septum proceeds only a short distance inwards from the dorsal wall.
A somewhat radiate arrangement of the fibres also takes place, and is best marked
ventrally in transverse section. After a short course the fibres terminate on the hypo-
dermic covering of the end of the pedicle, which at this stage presents proportionally
great development. The immature pedicle of the bud thus differs from that of the
adult in the outline of the basement-layer, which is simply reniform in transverse
section, whereas that of the adult presents two maxilla on each side ventrally, and a
median dorsal fold.

Externally, as indicated, the short pedicle almost immediately follows the anterior
dorsal projection of the body; and as a peculiar curvature of the latter has now taken
place, the tip of the pedicle scarcely projects beyond the margin of the disk. Shortly
after reaching the stage just described, and while the symmetrical series of filaments on
each side of the plumes is quite small, the bud separates from the parent. The pedicle
and its sucker-like hypodermic termination are fairly developed; and as soon as it is
detached (and sometimes before) a little bud appears near the tip. Thus the increase of
the species by budding alone must be remarkable, even comparatively young forms
giving rise to a succession of buds. One or two buds are most frequently seen on
the pedicle of the adult, though occasionally three or more exist.

Shortly before obtaining freedom the buds in some cases present a_ striking
resemblance to certain stages in the buds of Rhabdoplewra, as shown by Professor
Allman. Thus in examples in which the first pair of plumes are very long and the
succeeding short, while the stalk is in a state of extension, a condition closely
approaching Professor Allman’s figure 8* is produced.

The buds thus differ from those in Rhabdoplewra in attaining freedom on reaching a
certain stage, but both probably arise in a similar way, two at least of the embryonic
layers taking part in their production. The first layer is represented by the dermal
layers, nervous centre, buccal region, and the rectum, and the second by the skeleto-
genous tissue and longitudinal muscles. The presence of the third layer, as already
mentioned, is more doubtful, though it is possible that the cells and globules observed
towards the end of the pedicle may be of hypoblastie origin, being derived from the
central region of the alimentary canal. The sections of the younger buds present, in
the arrangement of the alimentary canal, a close resemblance to the young Pedicellina,
as shown by the careful researches of Dr. Barrois and Mr. Harmer. The position of the
ganglion in the diagram? of the latter would nearly correspond with the nerve-centre
in Cephalodiscus.

In Loxosoma the position of the buds is very different, viz., in the region of the
stomach, and there are never more than two.

! Quart. Journ. Mier. Sci., pl. viii. 2 Quart. Journ. Mier. Sct., pl. xxii. fig. 19.

32 THE VOYAGE OF H.M.S. CHALLENGER.

HoMOLOGIES.

Cephalodiscus approaches very nearly to Rhabdopleura in almost’ all the structural
features, and it is probable, when more complete investigation of both is carried out,
these resemblances will be increased rather than diminished.

Thus the Ceneciwm in both is largely developed and wholly independent of the
polypides, while it is mainly secreted by the buccal shield or disk. The regularly ringed
cylindrical cceneecium of Rhabdopleura is, however, very different in form from the
irregular, much branched and hispid ccencecium of Cephalodiscus. Moreover, in the
latter it is the secretion of the adults, whereas in Rhabdopleura much of it would
appear to be the product of the younger buds. Phoronis, again, secretes its simple
gelatinous investment in the sand, or in the form of tubes attached to stones or other
foreign bodies, while an Australian species betakes itself to the gelatinous case of Ceri-
anthus. There is thus comparatively little method in the formation of its isolated
dwelling. Balanoglossus, on the other hand, has only a mucous lining to its perforation
in the sand, though the secretion of this form is also very abundant. Moreover, Bateson
describes a peculiar odour in the living animals, and the spirit-preparations of Cephalo-
discus also give evidence of a characteristic odour, though it may differ from that of the
former.

The general form of the polypides of Cephalodiscus and Rhabdopleura diverges
very considerably, the former being free, while the latter is fixed by the axial stem.
Both, however, are small, while the size attaimed by Phoronis is a distinctive feature,
as also is the absence of a pedicle from its cylindrical body.

The Buccal Shield is much larger in Cephalodiscus than in Rhabaoeieua, and its
secreting powers more active. The buccal shield is absent in Phoronis as such, but is
represented by the epistome. As will be pointed out by Mr. Harmer, the proboscis of
Balanoglossus appears to be the homologue of the disk, though only one proboscis-pore
is present, while two exist in Cephalodiscus. Further examination is necessary in

regard to these organs in Rhabdopleura.

The Branchial Plumes have a kind of skeletal system or basement-tissue in both
Cephalodiscus and Rhabdopleura, but they are much fewer in the latter than in the
former, which, moreover, has a bulbous and glandular tip to the main axis, thus simulating
such organs as the large eye at the tip of the branchie of Branchiomma. The large
size and firm nature of the simple branchial filaments of Phoronis are sufficiently
diagnostic, as also is the fine, double, convoluted arrangement seen in the Philippine
and Australian forms. The skeleton and circulatory system of these organs is much
more highly developed than in either Cephalodiscus or Rhabdopleura. In Balano-
glossus, again, considerable divergence has happened, for the branchize are now arranged
in lateral series along the second region of the body, and are supported by an

REPORT ON CEPHALODISCUS DODECALOPHUS. 33

size and firm nature of the simple branchial filaments of Phoronis are sufficiently
diagnostic, as also is the fine, double, convoluted arrangement seen in the Philippine
and Australian forms. The skeleton and circulatory system of these organs is much
more highly developed than in either Cephalodiscus or Rhabdopleura. In Balano-
glossus, again, considerable divergence has happened, for the branchize are now arranged
in lateral series along the second region of the body, and are supported by an
elaborate skeleton of chitinous elements’ and furnished with numerous gill-slits. Such
a modification, however, does not seem very far fetched when a section of the bases of
the filaments after entering the axis of the plumes is made in Cephalodiscus. In
connection with the arrangement of the plumes it is also interesting that in the
Eupolyzoa (e.g., as described by Allman’ in Paludicella, Nitsch® in Flustra mem-
branacea, and Haddon* in Flustra earbasea) the growing tentacles in the bud present
bilateral symmetry.

The Circulatory System is evidenced only by the lacunz (nuchal or collar spaces)
and their connections with the bases of the plumes in Cephalodiscus, but it would
appear to be more largely developed than in Rhabdoplewra, for its presence has not yet
been indicated in that form. The circulatory system in Phoronis attains a much higher
degree of complexity, for its large vascular ramifications with the well-marked nucleated
corpuscles have no parallel in either. Cephalodiscus, however, agrees in that its collar-
spaces are in connection with the reticulated or lattice-like centre of the main stem in
each plume. The circulatory system in Balanoglossus, again, is also largely developed,
especially in connection with its branchial system, though the contents of the vessels are
less conspicuous. On this head all the foregoing widely diverge from the ordinary
Polyzoa.

The Digestive Apparatus in both Cephalodiscus and Rhabdopleura closely agrees
with the type in the Polyzoa, all being characterised by the flexure which causes the
close proximity of mouth and anus. Moreover, the pyloric differentiation indicated in
Cephalodiscus is prevalent in the Polyzoa and also in Phoronis, and though it has not
been described in Rhabdopleura, traces of it may yet be found. The environment of
the mouth in the latter and Cephalodiscus is related, but while the post-oral lamella is
connected with the buccal shield in Rhabdopleura, it forms a special structure in
Cephalodiscus. In Phoronis the general plan of the digestive system is the same,
though the pyloric region of the stomach attains much greater size. In regard to this
system all the foregoing closely approach the Eupolyzoa, the cesophagus, stomach, pyloric
vestibule, intestine and rectum showing a similar arrangement. When Balanoglossus,

1 Vide Monograph on the Brit. Nemerteans, Ray Society, 1872-73, p. 146.
? Fresh-water Polyzoa, p. 36.

3 Zeitschr. f. wiss. Zool., 1871, Bd. xxi. p. 457.

4 Quart. Journ. Mier. Sci., 1883, vol. xxiii. p. 518,

(ZOOL. CHALL, EXP —PART LXIL.— 1887.) Qaq 5

34 THE VOYAGE OF H.M.S. CHALLENGER.

however, is contrasted with them very considerable differences are encountered, one of»
the most decided being the straightness of the canal and its terminal anus.

The Nervous System is pre-oral in Cephalodiscus and it has a somewhat peculiar’
structure. It is situated between the hypoderm externally and the basement-tissue
internally. None has yet been described in Rhabdopleura, and thus comparison at
present must remain in abeyance. In Phoronis the nervous elements, which he along
the base of the branchial processes, are similar to those in Cephalodiscus, and there 1s
also a central area between mouth and anus. The nervous system is subhypodermic,
and is chiefly concentrated in the corresponding region to that in Cephalodiscus. So
far as known, therefore, all have something in common under this head.

Unless the oviducts in Cephalodiscus are to be credited with remarkable functions,
sen e organs, so far as can be noticed in the spirit preparations, are absent. Further
inquiry is necessary on this head, but I am inclined to consider with Dr. Marcus Gunn,
on whose special experience and caution I place reliance, that there is no refractive
mechanism. This localized pigment perhaps indicates either phosphorescent organs or
local heat-producers. In Rhabdopleura a pair of ciliated pads or papillee occur at the
bases of the plumes, the minute structure of which, however, is in need of careful
revision. Phoronis, again, presents only the ciliated furrows, which are external to the
anus, and have a nervous expansion beneath the hypoderm. In Loxoesoma papille similar
to those just described occur on the dorsal aspect, and the subcesophageal ganglion is
well developed, as shown in Harmer’s beautiful researches on Loxosoma crassicauda.

The structure of the Body-wall in Cephalodiscus considerably diverges from that in
Rhabdopleura, the definite layers of hypoderm and basement-tissue in this form
contrasting with the cuticular epithelium and underlying connective-tissue cells in the
latter. Something like basement-tissue seems to be indicated in Lankester’s pl. xl.
fig. 12 (though no mention of it is made), and he describes and figures the enteric
epithelium lining the body-cavity, the cells being connected with the wall of the stomach
by processes. The body-wall in Phoronis again deviates from that in either of the
foregoing, since, besides cuticle, hypoderm and basement-tissue, it shows a circular and a
longitudinal muscular coat, the latter being chiefly grouped m longitudinal bands which in
transverse section show a somewhat pennate arrangement. ‘There is little in common,
therefore, beneath the basement-tissue, and the absence of the pedicle in Phoronis is a
marked feature of divergence. The structure of the body-wall of Cephalodiscus most
nearly approaches that of Balanoglossus, though there is a wide gap in this respect as
there also is between it and Phoronis. In Loxosoma a transparent cuticle and a
hypodermic layer ‘associated at certain points with muscular fibres more or less
pronounced,” according to Vogt are present.

Cephalodiscus and Rhabdopleura agree in certain respects in regard to the Body-
cavity, but the former has the pedicle as an appendix. Phoronis on the other hand has

REPORT ON CEPHALODISCUS DODECALOPHUS. 39

. a much more spacious chamber divided by various mesenteries. In Balanoglossus this
. chamber posteriorly is inconspicuous in the adult. The condition again in the Ento-
proctous Polyzoa (e.g., Loxosoma) considerably diverges, for no body-cavity exists; while
in the Phylactolemata it is present in the adult, and is lined by ciliated epithelium, such
not being the case in the body-cavity of the Gymnolzmata.

It is an interesting fact that the Muscular System both in Cephalodiscus and Rhabdo-
pleura is connected with the pedicle, if we may for the moment so term the soft
contractile stalk of the latter. In the former, however, it is much more largely developed
and is continued directly from the body-cavity ; whereas in Rhabdopleura it is wholly
external to that chamber, and is less distinctly differentiated on the surface of the axial
skeleton, which forms another feature of distinction in this form. If the funiculus of
one of the Eupolyzoa be disconnected from the digestive system and formed into an
external process in the line of the ordinary communication-plate, something similar in
structure and function to the pedicle in the Aspidophora will be made. As a rule in the
same group the retractor muscles of the body and lophophore arise from the peritoneal
lining.

The funiculus of the Eupolyzoa, according to Haddon, is probably derived from the
irregular strands of funicular tissue which occur in the parent zocecium. It appears as a
thickish cord stretching from the fundus of the developing polypide to the base of the
zocecium. It is in direct communication with the brown body, directing ‘
alimentary tract to that nutritive mass, thereby ensuring the better nutrition of the

the developing

growing bud.” The bud is thus developed at a distance from the brown body, but
approaches it and extracts nutriment from it. This has been noted by other authors.
In Loxosoma the stem quite differs, since there is no communication with the body-
cavity.

The present condition of our knowledge of the Reproductive Organs, both in Cephalo-
discus and Rhabdopleura, is incomplete, so that a satisfactory comparison cannot be
made. The ova in the former are very large, but no male elements have been seen. In
Rhabdopleura the testis occurs as a long sac adjoining the intestine and even
projecting beyond the abdomen. It opens near the anus, and thus agrees with the
condition in Cephalodiscus and Phoronis, as well as offers certain resemblances to the
condition in the Entoproctous Polyzoa. ‘The reproductive organs in Phoronis are
posterior in position, and both male and female elements are usually conspicuous. In
Balanoglossus these elements occur between the liver and the anterior part of the body.

The early appearance of the ova in the young buds of the Eupolyzoa, for instance
Bugula flabellata, as noticed by Haddon, is worthy of mention. These ova are in close
relation to the wall of the digestive tract. The distinction of the Aspidophora from such
of the Eupolyzoa in which the ova of the parent pass ready-formed into buds is
marked.

36 THE VOYAGE OF H.M.S. CHALLENGER.

Budding.—The fact that Cephalodiscus is free while Rhabdopleura is fixed causes
considerable divergence in regard to the buds; and, moreover, the functions performed
by the bud in the latter species, while yet incompletely developed, and with a bifid
buccal shield (viz., the secretion of the ccencecium or tubarium) is an important difference.
Another essential divergence is the occurrence of the buds in a regular series on Rhabdo-
pleura, the youngest nearest the terminal polypide, the oldest next the distal. The
confinement of the buds in Cephalodiscus to the region just within the terminal
hypodermic plate is peculiar, and makes it difficult to institute anything like parallelism
between them in this respect. Further, Lankester is inclined to think that after the
complete development of the polypide in Rhabdopleura, there is no evidence that it
takes upon itself bud-production ; that is to say, the buds are given off at an early period
of its growth. It is not quite clear, however, that the budding of this form is in the
same category as that of Cephalodiscus, in which the stalk is a process of the body-cavity,
whereas the soft stalk of Khabdopleura, if the descriptions are understood correctly, has
not yet been shown to be so, though at first sight it might be interpreted otherwise.
Nothing like the arrested buds of this form is known in Cephalodiscus. The source of
the hypoblastic elements, if these are present, in the bud of Rhabdopleura is thus in
obscurity. In Phoronis no bud is known, while the small ova are extremely numerous,
and the embryos (having the form of the well known Actinotrocha) pelagic. In
Balanoglossus likewise no bud occurs, the ova are numerous and small, and the embryo
free-swimming (Tornaria).

On taking a general survey of the subject, then, it occurs to me that in the present
state of our knowledge, and while fully admitting the remarkable resemblances between
it and certain hitherto isolated types such as Balanoglossus (which I have for the most
part left in the able hands of Mr. Harmer), it will lead to no disadvantage if Cephalo-
discus be left as formerly near the Polyzoa ; and, further, though the divergences between
it and Rhabdopleura are noteworthy, in the same group as formerly, viz., the Aspido-
phora of Professor Allman. It is well to exhaust the structural, developmental, and
other features in the various forms reviewed in the preceding paragraphs before changes
in classification are promulgated.

Cephalodiscus approaches the Polyzoa in regard to its cceneecium, its digestive
system, and its buds, and it is peculiar that in these points there is a lack of conformity
in Balanoglossus, and to some extent in Phoronis. Viewed as a whole, the several
systems mentioned agree most with the type of the Polyzoa. Though Phoronis forms a
tube, and Balanoglossus secretes very abundant mucus, a feature common to many
diverse groups, such as the Nemerteans, Discophora, and Mollusca, nothing like the
regular ceenceecium of Rhabdopleura or Cephalodiscus is constructed. While again the
digestive system of Phoronis resembles that in the Polyzoa, the same system in Balano-
glossus is very different, for the straight alimentary canal with its terminal anus has no

REPORT ON CEPHALODISCUS DODECALOPHUS. 37

parallel in the life-history of Cephalodiscus, not even an embryonic approach occurring
in either form. The anus in Balanoglossus is posterior and terminal at all stages. The
relations of the dorsal and ventral surfaces in the two forms are also at variance. Buds
again, are unknown in either Phoronis or Balanoglossus, and in both the eggs are very
numerous and small, whereas in Cephalodiscus they are few and very large.

The main resemblances between Cephalodiscus and Balanoglossus lie in the structure
of the skin, the presence of three body-cavities (disk, collar, and body-proper), the
proboscis or disk-pores, collar-pores, gill-slits, and rudimentary notochordal structure,
and they are of a most interesting and suggestive character; and as Mr. Harmer, whose
valuable researches on the Entoproctous Polyies are well known, has most ably studied
these features and formed independent conclusions, I have thought it best to give his
views in his own words as an Appendix. These will show how difficult it is in some
cases to draw clear lines of distinction—so intimately are the several characters, in
apparently diverse groups, blended. In a former paper! I had observed with regard to
Phoroms and Balanoglossus—<If indeed the branchial skeleton supporting the vessels
(of Phoronis) were thrown in, and arranged at the sides of the anterior region of the
body, so that the water would enter by lateral slits to aerate the circulating fluid, and
the digestive canal enlarged and attached as a single tube to the body-wall, a form
resembling Balanoglossus would be indicated.” It has to be borne in mind also that
Alexander Agassiz thought that the latter resembled the Tunicates from the nature of
the gills and their mode of formation, in opposition to the views of Kowalevsky and others,
who placed its affinities with the Annelids proper.

Perhaps Balanoglossus may at present be ranged near the Aspidophorous group of
the Polyzoa, for though Metschnikoff’s view that it approaches the Echinoderms rests on
the remarkable fact that in Tornaria the original evagination from the gut is on the left
side, just as in Asteroid larvee the water-vessel is developed from the left primitive
diverticulum (Bateson), yet there are stronger reasons for associating it with other groups
as above mentioned.

1 Proc. Roy. Soc, Edin., Session 1880-81, vol. xi. p. 217.

APPENDIX,

By Srpyry F. Harmer, B.A., B.Sc., Fellow of King’s College, Cambridge, and of
University College, London.

The following observations on Cephalodiscus were made in consequence of a letter
received from Professor M‘Intosh, calling my attention to certain remarkable features
in the anatomy of the genus. I am very greatly indebted to Professor M‘Intosh for his
courtesy in giving me specimens of Cephalodiscus, and most of all for his kindly
expressed desire that I should publish my conclusions as an appendix to his ewn mono-
graph. ‘Time has not permitted of my seeing the proofs of this monograph, and I must
therefore claim indulgence for any descriptions which would
otherwise appear unnecessary repetitions of the results of Pro-
fessor M‘Intosh himself.

In examining sections of Cephalodiscus, I have been struck
with the existence of various organs which appear to me to
point to the conclusion that this remarkable genus is a near
ally of Balanoglossus. This very unexpected result will be
understood by comparing the following woodcuts (with the
remarks which accompany them) with Bateson’s papers on
the anatomy and development of Balanoglossus."

Fig. 1 represents a longitudinal, right and left section, of a

4 F Fia. 1.—p., proboscis; c., collar; ¢fr.,
young bud of Cephalodiscus. The resemblance between this See apatite gene rey
section and Bateson’s diagrams of the larvee of Balanoglossus? er ae ead
is, in all essential details, exact. The body of the young
Cephalodiscus is divided, by means of two transverse grooves, into three well-marked
regions. Of these the anterior (p.) may be compared to the proboscis of Balanoglossus ;
the middle division (c.) to the collar of the same animal, and the posterior division (ér.) to
the trunk or body. It will further be noted that the proboscis is provided with an
anterior, undivided body-cavity, the collar and the trunk each containing a body-cavity

1 Quart. Journ. Micr. Sct., vols. xxiv., Xxxv., XXVi.
2 Quart. Journ. Mier. Sct., vol. xxvi., pl. xxxiii. fig. 7.

40 THE Upp xce OF H.M.S, CHALLENGER.

which is composed of two halves separated by means of dorsal and ventral mesenteries.
These five spaces are completely separated from one another, and their arrangement is
in exact accordance with that of the corresponding sections of the body-cavity in
Balanoglossus. The similarity of Cephalodiscus to the same animal is rendered still
more striking by the existence in the former of a diverticulum (nch.) of the front part
of the alimentary canal, extending a short distance forwards into the region of the
proboscis, and homologous with the notochord described by Bateson.

The course of the alimentary canal is sufficiently explained by means of this figure.’
The mouth (m.) is seen to be overhung by the large proboscis (p.), otherwise known as

Fra. 2.—Longitudinal section of an adult Cephalodiscus, supposed to be taken sufficiently on one side of the middle line to
allow of the representation of one of the ovaries, and of one of the proboscis-pores. p., proboscis ; stk., stalk ; m., mouth ;
ph., pharynx or branchial region of gut ; es., esophagus ; st., stomach ; int., intestine ; a., anus; xch., notochord (really
visible only in a median section) ; ov., ovary ; ovd., pigmented oviduct ; b.c.1, .c., b.c.3, divisions of body-cavity as in
fig. 1; p.p., one of the proboscis-pores ; op., operculum ; 7.s., central nervous system.

the epistome or buccal shield. The dorsal and ventral mesenteries are not visible, since
the section is not exactly median. The third body-cavity (b.c.*) is very large, and contains
the alimentary canal and ovaries. The anterior body-cavity (b.c.1) continues to form the
lumen of the proboscis, whilst the relations of the collar-cavities are not quite those of
the preceding figure. Dorsally the two halves of the body-cavity of the collar have
extended forwards into the proboscis region, whilst ventrally they are to be found
(apparently fused ?) solely in the post-oral lamella or operculum. The cavities of the
proboscis and of the collar (and more particularly of the latter) are to some extent

1 A fold in the intestinal region of the alimentary canal, of the existence of which I have been informed by
Professor M‘Intosh, has not been inserted in the diagram.

REPORT ON CEPHALODISCUS DODECALOPHUS. 41

The course of the alimentary canal is sufficiently explained by means of fig. 2."
The mouth (m.) is seen to be overhung by the large proboscis (p.), otherwise known as
the epistome or buccal shield. The dorsal and ventral mesenteries are not visible, since
the section is not exactly median. The third body-cavity (b.c.*) is very large, and contains
the alimentary canal and ovaries. The anterior body-cavity (b.c.') continues to form the
lumen of the proboscis, whilst the relations of the collar-edvities are not quite those of
the preceding figure. Dorsally the two halves of the’ body-cavity of the collar have
extended forwards into the proboscis region, whilst’ ventrally they are to be found
(apparently fused ?) solely in the post-oral lamella or operculum. The cavities of the
proboscis and of the collar (and more particularly of the latter) are to some extent
obliterated by muscles and connective-tissue. The notochord (nch.) has, in the adult,
the form of a slender bar, provided with a fine lumen, stretching forwards in the proboscis-
stalk into the proboscis itself. It is continuous at its base, as in the young bud, with
the epithelium of the almentary canal.

The further relations of the notochord will be described in connection with fig. 4.

The central nervous system is developed on the dorsal side of the collar'as a mass of
ganglion-cells and netve-fibres lying outside the basement-membrane of the epidermis.
It is. however, contimuous anteriorly with a similar development of nervous tissue
situated on the dorsal aspect of the proboscis, and laterally with a well-developed nerve-
layer on the dorsal sides of the lophophoral arms. In the young bud, in which the
collar is represented by a region of the body separated by transverse grooves from the
proboscis on the one hand and the trunk: on the other, the condition of the central
nervous system as a development of the collar is particularly well marked, although even
at an early stage a thinner nerve-layer occurs on the proboscis. In the adult, there is no
sharp line between the nervous tissue of the collar and that of the probuscis. At about
the level of the anterior end of the notochord, the nerve-layer is perforated by a pair of
pores—apparently derivatives of the ectoderm, which pass from the exterior into the
body-eavity of the proboscis (p.p., fig. 2). These pores are disposed symmetrically with
regard to the median plane of the animal, and are at no great distance from that
plane.

In most species of Balanoglossus, it is well known that an asymmetrical proboscis-
pore occurs on the left side, whilst in Balanoglossus kupfferi* two proboscis-pores are
present. It is thus obvious that the proboscis-pores of Cephalodiscus are a further feature
in support of the view that this animal is related to Balanoglossus, the disposition of
these pores in Balanoglossus kupfferi being in this respect particularly noteworthy.

One of the two ovaries (ov.) is represented in section in fig. 2. The duct (ovd.) is

1A fold in the intestinal region of the alimentary canal, of the existence of which I have been informed by
Professor M‘Intosh, has not been inserted in the diagram.
4 Vide Bateson, Quart. Journ. Mier. Sct., vol. xxvi. p. 555,

(ZOOL. CHALL, EXP,—PART LX11.—1887.) Qaq 6

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Shi Hitec It a Pri
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42 THE VOYAGE OF H.M.S. CHALLENGER.

of a rich brown colour owing to the existence of pigment in its walls; the oviducts have
on previous occasions been described as eyes.

Fig. 3 will serve to illustrate the anatomy of the collar-region of Cephalodiscus.
Whilst in the bud, this region is distinctly marked out by transverse grooves passing
round the body of the animal, this distinct-
ness is no longer visible externally in the
adult form. The collar-region is, notwith-
standing, no less sharply. marked out
internally than at younger stages. Its
body-cavity (b.c.”) is perfectly distinct from
the remaining ccelomic spaces of the animal,
although it is to a considerable extent (and
especially in the lophophoral arms and the
operculum) filled by loose connective-tissue
(as in Balanoglossus). The dorsal part of
the collar is produced on each side into six
tentacular arms, into which (and into the

individual tentacles) the collar-cavity may
with ease be traced. The nervous system

(n.s.) extends on to the dorsal face of each
arm. The ventral border of the collar is
produced into a free fold, the operculum or
oral lamella, which reaches its highest deve-
lopment laterally and ventrally (with the
exception of the median line in the latter
region). It has before been stated that the
collar-cavities extend, dorsally, for some
distance along the proboscis region (wde fig.
2, b.c.”), and as a matter of fact, the anterior
limit of these cavities is coincident with the

Fra. 3.—Longitudinal right and left section through an adult origin of the most anteriorly placed lopho-
Cephalodiscus, passing through the pharnyx (ph.), esophagus
(@s.), stomach (st.), and intestine (nt.) ; n.s., nervous system ; phoral arms. The eollar 1S much less deve-
tj loprophers! enml 8 Op., Spencaany, CP. collar pores ii gs., 1 d th Yi eal aid hee & 9 it
gill-slits ; mes., dorsal mesentery ; 0.c.2, body-cavity of collar ; ventral side .C. i 1ts
6.c.3, body-cavity of trunk. ORe ou e . j ( tye )
cavity in this region being, however, con-
tinuous at the sides of the alimentary canal with the dorsal part. The posterior border
of the collar passes on each side of the body along a line, which would be roughly
indicated in fig. 2 by joining the posterior end of the nervous system, dorsally, to the
base of the operculum, ventrally. This line corresponds, on each side of the body, with

the origin of the oral lamella or operculum. Since fig. 3 represents a section taken near

REPORT ON CEPHALODISCUS DODECALOPHUS. 43

the posterior limit of the central nervous system, it is intelligible (from the relations of
the base of the operculum just explained) that the operculum is seen, in the section, to
spring from a region of the body quite near to the dorsal surface. It is, however, clear
that the operculum is merely a free fold of the posterior border of the collar-region,
containing a portion of the collar-cavity, and that it is therefore exactly comparable to the
operculum described by Bateson in Balanoglossus.

On each side of the body is found a well-marked “ collar-pore ” (fig. 3, c.p.), consisting
of a very short canal whose walls are formed of narrow, closely arranged epithelial cells,
and opening-on the one hand into the cavity of the collar, and on the other to the
exterior, the external openings of the pore bemg overhung by the base of the opercular
fold. Both in the structure and in the position of these canals, Cephalodiscus resembles
Balanoglossus to an extent which is almost inconceivable, except on the hypothesis of
some genetic connection between the two genera.

A further Balanoglossus-feature possessed by Cephalodiscus is the existence of a pair
of well-marked gill-slits (fig. 3, g.s.) opening to the exterior immediately behind the
collar-pores, and so far as I have-been able to make out from an examination of the buds,
apparently developed as outgrowths of the “ pharyngeal” region of the alimentary tract.
The relation of these slits to the collar-pores is precisely the same as that of the first pair
of gill-shts of Balanoglossus to the collar-pores of the latter. Unlike Balanoglossus,
Cephalodiscus possesses no more than a single pair of gill-slits, but it must be remembered
that the young Balanoglossus remains for some time in a similar condition (7.e., with
but a single pair of gill-shits), and that Bateson has assumed the existence of an ancestor
of Balanoglossus in which no metameric repetition of the gill-slits had taken place.

Fig. 4 illustrates the relation of the structures in the proboscis-stalk, which—as in
Balanoglossus—is a constricted region by which the proboscis itself is connected with
the rest of the body. The completely separated collar-cavities are clearly visible, as well
as the unpaired proboscis-cavity. The notochord is a slender rod, possessing a fine
lumen, and is supported by the mesentery, which forms the division between the two
halves of the collar-cavity. I am not at present certain. as to the existence or non-
existence of Bateson’s ‘‘ proboscis-gland” in this region of the body.

The lophophoral arms are deeply grooved on their ventral surfaces, and these grooves
are continuous with shallower furrows (gr.), which pass along the ventro-lateral portions
of the collar, on either side of the proboscis-stalk, as far as the region of the mouth. If,
as can hardly be doubted, the tentacles are ciliated, it may be assumed that a current of
water passes in the living animal down these grooves into the mouth, into which the
current is directed by means of the opercular flap developed from the posterior border of
the collar. It is probable that the gill-slits are, in this case, of great importance to the
animal. The two lateral currents which have just been supposed to enter the mouth
would doubtless introduce large quantities of water into the pharynx. The water would

44 THE VOYAGE OF H.M.S. CHALLENGER.

pass to the gill-slits by a very slight alteration of the direction of these currents, since
the gill-slits open ventro-laterally from the first division of the alimentary canal. Solid
particles conveyed by the current could presumably be readily retained in the alimentary
canal, whilst the water itself would naturally pour out by the gill-slits, which would be
protected from the afferent current due to the tentacles by means of the operculum. It
thus seems possible to conceive of a method in which the gill-slits may be of the greatest
importance in connection with the straining of the water from the food-particles. Bateson
has been led to assume that gill-slits are structures which have been developed within
the Chordata, and it is suggestive that in Cephalodiscus, owing to the rich development
of the tentacles, we appear to have a cause capable of inducing the evolution of perfora-

a1)
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Porters
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Fic. 4.—Transverse section through the collar and proboscis of an adult Cephalodiscus, passing in front of the mouth; 7.s,
nervous system; p., proboscis; U., two of the lophophoral arms cut horizontally ; gr., grooves continuous with the

grooves of the anterior lophophoral arms ; 0.c.1, body-cavity of proboscis ; 6.c.*, body-cavity of collar; mch., notochord ;
D., dorsal, and V., ventral surface.

tions.leading from the alimentary canal to the exterior. It may be perhaps profitable to
consider whether gill-slits may not possibly have originated in this manner, and whether
the arrangement found in Balanoglossus and other types may not have been developed
from a Cephalodiscus-like condition by the metameric repetition of the slits, accompanied
by a change in their function.

The preceding remarks relating to the supposed affinity of Cephalodiscus to Balano-

glossus may with advantage be summed up by a statement of the various features which
are common to the two genera.

1. Division of the body into proboscis, collar and trunk, this division being specially,
obvious, in Cephalodiscus, in the young bud.

REPORT ON CEPHALODISCUS DODECALOPHUS. 45

3. Existence of an unpaired body-cavity in the proboscis, and of paired cavities in
the collar and in the trunk.

3. Proboscis-pores (paired in Balanoglossus kupffer’), opening into the body-cavity
of the pre-oral lobe.

4. Collar-pores in similar relation to the collar-cavity, their external apertures being
overhung by an operculum developed from the collar.

5. Gill-slits (one pair for a considerable period in the embryonic history of Balano-
glossus) ; their relation (in Balanoglossus, the relation of the first pair) to the
operculum and to the external apertures of the collar-pores.

6. Existence of a notochord as a diverticulum of the alimentary canal, growing
forwards into the proboscis-stalk.

7. Dorsal central nervous system, most richly developed in the collar, but
extending on to the proboscis; the fact that the nervous tissue lies in the
epidermis.

Before leaving this subject, it will be well to refer briefly to the highly interesting
pelagic larva of Balanoglossus, discovered by Weldon in the Bahamas.’ A noteworthy
feature of this larva is the development of a series of tentacles arranged in six grooves
passing, equidistant from one another, in a longitudinal direction along the surface of
the pra-oral lobe. Although the tentacles are not in the same position as those of
Cephalodiscus, it is a suggestive fact that this larva affords another case of the
development of tentacles in the anterior part of the body in Balanoglossus or its alles,
and it is at least possible that their appearance in the Tornaria may be due to a process
of reversion or atavism.

It appears to me that whatever may be thought of any single similarity between the
two genera given in the above list, the cumulative evidence of the whole sequence of
resemblances points irresistibly to the conclusion that Cephalodiscus and Balanoglossus
are near allies, and I would propose to remove Cephalodiscus from its previous position
amongst the Polyzoa, and to place it definitely as a second genus in Bateson’s group of
the Hemichordata. The character of the Vertebrate features of Cephalodiscus (notochord,
gill-slits, nervous system) appears to justify an approximation of this genus to Balano-
glossus in particular rather than to any other group of the Chordata.

The most important difference between Cephalodiscus and Balanoglossus appears to
me to consist in the relations of the dorsal and ventral surfaces in the two genera. The
difference is, however, a non-essential one. Whilst in Balanoglossus the elongation of
the embryo takes place in the line of its long axis, the ventral elongation of a similar
embryo in a line at right angles to its primitive long axis would give rise to the condi-
tion found in Cephalodiscus. We may suppose that the stalk has originated in this

1 Vide Proc. Roy. Soc., vol. xlii. p. 146, 1887.

46 THE VOYAGE OF H.M.S. CHALLENGER.

manner, and that the alimentary canal has acquired its adult relations by its partial
passage into the ventral protuberance of the body.

Whilst it appears to me easy to compare Cephalodzscus and Balanoglossus, it does
not seem to me impossible that the former may have affinities in other directions as
well. For, imagine that the ventral elongation of the body would be conveniently post-
poned until after the end of a free larval life; the stalk might then be invaginated into

- the body of the larva in preparation for its evagination when metamorphosis should take
place, as actually occurs in Actinotrocha. After the metamorphosis of the latter, the
alimentary canal has the same dorsal flexure as in Cephalodiscus, and this explanation of
the metamorphosis of Phoronas is in accordance with the suggestions of previous observers.

The following considerations may perhaps indicate some affinity between Cephalodiscus
and Phoronis * :-—

1. The archenteron of Phoronis is developed by a well-marked invagination, whilst
part of the mesoblast (vide Caldwell) is formed by a process of (modified) archenteric
-pouching (as in Balanoglossus).

2. The pre-oral lobe is large in Actinotrocha, and is provided with a body-cavity
which is completely shut off, by means of a septum, from the body-cavity of the trunk.
The post-oral region is prolonged into tentacles, which, although differing in a striking
manner from the tentacles of Cephalodiscus, may still have some connection with these
structures, or with the operculum of the same genus.

3. The “foot” of Phoronis has precisely the same relations as the stalk of Cephalo-
discus.

4. The nervous system of Phoronis occurs outside the basement-membrane. The
ganglion of the pre-oral lobe of Actinotrocha is comparable with a portion of the nervous
system of the Hemichordata, whilst the post-oral nerve-ring of Actinotrocha (following
the line of the bases of the tentacles) may not impossibly be the homologue of the nerve-
ring which passes round the posterior border of the collar in Balanoglossus. If this were
the case, the lophophores of Actinotrocha and of Phoronis might be regarded as develop-
ments of the collar-region.

5. Phoronis possesses a complete ventral mesentery, the dorsal mesentery, however
(persistent in Cephalodiscus), having disappeared in the adult animal. The ovaries and
oviducts of Cephalodiscus are supported by lateral mesenteries which are apparently
arranged in the same manner as the lateral mesenteries in Caldwell’s diagram “ B.”?
The oviducts of Cephalodiscus do not, however, open into the body-cavity, and it is
possible that the collar-pores, rather than the oviducts, may be the homologues of the
nephridia of Phoronis.

1 Cf. W. H. Caldwell, Prelim. Note on the Structure, Development, and Affinities of Phoronis, Proc. Roy. Soc.,
No. 222, 1882 ; and Blastopore, Mesoderm, and Metameric Segmentation, Quart. Journ Micr. Sct., vol. xxv., 1885.
2 Proc. Roy. Soc., 1882,

REPORT. ON CEPHALODISCUS DODECALOPHUS. 47

6. Previous observers (M‘Intosh, Lankester, &c.) have been led to assume the affinity
of Phoronis to. Cephalodiscus and Rhabdopleura, this conclusion being based on such
features as the relations of the adult lophophore to the mouth and anus.

It must be noted, on the contrary, that Phoronis is not known to possess any repre-
sentatives of the notochord, gill-slits, collar-pores, and proboscis-pores of Cephalodiscus,
whilst there is no evidence of the existence of a collar body-cavity in the former. It
appears to me that.a renewed consideration of Phoronis, anatomically and development-
ally, can alone settle the question of the possibility of an affinity between it and Cephalo-
discus. i

The remarkable larva of Balanoglossus described by Weldon (loc. cit., fig. 3) is in
some of its features by no means unlike Actinotrocha. Such features are the general
form of the prae-oral lobe and trunk, the absence of the notochord and gill-slits, and the
existence of only three diyisions of the body-cavity. These are (1) the unpaired cavity
of the pre-oral lobe, and (2) the two cavities of the trunk-region. In the absence
of these cavities and of the notochord and gill-slits Actinotrocha differs from the
larval Balanoglossus described by Bateson. It cannot, however, be denied that the dif-
ference between the tentacles of Weldon’s larva and those of Actinotrocha is very
considerable, if not fundamental.

The relation between Cephalodiscus and Rhabdopleura is in need of further elucida-
tion. In spite of the great resemblance between the lophophores and epistomes of the
two genera, many of the most important structures found in Cephalodiscus are not known
to exist in Rhabdopleura, and there does not at present appear suflicient justification for
the removal of Rhabdopleura to the Hemichordata, although the balance of evidence
might perhaps be in favour of so doing.

I do not think that the above considerations are in any way calculated to strengthen
the view that Phoronis and the Polyzoa are nearly related. The result of the examina-
tion of Cephalodiscus appears to me to show that this genus (and &habdopleura also *)
must be entirely removed from the Polyzoa. If this is the case, it is obvious that any
affinity which may be shown to exist between Cephalodiscus and Phoronis can in no way
affect the question of the relationship of the latter to the Polyzoa.

CONT iN Ts:

PAGE
INTRODUCTION, - 1
DeEscrIPTION, 3

Coencecium, 3
Polypides, 6
Buccal Disk, 8
Branchial Plumes, 10:
Post-oral Lamella, 14
Digestive System, 15
Body-wall, ; 19
Muscular System and Pedicle, 20
Nervous System, 23
Sense-Organs, D4
Reproductive Organs, 25
Budding, 28
HoMoLoGiEs, . 5 ; : 32
AppEnDIx, by Sidney F. Harmer, B..., BiScy ie 39

PLATE: I.

(ZOOL. CHALL. EXP,—PART LX11.—1887.)—Qqq.

PLATE I.

Coencecium of Cephalodiscus dodecalophus, about the natural size; a few of the branches
terminate in somewhat flattened tips. Ata, one of the pillars, which like aerial
roots pass downwards to the stones and sponges on which it grows, is represented,
its tip being expanded into a broad surface. Numerous inosculations take place.
between the various branches.

The Voyage of HM.S."Challenger’ - Cephalodiscus. Pl.1.

W.C.M.& E.Prince del. | ; eet? "Hoth, Li? Edn!
CENGCIUM OF CEPHALODISCUS DODECALOPHUS, MCI.

(uncoloured)

PLATE Il.

PLATE I.

Polypide of Cephalodiscus dodecalophus, seen from the ventral surface, and enlarged
under a lens, the actual length of the entire animal being about 2 mm.
Only a few of the tentacular plumes are visible, the rest being concealed by the
dense mass of filaments. The tip of the pedicle bears an early bud, the pedicle of
which is somewhat elongated. This example presented numerous minute pigment-
spots of a brownish hue all over its surface. i

The Voyage of H.M.S"Challenger’

pose ee

Cephalodiscus. Pl.ll.

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ig)

PLATE III.

Fig. 1. Polypide of Cephalodiscus dodecalophus, obliquely seen from the ventral surface,
much enlarged, and having the buccal shield removed. The pedicle is in a
state of extension, with a fairly advanced bud at the tip; an, anus; pl.,
post-oral lamella ; m, mouth.

Fig. 2. Lateral view of a polypide, also deprived of the buccal shield, and much enlarged.
The pedicle is contracted and bent forward, with a pair of buds at the tip.
The same letters are used as in fig. 1; ov, the position of the large ovum,
which distends the lateral region just behind the pigment-spots (od); bp, torn
tissues at the base of the plumes, which have been removed.

Fig. 3. Lateral view of an entire specimen, with the pedicle as well as the buccal disk
thrust outwards, or ventrally. The buccal shield has fallen from the larger
of the two buds at the tip of the pedicle. The alimentary canal has been
somewhat diagrammatically outlined in this example; @, above the line
is the pharynx, below is the cesophagus ; vt, stomach, largely distended ; utd,
peculiar region following the stomach, and presenting a thick glandular coat
with a distinct fold beyond the point touched by the dotted line, and which
probably is homologous with the second stomachal dilatation in Phoronis ;
r, rectum, usually much dilated ; bs, buccal shield ; p/., , ost-oral 1: molla.

Fig. 4. An abnormal specimen, similarly magnified and viewed laterally. The pedicle
is absent, a promineuce only (ped) indicating its position. Instead of the
smoothly bulbous posterior extremity (almost like the bowl of a retort), a
somewhat sharp angle occurs ventrally. The anus is elevated on a rectal
cone.

Cephalodiscus. Pl. Ill.

F Huth, Lith? Ram?

CEPHALODISCUS DODECALOPHUS, MS 1

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Ga Hone ya

PLATE IY.

PLATE IV.

. Tentacular plume of Cephalodiscus, seen,as a semitranslucent object. The line

in the middle of the filaments indicates the axis or skeleton ; x 90.

2. Portions of the pinne or filaments acted on by dilute potash so as to exhibit the

central axis or skeleton, which at a has been exposed. The cellulo-granular
coating of the organs is hypodermic ; x 350.

. Shghtly oblique section of the bulbous tip of one of the plumes, showing the

large globules and gland-cells. The hypoderm has intruded on the left,
showing that the slice has been made close to the base of the process; x 470.

. Transverse section of the tip-of a plume just behind the foregoing, and while the

central lumen remains very distinct. The hypoderm shows somewhat regular
wedge-shaped divisions, as if composed of a single layer of large cells. The
wall of the central cavity presents numerous fibres projecting all round, as if
the reticulations were already commencing ; x470.

. Transverse section of the pedicle, showing the remarkable form usually assumed

by the elastic basement-tissue (bt) in contraction. The hypoderm (hp) occurs
externally ; and within the basement-tissue the large muscular fibres and
somewhat gelatinous connective-tissue fill up the central region. The small
dorsal and the large ventral incurvations are readily recognised, as well as the
two lateral ventral projections of the basement-tissue. The bypoderm on the
ventral surface has been somewhat stretched ; x 350.

The Voyage of H.M. S "Challenger" Cephalodiscus. Pi. lV.

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Fig.

PLATE V.

. Tip of one of the plumes of the polypide of Cephalodiscus, showing the

glandular nature of the enlarged region. ‘The filaments (/) have been turned
to the left ; ca, central axis of main stem; Ap, hypoderm. The longitudinal
fibres running along the axis are observed to the left as well as over the
axis; x 210.

. Portion of the middle of a plume with the bases of the filaments (/), viewed

laterally, after the action of a dilute solution of potash. The skeletal axis is
observed in the centre of each filament, and as this skeletal axis (sk) widens
out at its base, the double outline at each side is well marked ; ca, central
axis of main stem, with its longitudinal fibres ; x 350.

. Transverse section of a young bud on the appearance of the first two lophophoral

processes or plumes (/p) as two rounded bosses composed of tissue resembling
hypoderm. The buccal disk (bd) is cut at its anterior region, but the central
space (bc) of the organ is well developed. The collar space (ve) is com-
paratively large at this stage, and lies close beneath the nerve-centre ; x 350.

. Transverse section of the terminal region of the body-cavity of an older bud

than the foregoing, the tip of the alimentary canal (a/) being left as a thin
plate in the centre, and bound dorsally and ventrally by the median
mesentery (ms). The great longitudinal muscle is cut near the commence-
ment of the pedicle, and already shows the double ventral curvatures so
characteristic of the latter ; bt, basement-tissue ; co, the body-cavity ; x 350:

. Ovum on its escape from the adult; ec, egg-capsule; ov, ovum proper; st,

stalk; x 90.

. Outline of another ovum in which the yolk is ovoid, instead of circular as in the

former case ; x 90.

The Voyage of H.M.S."Challenger” Cephalodiscus. Pl. V.

E Prince dei

Fig 1,2,5,6,W.0 M. Figt 3,4

GEPHALODIS. CUS “DIOIDIEGALOPRIHUS:' MSI

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PLATE VI.

Fig. 1. Longitudinal section of the tip of the pedicle of an adult Cephalodiscus,
showing the attachment of a young bud just above the terminal surface
(which is somewhat sucker-like); /m, strands of longitudinal muscles; hps,
modified hypoderm forming the terminal surface of the pedicle; gm, section
of a young bud, showing the central chamber (ch) continuous with the axis of
the pedicle of the adult ; x 350.

Fig. 2. Transverse section of an adult Cephalodiscus through the region of the mouth
(m) and ovaries, one pigment-mass (od), however, only having been cut. The
buceal shield (bs) on the right is seen folding over dorsally (bsp), so as to run
into the tissues at the bases of the plumes (br); g, grooves at the bases of
the lophophoral arms. The notochordal region lies between this letter and m,
though the notochord is not seen in this section. The mouth is observed at
(m) and the pharyngeal region with its numerous folds and a gill slit (gs),
while on the left is a section of the post-oral lamella (p/) with its central cavity
or chamber; 7, greatly distended rectum ; od, pigment of oviduct ; ov, large,
and ov’, small ova, with nuclei and nucleoli; x 90.

Fig. 3. Transverse section of the shield and dorsal region in the long axis of the central
region of the nervous system (nc). The thick coating of hypoderm (hp)
bounds the latter externally, while internally it rests on the basement-tissue (bt.);
bp, sections apparently of the shield-pores in their progress inwards; bsm,
radial muscles of the buceal disk or shield; hs, hypoderm of shield; od, position
of the pigment of the oviducts ; x 210.

Fig. 4. Transverse section of the same bud as in PI. V. fig. 4, in the anterior region, so
as to strike the commencement of the nerve-centre (nc), with the central
eavity (c). The young plumes are irregularly cut from their variable position,
and the sides of the disk fold over into the basal region of the plumes. The
large size of the terminal process of the plumes is well seen in the larger
organ ; X 210.

Fig. 5. Section a little behind the foregoing, giving the nerve-centre (nc) in full develop-
ment, under the thick hypodermic coat (hp), while the tip of the anus (an)
has also been included ; ceva, collar space going to plumes ; bsm, radial muscles
of buceal disk; ¢, region of the notochordal. The plumes are more widely
separated in this region, and the young filaments have the form of hypodermic
papille ; x 210.

Fig. 6. A somewhat oblique section through the buccal shield (bs) and the post-oral
lamella (pl) with its central cavity, to which the dotted line goes. Beneath is
a collar pore (cp), which is, however, indifferently shown in this section. The
nerve-centre (nc) and a pore (bp) leading into the cavity of the shield are also
cut, the two body-cavities of the region lying above the former (nc) in this
view, that is ventrally in nature. The other parts are an ovary (ov) and: a
portion of the pigment-mass of an oviduct (od) ; x 90.

Cephalodiscus. PL.VL.

VUTT ii
Vig

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W.C.M. & E.Prince det. F. Suth, Lith® Edin®

CEPHALODISCUS DODECALOPHUS, MSF}.

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5.

PLATE VII.

Portion of the coencecium of Cephalodiscus, about natural size, tinted as in the

spirit-preparations.

. Transverse section of a pedicle of an unstained specimen, showing a somewhat

different arrangement of the folds of the basement-tissue and the central
muscular fibres ; letters as before ; x 350.

. Oblique section of the chief area of the nerve-tissue (nc), which hes under the -

thick hypoderm (hp) between the plumes (br). The collar spaces (cv) lie
next the basement-tissue, bounding the nerve-centre internally, and a trace
apparently of the notochord is observed at c. Some of the folds (m/f) of the
mouth have been included in the section, and the radiate muscles (bsm) of the
buccal shield are observed on the left ; x 350.

. Transverse section of the same bud as in PI. VI. fig. 5, somewhat behind the

former. The body-cavity (co) now shows the rudimentary generative organs
(ov), the rectum (7), and the cesophagus (@) in section. The collar spaces (cv)
are distinct, and the post-oral lamella (pl) is seen on the right. The position
of the buccal shield is indieated by the letters bs; x 210.

‘Transverse section of the same bud posterior to the former, and the three regions

of the alimentary canal now occupy the body-cavity, viz., 7, the intestine ;
vt, the stomach, while what is probably the pharynx (@) lies ventrally. A
collar pore is observed at cp; pl, post-oral lamella; other letters as before.

The Voyage of H.M.S."Chailenger’ Cephalodiscus. Pl. VIL

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EAE:

VOYAGE OF H.M.S. CHALLENGER.

ZOOLOGY.

REPORT on the Poryzoa collected by H.M.S. Challenger during the
years 1873-76. By Grorce Busk, F.R.S., V.P.LS., &e.

PART II.—The CYCLOSTOMATA, CTENOSTOMATA,
and PEDICELLINEA.

INTRODUCTION.

So much has been written of late years concerning the Polyzoa, that it is not possible for
me here to name all those to whom I have been indebted for assistance in the preparation
of this Report, but among the most important recent contributions to our knowledge of
all the three orders now under consideration, must be mentioned the valuable works
of Mr. Hincks* and Professor Smitt.” To M. L, Joliet® we owe papers, both anatomical
and descriptive, on the Polyzoa of the French Coast. Mr. P. H. Macgillivray,* has
described and figured many new species of CycLosromata belonging to the Australian
region. Mr. Waters® has given descriptions of recent species from the Bay of Naples, as
well as of fossil Australian species; and Dr. J. Jullien® of species collected in the

‘ Hincks, Brit. Mar. Polyz., 1880, and various papers in Ann. and Mag. Nat. Hist., &e.

*Smitt, Hafs-Bryoz. Uteckl. och Fettkr., 1864; Bryoz. Mar., 1867; Kritisk Forteckn., 1865, 1871; Florid
Bryoz., pt. 1., 1872.

3 Joliet, Les Bryozoaires des Cotes de France, Archives d. Zool. Expér., t. vi., p. 193, 1877.

* Macgillivray, P. H., Nat. Hist. Vict., decades iv. and vii.; Proc. Roy. Soc. Vict., Polyzoa, parts iv. vi., vii., Viii., ix.

5 Waters, Ann. and Mag. Nat. Hist., ser. 5, vol. iii.; Quart. Journ. Geol. Soc., vol. xl. p. 674, 1884.

® Jullien, Bull. Soc. Zool. de France, t. vii., 1882.

(ZOOL. CHALL., EXP.—PART L.—1886.) Ddd a

TEE:

VONAGE JOR EOI... CEIEIGE NG ER:

ZOOLOGY.

REPORT on the Poryzoa collected by H.M.S. Challenger during the
years 1873-76. By Grorce Buss, F.R.S., V.P.L.8., &e.

PART II.—The CYCLOSTOMATA, CTENOSTOMATA,
and PEDICELLINEA.

INTRODUCTION.

So much has been written of late years concerning the Polyzoa, that it is not possible for
me here to name all those to whom I have been indebted for assistance in the preparation
of this Report, but among the most important recent contributions to our knowledge of
all the three orders now under consideration, must be mentioned the valuable works
of Mr. Hincks* and Professor Smitt.? To M. L. Joliet* we owe papers, both anatomical
and descriptive, on the Polyzoa of the French Coast. Mr. P. H. Macgillivray,* has
described and figured many new species of Cyctosromata belonging to the Australian
region. Mr. Waters’ has given descriptions of recent species from the Bay of Naples, as
well as of fossil Australian species; and Dr. J. Jullien® of species collected in the

1 Hincks, Brit. Mar. Polyz., 1880, and various papers in Ann. and Mag. Nat. Hist., &e.

2 Smitt, Hafs-Bryoz. Uteckl. och Fettkr., 1864; Bryoz. Mar., 1867; Kritisk Forteckn., 1865, 1871; Florid
Bryoz., pt. i., 1872.

3 Joliet, Les Bryozoaires des Cotes de France, Archives d. Zool. Expér., t. vi., p. 193, 1877.

4 Macgillivray, P. H., Nat. Hist. Vict., decades iv. and vii.; Proc. Roy. Soc. Vict., Polyzoa, parts iv. vi., vii., Vili., ix.

5 Waters, Ann. and Mag. Nat. Hist., ser. 5, vol. iii.; Quart. Journ. Geol. Soc., vol. xl. p. 674, 1884.

6 Jullien, Bull. Soc. Zool. de France, t. vii., 1882.

(ZOOL. CHALL. EXP.—PART L.—1886.) Ddd «

il THE VOYAGE OF H.M.S. CHALLENGER.

Atlantic by the “ Travailleur.” With regard to the PEepiceLLinzEa I must express my
obligations to Drs. Nitsche,’ Hatschek,’ Salensky,’ &c., for the information derived from
their researches.

The total number of species enumerated in this part of my Report is forty-six, of
which number thirteen still appear to me to be new, and three or four others have only
been described and named since the Challenger collection was made ; if I have overlooked
the descriptions of any others I can only express my regret that it should be so, as I
have made every endeavour to keep pace with the recent additions to our knowledge on
the subject.

Of the number of species above mentioned by far the greater part, viz., thirty-three,
belong to the sub-order CycLtostomata, of which, however, only five are new. Of the
CrenostoMaTA there are only eleven species in all, but of these seven are new, though
none of them present any new generic type; this very much larger proportion of new
species can be accounted for probably by the fact that this sub-order has been much less
fully studied hitherto than either the CHEILostomMaTa or CycLostoMaTa. Belonging to
the PEpICELLINEA, only two species have come under my notice, of which but one is now
described for the first time, the other having been named by Mr. Hincks in 1884.

CLASSIFICATION.

1. The arrangement of the sub-order Cyctosromata followed in this Report, as
exemplified in the accompanying Table (see p. viii.), is nearly the same as that adopted in
my Monograph of the Crag Polyzoa, 1857, and in the British Museum Catalogue, pt. 11.,
1875; the number of species procured by H.M.S. Challenger belonging to this sub-order
not having been sufficiently large to lead to any material change in it.

2. In the sub-order CrenostoMaTa, again, the number of species in the collection was
too small to justify the attempt at forming any different general scheme, and therefore I
have followed, as nearly as may be, the arrangement adopted by Mr. Hincks in his
British Marine Polyzoa, only differing from him in the definition of the two principal
divisions.

3, With respect to the order PEpIcELLINEA all that I need say is, that though the
total number of species collected on the voyage only amounted to two, they have
appeared to me to deserve recognition as a new generic type, to which I have given the
name of Ascopodaria, but it does not seem necessary for me to enter into any disquisition
as to a scheme of classification beyond what has been already written by Mr. Hincks, Dr.
Nitsche, Professor Smitt and others.

1 Nitsche, Zeitschr. f. wiss. Zool., Bd. xx. p. 343, 1870.

° Hatschek, Zeitschr. f. wiss. Zool., Bd. xxix. p. 502, 1877.
3 Salensky, Ann. d. Sct. Nat., sér. 6, t. v. p. 27, 1877.

REPORT ON THE POLYZOA, ill

DistRIBUTION.

1. Geographical.

I have thought it convenient for the sake of uniformity, and to facilitate reference,
to arrange the species enumerated in this second part of the Report into the following
seven divisions of the ocean, in the same manner that the CuEILosroMATA were divided
in the first part.

. North Atlantic Region, between the parallels of 70° W. and 20° E.
. South Atlantic Region, from 70° W. to 20° E.
South Indian or Kerguelen Region, from 20° E. to 110° E.

. Australian Region, from 110° E. to 160° W. and 8.

. Philippine or Japanese Region, from 110° E. to 160° W. and N.

. North Pacific Region, from 160° W. to the coast of North America.

. South Pacific Region, from 160° W. to 70° W.; but from this region no species
belonging to any of the orders referred to in this part of the Report were

Pts} |cal lel ov lesh [=

procured.

In the following List, to the names of the species procured at each Station a reference
is added, by corresponding letters, to the other regions in which it was found, so that its
geographical distribution may be seen at a glance.

2. Bathymetrical.

The Stations in each geographical region, in the List, are arranged in bathymetrical
order, beginning with those of the greatest depth; it will be seen that only two species
of CycLosromata occur at depths greater than 1000 fathoms, viz., one at 1600 and one
at 1450, the former, however, also being found at various depths, from 50 fathoms
dewnwards ; four or five others were found at 450 to 600 fathoms, but by far the larger
number were procured at between 50 and 150 fathoms, and ten in shallow water. Of the
CrenostomaTa only three occurred at depths as great as 150 fathoms, the remaining
eight having all come from depths less than 40 fathoms. The only two species belonging
to the PEpICELLINEA group both came from 150 fathoms.

3. Geological.

To the sub-order Cyctostomata belong most of the oldest fossil Polyzoa that have
been found up to this time, whilst “as yet we have no clear evidence that Cheilo-

lv THE VOYAGE OF H.M.S. CHALLENGER.

stomatous types existed in Paleeozoic times;”* although in the Mesozoic and Tertiary strata
fossil CHEILOSTOMATA are numerous. The paleontological evidence as to the antiquity
of the CycLosromara is fully confirmed and strengthened by the embryological researches
that have recently been so carefully and accurately made by various authors ; for instance
M. Barrois? says that the study of the structure of the larva and of the formation of
the cell coincides with paleontology in furnishing us with perfectly concordant results,
which are conclusive as to the antiquity of the CycLosromata. Many of the species even
have a wide distribution in time, for out of the thirty-three included in this collection,
fourteen have already been identified in the fossil state.

No fossil forms belonging either to the CrenostomaTa or to the Entoproctan Polyzoa
have hitherto been identified, but Mr. Vine has thrown out a hint, in a paper on
Ascodictyon,’ that perhaps Ascodictyon filiforme may be a primitive representative of
the stoloniferous Vesiculariadee, or possibly of the Entoprocta. That this latter order is
of great antiquity is also confirmed by its embryonic history, for the same eminent
authority, above quoted, M. Barrois,* after the most careful and elaborate comparison of
the larvee of the various Ectoproctan and Entoproctan groups, comes to the conclusion
that “the larvee of Entoprocta represent the primitive type from which all the others are
derived.”

A.—NORTH ATLANTIC REGION.

Station 75, lat. 38° 38’ N., long. 28° 28’ 30” W.; 450 fathoms; volcanic mud.

Idmonea milneana, C. | Idmonea irregularis.

CaPE VERDE IsLANDS, 100 to 120 fathoms.

Hornera frondiculata.

Station 36, lat. 32° 7’ 25” N., long. 65° 4’ W., off Bermuda; 30 fathoms; coral.

Crisia denticulata, var. patagonica. | Amathia lendigera.

Cape VrrpgE IsLanps, 10 fathoms.

Crisia conferta, D.

Station 109, 0° 55’ 38” N., long. 29° 22’ 35” W., off St. Paul’s Rocks; shallow water.
Crisia denticulata, B, D.

1 Vine, Quart. Journ. Geol. Soc., vol. xl. p. 332, 1884.

2 Barrois, Ann. and Mag. Nat. Hist., ser. 5, vol. x. p. 391 (footnote).
3 Vine, Ann. and Mag. Nat. Hist., ser. 5, vol. xiv. p. 87.

4 Barrois, loc. cit., p. 401.

REPORT ON THE POLYZOA. Vv

B.—SOUTH ATLANTIC REGION.

Sration 320, lat. 37° 17’S., long 53° 52’ W.; 600 fathoms; green sand.

Crisia acuminata. Idmonea fissurata.
Idmonea marionensis, C. Hornera lichenoides.

StaTIon 135, lat. 37° 1’ 50” 8.; long. 12° 19’ 10” W., off Tristan da Cunha Islands; 60
to 360 fathoms.

Crisia biciliata. Alecto granulata.
Crisia denticulata, A, D. Diastopora patina.
Crisia acuminata. Lichenopora fimbriata.
Crisia cylindrica. Lachenopora hispida.
Idmonea atlantica. Fasciculipora ramosa.

Ascopodaria discreta.

Sratron 142, lat. 35° 4’ S., long. 18° 37’ E.; 150 fathoms; green sand.
Alcyondium flustroides.

Orr Banta, 10 to 40 fathoms.

Amathia distans. | Amathia brasiliensis.
Farrella atlantica.

Srmon’s Bay, Cape of Good Hope ; 18 fathoms.
Idmonea atlantica.

SraTion 315, lat. 51° 40’S., long. 57° 50’ W.; 12 fathoms; sand and gravel.
Tubulipora flabellaris. | Tubulipora fimbria.

C.—SOUTH INDIAN OR KERGUELEN REGION.
Station 147, lat. 46° 16’ S., long. 48° 27’ E.; 1600 fathoms; Diatom ooze.
Idmonea marionensis, B.

Prince Epwarp IsLanp, 80 to 150 fathoms.
Crisia holdsworthii. Idmonea milneana, A.
Idmonea marionensis, B. Pustulopora proboscidea,
SratTion 149, off Kerguelen Islands; 28 to 105 fathoms.

Crisia eburnea, var. laxa. | Idmonea atlantica.

vi THE VOYAGE OF H.M.S. CHALLENGER.

Sratron 151, off Heard Island; 75 fathoms; volcanic mud.

Idmonea marionensis, B.
Hornera violacea.

Pustulopora proboscidea.
Pustulopora deflexa.
Supercytis tubigera.

Sration 1444, lat. 46° 48’ S., long. 37° 49’ 30” K., Marion Islands; 69 fathoms; vol-
canic mud.

Crisia holdsworthiv. Idmonea australis, D.
Idmonea marionensis, B. Pustulopora proboscidiordes.

D.—AUSTRALIAN REGION.

Sration 176, lat. 18° 30’ S., long. 173° 52’ E.; 1450 fathoms; Globigerina ooze.

Crisia elongata.

Sration 1634, lat. 36° 59’ S., long. 150° 20’ E.., off Twofold Bay ; 150 fathoms; green

mud.
Crisia conferta, A. Amathia tortuosa.
Amathia spiralis. Ascopodaria fruticosa.

Sration 167, lat. 39° 32’ S., long. 171° 48’ E.; 150 fathoms; blue mud.
Supercytis digitata.

Sration 162, lat. 39° 10’ 30” S., long. 146° 37’ E., Bass Strait; 38 fathoms; sand
and shells.
Pustulopora regularis. | Amathia spiralis.

SraTion 1638, lat. 33° 51’ 15” S., long. 151 22° 15” E.., off Port Jackson; 35 fathoms ;
hard ground.
Idmonea australis, C. | Hornera folvacea.

SraTion 161, lat. 38° 22’ 30’S., long. 144° 36’ 30” E., off Port Philip; 33 fathoms; sand.

Crisia acropora. | Hornera foluacea.
Amathia spirals.

Sratron 188, lat.9° 59’ S., long. 139° 42’ E.; 28 fathoms; green mud.
Amathia senisprralis. | Vesicularia papuensis.
Cylindrecium papuense.

REPORT ON THE POLYZOA. Vil

Sration 172, lat. 20° 58’ S., long. 175° 9’ W., off Nukalofa, Tongatabu ; 18 fathoms ;
coral mud.
Idmonea radians, F.

Sration 186, lat. 10° 30’ S., long. 142° 18’ E., off Cape York; 8 fathoms; coral mud.

Crisia denticulata, A, B. | Idmonea eboracensis.
Amathia connexa.

E.—PHILIPPINE OR JAPANESE REGION.

Orr Zxexu, Philippine Islands.

Crisia denticulata, var. gracilis.

F.—NORTH PACIFIC REGION.

Orr Honotutv, Sandwich Islands ; 20 to 40 fathoms.

Idmonea radians, D.

G.—SOUTH PACIFIC REGION.

None.

MEASUREMENTS.

The metrical system is now so generally in use for scientific purposes that I have
adopted it for all the measurements of the magnified figures, and they are accordingly
given in millimetres or tenths of a millimetre. The figures are nearly all enlarged by
25 or 50 diameters, and scales are appended to all the plates.

Vili -’ THE VOYAGE OF H.M.S. CHALLENGER.

TABLE OF CLASSIFICATION.

Group A. ECTOPROCTA.

Sub-order II. CYCLOSTOMATA.

Division I. ARTICULATA s. RADICATA.

I. Crisiade,

Division II. INARTICULATA.

Subdivision A. Erzcra. II. Idmoneide, .

Subdivision B. Apnata

s. DECUMBENTIA. HOG eloairentets,

IV. Diastoporide,

V. Lichenoporide,

VI. Frondiporide,

Sub-order III. CTEN OSTOMATA.
Division ]. HabcyoNELLEA.

I. Alcyonidule,

Division II. VESICULARINA.
IL Vesicularide,

III. Cylindreecide,
Group B. ENTOPROCTA.
Order PEDICELLINEA.

L. Pedicellinide,

Crisia,

Hornera,

Idmonea,
Pustulopora,

Alecto,
Tubulipora,

Diastopora,

LTtchenopora,

{ Fasciculipora, .

Supercytis,

Aleyonidium, .

Vesicularia,

Amathia,
Farrella,

Cylindrecium,

Ascopodaria,

PAGE

31

‘DESCRIPTION OF GENERA AND SPECIES.

Sus-Orper II]. CYCLOSTOMATA, Busk.

Cyclostomata, Bk., Smitt, Hincks, Auctt.
Tubuliporina, M.-Edwards, Johnst., &c.
Auloporina and Myrioporina (pars), Ehrenberg.
Cerioporina (pars), Bronn.

Centrifuginea (pars), d’Orbigny.

Milléporés a cellules (pars), Blainville.

Character.—Zoccia tubular, calcareous, partially free or wholly connate or
mamersed ; aperture terminal, inoperculate.

Drviston I—ARTICULATA seu RADICATA.

Radicellata, dOrbigny, Hincks, Smitt, &c.
Articulate s. Radicatz, Bk., Crag Polyz.

Character.—Zoarium branched, divided into distinct internodes by flexible chitinous
joints; affixed by chitinous, or calcareous jointed stoloniform radical tubes. Zocecia
disposed in single or double longitudinal series, all facing in one direction.

Family I. Cristapz.

Les Crisies, M.-Edwards.
Crisiadz, Johust., Busk, &c.
Crisiidz, Busk, Hincks, &c.
Crisiex, Smitt.

Crisidea, Reuss.

Crisidex, d’Orbigny.

Character.—The only family.

(ZOOL. CHALL, EXP,—PART L.—1886.) Ddd 1

2 THE VOYAGE OF H.M.S. CHALLENGER. og

The Family here contains :—

1. Crisia..

(1) Crisia bieiliata, Macgilliv. (Pl. I. figs. 1, 2)..

(2) Crisia eburnea, var. laxa (Pl. IL. fig. 1).

(3) Crisia denticulata, Lamk. (Pl. I. fig. 3).
Crisia denticulata, var. a, gracilis (Pl. I. fig. 4).
Crisia, denticulata, var. B, patagonica.

(4) Crisia elongata, M.-Edw. (PI. I. fig. 3).

(5) Crisia acuminata, n. sp. (Pl. III. fig. 1).

(6) Crisia acropora, Bk.

(7) Crisia holdsworthi, Bk. (PI. III. -fig. 2).

(8) Crisia conferta, Bk. (PI. II. fig. 5).

(9). Crisia cylindrica, nu. sp. (Pl. IL figs. 2, 4).

1. Crisia.

Sertularia (pars), Linné.

Cellularia (pars), Pallas.

Cellaria, (pars), Solander, Lamk,

Tibiana (pars), Lamk., Schweigger, Blainville, Lister.
Falcaria (pars), Oken, Gray.

Eucratea (pars), Esper, Lamx., Fleming, &c.

Crista (pars), Lamx., Johnst., Gray, Auctt.

Crisidia (pars), M.-Edwards, Busk, d’Orbigny (1852).
Filicrisia, d’Orbigny (1851).

Character.—Zocecia disposed in a single. or double longitudinal series. Occia
modified zocecia, with a tubular aperture, walls punctate.

§ a. Uniserial.

Crisidia, M.-Edwards, Busk, Auctt.
Unicellaria (pars), Blainville.

Falcaria, Oken, Gray.

Tibiana, Lister (nec Blainville, Lamx.).
Unicrista, d’Orb., Vine.

No species belonging to this section occurs in the Challenger collection.

§ 8. Zocecia disposed in a double series, opposite or alternate.

§§ a. Zocecia opposite in pairs, from two to four (rarely six) in an internode.

Bicrisia, d’Orbigny.
Crisia (pars), Auctt.

REPORT ON THE POLYZOA. 3

(1) Crisia biciliata, Macgilliv. (PI. I. figs. 1, 2).
Crisia biciliata, Macgilliv., Nat. Hist. Vict., Dec. iv. p. 37, pl. xxxix. fig. 2.

Character.—An opposite pair of perfect zocecia in each internode, with a third
intermediate aborted one between them, from which the succeeding pair or a branch
arises. A pair of long, jointed spines articulated to the outer part of each zoccium,
excepting those bearing the secondary branches. Ovecia small, much elongated,
pyriform, situated at the angle of a bifurcation. Zocecia 0°07 mm. in diameter.

Habitat.—Station 135, Tristan da Cunha, 60 to 1100 fathoms, rock and shells;
| Williamstown, Mapleston ; Warrnambool, Watts].

As Mr. Macgillivray remarks (p. 38) “The aspect. and general arrangement of the
cells are the same as in C. edwardsiana, d’Orb. ‘There are two cells in each internode,
except in those from which the branches originate. The cells, as he observes, are not
so long as those represented in M. d’Orbigny’s figure of C. edwardsiana, and are wider
superiorly, and the free part is not so long, and is much more abruptly curved forwards ;
the ocecial cell is smaller, more elongated, and each lateral cell supports usually two,
but sometimes only one long-jointed spine.”

Mr. Macgillivray further remarks that he is doubtful to what species my description
and figures of Crisia edwardsiana (Brit. Mus. Cat., pt. i. p. 5, pl. i. figs. 5-8) refer,
and I am compelled to say that subsequent examination of the specimens from which
that description was chiefly drawn, some of which were from Tierra de Fuego, collected
by Mr. Darwin, and others from New Zealand, procured by Dr. Sinclair, has left
considerable doubt in my mind as to the identity of these two forms; the latter, it is
highly probable, is distinct from the Patagonian Crisia edwardsiana, in which the
zocecia, as represented by M. d’Orbigny, are very long and erect, whilst in the New
Zealand species they are short and curved forwards. There is also another form or variety
closely approaching the New Zealand species, but in some measure intermediate between
that and the South American one, which may turn out to be distinct from either, and
to form an intermediate variety, characterised by a tendency to have two or more
pairs of cells in some of the internodes, and less exactly opposite. All three, howe ver,
are furnished with only a single articulated spine, which arises close below the mouth,
instead of low down the back as in Crisia biciliata. One character is observable in the
New Zealand form which I have not noticed in the others, viz., that the dorsal aspect of
the pair of zocecia is entire, and faintly striated transversely.

§§ b. Zocecia numerous (more than six) in each internode, alternate on the
two sides. Ocecia irregularly disposed, often absent.

Crista (pars), Auctt.

4 THE VOYAGE OF H.M.S. CHALLENGER.

(2) Crista eburnea, var. laxa (PI. II. fig. 1).

Sertularia eburnea, Linné.

La Sertolara @avorio, Cavolini, Sprengel.

Cellularia eburnea, Pallas, Bruguiéres.

Cellaria eburnea, Soland., Bosc, Lamarck, Johnst., Transact. Newe. Soc., vol. ii. p. 262, pl. xi. fig. 5.

Crisia eburnea, Lamx., M.-Edwards, Fleming, Johnst., Templeton, Blainville, Risso, Couch,
Hincks, Norman, Alder, Hassall, Van Beneden, Rech. s. l’Anat. des Bryoz., Mém. Brux.,
t. xvill. p. 52, pl vi. figs. 12-16; Busk, d’Orbigny, Pal. Frang., p. 598; Joliet, Arch. de
Zool. Expér. et Gén., vol. vi., 1877.

Character.—Zoarium small, tufted. Zocecia usually three to seven in each internode
(rarely nine to eleven) loosely aggregated. Branches usually arising from the first or
lowest zocecium in an internode, sometimes from the second or third. Aperture circular,
sometimes slightly pointed on one side. Ocecia pyriform, surface even. Branches
0:15 mm., zocecia about 0°07 mm. in diameter.

Habitat.—Station 149, D. and IL, off Kerguelen Island, 28 to 105 fathoms,
volcanic mud.

[Seas of Europe ; Spitzbergen, Smitt ; Madeira; Adriatic ; Roscoff, Joliet. ]

Except in its rather more loose mode of growth this form does not differ in any
essential character from the common Crisia eburnea.

(3) Crista denticulata, Lamarck, sp. (Pl. II. fig. 3).

Cellaria denticulata, Lamk.

Crisia luaata, Fleming, Blainville, Johnston (ed. 1), Couch.

Crisia denticulata, M.-Edw., Johnst., ed. 2, p. 284, pl. 1. figs. 5-6; Gray, Sars, d’Orb., Gosse,
Alder, Busk, Hincks, Norman, Smitt, Krit. For. Ofyer. Skan. Hafs.-Bryoz., p- 117 (nee
Floridan Bryoz.) ; Waters, Ann. and Mag. Nat. Hist., ser. 5, vol. iii. p, 269; Vine, Joliet.

Cellaria arctica, Sars (teste Smitt).

Character.—Zoarium 1 to 3 inches high, of straggling growth. Zocecia almost
straight, connate nearly throughout their entire length. Aperture elliptical, usually
pointed on one side. Ocecial cells truncate, often with three or more transverse
annulations. Branches usually arising in an internode from or above the fourth cell
(sometimes from the second in the lower parts of the zoarium). Branches 0°23 mm.,
zocecia 0°07 mm. wide.

Habitat— Off St. Paul’s Rocks, shallow water. Station 186, lat. 10° 30’ S.,
long. 142° 18’ E., 8 fathoms, coral mud. Off Inaccessible Island, Tristan da Cunha, 60
to 90 fathoms. /

[Coasts of Britain and Ireland; Norway; Spitzbergen? Grand Manan? Stimps.; Bay
of Naples ; Roscoff. |

REPORT ON THE POLYZOA. 5

Var. a. gracilis (Pl. I. fig. 4).

Character.—Closely resembles Crista denticulata but of far slenderer habit, rarely
if ever presenting any longitudinal interspaces between the series of zocecia; branches
not more than 0°2 mm. wide; zocecia about 0°06 in diameter.

Habitat.—Off Zebu, Philippine Islands.

Var. 8. patagonica, d’Orbigny (?)
Crisia patagonica, d’Orb., Voy. dans l’Am. Mér. Polyp., p. 7, pl. 1 figs. 1-3.

“Cells from nine to nineteen, straight, very distinct ; branches arising from second
or third cell; sometimes two from an internode, when the second arises from the sixth
cell. Joints black.” Diameter of branches about 0°23 mm., and of zocecia 0°08 mm.

Habitat.—Station 36, off Bermudas, 30 fathoms, coral.

[ Patagonia. |

(4) Crisia elongata, M.-Edw. (PI. I. fig. 3).

Crisia elongata (?), M.-Edwards, Réch. sur les Crisies, p. 10, pl. vii. fig. 2; Busk, Brit. Mus. Cat.,
pt. iii. p. 3, pl. iv. figs. 5-6; Waters.

Character.—Zoarium composed of long straight branches. Zocecia, twelve to
“twenty-one or more in each internode; often much produced and curved forwards.
Aperture circular, even; branches arising from the fifth to the seventh zocecium.
Ocecial cells unknown. Surface finely granular. Branches 0°3 mm., zocecia 0°07 mm.
wide.

Habitat.—Station 176, lat. 18° 30’ §., long. 173° 52’ E., 1450 fathoms, Globi-
gerina ooze.

[Red Sea or Mediterranean? M.-Edw.; Algoa Bay. |

Whether the specimen (the only one in the Challenger collection) here described and
ficured really be the form described by M. Milne-Edwards I am by no means now con-
vinced, but it is the same as that to which I have given the same appellation in the
British Museum Catalogue. One reason for the doubt is that M. Milne-Edwards
describes his Crisia elongata as narrower than Crisia denticulata, while that I have to
name is certainly quite as wide, if not wider, than the usual form of Crisia denticulata.

(5) Crisia acuminata, n. sp. (Pl. III. fig. 1).

Character.—Zoarium 1 to 2 inches high, composed of long, strageling, flexuose
branches dividing once or twice dichotomously and terminating in two short bifurcations.
One of the terminal zocecia (usually the penultimate), is often produced into a long,

6 THE VOYAGE OF H.M.S. CHALLENGER.

acute, tapering spine. The internodes comprise from seven to eleven zocecia, usually
seven or nine, and the branches always arise from the second. Zocecia about half connate,
produced above and curved abruptly forwards; aperture circular, even, border thin.
Surface sparsely punctate ; dorsal aspect finely striated, with a row of punctures down
each interspace. Branches convex before and behind, and without any intermediate
longitudinal space. Joints white or pale brown. Ocecial cells? Branches 0-2 to 0:25 mm.,
zocecia 0°1 mm. wide.

Habitat.—Station 320, lat. 37° 17’ S., long. 53° 52’ W., 600 fathoms, green
sand.

Somewhat like Crisca denticulata, but differing in the general habit which is
characterised by the very long, straggling, wavy, or flexuose, sparingly forked branches,
sterminating in two or three short forks. Many of the ultimate segments exhibit a longer
or shorter, acutely tapering, pointed spine, formed of a metamorphosed zoccium. A
similar disposition may be occasionally seen in a species of Crisia, to which I have given
the name of Crisia sinclairensis (Brit. Mus. Cat., pt. iii. p. 6, pl. iv. figs. 7-11), but im
this species the spinous process thus formed is much more obtuse, and there are other
differences which prevent their being considered the same.

(6) Crisia acropora, Busk.

Crisia acropora, Bk., Voy. of Rattles., vol. i p. 351; Brit. Mus. Cat., pt. iii. p. 6, pl. v. figs. 3-4;
Macgilliv., loc. cit., Dec. iv. p. 38, pl. xxxix. fig. 3.

Character.—Cells nine to thirteen in each internode; a conical tooth (sometimes
bifid) behind the orifice. Zocecia slightly compressed ; surface closely punctured, brilliant,
sometimes porcellanous. Branches arising from the second to the fourth zocecium.
Ocecial cells large, pyriform, frequently annulated. Branches 0°25 mm., and zocecia about
0:06 mm. wide.

Habitat.—Station 161, off Port Philip, 33 fathoms, sand.

[Bass Strait, R.; Williamstown and Queenscliff, Macgilliv. |

In this species the radical tubes are much curled, always arising from the bottom of
the lowest cell in an internode, behind.

(7) Crisia holdsworthi, Busk (PI. IIL. fig. 2, ocecium).
Crisia holdsworthti, Busk, Brit. Mus. Cat., pt. iii. p. 7, pl. vip fig. 2.

Character.—Zocecia nine to eleven in each internode, connate throughout, with a
short, tubular, cylindrical prolongation projecting directly forwards; walls very delicate,
sparsely punctured ; branches arising usually from the third, but in the lower internodes

REPORT ON THE POLYZOA. 7

not unfrequently from the second cell. Ocecial cell infundibuliform, rounded at the top.
Branches 0:2 mm., and zocecia 0'08 mm. wide.

Habitat.—Off Marion Island, 50 to 75 fathoms; off Prince Edward Island, 80 to
150 fathoms.

[ Ceylon, Holdsworth. ]

Habit very delicate and slender. May be allied to Crisia tenuis, Macgilliv. (loc. cit.,
p. 39, pl. xxxix. fig. 5), in which, however, the zoccia appear to be less closely connate.
In the specimens brought by Mr. Holdsworth from Ceylon there were no occia; on
which account I have given a figure of that organ from the Challenger collection.

(8) Crisia conferta, Busk (PI. IL. fig. 5).

Crisia conferta, Bk., Brit. Mus. Cat., pt. ii. p. 7, pl vi.a fig. 5.

Character.—Zoarium tufted, composed of short, thick, curved branches radiating as
it were from a short central stem. Zocecia thirteen to twenty-one in an internode ; nearly
the upper half free, cylindrical, curved abruptly forwards ; orifice orbicular or subelliptical,
of the same diameter as the tube; branches one to four from each internode, not opposite.
Ocecial cells closely adnate, median or axillary; usually broadly truncate. Branches
0°35 mm., and zocecia 0°07 .mm. wide.

Habitat—Off St. Vincent, Cape de Verde Islands, depth 10 fathoms. Station 163a,
off Twofold Bay, 150 fathoms.

[Cape de Verde Islands, H.M.S.‘ Herald.” ]

A well-marked species, growing usually in dense tufts, and peculiar for the number of
branches springing from an internode. The curved free portion of the cell is not, as is
most usually the case, a mere production of the peristome marked with annular lines of
growth, since the wall of that part is punctured like the rest of the zocecium.

(9) Crista cylindrica, n. sp. (Pl. IL. figs. 2, 4).

Character.—Zoarium about 4 an inch high, furcately branched; ten to thirty
zocecia in an internode ; usually two branches given off from the longer segments, the
lower from about the seventh zocecium, and the upper near the summit of the internode.
Zocecia about half immersed, the upper part curved forwards, exceedingly delicate and
thin-walled, without puncta ; orifice circular, margin even. Branches perfectl¥ cylindrical,
with an even shiny surface, distinctly punctate; dorsal aspect obliquely striated, but
quite even. Ocecial cells pyriform, usually axillary, with a wide tubular orifice. Diameter
of branches about 0°15 mm., and of zocecia 0°06 to 0:08 mm.

8 THE VOYAGE OF H.M.S. CHALLENGER.

Habitat.—Off Nightingale Island, Tristan da Cunha, 100 to 150 fathoms.

A beautifully delicate form, distinguishable by its very slender habit and the perfectly
cylindrical aspect of the branches, with the projecting cylindrical zocecia, the projecting
portion wholly oral. Its nearest ally would be Crisia holdsworthit.

Division I1.—INARTICULATA.

. Centrifuginés empatés a cellules non operculées, d’Orb., Paleeont. Franc.,
p. 605 (pars).

Inarticulatez seu affize, Bk., Crag Polyzoa, p. 98.

Incrustata, d’Orbigny, Smitt.

Character.—Zoarium continuous, not divided into distinct internodes, fixed by a
contracted calcareous base, either erect and free, or immediately adnate upon foreign
bodies, and recumbent in whole or in part.

Sugppivision A. ERECTA.

Family II. InmMonrm#, Busk.

Tubigeridz (pars), d’Orbigny, loc. cit., p. 698.
Tubuliporide (pars), Johnst., Smitt, Hincks.
Les Tubuliporiens (pars), Milne-Edwards. :
Idmoneidz, Bk., Crag Polyzoa, p. 94; Brit. Mus. Cat., pt. iii, p. 10; Macgilliv.
Idmoneadz, Bk., Engl. Cyclopedia, art. Polyzoa.
Horneridz, Hincks.
Character.—Zoarium usually erect and rarely adnate, simple or branched ; branches
cylindrical, subcylindrical, or triangular, free or anastomosing.
The Family here contains the following genera :—

1. Idmonea, Lamx.

§ a. The zocecia all disposed in alternate series on each side of the front of the
branches ; the innermost the longest.

(1) Idmonea atlantica, BK. Forbes.

(2) Idmonea radians, Lamk.

(3) Idmonea marionensis, Busk.

(4) Idmonea australis, Macgilliv. (Pl. III. fig. 3).
(5) Idmonea eboracensis, n. sp. (PI. III. fig. 4).

REPORT ON THE POLYZOA. © 9

§ 8. The outermost zocecia in the lateral series the longest ; isolated zocecia opening
in the space on the front between the lateral series.

(6) Idmonea nmulneana, d’ Orb.
(7) Idmonea wrregularis, Meneghini.
(8) Idmonea fisswrata, n. sp. (Pl. II. fig. 5).

2. Hornera, Lamx.
§ a. Zoarium branched, branches free or rarely inosculating.
§§ a. Ocecia dorsal; anterior surface of branches reticulato-fibrillate.

(1) Hornera frondiculata, Lamx.
(2) Hornera lichenoides, Linn.

§§ b. Ocecia anterior, either wholly or in part ; surface in front not fibrillated
or sulcate.
(3) Hornera violacea, Sars.

§ B.. Zoarium foliaceous, branches connected by transverse tubules.

(4) Hornera foliacea, Macgilliv.

3. Pustulopora, Blainv.

(1) Pustulopora proboscidea (Pl. IV. fig. 1).

(2) Pustulopora proboscidioides, (Pl. IV. fig. 4).

(3) Pustulopora deflexa, Smitt (Pl. IV. fig. 3).

(4) Pustulopora regularis, Macgilliv. (Pl. IV. fig. 2).

1. Idmonea, Lamouroux.

Idmonea, Lamx., Exp. Méth., p. 80; Defrance, Blainville, M.-Edwards, Johnst., Lonsdale,
Reuss, Michelin, Hagenow, d’Orb, 1852 (pars); Busk, Van Beneden, Hincks, Smitt
(subgenus), &c.

Crista (pars), d’Orbigny, Stoliczka.

Retepora (pars), Goldfuss, Lamk. .

Diastopora (pars) Michelin.

Tubulipora (pars), Lamk., Smite.

Crisina (pars), d’Orbigny, Smitt.

Character.—Zoarium erect, free or very partially adnate, branched dichotomously or
irregularly ; springing from a single tubular cell, having a constricted, basal, discoid
expansion. Branches free or anastomosing; orifices of zocecia disposed in parallel or
subparallel, transverse or oblique, usually alternate series on the sides of the front of the

(ZOOL. CHALL. EXP.— PART L.—1886.) Ddd 2

10 THE VOYAGE OF H.M.8. CHALLENGER.

branches, which are usually flattened behind, and either angular or rounded on the
anterior aspect.

§a. The zocecia all disposed in alternate series on each side of the front of —

the branches ; the innermost the longest.

(1) Idmonea atlantica, EB. Forbes.

Idmonea radians, Van Beneden, Bryoz. de la Mer du Nord, Bull. Brux., xvi. pt. ii. p. 646, pl. i.
figs. 4, 6.
4 Idmonea coronopus, Defrance, Dict. d. Sci. Nat., vol. xxii. p. 565; d’Orbigny, Milne-Edwards,
Réch. sur les Crisies, p. 23, pl. x. fig. 3.
Idmonea atlantica, E. Forbes, MSS., Smitt, Johnst., Gray, Sars, Busk, Ann. and Mag. Nat. Hist.,
ser. 2, vol. xviii. p. 34, pl. i. figs. 6a-e; Quart. Journ. Micr. Sci., vol. vi. p. 128, pl. xviii.
fig. 5; Rep. Brit. Assoc., 1859 (Trans. Sect.) p. 146; (var. tenuis) Brit. Mus. Cat., pt. iii.
p. 11, pl. ix.; Smitt, Florid. Bryoz., p. 6, pl. ii. figs. 7, 8; Hincks, Waters, &c.
1 Idmonea angustata, d’Orb., Paleont. Frang., p. 731.

Character.—Zoarium irregularly branched and usually more or less in one plane;
branches triangular, one to four or five cells in each series, the innermost the longest ;
dorsal surface very minutely punctate; peristome entire, even. Ocecium anterior,
subpyriform.

Habitat.—Off Nightingale Island, 100 to 150 fathoms. Station 149x, off Cape
Maclear, Kerguelen, 30 fathoms. Simon’s Bay, Cape of Good Hope, 18 fathoms.

[Arctic Seas; coast of Norway and Finmark ; Shetland ; var. tenuis, North Atlantic ;
Gulf of Florida, Smitt; Madeira (?), Bay of Naples; fossil in Italian Miocene and Canadian
Post Pliocene (?). |

(2) Idmonea radians, Lamarck (sp.).

Retepora radians, Lamk., d’Orbigny.
Idmonea radians, Busk., Brit. Mus. Cat., pt. iii. p. 11, pl. vii. figs. 1-4; Macgilliv., Nat. Hist.
Vict., Dec. vii. p. 30, pl. lxviii. fig. 3; Waters; Haswell, Proc. Linn. Soc. N.S. Wales,
vol. iv. p. 350, vol. v. p. 35.
? Hornera radiata, Blainy., Man. d’Actin., p. 419.
Idmonée rayonnante, M.-Edw., loc. cit., p. 25, pl. xii. fig. 4.

Character.—Zoarium usually procumbent, radiate in a more or less regular circle,
stipitate, sometimes suberect, with elongated, straight, subparallel bifurcating branches.
Branches keeled in front, rounded behind. Dorsal aspect longitudinally sulcate, with a
series of long perforations or alveoli along the sulci; the sides and front pitted, some-
times almost reticulate. Zoccia produced, gently curving forwards, somewhat tapering,
often with a bilabiate orifice, about 0°06 mm.. Branches 0°3 mm., series about 0:4 mm.
apart. Usually only one or two zoccia on the sides.of the front, alternate, when more
than one the inner one the longer. Ocecial chambers subglobular on the anterior aspect,
close below, but not at a bifurcation ; surface coarsely pitted or foveolate.

REPORT ON THE POLYZOA. . il

Habitat.—Station 172, off Tongatabu, 18 fathoms, coral mud. Off Honolulu, 20 to
40 fathoms.
[Australian Seas ubsque, New Zealand, &c.]

This species appears to occur under two rather distinct forms. In one (the typical)
it constitutes a beautiful circular expansion, about one inch or more in diameter,
composed of short bifurcating branches radiating from a central short stem (vide Brit.
Mus. Cat., pt. iii. pl. vii. fig. la), or a more straggling growth in which the branches,
though still springing from a more or less excentric point, are much longer, forming
elongated forks (loc. cit., fig. 1b), constituting a variety to which the term stricta might
be applied. Very fine specimens of this form occur in the Challenger collection, from
Honolulu, whilst a beautiful specimen of the radiate type was procured at Station 172,
off Nukalofa, Tongatabu.

In all the Challenger specimens there is rarely more than one zocecium to represent
the lateral series, but in others there are occasionally as many as four (wde Brit. Mus.
Cat., pt. ii. pl. vii. fig. 4), as described by Mr. Macgillivray. The great peculiarity of the
species, however, is seen in the coarsely pitted or foveolate surface on the sides of the
branches, and the series of large pores or pits along the dorsal sulci; the ocecial chambers
also have peculiar sculpture.

(3) Idmonea marionensis, Busk.

Idmonea marionensis, Busk, Brit. Mus. Cat., pt. iii. p. 13, pl. xiii. figs. 3, 5; pl. vii. figs. 7, 8
(young state); Waters, Haswell.
tCrisina hochstetteriana, Stoliczka, ‘‘ Novara” Exp. Geol., Theil, Bd. i. p. 113, Taf. xviii. fig. 3 ;
Smitt, Florid. Bryoz., p. 6, pl. ii. figs. 11-13.

_ Character.—Zoarium slender, elongate, very sparingly branched ; stem and branches
cylindrical or subcylindrical. Zocecia two to four in each series (most usually two)
about 0°15 to 0°20 mm., series wide apart, 0°7 to 0°8 mm., when entire the innermost the
longest. Surface finely but sparsely punctured; dorsal surface convex, with a fine
longitudinal striation.

Habitat.—Off Marion Islands, 50 to 75 fathoms; off Prince Edward Islands, 80 to
150 fathoms. Station 147, lat. 46° 16’ S., long. 48° 27’ E., 1600 fathoms, Diatom ooze.
Station 151, off Heard Island, 75 fathoms, voleanic mud. Station 320, lat. 37° 17’ S., .
long. 53° 52’ W., 600 fathoms, green sand.

[? Auckland, New Zealand, fossil, Stoliczka; Bay of Naples and Marion Islands, Waters;
Queensland, Haswell. }

As Ihave remarked in Brit. Mus. Cat., this species seems to mark a transition between
Pustulopora and Idmonea. The cells, however, are always disposed in rows or series on
each side of the anterior aspect of the branch, and are for the most part deeply immersed ;

12 THE VOYAGE OF H.M.S. CHALLENGER.

the exserted portion being of a very thin and delicate texture rarely shows the orifice
in a perfect condition. It may perhaps be identical with M. d’Orbigny’s Idmonea
canoriensis (Palzont. Frang., p. 732); but as neither figure nor sufficient description of
that species are given, and it is merely stated to be ‘“‘slender as a thread and almost
round, with very few cells,’ it is impossible to be certain.

(4) Idmonea australis, Macgillivray (Pl. III. fig. 3).
Idmonea australis, Macgilliv., loc. cit., Dec. vii. p. 30, pl. Ixviii. fig. 2.

. Character.—Zoarium of small size (4 to 2 inch), irregularly branched once, each
short branch terminating in a single fork; branches contorted and sometimes twisted ;
four to six zocecia in each series, the inner the longest; no intermediate longitudinal
space in front between the series. Zocecia very slender (0°12 mm.), connate below, but
when perfect much produced or free for one-half or two-thirds of their length, slightly
tapering, some nearly straight and ascending obliquely, but towards the upper part of
the branches curved forwards, not flattened in front; series 0°7 to 1°0 mm. apart.
Branches compressed, rounded both in front and behind, about 0°6 mm. wide, everywhere
minutely dotted, up to the border of the aperture; dorsal surface very finely striated
longitudinally, intermediate spaces with very minute dots in irregular longitudinal series.

Habitat.—Station 1638p, off Port Jackson, 30 to 35 fathoms, rock. Off Marion Island,
50 to 75 fathoms.
{Port Phillip Heads, 10 to 15 fathoms, Macgilliv. ]

A very distinct and well-marked species, easily recognisable by the compressed form
of the branches, which on section are oval, as well as by the extremely fine punctation,
or rather white dotting of the surface, and the fine or close longitudinal striation of the
dorsal aspect. It appears to vary very much in the length of the exserted portion of the
zocecia, Which, in the specimens from Marion Island, forms more than half the length of
the cell (PI. III. fig. 3). The exserted part is very slightly tapering and no part of it
appears to be peristomal, as the wall exhibits the minute punctation quite up. to, the
orifice, and there is very rarely any appearance of annular lines of growth... None of. the
specimens present any ocecial chamber.

Mr. Macgillivray suggests that this species may prove to be a form of Jdmonea
atlantica, but for this view I can see no grounds whatever.

(5) Idmonea eboracensis, n. sp. (Pl. III. fig. 4).

Character.—Zoarium very small, not more than } inch high; branches very short
and irregular, once furcate, much compressed, 0°6 mm: wide ; dorsal aspect rounded, longi-
tudinally striated but not grooved. Strie (fig. 4c), about 0°01 mm. apart, a single irregular

REPORT ON THE POLYZOA. 5-13

row of-dets: down each interspace. Zocecia (0°1 mm.), usually four in each series, of
uniform length, except the innermost, which is the longest ; series 0°4 to 0°5 mm. apart.
Habitat.—Station 186, off Cape York, 8 fathoms, coral mud.

The collection affords only a single such specimen, but apparently mature, inasmuch
as.two of the branches are widely dilated at the second bifurcation into an elongated,
deeply immersed ocecial chamber.

§ B. (subgenus Tervia).—The outermost zocecium in each lateral series the longest ;
scattered zocecia opening irregularly in the space between the lateral series.

Tervia, Jullien, Bull. Soc. Zool. de France, vol. vii. p. 500,:1882.

(6) Idmonea milneana, ‘@Orbigny.

Idmonea milneana, VOrb., Voy. d. ’Amér. Mérid., “ Polypiers” p. 20, pl. ix. figs. 17-21,
Paleont. Frang., p. 732; Smitt, Florid. Bryoz., p. 8, pl. iii. figs. 14-17 ; Macgilliv., loc. cit.,
Dec. vii. p. 29, pl Ixviii. fig. 1; Busk, Brit. Mus. Cat., pt. iii. p. 12, pl. xi..; Waters,
Haswell, Ridley.
2 Idmonea transversa, Milne-Edw., loc. cit., p. 26, pl. ix. fig. 3

Character.—Zoarium spreading from a central peduncle, branching dichotomously.
Branches depressed, broad, flattened or. slightly rounded behind, 0°8 to 1°5 mm. wide ;
surface thickly punctate ; on dorsal aspect irregularly striated longitudinally, and, except
in the younger part, transversely wrinkled. Zocecia about 0°2 mm. in diameter, usually
four or more in a series, the outer the longer ; a few intermediate zocecia opening in the
space in front between the lateral series; series 0°6 to 1 mm. apart. Ocecial chamber ?

Habitat.—Station 75, lat. 38° 38°N., long. 28° 28’ 30” W., 450 fathoms, voleanic mud.
Station 151, off Heard Island, 75 fathoms, voleanic mud. Off Prince Edward Island, 80
to 150 fathoms.

[Port Philip Heads, 10 to 15 fathoms, Macgilliv.; Falkland Islands, d’Orbigny ; coast
of Tierra del Fuego, and Patagonia, 30 fathoms; Chonos Archipelago, Darwin; Port
Jackson and Queensland, Haswell. |

The cells, as Mr. Macgillivray observes, are usually four in series, the inner the least
prominent, the others gradually increasing in length to the outer, which projects very
much. ‘They are united side to side throughout almost their whole length, so as to form
regular walls, rising up and projecting far beyond the sides of the branches. As in
several other species of Jdmonea numerous radical tubes are given off from the back of
the branches by which the growth is attached. The anterior median single zoccia are
few in number and usually nearly level with the surface. Jdmonea milneana belongs to
the group for which M. Jullien has proposed the name of Tervia, characterised by the

14 THE VOYAGE OF H.M.S. CHALLENGER.

possession of an intermediate or azygos set of zocecia on the front, and, it may be added,
by the circumstance that the outermost zocecium in the lateral series is the longest.

(7) Idmonea irregularis, Meneghini.

Idmonea irregularis, Meneghini, Mém. sui. Polypi della Famiglia Tubuliporiani, p. 12 (teste
Heller); Heller, Adriat., p. 121; Busk, Brit. Mus. Cat., pt. iii. p. 13, pl. xii.; Waters, Haswell.
4 Tervia folini, Jullien, Bull. Soc. Zool. de France, vol. vii. p. 501, pl. xiii. figs. 8-9, 1882.
Character.—Zoarium composed of irregularly dichotomous, slender, rounded branches,
05 to0'6 mm. wide. Zocecia four to six in each lateral series, and the intermediate space
in front occupied by numerous others irregularly scattered ; series 0°6 to 0°8 mm: apart.
Diameter of zocecia 0°1 to 0°15 mm.; surface uniformly and thickly punctate ; dorsum with
longitudinal strize wide apart. Ocecial chamber ?
Habitat.—Station 75, lat. 38° 38’ N., long. 28° 28’ 30” W., 450 fathoms, volcanic
mud.
[ Adriatic, Meneghini, Heller; Mediterranean, H.M.S. “ Porcupine”; Bay of Biscay,
Jullien ; Bay of Naples, Waters; Queensland, Haswell. |

(8) Idmonea fissurata, n. sp. (Pl. III. fig. 5).

Character.—Zoarium procumbent, composed of branches radiating irregularly from a
central peduncle, dividing about twice dichotomously and appearing strongly serrated
on the borders; branches 0°7 to 1 mm. wide. Zocecia 0°15. to 0°2 mm. in diameter, with
an elliptical aperture, closely adnate, the outermost the longest; a few isolated median
zocecia whose apertures are usually level with the surface. Lateral series 0°9 to 1:1 mm.
apart. Surface of branches in front and behind deeply and irregularly sulcate and
pitted.

Habitat.—Station 320, lat. 37° 17’ S., long. 53° 52’ W., 600 fathoms, green sand.

This species is at once recognisable by the peculiar fissured aspect of the surface, both
in fronc and behind, and the numerous irregular pits with which it is studded. Its habit
in some specimens is something like that of Jdmonea radians, but much stronger. Like
the others of the group to which it belongs, the branches appear serrated on each side.

2. Hornera, Lamouroux.

Hornera, Lamx., Expos., p. 41 (1821); Milne-Edwards (pars), Reuss (pars), Blainville (pars),
Defrance, Michelin, Hagenow, d’Orbigny, Smitt, Hincks, Busk, Sars, &c.

Millepora (pars), Linné, Pallas, Esper, Solander.

Retepora (pars), Lamarck, Goldfuss.

Syphodictyum (pars), Lonsdale.

REPORT ON THE POLYZOA. 15

Character.—Zoarium ramose or foliaceous ; zocecia opening only on one side; oecia
dorsal or anterior.

§ a. Ramosa.—Zoarium branched, branches free or rarely inosculating, cylindrical
or subcompressed.

§§ a. Ocecia dorsal ; anterior surface of branches reticulato-fibrillate.

(1) Hornera frondiculata, Lamouroux.

Hornera frondiculata, Lamx., Exp., p. 41, pl. lxxiv. figs. 7-9 ; Milne-Edwards, loc. cit., p. 17,
pl. ix. figs. 1-lc.; Blainville, Man. d’Actin., p. 419; Heller, Adriat., p. 124; Busk, Brit.
Mus. Cat., pt. il. p. 17, pl. xx. figs. 1, 2, 3, 6; Manzoni, Waters.
Millepora tubipora, Ell. and Soll, p. 139, pl. xxxi fig. 1.
Millepora lichenoides, Linné, Pallas, Esper.
1 Hornera affinis, M.-Edw., loc. cit., p. 9, pl. x. fig. 1.
4 Hornera andeyavensts, Mich., Icon. Zooph., p. 318, pl. lxxvi. fig. 8.
Hornera serrata et tubulosa (?), Meneghini, loc. czt., p. 10.

Character.—Branches tapering, ramifying more or less in one plane, cylindrical or
subcompressed ; anterior surface strongly fibro-reticulate, divided into rhomboidal spaces
in which are situated the orifices of the zocecia, surrounded with numerous small pores.
Orifice exserted, usually bifid; dorsal surface coarsely reticulate, granular or nearly
smooth, with small elongated pores in the sulci. Ocecia oblong, carinate, ribbed ; aperture
tubular, superior. Diameter of branches about 0°6 mm., and of orifice 0°08 mm.

Habitat.—Porto Praya, St. Iago, Cape de Verde, 100 to 120 fathoms.

Mediterranean, Adriatic (very abundant). Fossil in the Crag and Upper Tertiaries
of Sicily, &c. ] '

(2) Hornera lichenoides, Linné (sp.).

Corallium, Pantoppidan, Norg. Natuurb., vol. i. p. 258, pl. xiv. figs. D.E.

Millepora lichenoides, Linné, Miiller, Prodr., p. 252, No. 3046; Strém, Act. Hafn., vol. xii.
p. 309, pl. ii fig. 12; Fabricius, Zool. Samml. (teste Smitt), and Fauna Greenl., p. 432
(nec Pallas).

Hornera frondiculata, Sars, Reise, Lof. oz Finm. nyt Magazin f. Nat. Vid., t. vi. p. 146; Busk,
Ann. and Mag. Nat. Hist., ser. 2, vol. xviii. p. 34, pl. i. fig. 7a.

Hfornera borealis, Busk, Crag Polyzoa, pp. 95-103; Alder, New British Polyzoa, Quart. Journ.
Mier. Sci., N.S., vol. iv. p. 108, pl. v. figs. 1-6.

Hornera lichenoides, Smitt, Kritisk Forteckn., pp. 404, 469, pl. vi. fig. 10, pl. vii. figs. 1-14;
Busk, Brit. Mus. Cat., pt. iii p. 17. pl. xviii. figs. 5-6 ; Hincks, Brit. Mar. Polyz., p. 468,
pl. lxvii. figs. 1-5.

Character.—Zoarium rising from a rather thick furrowed base, branched irregularly;
branches dichotomous; crowded and straggling, often spreading out in a flabelliform

16: THE VOYAGE OF H.M.S. CHALLENGER.

manner. Anterior surface obscurely fibro-reticulate, sparsely furnished with subtubular
pores. Zocecia on the front of the branches, immersed or very slightly prominent, those
of the outer sides of the branches tubular, slightly expanded towards the orifice, which is
more or less elliptical, with an entire border often much produced on one side; dorsal
surface finely sulcate with minute pores in the sulci. Ocecia dorsal, subglobular or
gibbous, the surface reticulate or coarsely punctured. Aperture tubular, lateral (from
which a very slender rib stretches across to the opposite side, Hincks). Diameter of
branches 0°5 to 0°6 mm., and of orifice about 0°1 mm.

Habitat.—Station 320, lat. 37° 17’ S., long. 53° 52’ W., 600 fathoms, green sand.

[Arctic Seas, Lovén ; coasts of Scandinavia, Pantoppidan, Sars, Macandrew ; Shetland,
Barlee ; Hebrides, Norman ; Nova Zembla; Greenland, Liitken ; St. Georges Banks, Smitt
and Harger. |

§§ b. Ocecia anterior, either wholly or in part; dorsal surface granular or
finely striate.

(3) Hornera violacea, Sars.

Hornera violacea (forma violacea), Smitt, loc. cit., p. 404, Tab. vi. fig. 6-9; Sars, Geol. og.
Zool. Jagtt Reise, Jaondj., 1862, Nyt Magaz. Nat. Vid., vol. xii. p. 282; Busk, Brit. Mus.
Cat., pt. iii. p. 18, pl. xviii. figs. 1-4; Norman, Shetl. Dredg. Rep. Brit. Assoc., 1867,
p. 310; Hincks, Brit. Mar. Polyz., i, p. 469, pl. xvii. figs. 6-8, pl. 1xi. figs. 2, 3.

Pustulopora orcadensis, Bk., Quart. Journ. Micr. Sci., 1860, vol. vill. p. 214, pl. xxxix.
figs. 1, 2.

Character.—Zoarium more or less of a violet colour, branched, strageling ; branches
short, truncate, irregularly dichotomous. Zocecia very irregularly disposed, sometimes
crowded into small fasciculi, usually elongated ; surface punctate (not reticulate) ; dorsal
surface granular, or very finely striated with minute pores, often a rib-hke elevation
down the centre of the branch. Ocecia elongated, situated in the axils of the branches,
usually more towards the dorsal aspect; surface smooth, finely punctate, with a thin
mecian costa; orifice bilabiate near the top. Diameter of branches 0°4 to 0’'7 mm., and
of orifice 0°12 mm.

Habitat.—Station 151, off Heard Island, 75 fathoms, volcanic mud.

[Arctic and Northern Seas, generally distributed ; Shetland. ]

§ B. fenestrata (subgenus Retzhornera).—Branches sub-parallel, connected by.

transverse tubules, so as to form an expanded frond with uadeueae
fenestree.

Retihornera (pars), Kirchenpauer, Cat. iv. of the Museum Godeffroy, 1869; Busk, “Brit. Mus,
Cat., pt. iii. p. 19.

REPORT ON THE POLYZOA. 17

(4) 'Hornera foliacea, Macgillivray.

Hornera foliacea, Macgilliv., Proc. Roy. Soc. Vict., vol. ix., p. 142, 1868.
Retihornera foliacea, Busk, Brit. Mus. Cat., pt. iii, p. 19, pl. xiii. figs. 1, 2, and pl. xix.; Haswell.
1 Retihornera dentata, 4 Retthornera plicata, Kirchenpauer.

Character.—Zoarium expanded, foliaceous, irregularly plicate or convoluted, rising
from a short stem with a discoid base; main branches straight, parallel, connected by
numerous transverse celliferous branches or trabeculee, forming quadrangular fenestre of
pretty uniform size, from 0°7 to 2 mm. in length by 0°3 to 0°4 mm. wide, or about the width
of the branches. Zocecia in the young state exserted, with a usually bifid or toothed
orifice, about 0°05 mm. in diameter. In the older condition more immersed, with an
irregularly bifid or toothed, thickened, somewhat expanded orifice. Anterior surface
fibro-reticulate, obscurely punctate and uneven; posterior sulcate, granular, obscurely
punctured or pitted. Ovecia subglobose, dorsal; usually three zocecia in the width of a
branch, and one in a trabecula.

Habitat.—Station 161, off Port. Phillip, 33 fathoms, sand. Station 163B, off Port
Jackson, 35 to 38 fathoms, rock.

[South Australia, Gould, Macgillivray, Queensland, Haswell. |

Although at one time inclined to regard the fenestrate form of Hornera as entitled
to the rank of a distinct genus or subgenus, I no longer regard it as forming more than a
subgenus, as in all essential characters it perfectly agrees with such forms as Hornera
lichenoides, Hornera frondiculata, and Hornera cespitosa, Mibi., differmg as do
those species from Hornera vidacea in having the anterior aspect fibro-reticulate, and
the ocecia dorsal. In the Brit. Mus. Cat., pt. iii, p. 19, I have described Hornera
folacea as being furnished with delicate spicule projecting from the sides of the
fenestre, but it is highly probable that these are merely the spicule of some parasitic
encrusting Sponge; in all other respects the form brought by Mr. Gould from
South Australia in my collection, from which the account in the Brit. Mus. Cat. was
drawn up, exactly agrees with the specimens in the Challenger collection, which again
are undoubtedly the Hornera foliacea of Mr. Macgillivray. In one of the spec’mens
is a shallow, circular, cup-shaped depression on the dorsal aspect, doubtless the remaant
of an ocecium, but these organs would appear to be very rare.

(ZOOL, CHALL, EXP,—PART L,—1886.) Ddd 3

18.. THE VOYAGE OF H.M.S.. CHALLENGER..

3. Pustulopora, Blainville. .

Pustulopora, Blainville (text), Man. d’Actin., p. 418, 1834; Milne-Edwards, Hagenow (nec
Geinitz), Reuss, Michelin (?), Grube, Meneghini; Busk, Brit. Mus. Cat., pt. iii. p. 20, &c.;
Macgilliv., Proc. R. Soc. Vict., December 1880, p. 6.

Pustulipora, Blainv. (index), Johnston, Gray, Sars, Joliet.

Tubulipora (pars), Couch.

Entalophora (pars), d’Orbigny (nec Lamouroux), Hincks, Brit. Mar. Polyz., p. 455; Smitt,
Florid. Bryoz., vol. i. p. 11; Stoliczka, Waters, &c.

Character.—Zoarium erect, simple or branched, cylindrical ; branches irregular, com-
posed of tubular zocecia partially or wholly connate or immersed ; opening on all sides of
the branch, and disposed quincuncially or irregularly, sometimes in more.or less annular
or subspiral order. :

Although most recent writers, including such high authorities as Professor Smitt and
Mr. Hincks, have adopted the name Hntalophora for the genus here intended, I am
inclined, with the greatest deference, to prefer M. de Blainville’s and M. Milne-Edwards’
name, for the reason that the species named Hntalophora by Lamouroux appears to
me to differ in at least one most important respect, it may be said, from all the other
known Cyclostomata, and most certainly from all with which I am acquainted, either
recent or fossil, viz., in the appendages, as he terms them, being trumpet-shaped, or
gradually increasing in diameter as they increase in length. Whether this arises from an
error of observation on the part of Lamouroux or of his draughtsman, or is the true
condition, may perhaps admit of doubt; with the exception of M. Michelin (Iconog.,
pl. lvi. fig. 4), whose figure very strongly resembles that of Lamouroux, no one seems to
have recorded any other form with trumpet-shaped tubes, and as even his figure does not
represent them as having that form, lam much inclined to assume that Lamouroux’s speci-
men is unique in that respect, and if correctly figured and described, that it must on that
account alone be referred to a distinct generic type from all other known Pustuloporide,
and in fact, as above observed, from all other Cyclostomata. (May it not be a coralline?).

On the other hand; M. de Blainville’s definition of Pustulopora, as distinguished from
Lamouroux’s Hntalophora, is so clear and precise, and his genus has met with the
acceptance of M. Milne-Edwards, Hagenow, Reuss, and numerous others, and in fact
may be said, until quite recently, to have been in full possession of the field, that I feel
no hesitation in retaining it for all forms with cylindrical tubes of the same diameter
throughout ; and in relegating those forms, if there really be any, with trumpet-shaped
tubes, to at least a distinct genus.

With respect to the spelling of the name there can be no doubt that Pustulopora is
the correct way, Pustulipora being apparently merely a printer's error in the index to
the Manuel d’Actinologie. In the text (Joc. cit.) M. de Blainville has it Pustulopora.
Mr. Macgillivray has passed over a similar misprint (Joc. cit.) the name being spelled
Pustulopera in the text and Pustulopora in the description of the plates.

REPORT ON THE POLYZOA. 19

{1) Pustulopora proboscidea, Milne-Edwards (Pl. IV. fig. 1).

Pustuloporda proboscidea, M.-Edw., Sur les Crisies, p. 27, pl. xii. figs 2; Heller, Adriat., p. 125;
Grube, die Insel Lussin, p. 68; Busk, Brit. Mus. Cat., pt. iii. p. 21 (mec pl. xviii.a); Haswell.
Pustulipora proboscidea, Johnst., p. 279, pl. xlviii. fig. 4; Gray.
Entalophora proboscidea, Waters, Bryoz. of the Bay of Naples, Ann. and Mag, Nat. Hist., ser. 5,
vol. iii. p. 274 (1879); Vine.
To these Mr. Waters, Fossil Cyclostomatous Polyzoa from Australia, Quart. Journ. Geol. Soc., vol. xl.,
1884, p. 686, adds the following fossil forms :—
Entalophora raripora, d’Orb., Prod. Pal. Strat., p. 267; Paleont. Frang., p. 787, pl. dexxi.
figs. 1-3, pl. dexxiii. figs. 15-17 ; Beissel, Bryoz. Aach. Kreid., p. 82, pl. x. figs. 120-128.
Pustulopora virgula, Hagenow, Maast. Kreid., p. 17, pl. i. fig. 3.
Entalophora icaunensis, d’Orb., Palzont. Frang., p. 781, pl. dexvi. figs. 12-14.
Entalophora attenuata, Stol., Bry. von Latdorf., p. 77, pl. i. fig. 1; Reuss (?), Bry. Crosaro,
p. 74, pl. xxxvi. figs. 1, 2.
Entalophora anomale, Manzoni, Bry. Mioc. Aust. ed Ungh., p. 10, pl. ix. fig. 33.
Entalophora haastiana, Stol., Bry. Ora. Bay., p. 102, pl. xvii. figs. 4, 5.
Character.—Zoarium composed of long, straight, alternate, furcate, cylindrical
branches, 0°4 to 0°9 mm. in diameter, constituted usually of four longitudinal alternate
series of zocecia which are exserted for about one-third of their length, the exserted tube
curving outwards nearly at a right angle and constituted mainly of a peristomal produc-
tion, ringed, thin, not punctate, with an entire circular orifice about 0°15 mm. in
diameter; surface elsewhere finely punctate. Ocecia consisting apparently of a terminal
expansion, or of one situated close to a bifurcation.
Habitat.—Station 151, off Heard Island,75 fathoms, volcanic mud. Off Prince Edward
Island, 80 to 150 fathoms.
[Shetland (?), E. Forbes; Mediterranean, Milne-Edwards; Adriatic, Heller; Naples,
Waters; Teneriffe and Canaries, d’Orbigny; Madeira, I. G. I.; Gulf of Florida, Smitt ;

Port Jackson and Queensland, Haswell. |

With respect to the Shetland locality assigned to this species in the Brit. Mus. Cat.
on the authority of E. Forbes, as its occurrence in that locality is not noticed either by
Mr. Norman or by Mr. Hincks as a British form, and, moreover, is omitted by Professor
Smitt in Lists of Scandinavian or Arctic Polyzoa, it is highly probable that some mistake
has arisen. It would appear to be a Mediterranean and Atlantic form, extending as far
south as the Kerguelen region.

(2) Pustulopora proboscidioides, Smitt (sp.) (Pl. IV. fig. 4).
Entalophora probosidiotdes, Smitt, Florid. Bryoz., vol. i. p. 11, pl. iv. figs. 26, 27.
Character.—Zoarium composed of elongated, forked, cylindrical branches, 0°7 to 1 mm.

in diameter, constituted of about six longitudinal series of zoccia, almost entirely
immersed, except a short, cylindrical, exserted portion with a circular orifice, about

eel

20 THE VOYAGE OF H.M.S. CHALLENGER.

0°17 to 0°2 mm., which are disposed irregularly in circular whorls, about 1 mm. apart ;
surface rough, punctate, even, with very faint indication of longitudinal striation.
Habitat.—Off Marion Island, 50 to 75 fathoms.

(3) Pustulopora deflexa, Smitt (sp.) (PL. IV. fig. 3).

Entalophora deflexa, Smitt, Florid. Bryoz., vol. i. p. 11, pl. v. figs. 28-30; Waters, Ann. and
Mag. Nat. Hist., ser. 5, vol. iii. p. 274.

Pustulipora deflexa, Johnst., p. 279, pl. xlviii. fig. 5; Norman, Rep. Brit. Assoc., 1868, p. 310;
Marion, Ann. d. Sci. Nat., sér. 6, t. viii. p. 1; Joliet.

Pustulopora deflewa, Heller, Adriat., p. 125.

4 Tubulipora déflexa, Couch, Corn. Fauna, vol. iii. p. 107, pl. xix. fig. 4.

1 Stomatopora deflexa, Hincks, Brit. Mar. Polyz., p. 437, pl. vii. fig. 4.

1 Pustulopora clavata, Busk, Crag Polyzoa, p. 107, pl. xvii. fig. 1.

Character.—Zoarium composed of very irregular furcate branches, 1 to 1:2 mm. in
diameter, constituted of very long cylindrical or very slightly terete ascending zoccia,
often crowded together in fasciculate bundles and varying greatly in length; slightly
produced orally, the produced portion curving slightly outwards; surface granular or
uneven, sometimes transversely rugose, about 0°2 mm. in diameter. Ocecia ?

Halbitat,—Station 151, off Heard Island, 75 fathoms, volcanic mud.

[South coasts of Britain ; Shetland, Norman; Gulf of Florida, Smitt ; Bay of Naples,

Waters; Adriatic, Heller; Marseilles, Marion; Roscoff, J oliet. }

A peculiar feature of this species is the great disposition of the zocecia to be
collected into fasciculate bundles, somewhat in the same way apparently as they are
described by Mr: Hincks in his Stomatopora fasciculata, from which, ‘however, it differs
in other more important particulars, such as the perfectly free and erect habit, and to
judge from Mr. Hincks’s figure, the less diameter of the zocecial tubes, and their less entire
immersion or connation. In Stomatopora fasciculata, moreover, the zoarium is described
as having a dense and smooth surface and a dark brown colour.

Mr. Couch’s description of Tubulipora deflexa is far too incomplete to afford any
assistance towards its determination, and his figure is still less reliable. All he says is
that the zoarium is erect, cylindrical, with waved tubes projecting from all parts. Mr.
Hincks, however, states, with respect to his Stomatopora deflexa, that the “zoarium is
in great part adherent; with linear branches expanding very slightly upwards, the
extremities free, erect, subclavate. The zoccia slender, disposed in pairs along the
creeping portion, and semialternate or alternate, the oral extremity free, bent’ upwards,
and projecting considerably.” To this it may be added that Mr. Hincks rejects
Professor Smitt’s Entalophora defleca as a synonym of his Stomatopora deflexa. So
that on the whole it seems extremely doubtful what name should be assigned to the form
here described, with respect to which all that appears tome to be certain is that the
specimens (mere’ fragments) in the Challenger collection ‘are identical with thé: form

REPORT ON THE POLYZOA. 7a

described by Professor Smitt as Hntalopora deflexa. It is scarcely possible that Mr.
Hincks’s Stomatopora should be the same, but to indicate the possibility that it may be
a recent variety, I have retained the specific appelation for a decided Pustulopora,
for which otherwise the name ‘‘fasicularis” would have been very appropriate.

(4) Pustulopora regularis, Macgillivray (Pl. IV. fig. 2).
Pustulopera (sic) regularis, Proc. Roy. Soc. Vict., vol. xix., 1882, p, 292, pl. i. fig. 3,
4 Pustulopora subverticillata, Busk, Crag Polyzoa, p. 108, pl. xviii. fig. 1d.

Character.—Zoarium branched, branches of uniform thickness (about 1 to 2 mm.),
fureate and ending in a short fork. Entire surface studded with the exserted extremities
of the immersed zocecia, disposed quincuncially or in nearly regular subspiral series, and
about eight in the width of the zoarium. Orifice 0°12 to 015 mm. in diameter. Surface
of zocecia punctate, except the peristomal production which is clear, vitreous, shining
and ringed. Occia ?

Heabitat.—Station 162, off East Moncceur Island, Bass Strait, 38 fathoms, sand and
shells.

[Port Philip Heads, Macgilliv. |

Probably, as suggested by Mr Macgillivray, allied to Hntalophora subregularis,
d’Orbigny.

Suppivision B. ADNATA sev DECUMBENTIA,

Family III. Tusvtiorm2, Busk.
Tubuliporide, Bk., Crag Polyzoa; Brit. Mus. Cat. pt. iii. p. 23.
Tubuliporidz (pars), Johnst., Blainville, Milne-Edwards (“ Tubulipores”), Smitt, Alder,
Gray, Hincks, Vine, &c.
_ Sparside (pars) d’Orbigny.

Character.—Zoarium ‘entirely adnate, partially erect from an expanded base, in
shape linéar, reniform, flabelliform, or claviform; simple or divided into branching
lobes. Zocecia distinct, more or less free and much elongated ; irregularly disposed or
ranged in more or less regular series, diverging from a mesial line. Ocecia formed by
an inflation of the branch.

The Family here contains :—

1, Alecto, Lamx.
(1) Alecto granulata, M.-Edw.

2. Tubulipora, Lamk.

(1) Tubulipora flabellaris, Fab. (Pl. V. fig. 1).
(2) Tubulipora fimbria, Lk. (Pl. V. fig. 2).

ADD . THE VOYAGE OF H.M.S. CHALLENGER. %

1. Alecto, Lamouroux.

», Alecto, Lamx.,;1821; Blainville, Johnston, M.-Edw., Busk., Michelin, Gray, Norman, Heller, &c.
- Tubulipora (pars), Lamk., Smitt.

Stomatopora, Bronn, d’Orb., Hincks (pars), é&c.

Aulopora (pars), Goldfuss, Reuss.

Diastopora, (pars), Smitt. :
4 Proboscina (pars), Audouin, d’Orb., Smitt (subgenus).

Character.—Zoarium closely adnate throughout; simple or branched; linear .or
ligulate. Zocecia uniserial, or disposed in distant, more or less regular, transverse series
-of two to four.

(1) Alecto granulata, Milne-Edwards.

Alecto granulata, M.-Edw., Réch. sur les Crisies, p. 13, pl. xvi. fig. 3, 3a; Johnston (pars),
Busk, Brit. Mus. Cat., pt. iil. p. 24, pl. xxxii. fig. 1 ; Joliet.
4 Alecto parasitica, Heller, Manzoni.
Stomatopora granulata, d’Orb., loc. cit., p. 836, pl. 628, figs. 5-8; Hincks, Brit. Mar. Polyz.,
p. 425, pl. lvii. figs. 1, 2.

Character.—Zoarium linear, branched, the branches often anastomosing. Zoccia
uniserial, decumbent, with the oral extremities raised, subventricose below; surface
granular or coarsely ringed.

Habitat.—Off Inaccessible Island, Tristan da Cunha, 60 to 90 fathoms (on dead shell).

[British and Irish coasts; Norway and Sweden, Roscoff, &c. |

2. Tubulipora, Busk.

Tubulipora, Bk., Engl. Cyclop., art. Polyzoa, col. xv.; Crag Polyzoa, p. 110; Lamouroux,
Hagenow, &c., Bk., Brit. Mus. Cat., pt. iii. p. 24.

Tubulipora (pars), Lamarck, Blainville, M.-Edwards, Johnston, Lonsdale, Michelin, Reuss,
@Orbigny, Gray, Smitt (1867), Hincks, &c.

Ceriopora (pars), Hagenow.

Phalangella sp., Gray, Smitt (subgenus).

Proboscina sp., d’Orbigny.

Characters.—Zoarium springing from a minute subglobular or discoid cell, and
expanding as it grows, into an irregularly lobate, or entire, reniform or fan-shaped, adnate
growth, from which spring the elongated, cylindrical, tubular zocecia, free or partially

connate and ascending; disposed more or less regularly in series diverging from a
mesial line or irregularly.

REPORT ON THE POLYZOA. 23°

(1) Tubulipora flabellaris, Fabricius (sp.) (Pl. V. fig. 1).

Tubipora flabellarts, Fab., Faun. Greenl., p. 430, 1780.

Tubulipora flabellaris, Manzoni, Hincks, Brit. Mar. Polyz., vol. i. p. 446, pl. Ixiv. figs. 1-3.

Tubulipora (subgenus Phalangella) flabellaris, Smitt, 1866; Kritisk Forteckn., pp. 401, 455,
pl. ix. figs. 6, 8.

Tubulipora phalangea, Couch, Corn. Fauna, vol. iii. p. 106, pl. xix. fig. 7; Johnston, Busk,
Crag Polyzoa, p. 111, pl. xviii. fig. 6; Hincks, Devon. Cat., Ann. and Mag. Nat. Hist.,
ser. 3, vol. ix. p. 308; Busk, Brit. Mus. Cat., pt. iii. p. 25, pl. xxiii.; Waters, &.

Tubulipora verrucaria, M.-Edw. (pars), Réch. sur les Tubulipores, p. 3, pl. xii. fig. 1 ; Heller.

Phalangella phalangea, Gray.

Character.—Zoarium wholly adnate, suborbicular or reniform, or obsoletely lobate ;
tubular cells long, slender, 0°15 mm. in diameter, disposed in more or less regular,
uniserial rows radiating from a mesial line. Walls of free portion of zocecia ringed, not
punctate. Basal expansion thickly punctate.

Habitat.—Station 315, lat. 51° 40’ S., long. 57° 50’ W., 12 fathoms, sand and gravel.

[British and Irish Seas; Arctic Sea; coast of Norway; South Labrador; Adriatic,

Bay of Naples. ]

Professor Smitt and Mr. Hincks appear to be so convinced that this is the form
intended by Fabricius that I have thought it better to adhere to their determination and
to adopt his appellation instead of Mr. Couch’s.

One peculiarity as distinguishing this form from the very closely allied Tubulipora
jimbria, Lamk., consists in the absence, so far as I have observed, of punctation of the
walls of the tubular or free portion of the zocecia, which in the latter species are
sparsely punctate up to the border of the orifice, also the punctation of the basal
expansion in Tubulipora fimbria is rather more sparse, and the spots or pores larger.

(2) Tubulipora fimbria, Lamarck (Pl. V. fig. 2).

1 Tubipora serteus, Fab, 4

Tubulipora fimbria, Lamk., Hist. Anim. sans Vert., ed. 1, vol. i. p. 163, ed. 2, vok ii
p- 243; Smitt, (subgenus Phalangella), loc. cit., p. 401, 452, pl. ix. fig. 5; Hincks, Brit.
Mar. Polyz., p. 448, pl. lx. fig. 3.

Tubulipora fimbriata, M.-Edw., loc. cit., p. 10, pl. xiv. fig. 2; Michelin, Iconog., p. 321,
pl. Ixxvii. fig. 7.

Tubulipora flabéellaris, Johnst., p. 274, pl. xlvi. figs. 5,6; Landsb., Pop. Hist. Brit. Zooph.,
p- 274, pl. xv. fig. 50; Busk, Crag Polyzoa, p. 111, pl. xviii. fig. 3, pl. xx. fig. 9; Brit.
Mus. Cat., pt. iii. p. 25, pls. xxiv., xxv.; Hincks, Ann. and Mag. Nat. Hist., ser. 4,
vol. xix. p. 109 ; Haswell, Joliet:

Character.—Zoarium adnate, flabelliform, often. recurved on the sides. Zowmcia
decumbent, irregularly disposed or very obscurely serial. Surface of basal expansion
and tubes punctate, often transversely rugose. Zocecia about 0°15 to 0°17 mm.

Habitat.—Station 315, lat. 51° 40’ S., long. 57° 50’ W., 12 fathoms, sand and gravel.

[Northern coast of Britain; Shetland; Ireland; Greenland, Fabricius; Davis Strait,

24° THE VOYAGE OF H.M.S. CHALLENGER.

100 fathoms; Gulf of St. Lawrence; Spitzbergen ; West of Nova Zembla, lat. 72° 30’ N.,.
long. 52° 45’ E., 5 to 20 fathoms, Stuxberg and Théel; Roscoff, Joliet; Port Jackson, -
Haswell. |

Distinguished from the preceding species, as above observed, by the tubular portions
of the zocecia being punctate up to the border of the orifice, and their rather larger size.
There can, I now think, be no doubt as to the distinctness of the two species.

Family IV. Diastoporip#, Busk.
Diastoporidz (pars), Bk., Crag Polyzoa, p. 113, Smitt.
Tubuliporide (pars), Hincks, &c.
Character.—Zoarium crustaceous or foliaceous, discoid or of indefinite outline ; adnate =.
and sessile, or pedunculate and erect; no interstitial cancelli.
The Family here contains :—

1. Diastopora, Johnston.
(1) Diastopora patina.

ty Diastopora, Johnston.

“ Diastopores simples,” M.-Edwards, Réch. sur les Crisies, p. 39.

Diastopora, Johnst., Bk., Crag Polyzoa, p. 113; Brit. Mus. Cat., pt. ii., p. 28 ; Hincks, Brit. Mar.
Polyz., p. 457.

Diastopora (pars), Lamx., M.-Edwards, Blainville, Reuss, ae Michelin, d’Orbigny, Smitt.

Tubulipora sp., Johnst., Auctt.

Berenicea (pars), Lamx., d’Orbigny.

Patinella,; Gray, Hincks, Zooph..S. Devon, Ann. and Mag. Nat. Hist., ser. 3, vol. ix. p. 468.

Character.—Zoarium adnate, discoid or flabelliform, centric or excentric; outline
lobed or entire. Zocecia. towards the centre wholly immersed, usually sub-erect and
partially free towards the periphery ; orifice orbicular or elliptical ; horizontal or oblique.

(1) Diastopora patina, Lamarck (sp.).
Tubulipora patina, Lamk., Johnst., Gosse, Mar. Zool., pt. iii., p. 8, fig. 1 (nec Milne-Edwards) ;
Joliet.
1 Patinella verrucaria, Gray.
Patinella patina, Hincks, Zooph. 8. Devon, Ann. and Mag. Nat. Hist., ser. 3, vol. ix. p. 468.
Diastopora patina, Smitt., Busk, Brit. Mus. Cat., pt. iii, p. 28, pl. xxix. figs. 1, 2, pl. XXX.
fig. 1; Hincks, Brit. Mar. Polyz., vol. i. p. 458, pl. lxvi. figs. 1-6 ; Waters.
t Diseosparsa marginata (pars), d’Orbigny:.
Discosparsa patina, Heller, Marion.

Character.—Zoarium when mature, discoid, circular, cupped, and bordered by a “en
expansion. Central zocecia immersed and usually occluded; marginal cones erect and

REPORT ON THE POLYZOA. 25

open, usually disposed in irregular wavy lines radiating from the centre. (Sometimes
gemmiparous, Hincks).

Hatbitat.—Off Nightingale Island, Tristan da Cunha, 100 to 150 fathoms.

[British and Irish Coasts, northern and southern; North Sea, Arctic Ocean, 5 to 10
fathoms, on Fucus, Flustra, &c., and on shells and coral from 50 to 100 fathoms,
Smitt; coast of Norway, Lovén; Shetland, Barlee, 170 fathoms; Adriatic, Heller;
South Labrador; Marseilles, Marion ; Roscoff, Joliet. ]

Family V. LicHENoPpoRIDE.
Lichenoporidz, Smitt, Hincks, &c.
Discoporadz, Bk., Engl. Cyclop.
Caveidz (pars), d’Orbigny.
Tubigeridz (pars), d’Orbigny.
Discoporellidx, Bk., Brit. Mus. Cat., pt. iii. p. 30, 1875.

Character.—Zoarium discoid, simple or confluent; adnate or substipitate, inter-
zocecial spaces cancellate (cancelli sometimes obsolete). Zocecia erect or suberect,

disposed more or less regularly in series diverging from an open ceutral area.
The Family here contains :—

1. Lachenopora.

(1) Lichenopora fimbriata, Bk.
(2) Lachenopora hispida, Flem.

1. Lichenopora, Defrance.

Madrepora (pars), Fabr., Esper.

Itchenopora, Defrance (1823), Blainville, Michelin, Smitt (1878), Hincks, Brit. Mar. Polyz,
p. 471.

Discoporella, Gray, Brit. Mar. Rad.; Busk, Crag Polyzoa, and Brit. Mus. Cat., pt. iii p. 30;
Smitt, Kritisk Forteckn., p. 405 (1865).

Discopora (pars), Flem. (non Lamk.), Busk, Engl. Cyclop. Polyz.

Tubultpora (pars), Johnst., M.-Edw., &c.

Defrancia (pars), Actinopora, Discocavea, Unicavea, &c., d’Orb.

Heteroporella sp., Hincks.

Character.—Zoarium sessile, usually closely adnate, with a thin calcareous border ;

discoid, raised in the centre (hemispherical, conical, or subconical). Zocecia partly free,

disposed irregularly or in lines radiating from the centre. Mouth acuminate or
toothed.

(ZOOL, OHALL. EXP.—PART L.—1886.) Ddd 4

26 THE VOYAGE OF H.M.S. CHALLENGER. .

(1) Lichenopora fimbriata, Busk.
Discoporella fimbriata, Bk., Brit. Mus. Cat., pt. iii. p. 32, pl. xxvii.

Character.—Zoarium subconical or hemispherical; zocecia indistinctly serial, distant;
interstitial cancelli or pores small, circular, often more or less obsolete ; orifice somewhat
expanding ; peristome fimbriate, with a variable number of pointed teeth.

Habitat.—Off Nightingale Island, Tristan da Cunha, 100 to 150 fathoms.

[Chonos Archipelago, 13 fathoms; Tierra del Fuego, Cape Horn, 40 fathoms; Chiloe,
96 fathoms, Darwin ; Tasmania, Mr. Smith. |

(2) Lichenopora hispida, Fleming (sp.).
Discopora. hispida, Fleming, Blainville, Couch.

Tubulipora hispida, Johnst.

Discoporella hispida, Gray; Busk, Crag Polyzoa, p. 115, pl. xvii. fig. 5; Brit. Mus. Cat.,
pt. iii. p. 30, pl. xxx. fig. 3; Smitt, Sars, Alder, &.

Heteroporella radiata, Bk., Crag Poly coe) p. 127, pl. xix. fig. 2

Heteroporella hispida, Hees Ann. and Mag. Nat. Hist., ser. 3, wal f ix. p. 469.

Lichenopora hispida, Hincks, Brit. Mar.. Polyz., p. 473, i Ixviii. figs. 1-8.

Charcter.—Zoarium suborbicular, convex, with or without a narrow marginal
lamina; surface uniformly covered with circular openings level with the surface, of
tolerably uniform size; towards the border some of the orifices raised, subtubular, and
bi- or tridenticulate, disposed in obscure irregular series. ;

Habitat.—Stations 135 to 135¢, Tristan da Cunha, 100 to 1100 fathoms.

[British Coasts, north and south; Northern Seas, Greenland, Labrador, &c. (fossil,
Coral Crag ; Post Pliocene, Canada). ]

Family VI. Fronpiporip&, Smitt.
Fasiculinea (pars), d’Orbigny, Smitt, 1866.
Fascigeride (pars), d’Orbigny.

Frondiporidz, Smitt, Kritisk Forteckn., pp. 407, 408 (1866); Busk, Brit. Mus. Cat., pt. iii.
p. 37.

Cerioporid (pars), Busk, Crag Polyzoa, p. 118.
Cerioporine (pars), Hagenow.

Character.—Zoarium massive, stipitate, simple or lobate, or ramose. Zocecia connate
. throughout, aggregated into fasciculi; lumen of tubes angular; walls finely porous ; sides

of lobes or fasciculi faintly striated or subporcellanous; no intermediate pores or
cancelli.

REPORT ON THE POLYZOA. 27
“The Family here contains :—

1. Fasciculipora, @Orb.

(1) Faseiculipora ramosa, d’Orb.

2. Supercytis, d’Orb.

(1) Supercytis digitata, d’Orb. (Pl. V. fig. 3).
(2) Supercytis tubigera, nu. sp. (Pl. V. fig. 4).

1. Fasciculipora, dOrb.

Fasciculipora, d’Orb. (1839), Busk, Brit. Mus. Cat., pt. iii p. 37 (pars).
Frondipora, Michelin (pars) ; Hagenow.

Corymbopora (pars), Michelin.

Corymbosa, sp,, d’Orbigny.

Fungella, Hagenow, Bk., Crag Polyzoa, p. 118.

Character.—Zoarium stipitate ; capitulum lobate. Zocecia opening only at the ends
of the fasciculi.

(1) Fasciculipora ramosa, d’Orbigny.

Fasciculipora ramosa, @’Orb., Voy. Amér. Mérid., Polypiers, p. 20, pl. ix. figs. 22-24.
4 Frondipora ramosa, Hagenow.

Corymbosa ramosa, @Orb., Cours Elém. de Pal., tom. ii. p. 109, 1851.
1 Fungella prolifer, Hagenow, Maast. Kreid., p. 37, pl. iii. figs. 6, 7 (?).
Character.—Zoarium fungiform ; capitulum composed of numerous obtuse, rounded
lobes (usually in pairs); each lobe constituted of a thick fasciculus of tubular cells of
large calibre and very thin walls, with a few intermediate tubes of less diameter inter-
spersed ; outer surface smooth, dotted obscurely, showing the outline of the elongated
zocecia, or thickened and procellanous.
Habitat.—Off Inaccessible and Nightingale Islands, Tristan da Cunha, 60 to 150
fathoms.

[South Patagonia, 48 fathoms, Darwin, d’Orbigny. ]

Fasciculipora ramosa bears a close resemblance to Fungella multifida, mihi, of the
Crag (pl. xvii. fig. 4), but in that species, which probably corresponds with F’rondipora
marsilli of Michelin (Iconog., p. 68, pl. xiv. fig. 4). The whole growth appears more
squat or depressed, and the lobes shorter and not in pairs, whilst the outer surface
towards the base is marked with hexagonal areole, an appearance not seen in Fasciculi-
pora ramosa. Otherwise the two forms appear to be closely allied.

28 THE VOYAGE OF H.M.S. CHALLENGER.

2. Supercytis, d’Orbigny.
Supercytis, d’Orbigny, Paleont. Frang., p. 1060; Waters, Quart. Journ. Geol. Soc., vol. xh,
1884, p. 692.
Fasciculipora (pars), d’Orbigny ; Buek, Brit. Mus. Cat., pt. iii p. 37.

Character.—Zoarium stipitate ; capitulum expanded, flat or cupped, with numerous
furcate or trifid fasciculi projecting round the border. Fasciculi compressed, constituted
of coalesced, almost completely immersed zocecia of varying lengths, all of which open on
the upper flattened side of the fasciculus or at the extremity. Dorsal surface rounded,
even, longitudinally striated and minutely punctate. Ocecia (when present) hemi-
spherical, at the base of the fasciculi, and usually on the upper surface.

It is not easy to assign its proper family place to this peculiar type, but on the
whole it would perhaps be more at home among the ‘Fasciculine or Frondiporide, than
elsewhere, the main difference between it and the other members of the group consisting
in the openings of the zocecia not being altogether terminal but partly on the upper side
of the lobes or lateral fasciculi, or more rarely on the central area of the capitulum,
which in one of the forms here described, in the perfect and perhaps more or less
immature state, is covered with an even, calcareous, minutely punctate lamina, marked
out into very regular hexagonal areole, from some of which, towards the border, may be
seen the slightly projecting orifices of zocecia. In the second species the hexagonal areola-
tion is apparently wanting, and in this form a few long tubular zoecia project at the base
of some of the fasciculate lobes.

In the British Museum Catalogue I have described and figured, under the name of
Fasciculipora digitata, a species, which as pointed out by Mr. Waters (Joc. cit., p. 692), is

in all probability identical with M. d’Orbigny’s Supercytis digitata, but in that specimen,
which was a good deal worn, the hexagonally areolated, calcareous lamina of the central
area is absent, and nothing is seen but the open orifices of what might be taken for the
interstitial cancelli characteristic of the Lichenoporidan group. There can, however, I
think, be no doubt that they represent the orifices of stunted or undeveloped zocecia,
because, firstly, towards the base of the digitiform lateral fasciculi many of the areole
are actually developed into short zoccial tubes; and secondly, in none can be traced
a vestige of the internal ciliary processes which are seen almost universally in true
interstitial cancelli. Besides these marginal stunted zocecia, there may be seen in all
parts of the central area similar projecting orifices, which are described by Mr. Waters
as the ends of centra] zoccia slightly exserted, and which, as he remarks, give this portion
the aspect of a Diastopora, such as Diastopora sarniensis.

REPORT ON THE POLYZOA. 29

(1) Supercytis digitata, d’Orbigny (PI. V. fig. 3).

Supercytis digitata, d’Orb., Paleont. Frang., p. 1061, pl decxeviii. figs. 6-9; Waters, loc. cit.,
p. 692, pl. xxxi. figs. 22, 26, 27.
Fasciculipora digitata, Bk., loc. cit., p. 37, pl. xxxiii. fig. 1.

Character.—Zoarium oblong, 0°12 x 0°8 mm.; the stipitate capitulum flattened above,
‘presents a large central area covered with a hexagonally areolated lamina, and from
‘the sides project twelve digitate, forked, or sometimes trifid compressed lobes, composed
of longer or shorter tubular zocecia, about 0°2 mm. in diameter, almost completely
immersed or sometimes slightly projecting, and opening throughout the whole length
of the lobe on its upper flattened aspect, and some from the areole of the central
area. Dorsal aspect of the lobes rounded, even, longitudinally striated and minutely
punctate. Ocecia ?

Habitat.—Station 167, lat. 39° 32’S., long. 171° 48’ E., 150 fathoms, blue mud.

[Cape Capricorn, Australia, H.M.S. “ Rattlesnake.” Fossil, Cretaceous, Meudon, &c.,
d’Orbigny ; South Australia, Waters. |

(2) Supercytis tubigera, n, sp. (2) (Pl. V. fig. 4).

Character.—Zoarium stipitate, capitulate; capitulum irregular or inequilateral;
central area small, not areolated, but covered with a thickish calcareous lamina, with
concentric rug, giving it a conchoidal aspect; ten or twelve marginal fasciculate or
digitate bi- or trifurcate compressed processes, in which the zocecia are disposed more or
less regularly in series of connate tubes, opening either at the extremity of the fasciculus
or on its upper flattened aspect; at the base of some of the fasciculi a few much
elongated tubular zocecia arise nearly vertically, with punctate walls, and about 0°25 mm.
in diameter. Dorsal surface of fasciculi and capitulum striated and minutely punctate.
Ocecia in the form of hemispherical projections at the base of the lateral fasciculi and
usually on the upper aspect.

Habitat.—Station 151, off Heard Island, .75 fathoms, volcanic mud.

As the collection affords only a single specimen, which conveys the impression of a
somewhat distorted growth, it may, perhaps, be merely a variety of the preceding. But
the absence of areolation of the central area of the capitulum and the presence of the
much elongated tubular zocecia, together with the occurrence of the hemispherical occia,
appeared to me to justify its being considered specifically distinct.

30 THE VOYAGE OF H.M.S. CHALLENGER. ae

Sus-Orver III. CTENOSTOMATA, Busk.

Ctenostomata, Busk, Hincks, Smitt, Auctt.
Halcyonellea and Vesicularina, Johnst.

Character.—Zocecial orifice simply circular, bilabiate (?) or quadrangular ; retractile ;
border contractile, furnished with a setose or membranous fringe or velum. Zoarium
corneous or membranaceous, or carnose ; never calcified. No marsupial or appendicular
organs.

Drviston I—HALCYONELLEA.

Halcyonellea, Ehrenberg, Hincks.
Polyzoa carnosa, Gray.
Alcyonidulz, Johnst.
Halcyonellz, Smitt.

Character.—Zoarium membranous or carnose, or semigelatinous, developed by
continuous gemmation of the zocecia from each other.
This division, embracing in Mr. Hincks’ classification the genera

Alcyomdium,
Flustrella,
Arachnidium,

is represented in the Challenger collection by a single species referable to Alcyonidium.

Family I. ALcYoNIDULA.

Alcyonidulz, Couch.
Halcyonellex, Smitt.
Alcyonidiide, Hincks.

Character.—Zocecia more or less closely united, immersed in an expanded and
adherent gelatinous crust, or forming an erect, cylindrical or compressed zoarium ; orifice
closed by the invagination of the tentacular sheath. ay

The Family here contains :—

1. Aleyonidium, Lamouroux.

(1) Alcyonidium flustroides, n. sp. (Pl. X. figs. 13, 14).

REPORT ON THE POLYZOA. 31

1. Aleyonidium.

Alcyonidium, Lamx., Johnst., Couch, Busk, Engl. Cyclop., art. Polyz.; Hincks, &c.
Alcyoniwm (pars), Linné, Pallas, Miiller, Fleming, &c.

Halodactylus, Farre, v. Beneden.

Cycloum and Sarchochitum, Hassall.

Character.—Zocecia immersed or subimmersed. Orifice usually papilleform, more
or less exsertile. Zoarium erect and lobate or crustaceous or repent.

(1) Alcyonidium flustroides, n. sp. (Pl. X. figs. 13, 14).

Character.—Zoarium erect and foliaceous, much branched, extending to 4 or 5
inches ; bilaminate, compressed and flustroid. Zocecia polygonal, arranged in irregular
longitudinal series, the septa. between which are raised and strongly marked. The
substance of the walls semigelatinous, irregularly dotted with small black granules.
Orifice minute, papilleform, superior.. Polypide with about sixteen tentacles. Ova
scattered, usually singly, in the zocecia. Width of branches about 4 mm. ; zocecia irregular
in size, from about 0°8 x 0'4 mm. to 1°6 x 0°6 mm.

Habitat.—Station 142, lat. 35° 4’ S., long. 18° 37’ E., 150 fathoms, green sand.

This species forms straggling tufts of loosely entwined and sometimes anastomosing
branches, which are quite soft and flexible in the upper part, though the stem and lower
branches become hard and firm near the base. Sometimes the branches embrace and
adhere firmly to some foreign substance, such as worm tubes, &c. The structure is at
first sight very obscure, as the substance is very thick and opaque; immersion for a
short time in acid, however, renders it much more transparent and enables the nature of
the zocecia to be seen. Many of these contain polypides alone, others polypides and
ova together, and others again either “‘ brown bodies” or scattered ova only. The orifices
are very small and often quite obscure. The walls seem to be partly membranous and
partly of a semigelatinous nature, irregularly dotted with small black granules which are
possibly argillaceous. In the form of the cell and the raised septa this species resembles
Aleyonidium mytili, as described by Mr. Hincks,’ but entirely differs from that form in
its erect bilaminate mode of growth.

1 Brit. Mar. Polyz., p. 498, pl. lxx, figs. 2, 3.

$2 THE VOYAGE OF H.M.S. CHALLENGER.-

DPrviston II.—VESICULARINA.

Vesicularina (pars), Johnst.

Stolonifera, Ehlers, Hincks.

Les centrifuginées radicellés (pars), d’Orb.
Vesiculariea, Smitt.

Character.—Zoarium corneous, developed by the continuous segmentation of a
branching stem or stolon, having a transverse diaphragm at each node. Zoccia
budding directly from the internodes and not from each other.

\

Family II. Vestcutarm2.

Vesiculariadz, Johnst., Alder, &c.
Vesiculariide and Valkeriidx, Hincks.
Vesiculariex, Smitt.

Character.—Zoarium erect, free and ramose or radicate, repent or stoloniferous.
Zocecia deciduous or readily detached, leaving a circular area filled in by a perforated
diaphragm. Wall entire all round, without any membranous area.

The Family here contains the following genera :—

1. Amathia, Lamouroux.

(1) Amathia lendigera, Linn.

(2) Amathia distans, n. sp. (Pl. VII. fig. 1).

(3) Amathia brasiliensis, n. sp. (Pl. VII. fig. 2).

(4) Amathia spiralis, Lamx. (Pl. VI. fig. 2).

(5) Amathia tortuosa, Woods (Pl. VI. fig. 1).

(6) Amathia connexa, n. sp. (Pl. VI. fig. 3).

(7) Amathia semspiralis, Kirchenpauer (Pl. VIII. fig. 3).

2. Vesicularia, J. V. Thompson.
(1) Vesicularia papuensis, n. sp. (Pl. VIII. fig: 1).
(2) Vesicularia trichotoma, n. sp. (Pl. VIIL fig. 4)
3. Farrella, Khrenburg.
(1) Farrella brasihensis, n. sp. (Pl. VIE. fig. 3).

REPORT ON THE POLYZOA. 33

1. Amathia, Lamouroux.

- Sertularia (pars), Linn.
Amathia, Lamx., d’Orbigny (pars) ; Kraus, Heller, Hincks, &c.
Serialaria, Lamk., Fleming, Johnst., Blainville, Kirchenpauer, d’Orbigny (pars), Busk, Engl.
Cyclop., art. Polyz.; Joliet, Barrois, &c.
Valkeria (pars), Dalzell.

Character.—Zoarium radicate, erect or creeping, with free dichotomous branches.
Zocecia cylindrical or subovoid, with a broad adherent base, and more or less connate
laterally ; arranged alternately in a double series, disposed spirally, entirely or partially
surrounding the internodes, or in a straight line parallel with the axis, or in short
distant groups at the upper ends of the internodes.

(1) Amathia lendigera, Linné (sp.).

“Nit Coralline,” Ellis.

Sertularia lendigera, Linné, Pallas, Ellis and Sol., Lister.

La Sertolara lendinosa, Cavolini.

Amathia lendigera, Lamx., Pol. flex., p. 159; Heller, Hincks, Brit. Mar. Polyz., p. 516, pl. lxxiv.
figs. 7-10, &e.

Serialaria lendigera, Lamk, Auctt.

Valkeria lendigera, Dalyell.

Character.—Zoarium much branched, tangled, filamentous; branches dichotomous,
about 0°5x 0715 mm. Zocecia subcylindrical, ovate, subcompressed, tapering gradually
in a long neck, disposed obliquely in series of four to five pairs close below each joint or
bifurcation, and gradually diminishing in length from below upwards. Cells sub-
distinct, and scarcely connate.

Habitat.—Station 36, off Bermuda, 30 fathoms, coral.

.{British and European Seas, ubique. |

(2) Amathia distans, n. sp. (Pl. VII. fig. 1).

Character.—Zoarium very slender and delicate, straggling, filamentous, very regularly
dichotomous. Internodes long, straight, rigid, thick-walled, about 0°15 mm. in diameter,
of pretty uniform length, and each completely encircled with a spiral coil, occupying
usually not more than the upper half of the internode, the lower portion of which is left
bare. Zocecia ovoid or oblong, about 0°4 or 0°5 mm. by 0°1 to 0°15 mm., distinct or not
closely connate, with a short conical neck.

Habitat.—Off Bahia, 10 to 20 fathoms, mud.

This form is at once recognisable by its delicate filamentous growth, and the great
distance between the spiral coils, giving it somewhat the aspect of Amathia lendigera

Another character is the comparative shortness and distinctness of the zocecia.
(ZOOL. OHALL. EXP,—PART L.—1886.) Ddd 5

34 THE VOYAGE OF .H.M.S. CHALLENGER.

(3) Amathia brasiliensis, n. sp. (Pl. VII. fig. 2).

Character.—Zoarium several inches high (?), irregularly branched; branches frequently
terminating in two long jointed filaments, which occasionally throw out one or two
isolated zocecia or stunted branches at the nodes. The branches sometimes also
commence with two or three barren internodes. Stems about 0°3 mm. in diameter, wall
white and delicate. Zocecia disposed in a more or less complete spiral, which in the
younger internodes occupies only the upper part, but im the older nearly their entire
length; very distinct, subcylindrical, tapering from the base upwards, about 0°6 x 0°l mm. ;
neck long and slender.

Habitat—Off Bahia, 10 to 20 fathoms, mud.

The striking peculiarity of this form is the tendency of the branches to terminate in
two long jointed tags (terminals), usually barren, but sometimes giving off one or two
scattered isolated cells in the manner of some of the Vesiculariz, &. The comparative
distinctness of the zocecia in the spiral series shows a tendency in the same direction.

(4) Amathia spiralis, Lamouroux (PI. VI. fig. 2).

Amathia spiralis, Lamx., Polyp. Flex., p. 161, pl. iv. fig. 2.; Expos., p. 10, pl. lxv. figs. 16-17;
Encyclop., p. 44.
Serialaria convoluta, Lamarck, Schweigger.
1 Serialaria spiralis, Woods, Proc. Roy. Soc. N.S.W., vol. xi. p. 84, 1877.
1 Amathia bicornis,- Woods, Trans. Roy. Soc. Vict., vol. xvi. p. 102, 1880.

Character.—Zoarium very thick, branched subdichotomously or irregularly, several
inches high. Zocecia subcylindrical, of uniform diameter, very closely connate, 1°0 mm.
long, by 0°2 mm. in diameter (at base); the exserted neck thick and very strongly
wrinkled ; transversely disposed in an apparently continuous spiral from one internode to
another, though in reality probably discontinuous at each internode.

Habitat.—Station 161, off entrance to Port Philip, 33 fathoms, sand. Station 162,
off East Monceeur Island, Bass Strait, 38 fathoms, sand and shells. Station 1634, off
Twofold Bay, 150 fathoms, green’ mud.

[Bass Strait and Australia, ubique(?), Lamx., &c. |

(5) Amathia tortuosa, Woods, (Pl. VI. fig. 1).
1 Amathia tortuosa, Woods, Proc. Roy. Soc. Vict., vol. xvi. p. 89, fig. 6.

Character.—Zoarium 3, 4 or 5 inches high, in thick tufts, when spread out
divaricate, with long subalternate branches; rooted by radical fibres. Dull olive green
colour. Stem 0°5 to 0°6 mm. in diameter. Zocecia slender, about 1 mm. x 0°15 to 0°2 mm.,
disposed spirally round the internodes, but not always forming quite one turn.

REPORT ON THE POLYZOA. . 35

‘Habitat. —Station 163a, off Twofold Bay, 150 fathoms, green mud.
[Australia, J. T. Woods. ]

It appears to me very doubtful whether this is really the form so named by Mr
Woods, who may probably not have’ distinguished it from the next species, which in its
general habit seems to resemble the figure of his Amathia tortuosa more than the present.
However, I am led to suppose that he had this one in view from his remark respecting
the great length of the cells, which in my Amathia conneaa are rather short. What
Mr. Woods intends by “‘a crescentic mouth, without sete or spines,” I do not clearly
understand ; and it should moreover be remarked, that in his figure of Amathia tortuosa
the cells are not represented by any means as unusually long.

(6) Amathia connexa, n. sp. (PI. VI. fig. 3).

Character.—Zoarium 3 to 4 inches high, very irregularly branched, straggling, forming
dense tufts. Stem and branches from 0°5 to 0°6 mm. in diameter, transparent as glass,
each internode encircled with a spiral series of zocecia not extending its entire length,
but leaving a space at each end clear. Branches here and there connected by transverse
barren tubes. Zocecia oblong, 0°5 x 013 mm., abruptly rounded (the neck projecting
about 0°2 mm.), connivent, very delicate walls, so that the outlines towards the summits
are very indistinct.

Habitat.—Station 186, off Cape York, 8 fathoms, coral mud.

The main characteristics of this form consist in—

1. The comparatively large diameter of the segmented stems and the beautiful glassy
transparency of their walls, upon which the encircling series of zocecia appear to stand
out in strong relief, so as at first sight to seem as if they
were disposed on one side only of the segment; but
; examination shows that in reality they form nearly or
oth / wholly complete circles round the stem.

4 2. A second very striking feature, that I have not
noticed in any other species of Amathia, is the occasional
connection of the branches by transverse, barren, segmented
tubes, resembling a similar arrangement in some of the

Fig. 1.—Amathia connexa. Cheilostomata. As observed in the description of the pre-
Fic. 2.—jpmath ia tortuosa, Woods.

Fig. 1 Fig 2.

ceding species, the general habit of Amathza connexa
closely resembles that of Mr. Woods’ Amathia tortuosa, as shown in his figure, which is
copied in the accompanying woodcut. But that Amathia connexa should be the species
intended by him under the name tortuosa is contradicted, as has been remarked, by the
comparative shortness of the zocecia.

36 THE VOYAGE OF H.M.S. CHALLENGER.

(7) Amathia semispiralis, Kirchenpauer (sp.) (Pl. VIII. fig. 3).
- Serialaria semispiralis, Kirchenpauer,; Cat. Mus. Godefroy, voliv. p. xxxiv., 1869.

Character.—Zoarium filamentous, dichotomous; stem brownish, about 0°3 mm. in
diameter. Zocecia disposed in short series, composed of four to eight pairs of cells ;
series distant, placed obliquely, three or four in each internode; zocecia slender,
eylindrical or somewhat quadrangular in form, about 0°6 to 0°7 x 0°15 mm., obtuse and
strongly wrinkled transversely at the closed end; neck very short, and setz short.

Habitat.—Station 188, lat. 9° 59’ S., long. 189° 42’ H., 28 fathoms, green mud.

[Samoa, Kirchenpauer. |

It may be doubtful whether this form is really that intended by Kirchenpauer, who
(loc. cit.) describes the zoartum as “dichotomously branched. The cells dispersed in
biserial groups, at certain distances apart, and spirally round the stem; each spiral,
however, extending only about one-half round the axis. From Servalaria semiconvoluta,
Lamk., it differs in the character that in that species the tubular cells form much longer
rows, whilst it also has an entirely different habit.” How M. Kirchenpauer can bring it
at all in comparison with the Serialaria continhii, which in habit more resembles
a Mimoéella, is more than I can imagine. No two things would appear to be more
distinct.

2. Vesicularia, Thompson.

Vesicularia, J. V. Thompson (pars); Farre, Jobnst. Busk, Engl. Cyeclop.; Hincks, Brit. Mar.
Polyzai pip iczcven

Sertularia (pars), Linné, Pallas, &ec.

Laomedea (pars), Lamx., Blainville.

Valkeria (pars), Fleming.

Character.—Zoarium erect, radicate, or rooted by a fibrous base. Zocecia distinct,

usually distant, disposed in a single row or alternately in two rows on one face only of
the stems. (Polypides with a gizzard, Hincks).

(1) Vesicularia papuensis, n. sp. (Pl. VIII. fig. 1).

Character.—Zoarium about 3 inch high, very delicate, branching dichotomously in
one plane, at an acute angle, rooted by short radical fibres. Branches composed of three
or four internodes, about 0°15 mm. in diameter, and each supporting on one face a double
row of zocecia disposed alternately on each side. Zocecia ovate, 0°5 x 0°15 mm. (with the
neck retracted); neck thick and rather bulbous; surface generally smooth. No gizzard.

Habitat.—Station 188, lat. 9° 59’ S., long. 139° 42’ E., 28 fathoms, green mud.

REPORT ON THE POLYZOA. 37

The distinction between this form and Vesicularia spinosa is too obvious to require
remark. But theré is a second species, which occurred in the “ Rattlesnake ” collection, and
was procured between Cumberland Island and Point Slade, which appears to be very
closely allied, and I have, therefore, thought it might be useful to give a description
of it, thought not strictly belonging to the Challenger Expedition.

(2) Vesicularia trichotoma (Pl. VIII. fig. 4).

Character.—Zoarium of irregular straggling growth, main stems or primary branches
about 0°2 in diameter, and usually barren, thick-walled. Primary branching, trichotomous,
secondary usually furcate. Secondary and tertiary branches much slenderer, thin-walled.
The internodes support eight to ten zocecia, disposed alternately in a double series on
only one side of the branch; in the youngest segments there is only a single row.
Zocecia very readily detached, ovoid, and about 0°4x0°'2 mm. The surface is smooth and
the neck short.

Habitat.—Bass Strait, between Cumberland Island and Point Slade, Voyage of
H.M.S. “ Rattlesnake.” *

A peculiarity at once distinctive of this form is the trichotomous division of the
primary branches; the great difference in diameter of the branches is also characteristic,
as distinguishing it from the preceding, with which it agrees in the alternate arrange-
ment of the zocecia on the internodes.

2. Farrella, Ehrenbure.

Farrella, Ehrenb., Johnst., Busk, Engl. Cyclop.; Hincks, Brit. Mar. Polyz., p. 528, &e.
Lagenella, Farre, W. Thomson, Hassall.
Laguncula, Van Beneden.
Character.—Zoarium stolonate, free, or creeping and adherent ; branching irregularly
or at definite intervals. Zocecia cylindrical or subventricose below, pedunculate. Orifice,
when the neck (goulot) is retracted, bilabiate or quadrangular. Neck long, tapering,

with or without a crown of setz.? (No gizzard). s

(1) Farrella atlantica, nu. sp. (Pl. VIL. fig. 3).

Character.—Zoarium stolonate, filamentous, jointed at regular intervals, free or
creeping and adnate. Stolon 0°02 to 0°04 mm. in diameter, throwing out three or four
short branches or zocecia close below each joint at regular intervals. Zocecia with the

1 This species does not occur in the Challenger collection.

* It does not seem to have hitherto been remarked that the genus Laguncula (V. B.), as exemplified in Laguncula
repsus and Laguncula elongata, has no sete.

38 THE VOYAGE OF H.M.S. CHALLENGER.

neck retracted, about 0°4 mm. long by 0°07 to 0:09 in diameter, cylindrical and of uniform
diameter throughout, quadrangular at the orifice when the neck is retracted. Supported
on a long peduncle. Surface of peduncle and lower part of cells very finely wrinkled.

Habitat.—Off Bahia, 10 to 20 fathoms, mud. On Amathia brasiliensis and Amatha
distans.

Family II. Cytinpracip2.

Cylindrectidx, Hincks, Brit. Mar. Polyz., p. 534.
Vesiculariade (pars), Bk., Alder, Hincks.
Vesiculariex (pars), Smitt.
Character.—Zoccia not deciduous, arising from, and apparently continuous with, the
stolon or segment from which they spring. Walls earthy or argillaceous.
The Family here contains the following :—

1. Cylindrecium, Hincks.

(1) Cylindrecium papuense (Pl. VIII. fig. 2).

1. Cylindrecium, Hincks.

Farrella (pars), Bk.

Avenella, Hincks, Gosse (nec Dalzell).
Cylindreecium, Hincks, Brit. Mar. Polyz., p. 535.
Vesicularia (subg. Avenella, pars), Smitt.

Character.—Zocecia uniformly cylindrical or slightly ventricose below, sometimes

dilated at the base. Stolon slender, creeping, with occasional enlargements. Zocecia
wide apart or sometimes crowded.

(1) Cylindracium papuense, n. sp. (Pl. VIIL fig. 2).

Character.e—Zoarium a creeping adherent stolon with occasional bulbous thickenings.
Zocecia cylindrical, of uniform diameter and not dilated at the base, 1°3 mm. long by
0:1 to 0°11 mm. in diameter, springing either singly and widely apart from the stolon, or
four or five together from a bulbous thickening.

Habitat.—Station 188, lat. 9° 59’ S., long. 139° 42’ E., 28 fathoms, green mud.
Parasitic on Amathia senuspiralis, Kirchenp.

REPORT ON THE POLYZOA. 39

The forms known to me as referable to the genus Cylindraciwm as above defined
are -——
(1) Cylindrecium giganteum, Busk.
Farrella gigantea, Bk., Quart. Journ. Micr. Sci., vol. iv. p. 93, pl. v. figs. 1, 2; Gosse,
Mar. Zool:, pt. ii. p. 22, fig. 40.
Avenella gigantea, Hincks, Ann. and Mag. Nat. Hist., ser. 3, vol. ix. p. 473.

Avenella fusca (forma producta), Smitt, Kritisk Forteckn., p. 503.
Cylindrecium giganteum, Hincks, Brit. Mar. Polyz., p. 635, pl. xxvii. figs. 3, 4.

(2) Cylindrecium dilatatum, Hincks.

Farrella dilatata, Hincks, Quart. Journ. Micr. Sci., vol. viii. p. 279, pl xxx. fig. 7.
Avenella dilatata, Hincks, Ann. and Mag. Nat. Hist., ser. 3, vol. ix. p. 473.
Cylindrecium dilatatum (pars), Hincks, Brit. Mar. Polyz., p. 536, pl. Ixxix. figs. 1-3.

(3) Cylindracium fuscum, Busk.

Farrella fusca, Bk., Quart. Journ. Micr. Sci., vol. iv. p. 94, pl. vi. fig. 3.

Avenella fusca, Alder, North. Cat., p. 69; ? Norman, Shetland Polyz., Rep. Brit. Assoc.,
1868, p. 311; Smitt (forma simplex), Kritisk Forteckn., p. 503.

Cylindracium dilatatum (pars), Hincks, Brit. Mar. Polyz., p. 537, pl. Ixxvii. figs. 1, 2.

(4) Cylindrecium pusillum, Hincks.
Cylindrecium pusillum, Hincks, loc. cit., p. 537, pl. Ixxx. fig. 8.

(5) Cylindrecium pusillum, var. “ dwarf,” Hincks.
Cylindracium pusillum, var. “ dwarf,” Hincks, loc. cit., p. 538, pl. Ixxx. fig. 9.
(6) Cylindrecium papuense, n. sp.

The respective dimensions of the zocecia in these species, so far as they can be made
out (mostly from Mr. Hincks’s careful figures), are as follows, given in millimetres:—

Length. Breadth.

1. Cylindrectum giganteum, : : c 3 35 x 0:20-0:25
2. Cylindrecium dilatatum, : q 3 ; OS xe OS

3. Cylindracium fuscum, . . ¢ . : 17 x © 0°2-0°3
4. Cylindracium pusillum, ; ‘ : 6 13 x = =©0710-0°13
5. Cylindrecium pusillum, var., . : : - O:ty are By OF

6. Cylindrecium papuense, - 5 : : 13 x 010—11

From these dimensions it would seem that the form most nearly approaching that in
the Challenger collection is the one named Cylindracium pusillum by Mr. Hincks, from
this, however, it differs in the uniform diameter of the zoccia, which in the latter
become wider or subventricose below.

I may take this opportunity of remarking that the form named Farella fusca by me,
from specimens collected at Newhaven, Firth of Firth, by Mr. W. Thompson in 1849,
and which is considered by Mr. Hincks synonymous with his Cylindraciwm diatatum,

eis

40 THE VOYAGE OF H.M.S. CHALLENGER.

seems to differ so much-in its: comparative dimensions,as perhaps to deserve recognition
as a distinct species, which might be named Cylindrecium fuscum, as being the first of
the genus to which that appellative was given.

Group B. ENTOPROCTA, Nitsche.
Entoprocta, Nitsche, Zeitschr. f. wiss. Zool., Bd. xx. p. 34; Hincks, Brit. Mar. Polyz., p. 563.

Character.—Both oral and anal orifices lying within the crown of tentacles; no
tentacular sheath. Tentacles contractile but not retractile, arranged bilaterally and
symmetrically.

Order PEDICHLLINEA.
The only order.

Family I. PepiceLuinipa, Hincks.
Polypiaria pedicellinea, Gervais, 1837. |
Pedicellinz, Johnst. ;
Pedicellinidz, Smitt, 1867; Hincks, 1880; Jullien, 1885.

Character.—Polypides deciduous, borne on a more or less muscular, rigid or
contractile peduncle ; united into colonies by a chitinous ramified stem or stolon.

The general characters of the family Pedicellinide are so well and succinctly given
by Mr. Hincks* as scarcely to require further observation. -The chief points to be
noticed, as he remarks, besides the Entoproctous anal orifice are—

1. That there is no invagination of the anterior region and therefore no tentacular
sheath, and consequently an absence of the retractor muscular fibres by which it is
retracted in the Ectoprocte.

2. That the integument is soft and never calcified, and is closely applied to its
contents ; 2.¢., there is no perivisceral cavity containing a fluid as in most other Polyzoa,
such small space as there is between the inner wall of the calyx and the contained
organs is occupied by a more or less delicate parenchymatous tissue. The integument is
composed of a very delicate outer membrane lined by a layer of flattened polygonal
cells. The outer membrane or ectocyst is prolonged beyond the visceral mass and forms
the side of the vestibular cup-like chamber, within the transparent walls of which the
tentacles are usually seen coiled. The tentacles arise from the upper edge of the inner
surface of this cup, and their outer surface is formed by a prolongation of the transparent
‘ectocyst, whilst the inner is covered by a more opaque layer of ciliated cells. The
vestibular chamber is separated from the visceral part of the polypide by a thin lamina

1 Brit. Mar. Polyz., vol. i. p. 563.

REPORT ON THE POLYZOA. 41

(intra-tentakulire Leibeswand, Nitsche), through which passes on one side the
cesophagus and on the other the rectum.

3. All the Pedicellinide are furnished with a more or less mobile stem, which is
either flexible and contractile throughout, or as in Pedicellina gracilis, partially flexible
and partially rigid, or as in Ascopodaria, wholly rigid and chitinous, its motions
being effected by a peculiar muscular apparatus at the lower end.

The only forms belonging to this Family that I have noticed in the Challenger
collection belong to an apparently distinct genus, to which in 1878 I had given the
MS. name of “ Ascopodaria,” as stated in Professor Allman’s Linnzean address of 1879.
In 1880, however, Mr. Hincks, in a description of some Arctic Polyzoa, described and
figured under the name of Barentsia bulbosa, a pedicelline species, which, though
apparently quite distinct specifically from either of the two Challenger forms, evidently
belongs to the genus I had already proposed to establish. In strict right of priority of
publication, therefore, his name should have precedence over that merely provisionally
given by me, and I should without hesitation have adopted it, but since then he has
described and figured a second species, referable, from my point of view, to the same
genus, under the name of Pedicellinopsis fruticosa,’ thus giving two distinct names to
the same generic type. I have, therefore, felt justified in retdining my original
appellation, and in regarding Barentsia and Pedicellinopsis as synonyms. As an
additional argument, though one of less weight, in favour of the course I have pursued,
I might cite the appropriateness of the title I chose, indicative as it is of the main
peculiarity of the genus.

The Family here contains :—

1. Ascopodaria.

(1) Ascopodaria fruticosa, Hincks, sp. (Pls. IX., X. figs. 1-5).
(2) Ascopodaria discreta, n. sp. (Pl. X. figs. 6-12).

1. Ascopodaria, Busk.’

Ascopodaria, Bk. (MS.), Add. by Prof. Allman, Journ. Linn. Soc. Lond. (Zool.), vol. xv. p. 2.

Barentsia, Hincks, Ann. and Mag. Nat. Hist., ser. 5, vol. vi. p. 285; Vigelius, Bijd. Dierk. Genoot.
Nat. Art. Mag. Amsterdam, II. Afley., pt. 2, p. 89.

Pedicellinopsis, Hincks, loc. ctt., vol. xiii. p. 363.

Pedicellina (pars), Sars, Leidy.

Character.—Polypide budding from and supported at the extremity of a chitinous,
tubular, perforated stem, which expands below into a cylindrical, barrel-shaped dilatation,
lined internally by a layer of longitudinal muscular tissue.

1 This species is the same as one of the two Challenger forms to which I had given the name of A scopodarta socialis
but I have now as a matter of course adopted Mr. Hincks specific name.

2 From dox0és, a wine-skin, rovs, a foot, an illusion to the dilatation at the base of the stem.

ZOOL. OHALL. EXP.—PART L.—1886.) Ddd 6

49 THE VOYAGE OF H.M.S. CHALLENGER.

The structure of the peduncle is the character by which this genus is distinguished
from Pedicellina. The pedicel is rigid and chitinous throughout, and depends for its
motion on the muscular fibres which line the barrel-shaped expansion at the base; the
central cavity of this expansion as well as of the rest of the stem being filled with an
extremely delicate parenchymatous tissue. :

The anatomy of the polypides appears to agree almost entirely, as far as I have been
able to observe it in the spirit specimens, with the very careful descriptions given by Dr.
Nitsche in his paper on Pedicellina echinata.t The whole polypide or calyx is enveloped
in a delicate transparent membrane or ectocyst, lined with a more or less distinct tesselated
epithelium. The alimentary canal consists of an cesophagus, stomach, intestine and
rectum (Pl. IX. fig. 6); the liver cells extending along the upper side of the stomach
present the usual deep yellow colour. In all the specimens that I have examined the
rectum lies in a horizontal position forming an angle with the rest of the intestine;
whether this is its normal position, as it appears to be in the closely allied genus
Urnatella * or whether it merely is the case during a young stage of growth, as mentioned
by Dr. Nitsche, Iam unable to decide. I have not been able to observe with any certainty
the reproductive organs; but in nearly all the polypides of one species, Ascopodaria frutt-
cosa, between the stomach and the base of the vestibular cavity, there are two large, round,
ovarian masses (PI. IX. figs. 6, 8, 9), which are separated from one another by a thin
lamina (Pl. IX. fig. 9). In the other species these masses are not apparently always present.

Mr. Hincks has suggested * that his genus Pedicellinopsis would properly include the
Pedicellina gracilis of Sars; in this I am disposed fully to agree with him and should
therefore propose to include it in my genus Ascopodaria. Professor Leidy * refers to a
species of Pedicellina found by him in 1859, which, from the short description given, if
not identical with Pedicellina gracilis, ought also to be placed in this genus. The known
species therefore would be four or five, as follows :—

(1) Ascopodaria gracilis, Sars.

(2) Ascopodaria bulbosa, Hincks.

(8) Ascopodaria fruticosa, Hincks =socialis, Bk., MS.
(4) Ascopodaria discreta, Bk.

(5) Ascopodaria (?), Leidy.

(1) Ascopodaria fruticosa, Hincks, sp. (Pls. IX., X. figs. 1-5).

Pedicellinopsis fruticosa, Hincks, Ann. and Mag. Nat. Hist, ser. 5, vol. xiii. p. 364, pl. xiv.
fig. 3.

Character.—Zoarium arborescent, constituted of thick, erect, chitinous, jointed,
branching stems, arising from tubular stoloniform fibres. The deciduous polypides (or

1 Zeatschr. f. wiss. Zool., Bd. xx. p. 13. 1 Leidy, Journ. Acad, Nat. Sct. Philad., 1884, vol. ix. p. 12.
§ Loc. cit., vol. xiii. p. 364. 4 Loc. cit., p. 14.

1. REPORT ON -THE POLYZOA. 43

-calices, Auctt.) are seated on the upper end of slender tubes or pedicels, which are pro-

duced into a single or double point on one side at the top; at its base the pedicel dilates
into a thick barrel-shaped cylinder (Pl. IX. fig. 7), which is covered by a transparent,
ringed, chitinous envelope (Pl. X. fig. 1), led with a strong muscular layer, the cavity
being occupied by a very delicate fibro-cellular tissue (Pl. IX. fig. 14). The chitinous
pedicels have four more or less regular longitudinal series of funnel-shaped perforations.
These polypiferous peduncles are seated in a cup-shaped hollow, and attached by a much
restricted termination in a spiral direction around the upright stems, communication with
the interior of which is maintained through a fine funnel-shaped orifice (Pl. XI. figs. 12,
13). The polypides are of the usual pedicelline character, and have a very short flexible
stalk, which is attached just within the upper edge of the chitinous pedicels, and when
young is continuous with the inner cellular tissue ; when mature the polypides appear to
be quite cut off from the pedicels on which they are placed, and from which they bud
in succession (Pl. LX. fig. 5). The tentacles vary in number from twenty in a bud to
twenty-six or twenty-eight in an adult, and are arranged more or less bilaterally and
symmetrically. The pedicels and stems are of a bright light brown colour usually ; the
stems turning nearly black when old. The polypides are white and the barrels white or
nearly so, the transparent chitinous envelope being so thin that the white inner layer
shows through.

The total length of the calyx and peduncle is 35 to 38 mm. The polypide
measuring about 0°65 x 0°5 mm., the pedicel 2°3 x 0°07 mm., and the barrel 0°75 x 0°5 mm.

Habitat.—Station 163, off Twofold Bay, 150 fathoms.

[Port Philip Heads. ] | |

The arborescent growth of this beautiful species distinguishes it at once from all
other known Pedicelline forms, but the rest of its structure leaves no doubt as to its
belonging to that order.

At first sight it is difficult to observe that the tentacles are not arranged in a
perfectly regular and continuous circle, but here and there indications may be noticed
that a wider space does occur between two at opposite sides of the circumference, viz., at
the two ends of the symmetrical plane of the animal; the bilateral arrangement is most
clearly seen in a young budding Polypide (PI. X. fig. 2) which appears closely to resemble
the figures given by Hatschek" in his paper on Pedicellina echinata, and also the figure
and description by Salensky.” The buds arise in succession spirally and somewhat in
pairs (Pl. X. fig. 1) round the growing ends of the chitinous stems and branches. Fresh
polypides also bud from the ends of the pedicels after others have died and dropped off ;
that this also oceurs in Pedicellina has been noticed and described by Salensky,’ and

1 Zeitschr. f. wiss. Zool., Bd. xxix. pl. xxx. figs. 39, 40, 45. 2 Ann. d. Sct. Nat., sér. 6, t. v. p. 36, pl. xv. fig. 36.
® Loc. cit., pp. 30, 31.

44 THE VOYAGE OF H.M.S. CHALLENGER.

is mentioned by Professor Leidy! as occurring in Urnatella, but I have not found it
referred to by any other writers on the Pedicellinea.

Pl. X. fig. 1, represents a group of buds at the end of one of the branches, and
also shows the barrel-shaped expansion at the base of one of the peduncles, from which
the transparent ringed covering has been partially loosened and torn off by the process of
boiling. Figs. 3 to 5 on the same plate are taken from sketches made by the late Sir
C. Wyville Thomson when the specimens were fresh and alive.

(2) Ascopodaria discreta, n. sp. (Pl. X. figs. 6-12).

Character.—The zoarium consists of a creeping stoloniferous stem, jointed at
intervals where the branches are given off or where the polypides arise. The deciduous
polypides are seated at the upper end of slender chitinous pedicels, which are dilated
below into barrel-shaped cylinders that have a thick, ringed, chitinous envelope, and
exactly resemble those of the preceding species. The polypiferous peduncles are seated
by a broad base on the stoloniform stems; usually singly on the somewhat expanded
jointed bifurcation of four branches (fig. 11), but sometimes scattered along the stolons
(fig. 12). The chitinous pedicels are irregularily punctured by minute funnel-shaped
pores. The polypides are united to the pedicels by a spirally ringed flexible joint (fig.
12). The tentacles are from sixteen to twenty in number. ‘The pedicels and stolons are
of a bright brown, horny colour, the polypides white, and the barrels also white or very
light brown, appearing darkest when quite young, the chitinous envelope becoming
thinner and more transparent as the animal grows older.

The total length varies considerably, apparently according to age; the majority of
the older ones measure as much as from 4°25 to 444mm. The polypide being about
0°5 x 0'4 mm., the pedicel 3°0 x 0°6 mm., and the barrel 0°7x 0°24 mm. This species
is, therefore, on the whole, taller and more slender than the preceding one.

Habitat.—Station 135, off Nightingale Island, Tristan da Cunha, 100 to 150 fathoms.

There were very few specimens in all of this species in the collection, and, therefore,
it has not been possible to enter into a full and minute examination of the polypide, but
it appears to present all the usual Pedicelline characters.

! Journ, Acad. Nat. Sci. Philad., vol. ix. pt. i. p. 13.

INDEX.

GENERA, SPECIES, AND VARIETIES.
(Synonyms printed in 7talics).

PAGE | CezrzArra—continued.

ACTINOPORA, a ' 25 eburnea,
ADNATA sev DECUMBENTIA, 21 | CELLULARIA,. 5
ALCYONIDIIDE, 30 eburnea, . :
ALCYONIDIUM, . 31 | CewrRIFUGINEA,

flustroides, 31 | Cewrrirucivnés empdtés
ALCYONIDULA, 30 operculées,
ALcYonium, CENTRIFUGINES radicellés,
ALECTO, 22 | CERIOPORA,

granulata, . 22 | CeRIoPORIDs, 5

parasitica, 22 | Cerrororiva,
AMATHIA, 33 | CERIOPORINE,

bicornis, 34 | CoRALLiom, .

brasiliensis, 34 | CoRYMsOPrORA,

connexa, . 35 | CorymsBosa,

distans, 33 ramosa,

lendigera, . 33 | Cruisra4,

semispiralis, 36 | Crisra,

spiralis, 34 acropora, .

tortuosa, . A q 34 acuminata,
ARTICULATA sev RADICATA, 1 biciliata, .
ASCOPODARIA, . ; 4] conferta, .

discreta, 44 cylindrica,

fruticosa, . 42 denticulata,
AULOPORA, 22 var. gracilis,
AULOPORINA, . 1 var. patagonica,
AVENELLA, 38 eburnea, var. laxa,
BARENTSIA, 4] elongata, .
BERENICEA, 24 holdsworthii,
BICRISIA, 2 luxata,
CAVEIDA, 25 | CRISIADA, .
CELLARIA, 2 | Crisipe#, ¥ .

artica, 4 | CRIsIDEA,

denticulata, 4 | Crisipra,

bo bo

Nome RK OOK OOF AT AT Oo mb OO OAT A

46

CRISIEZ,
Crisres, Les, .
CRISIIDE,
CRISINA,
hochstettervana,
CTENOSTOMATA,
CYCLOSTOMATA,
CrcLoum, : 4
CYLINDRGCID4, .
CYLINDR@cIUM,
papuense, .
DEFRANCIA,
DIASTOPORA, .«
DIAsTopora,
patina, 3
PYIASTOPORES simples,
DIASTOPORIDA,
DISCOCAVEA, .
DiISCOPORA,
hispida,
DISCOPORADA,
DISCOPORELLA,
Jimbriata,
hispida,
DISCOPORELLIDE,
DISCcOSPARSA marginata,
patina,
ENTALOPHORA,
anomale, .
attenuata,
deflexa,
haastiana,
tcaunensis,
proboscidea,
raripora, .
ENTOPROCTA,
ERECTA,
EUCRATEA,
FALCARIA,
FARRELLA,
FARRELLA,
atlantica, .
FYASCICULINEA,
FASCICULIPORA,
FAscICULIPORA,
digitata, .
ramosa,
FASCIGERIDE,
FAILICRISIA,

THE VOYAGE OF H.M.S. CHALLENGER.

24

24

9

a

FRONDIPORA, .
ramosa,
FRONDIPORIDA:,
FUNGELLA,
prolifer,
HALCYONELLEA,
HIALCVYONELLEZ,
HIALODACTYLUS,
HIETEROPORELLA,
radiata,
hispida,
HoRNERA,
affinis,
andegavensis,
borealis,
foliacea,
frondiculata,
lichenoides,
radiata,
serrata,
tubulosa, .
violacea, .
HORNERIDE, .
IpmMonea,
~ angustata,
atlantica, .
australis, .
coronopus,
eboracensis,
fissurata, .
marionensis,
milneana, .
irregularis,
radians,

- transversa,
IDMONEAD, .
IDMONEID4,
INARTICULATA,
INCRUSTATA, .«
LAGENELLA,
LAGUNCULA,
LAOMEDEA, _
LICHENOPORA, .

fimbriata, .
hispida,

LICHENOPORID#, .

MADREPORA, «
MILLEPORA,
lichenoides,

PAGE

12

Mitrepora—continued.
tubipora, . :
MILLEPORES & cellules.
MVRIOPORINA,
Nir CORALLINE,
PATINELLA,
verrucaria,
patina,
PEDICELLINA,
PEDICELLINE,
PEDICELLINEA,
PEDICELLINIDA, .
PEDICELLINOPSIS,
Fruticosa, .
PHALANGELLA,
flabellaris,
phalangea,
POoLyPraRia pedicellinen,
POLYZOA carnosa,
PROBOSCINA, .
PUSTULIPORA,
proboscidea,
deflexa,
PUSTULOPORA, .
clavata,
deflexa,
orcadensis,
proboscidea,
proboscidioides,
regularis, .
subverticillata,
virgula,
RADICELLATA,
RETEPORA,
radians,
RETIHORNERA,
foliacea,
dentata,
plicata,
SARCHOCHITUM,
SERIALARIA,
lendigera, .
convoluta,
spiralis,
semisptralis,
SERTOLARA davorio, La,
SERTOLARA lendinosa, La,
SERTULARIA, .
eburneu,

REPORT ON

22

22

THE POLYZOA.

SERTULARIA—continued.
lendigera, .
SPARSIDE,
STOLONIFERA,
STOMATOPORA,
deflexa,
granulata,
SUPERCYTIS,
digitata,
tubigera, .
SYPHODICTYOUM,
TERVIA,
Solini,
TIBIANA,
TUBIGERIDZ, .
TusrrorA flabellaris, .
serteus,
TUBULIPORA, .
TUBULIPORA,
deflexa,
fimbria,
Jinbriata,
flabellaris,
hispida,
patina,
phalangea,
verrucaria,
TUBULIPORID&,
TUBULIPORIDA,
TvUBULIPORIENS, Les, .
TUBULIPORINA,
ONICAVEA,
ONICELLARIA,
ONICRISIA,
VALKERIA,
lendigera, .
VALKERUD,«
VESICULARIA,
| VESICULARIA,
papuensis,
trichotoma,
VESICULARIADZ,
VESICULARID&,
VESICULARIEA,
VeESICULARIER,
VESICULARIIDA,
VESICULARINA,
VESICULARINA,

ete 123
9, 18, 22, 24, 25
29
20
23
23
23

1 eapienks

PLATE I.

CRISIA.
Diam. Page
Figures 1, 2.—Crisva biciliata, natural size, 3
la, front; 16, back; 1c, ocecium ; 2a, side view, x 50
zs 3.—Crisia elongata, 5
3a, part of the zoarium, front view, : ; x25
a 4.—Crisia denticulata, var. gracilis, 5
da, part of the zoarium, front and back; 46,
ocecium ; 4c, occasional mode of attachment
to a sponge spicule ; 4d, terminal process, 54 245)

1A scale in millimetres is marked. near the lower right-hand corner of Plates I.-VIIL., which applies to all the
figures on each, except where a different scale is marked.

The Voyage of HM S. Challenger” Polyzoa. (Part li) Pl}. -

——!
C-Tram.

GB del. C Berjoau ith. Matern Bros.imp

CRISIA.

PLATE II.

CRISIA.

Figure 1.—Crisia eburnea, var. laxa,
la, part of the zoarium, front,
» 2-—Crisia cylindrica,
2a, lower portion of a young zoarium,
» 38—Crisia denticulata,
3a, front; 36, ocecium,
» 4—Crisia cylindrica,
Aa, older part of zoarium, front,
» 9.—Crisia conferta, .

5a, part of the zoarrum, with ocecium,

25

25

25

25

The Voyage of H.M. S. Challenger” Polyzoa. (Part I) PLU.

woos ilies

GB.dd. C\Berjean lith. Mintern Bros. imp.
CRISIA.~

Ly

.7
oar
eae aN

PLATE I.

(ZOOL. CHALL, EXP.—PART L.—1886.)—Ddd

PLATE ITI.
Crista.—IDMONEA.

Figure 1,—Crisia acuminata, : :
la, part of a branch, front view ; 10, 1¢, 1d, terminal
processes,

» 2—Crisia holdsworthir, ocecium,

» 3.—Ildmonea australis,
3a, front; 3b, back,

» 4.—Idmonea eboracensis,

4a, front; 4b, ocecial dilatation, . A b
Ac, back,

» 90.—Idmonea fissurata,

5a, front of young portion of zoarium; 56, older
part ; 5c, back,

Diam.

25

25

25

25
50

25

Page

12

12

14

The Voyage of H.M.S.Challenger ” Polyzoa (Part 2) Pl. II.

Biigads.

J.B. del. Geo West & Sons lith.et imp.

, CRISIA, IDMONEA.

fe
4 if

ae

rq
Ppa

PLATE TV,

PLATE IV.

PUSTULOPORA.

Diam. Page

Figure 1. Pustulopora proboscidea, . ; 5 . : : 19
la, part of zoarium ; 1b, ocecial dilatation, . 3 25

» 2. Pustulopora regularis, . : a A i i 21
2a, terminal fork, : , : : : x25

» 98 Pustulopora deflexa, ; ; : at , ; 20
3a, bifurcation of zoarium, . s : te Sin?)

» 4. Pustulopora proboscidioides, i : : : 2 19

4a, 4b, two portions of the zoarium, . : 3 iH 25)

TheVoyage of HM.S. "Challenger." Polyzoa (Part 2) Pl. ly.

J.B. del. Geo. West & Sons, lith et imp

PUSTULOPORA.

hes

i
iN

rs

(coon. onALL Exe—panr t.—l

PLATE V.

TUBULIPORA.—SUPERCYTIS.

Diam. Page

Figure 1.—Tubulipora flabellaris, . : : 5 : 23
la, front; 10, back, . : 3 : : Se OS
le, orifice, . 2 : ; : f Soro 0

» 2.—Lubulipora fimbria, : : 5 : : : 23
2a, front, with ocecium, : : : : <p 25)
2b, orifice, . : 5 : : : oO)

» 3.—Supercytis digitata, : é : é ; sai 29
3a, the zoarium, : : é : # x 9

» 4.—Supercytis tubigera,

4a, the zoarium, with occia, ; : ; x 9 29

Polyzoa (Part PVBUNE

The Voyage of HM.S."Challenger ”

1
‘
'
‘

O-f mre

Geo West & Sons, lith et imp

GB&ad.B. del.

SUPERCYTIS.

TUBULIPORA,

PLATE VI.

PLATE VI.

AMATHIA.
Figure 1.—Amathia tortuosa,
la, part of a branch ; 16, showing the exserted neck, x
» 2—Amatha spiralis,
2a, 2b, portions of the zoarium, : : i x

3.—Amathia connexa,

3a, part of the zoarium; 36, another part, showing

39

the commencement of a branch, ‘ : x

Diam. Page
34

25
34

25
35

25

The Voyage of H.M.S.” Challenger” Polyzoa (Part 2) Pl. VI.

J.B.&F B-del. Geo West & Sons, Lith et imp

AMATHIA.

PLATE. VIE.

(ZOOL. OHALL, EXP.—PART L.—1886.)—Ddd.

PLATE VIL.

AMATHTA.—F ARRELLA.

Diam. Page

Figure 1.—Amathia distans, : ; : 33
la, part of the zoarium, é : : x 25
1b, young spiral not fully developed; 1c, showing
exserted necks, ~. | g : : x 50
a 2.—Amathia brasiliensis, . g ; . 5 5 34
2a, 2b, portions of the zoarium; 2c, long, barren-
jointed, terminal filaments; 2d, 2e, occa- ‘
sional scattered zocecia, . : 4 Se
,, 3, 3¢.—Farrella atlantica, : : : : i x7 50 37
3b, 3c, zocecia with polypides ; 3d, with quadrangular
orifice ; 3g, young zocecium, x 110

3e, 3f, different forms of zocecia, . ; : 0)

TheVoyage of H.M.S."Challenger” Polyzoa (Part 2) PLVI.

oe

Sf

Fig. 1

G.B.&J.B. del Geo West & Sona hth.etimp

AMATHIA, FARELLA.

PLATE VIII.
AMATHIA.— VESICULARIA.—CYLINDRECIUM.

Figure 1.—Vesicularia papuensis,

la, part of the zoarium,
1b, zocecia with polypides,
le, bifurcation of the zoarium.

» 2—Cylindracium papuense,

» 8—Amatha semspiralis,

3a, part of the zoartum ; 3b, young growing end,

» 4—Vesicularia trichotoma, .
4a, magnified,
4b, zocecium and buds,

x

Diam. Page
36

25

110

50
25 38
36

25
37

25

50

The Voyage of H.M.S.” Challenger.” Polyzoa Part II, Pl. Vil.

Geo.Weet & Sons lith.et amp

G.B. del.

AMATHIA, VESICULARIA, CYLINDRGCIUM.

Stee

PLATE IX,'

ASCOPODARIA.
Diam. Page
Figure 1.—Ascopodaria fruticosa, natural size, . : : ; 42
ib 2.—A single zocecium and polypide, : : A a) 2)
p 3.—A single polypide, with the tentacles coiled within
the open edge of the cup, : : i xe 50
a 4.—Another polypide, with the edge of the cup con-
tracted, . ‘ : 5 : Z x 50
5p 5.—A young polypide budding from the end of an old
pedicel, . : ‘ é ; ; x50
5 6.—A single polypide, showing the visceral organs, 5 eNO
Hh 7.—Barrel-shaped expansion at the base of a pedicel, 3 0
» 8, 9.—Longitudinal sections through a polypide, 5 i x 110
ve 10.—Portion of stem, with bases of peduncles, : : 54 ON
is 11.—Longitudinal section of stem, . : : ; x50
,, 12, 13.—Transverse sections of stem, . : j g x) 50
55 14.—Portions of the parenchymatous tissue, from the
centre of the stem, : : ; 5 x 360

1 Several references used on this plate :—i, intestine; J, liver cells; @, oesophagus; om, ovarian masses; 7, rectum;
s, stomach ; ¢, tentacles.

The Voyage of H.M.S.Challenger’ Polyzoa. Part II, Pl. TK.

SocooncUGUCObe eS

io

C.B.J3.B& F.B. del. FP Huth, Lith? Edn?

ASCOPODARIA.

2) iapluusie

Figure

99

29

33

99

PLATE X*

ASCOPODARIA.—ALCYONIDIUM.

1.—Ascopodaria fruticosa, group of young buds at the
end of a branch, also showing the transparent
envelope of a barrel which has been partially

torn off, and the cup-like sockets in which the

peduncles are seated,

2.—A single bud, showing the bilateral arrangement of

the tentacles,

3, 4, 5.—After sketches of the same, taken when fresh by the

late Sir C. Wyville Thomson,
6.—Ascopodaria discreta, a single polypide,
7.—Two buds at the end of a stolon,
8.—A single zocecium and polypide,
9.—A single zocecium, also showing stolon and buds,
10.—A group of zocecia,

11.—Stolon with bud and the base of two peduncles,

12.—The spirally ringed segment by which the eee

is attached to the pedicel,
13.—Alcyonidium flustroides,

14.—Portion of the zoarium, with scattered ova
“brown bodies,”

and

Xx

Diam.

50

110

50

50

25

50

25

50

110

25

Page

43

44

31

1 Several references used on this plate :—7, intestine; J, liver cells; @, esophagus; om, ovarian masses; 7, rectum ;
s, stomach; ¢, tentacles.

The Voyage of H.M.S “Challenger.” Polyzoa. Part Ill, Pl K.

P.Huth, Lith? Edt

CMT, G.B & J.B. del.
ASCOPODARIA, ALCYONIDIUM.

Siac

rege ee

nee) ik EP

ON THE

SCIUIGIN TW Wa IE IIe S UI An Ss

OF THE

Pea Ol TMS. CHALLENGER

DURING THE YEARS 1873-76

UNDER THE COMMAND OF

Captain GEORGE S. NARES, R.N., F.R.S.

AND THE LATE

Captain FRANK TOURLE THOMSON, R.N.

PREPARED UNDER THE SUPERINTENDENCE OF

THE LATE

Silt Com GVey ele LO MESON a rKants iB ORISee ccc!

REGIUS PROFESSOR OF NATURAL HISTORY IN THE UNIVERSITY OF EDINBURGH
DIRECTOR OF THE CIVILIAN SCIENTIFIC STAFF ON BOARD

AND NOW OF

IKQUEUN IMOUIRIROYC ILICID) lesOL. ae.

ONE OF THE NATURALISTS OF THE EXPEDITION

LOOLOGY-— V Ole Orv I.

PART LXXIII.W_REPORT ON THE ACTINIARIA—SUPPLEMENT

By PRoFrEssoR RICHARD HERTWIG

Published bp Order of ber Majestp’s Government

PRINTED FOR HER MAJESTY’S STATIONERY OFFICE
AND SOLD BY
LONDON :—EYRE & SPOTTISWOODE, EAST HARDING STREET, FETTER LANF
EDINBURGH :—ADAM & CHARLES BLACK
DUBLIN :—HODGES, FIGGIS, & CO.
1888

Price Four Shillings

PRINTED BY MORRISON AND GIBB, EDINBURGH

‘FOR HER MAJESTY’S STATIONERY OFFICE.
x ‘ ey 4 2 iS " = * af E

HDIMOnRTAL NOTH

Tue Report on the Actrxraria, by Professor Richard Hertwig, was published
in 1882, forming Part XV. of the Zoological Series of Reports, in Volume VI.,
Zoology.

This Part forms the Supplementary Report promised at that time on a
number of forms which reached Professor Hertwig too late for the descriptions
to be included in the original Report. It consists of 56 pages of letterpress
and 4 lithographic plates.

The manuscript was received 21st January 1888, and the Memoir was
translated from the German by G. Herbert Fowler, Esq., Ph.D., of University
College, London.

JoHN Murray.

CHALLENGER OFFICE, 32 QUEEN STREET,
EpinpureGH, 21st June 1888.

THE

VOYAGE OF HM.S. CHALLENGER.

ZOOLOGY.

REPORT on the ActinrariA dredged by H.M.S. Challenger during the
years 1873-1876. By Prof. Rrcoarp Herrwie.

SUPPLEMENT,
INTRODUCTION,

Arter I had concluded my Report on the Actiniaria of the Challenger Expedition,
a number of additional specimens were sent to me, on which I now present a short
Supplementary Report. Unfortunately the work has been delayed longer than I could
have wished, partly on account of a series of experimental mvestigations upon the
fertilisation and segmentation of the ovum, which I had undertaken in concert with my
brother, but mainly owing to the claims on my working-time caused by my trans-
ference from Konigsberg to Bonn, and from Bonn to Munich.

Amongst the material occurred several specimens of species which have been prey1-
ously described and can therefore be treated in few words ; besides these, there are also
several new forms, representing new and interesting genera, which require a detailed
description, and which are, for the sake of clearness, designated by an asterisk. At the
end (p. 54) will be found a list of those Actinixe of which a systematic study was
impossible, either because they were not sutficiently well preserved, or because their
appearance was no longer characteristic owing to the absence of sculpturing and colour,
the necessary result of the method of preservation.

Since the publication of the earlier part of this Report, the great monograph of
Angelo Andres on the Actiniaria has appeared.’ During the progress of his work this
1 Fauna und Flora des Golfes von Neapel, Le Attinie, 1884.

(ZOOL, CHALL. EXP.—PART LXXUI.—1888.) Dddd 1

2 THE VOYAGE OF H.M.S. CHALLENGER.

author was acquainted only with the short preliminary notice of my researches published
in the Jena Proceedings,’ not with the Report itself; a fact easily understood when one
considers how long before the date of publication a monograph constructed on such a
plan must be completed. In his comprehensive revision of the Actinie, and re-definition
of families and genera, he has been prevented from referring to my contemporaneous
attempt at revision, since this first appeared in the detailed Report. As it is most
desirable that two systems, appearing within a short time of one another, should be
brougnt into such relation as to avoid future discordance and mistake, I accept with
pleasure the opportunity of a critical utterance on their mutual relations.

As against the six chief divisions into which I divide the Actiniz (Hexactinie,
Paractiniz, Monaulee, Edwardsize, Ceriantheze, Zoanthee), Andres erects seven, viz.
Edwardsine, Actininee, Stichodactyline, Thalassianthine, Zoanthine, Cerianthine,
Minyadine. With regard to three chief groups we are in complete accord (Edwardsie,
Cerianthee, Zoantheze), except for the fact that Andres, in my opinion, relies on too
inconstant and unimportant external characters ; while, as 1 have shown, these groups,
at least, admit of anatomical characterisation by the arrangement of their mesenteries,
and thus can be far more clearly and sharply circumscribed. If the reader compare in
this connection the definitions of the Zoanthez furnished by myself and by Andres, it
will be readily admitted that none of the characteristics of the latter author, such as
colony-formation or incrustation, are constant within the group; that, on the other
hand, all the forms follow one and the same law of mesenterial arrangement, first
recognised by G. von Koch.

If we carry the comparison further, we find that Andres places beside the Actinine,
as separate groups, the Thalassianthine, the Stichodactyline, and the Minyadine ;
though with a certain caution, as having himself studied no representative of them.
I believe that he has here exceeded the systematic value which can be safely assigned
to the form of the tentacles and their distribution on the mesenterial chambers. I have
studied certain Stichodactyline (Corallimorphus rigidus, Corallimorphus profundus,
and Heterodactyla hemprichi), and of the Thalassianthine, Thalassianthus aster,
and can assert, as the result of a thorough examination of their structure, that im all
important points they agree with the hexamerous Actiniz ; nor have I any doubt that
these forms, even if united into separate families, must be ranged among the Hexactinie.
Finally, the group of Minyadine has for many reasons, which I entirely recognise,
undergone at the hands of Andres so sharp a criticism, that one can hardly see why he
retains it, or why at least he does not allow it to rank merely as a subdivision of
Hexactiniz, until the necessity of its removal from that group is rendered apparent by
anatomical investigation.

From the point of view explained, I am of opinion that all the forms referred to

1 Jenaische Zeitschr., Bd. xy. p. 10, 1881.

REPORT ON THE ACTINIARIA. 3

by Andres must be comprehended in the four divisions, Edwardsiz, Hexactinie,
Zoantheze, and Ceriantheze, and accordingly hold to the systematic classification which
I have published. The groups of Paractiniz and Monaulez are in all respects natural,
and would also certainly be retained by Andres had representatives of them been
known to him.

Even greater discordance than that of which I have hitherto spoken, between the
classifications of Actiniz followed by Andres and myself, presents itself when the
determination and nomenclature of families and genera are regarded. Independently
of each other, and from different standpoints, we have taken in hand a systematic
revision of Actiniz: Andres starting with the advantage of a richer material, and
studying species with which earlier publications are especially concerned, and which he
could command in a living condition; while my qualification for a systematic classifica-
tion was that afforded by close anatomical investigation, namely, that I relied for
systematic characteristics upon such weighty differences as the structure of the
sphincter, the arrangement of the mesenteries, the structure of the musculature and of
the oral disc, ete., pomts which Andres has, hitherto at any rate, entirely left out of
consideration. Thus it has resulted that in the determination of families and genera,
and also in the value assigned to existing names, we have in many cases taken up a
totally different attitude; and as, in consequence of this, no inconsiderable confusion
has arisen in the method of diagnosis, I hold it advisable to inquire critically what
must be retained of the system of the Italian observer.

Of least importance are our differences of opinion relating to those Actinize which
possess acontia. Andres has here adopted the separation, instituted by Verrill, into
Sagartidee and Phellide. Having regard to his wider acquaintance with the species, I
agree with him in accepting as a distinctive character the chitinous covering extending
over two-thirds of the body-wall; and for clearer characterisation of both families the
following marks not mentioned by Andres should be included in the diagnosis, —a
mesodermal sphincter, and a differentiation of the mesenteries into sterile complete
primary mesenteries, and incomplete secondary mesenteries provided with generative
organs. Of the Challenger Actinize, there would belong to the Phellidae only Phellia
pectinata ; to the Sagartide, Sagartia sp., Cereus spinosus, Calliactis polypus,
Bunodes minuta. Of these, the two latter require an alteration of name ; Calliactis
polypus must be termed Adamsia polypus,' and Bunodes minuta be known as Cylista
minuta, since it has been shown by Andres that the typical Bunodes possesses no
acontia, and therefore cannot belong to the Sagartide.

Andres has incorrectly allowed the generic name Cereus (Oken) to drop, and has

1 The specific name Rondeletii has been wantonly substituted by Andres for the older polypus, the former being

used for the first time by delle Chiaje in 1825, while the latter was already instituted by Forskal in 1775. Milne-
Edwards is therefore correct in calling the animal Adamsia polypus.

4 THE VOYAGE OF HMMS. CHALLENGER.

introduced in its place the more recent name Heliactis, for Sagartidze with numerous
large papille ; although Oken adduces Cereus bellis as the type form, which stands in
the same relation to the genus Heliactis. The papillate Sagartidee are of two kinds, the
one having a soft surface, while in the other the body-wall is covered as far as its upper
edge with a bark-like cuticle which recalls the Phellidee ; it is therefore advantageous to
confine to the former the name Heliactis, applied, though unjustifiably, by Andres, and
for the latter to restore Cereus, the old designation of Oken, a representative of the
newly characterised genus being Cereus spinosus.

In discussing the families instituted by Andres, we next come to the Paractide.
As I understand the diagnosis given for this family,—‘‘margine tentaculato, non
tilevato e privo d’ acroragi,’—the tentacles spring at the edge where body-wall and
oral dise pass into one another, just as is the case both in the Corallimorphide and
Antheomorphide, which I have described in more detail, and, generally speaking, in
such Actinize as are devoid of a circular muscle. But this relation also holds good in
Actinize with a weak sphincter, as, for example, in Anemonia cereus (to which Andres,
strange to say, ascribes a “ margine rilevato”); and, finally, in Actinize, in which the
sphincter is developed at some distance outwards from the upper edge of the body-wall.
The facts adduced are sufficient to prove that this characteristic is systematically
useless ; and in addition to this I insist that the few forms grouped in the family do
not appear to agree with the diagnosis. The tentacles of an Anemonia are, according
to Andres, formations placed more at the edge than are those of a Paranthus or a
Paractima. On the contrary, the Paractis peruviana, which Andres adduces as the
type of the family, seems to me to have no tentacles which would be marginal. Indeed,
it agrees so entirely with a Challenger form, Paractis excavata, that I long doubted
whether it were not right to unite the two. In Paractis excavata, 1 am certain that a
strong mesodermal sphincter is present, and, corresponding to this fact, body-wall and
oral dise are sharply marked off from each other, whence I conclude that the same holds
for Paractis peruviana. Since I have thus good ground for holding unsuitable the
mechods by which Andres has instituted his family Paractidee, and can, in addition,
claim the right of priority, I adhere to the definition which I previously published,
leaving only to future investigators to decide upon the advisability of erecting’ Actinic
with marginal spherules, sucking-papille, and papille into a family separate from the
Paractidee (sensu stricto) with smooth body-wali.

The next family in the system of the Italian naturalist is formed by the Actinide,
and corresponds to the Antheadz and Actinidee of Gosse. I formerly followed Gosse
in separating these two families, but had previously maintained that anatomically they
are closely related, and should perhaps on that account be united. I have therefore
nothing to adduce against this proceeding of Andres, though the detailed investigation
of the Actinide, which I recommended, has not yet been carried out. It is also

REPORT ON THE ACTINIARIA. 5

correct to replace the name Anthea by the older Anemonia, and to range the genus
Comactis under it. On the other hand, my Comactis jlagellifera is not identical with
Anemona sulcata (Anthea cereus), and should therefore be referred to as Anemonia
flagellata.

In the system of Andres the Bunodide bear the closest relation to my family
Tealide. I was unacquainted with any typical Bunodes, and had supposed (cf. supra)
that they possessed acontia. This supposition is, according to Andres, incorrect ; and
the close relationship to Tealia is thus anew proven. Accordingly I withdraw the
name Tealidz in favour of the older designation Bunodide ; but, now as formerly, the
endodermal sphincter must occupy the first place in the diagnosis, I relinquish, how-
ever, to future observers, as with the Paractide, the decision whether forms with
smooth and with papillate body-wall should be separated from one another, or not.

A last point of dispute with Angelo Andres lies in the fact that I reckon the
Halcampe among the Ilyanthide, while he erects them into a separate family. I will
not decide in this place either for the one opinion or the other, but will discuss merely
the point of view, which, as it seems to me, must be of importance for a decision.

The more we have learnt in late years of the structure of these forms, the
more has it become apparent that Actimie, which are rounded posteriorly and
devoid of pedal disc, exhibit in most cases a sort of ancestral character; eminently
primitive forms are, above all others, the Edwardsiz. Among such forms is the
genus Halcampa, from which again the genus Halcampella is a transition to the
remaining Actiniz, in virtue of its numerous tentacles, and of its commencing to
exhibit accessory mesenteries. I opine that the genus Jlyanthus stands in close
relation to the Halcampelle ; the regular increase of the mesenterial pairs by multiples
of six, which is commencing in the one case, is in the other clearly expressed,
as may be inferred from the presence of the numerous longitudinal furrows of the
body-wall ; while the siphonoglyphes (ciliated grooves), the hinder edge of the body,
and the sphincter, are obviously of weak development, as among the L/aleampe.
Possibly a study of the mesenteries may yield further points of agreement, but,
unfortunately, nothing is accurately known of these important features in the structure
of Ilyanthus; and so long as this is the case, no conclusion can be certain. If my
expectations be confirmed, a union cf the Halecampe with the Ilyanthidze would be
desirable ; the latter would form a transitional family placed at the top of the
Hexactiniz, and bridging the gap between them and the Hdwardsiz; while, as a
peculiar and aberrant branch of the Actinizw, would be ranged near them the
Siphonactidee, the forms possessing a conchula.

All the forms of which we have as yet spoken possess the typical digitate
or tubular Actinian tentacles, so arranged that one tentacle corresponds to each

radial chamber; there are, however, two variations of this arrangement. In the one

6 THE VOYAGE OF H.M.S. CHALLENGER.

the tentacles are replaced by appendages of a different value, for instance, by stomidia
in the Liponemide which I have described, or by bushy or arborescent growths in
the families Sarcophianthide and Thalassianthide erected by Andres. On the other
hand, there are forms in which more tentacles than one correspond to a mesenterial
chamber ; accessory tentacles, placed on the oral disc, being present in addition to the
primary tentacles. This is conclusively proved only for species of Corallumorphus, but
Andres has rendered it excessively probable also for species of Corynactis (compare the
account of Corynactis? sp.? p. 10, infra). For such forms I have instituted the family
Corallimorphidze, Andres the family Corynactide. I believe that my designation
deserves preference, because it is the older, and because my diagnosis of the family
alone insists upon the important anatomical characteristic ; on the other hand, I concede
to the Italian naturalist that the family may be restricted to species with knobbed
tentacles, and that all Actinize with modified tentacles, of which an accurate investigation
is still required, may be brought under a series of further families.

For a comprehension of the above discussion, I give a view of that arrangement of
Hexactinian families which I hold the most advantageous, in the form of a synoptic
table.

A few changes have been made in the English terminology used in the former part

?

of this Report: ‘‘cesophagus” has been replaced by “stomatodeeum,” ‘‘ mesoderm’

by “mesogloea,” and ‘“ cesophageal groove” by “ siphonoglyphe,” *

REPORT ON THE ACTINIARIA..

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DESCRIPTION OF GENERA AND SPECIES.

Tribe I. Hexacrinr.
Family, CoraLtimorpHips&, R. Hertwig,
Genus Corallimorphus, Moseley,

Corallimorphus rigidus, Moseley.

Amongst the supplementary material I have found the original specimen on which
Moseley formerly founded the species Corallimorphus rigidus. I had already mentioned
this on Moseley’s authority in my earlier Report, though I had not myself seen it,
and had described from my own observation four more specimens, of which one, from
Station 157, agreed in all essential particulars with the three others from Station 146.
I am now in a position to confirm the statement that the three latter agree with
Moseley’s specimen in form, in colour (of which traces only remain in spirit specimens),
and in the condition of the body-wall,—they exhibit no thickenings, but merely forty-
eight longitudinal furrows corresponding to the insertions of the mesenteries. Another
specimen, from Station 299, also agreeing with Moseley’s type, is of interest, since, of
the twenty-four tentacles on the oral disc, one accessory tentacle of the first order is
duplicated, two little tentacles being planted close together. I have already described
a similar, though more strongly expressed, development of supernumerary tentacles
in Corallimorphus profundus, so that it appears probable that the law of increase in
the tentacles of Corallimorphidee is not yet so definite as among other Actiniz, and
allows of more variation than in other cases.

Corallumorphus obtectus, n. sp.

While the five last-named specimens agree with one another, that from Station
157, on which I chiefly based my former description, demands a separate position, so
that [ now account it the representative of a new species to which I give the name
Corallimorphus obtectus, having regard to the buckle-like thickenings which cover the
insertions of the mesenteries. A further difference lies in its disc-like shape, due to the
relations of size between pedal and oral disc. Both are in this case of the same size, but
in Corallimorphus rigidus the former is considerably the smaller, producing a saucer-
shaped profile. The two species may be differentiated by the following diagnosis :—

1. Corallimorphus rigidus—Twenty-four tentacles are planted on the oral disc,

(Z00L. CHALL. EXP,—PART LXXIII1.—1888.) Dddd 2

10 THE VOYAGE OF H.M.S. CHALLENGER.

and forty-eight at its edge; the insertions of the mesenteries are recognisable by
longitudinal furrows ; the oral disc essentially larger than the pedal.

In addition to the examples referred to aboye, there belongs to this species one
specimen from Station 299, December 14, 1875; lat. 33° 31’S., long. 74° 43) Wi; depths
2160 fathoms.—Dimensions, height,-1°3 cm.; breadth of the oral disc, 4 cm., of the
pedal disc, 1°7 em.

2. Corallimorphus obtectus.—Twenty-four tentacles are situated on the oral dise,
and forty-eight at its edge; the mesenterial insertions are covered, in the lower third of
the body-wall and the peripheral third of the pedal disc, by cylindrical thickenings ;
the pedal and oral discs of approximately the same size.

To this species belongs only the example from Station 157, with which my former

description was concerned.

Genus Corynactis, Allman.

Corynactis (2) sp. (2)*

The tentacles, both on the dise and at its edge, are knobbed ; those on the disc are
arranged in several circles, so that more than one tentacle communicates with each
intra-mesenterial chamber.

Habitat.—Station 219, March 10, 1875; depth, 150 fathoms.

Dimensions.—Diameter of the oral disc, 2°5 em. ; height of the column, 0°8 cm. ;
ereatest length of the tentacles, 1°6 cm.

Angelo Andres gives in his monograph a description of the genus Corynactvs,
based partly on personal observation, partly on the account of Allman, from which I
infer that, with one and the same radial chamber communicate one of the marginal
tentacles and, in many radii, several of those placed on the disc ; five cycles are present,
of which the first contains four tentacles, the second sixteen, the third, fourth, and
fifth twenty-four. Gosse records other numbers, namely, four rows with sixteen, twenty-
four, thirty-two, and thirty-two tentacles respectively. In such remarkable contra-
dic.ion, one may well doubt whether one has any right to deduce a law of position from
either account; and the descriptions of the manner of distribution of the tentacles
are so inadequate, that it is impossible to conjecture how many of the tentacles placed
on the dise correspond to a radial chamber.

Amongst the Challenger material was an Actinian which I originally took for a
Corallimorphus, till I recognised that on four radii of the body two tentacles on the dise
and one at its edge proceed from one and the same radial chamber. ‘This is in contra-
diction to the law of the position of tentacles in Corallimorphus, but on the other hand
is related to that in Corynactis; to the latter genus I therefore provisionally refer it, even
though many characters do not agree in the two forms. Especially is its shape divergent,
being saucer-like as in Corallimorphus, and not elongated as in Corynactis. Further,

REPORT ON THE ACTINIARIA. ll

the animal is very irregularly developed ; the number of marginal tentacles amounts to
fifty-six, larger and smaller generally alternating ; two cycles, each of twenty-eight, might
thus be recognised, did one not consider that the tentacles of each cycle differ markedly
and somewhat irregularly in size. One is compelled to rank under the primary circlet,
tentacles which in diameter are far short of tentacles of the second order. Even more
irregular is the arrangement of those tentacles which are situated on the dise: their
total number, twenty-three, falls into three cycles, six tentacles being placed near the
mouth (oral tentacles), ten near the edge (peripheral tentacles), and seven intermediately.
Despite these apparently irregular numbers, I have noticed the complete validity of a
law in one-half of the animal, and it is of importance that this regular half commences
with the one pair of directive mesenteries and reaches to the other, thus just completing
one side of the animal. In the half in which a regular arrangement is followed, we
have three oral, six intermediary, and six peripheral, accessory tentacles. The six inter-
mediary alternate with the six peripheral, three of them standing on the same radius
as the oral tentacles. If we compare with these the marginal tentacles, the larger
twelve are on the radii already occupied by the tentacles on the disc, while the smaller
twelve are placed on the intermediate radii. At each of two points two tentacles are
present, a larger and a smaller; and, being out of accord with the law which governs
Actiniz, are either a token of the commencement of further crowth, or constitute a case
of those numerous abnormalities which occur in the group.

In the other half of the animal occur important gaps in the ground plan just
quoted. The three oral tentacles are in the same place as in the other half, (one is over
the chamber bounded by the directive mesenteries), but five of the imtermediary
tentacles and two of the peripheral are wanting. The single intermediary tentacle
occurs in the region bordering on the directive mesenterial chamber just mentioned ;
this region is normally arranged, the peripheral tentacles being also present on it. As
with the tentacles on the disc, so also the marginal ones exhibit great irregularities ; their
number amounts to twenty-eight; in size their relations are also variable, so that the
rule, that larger and smaller tentacles alternate, is in places infringed.

The peculiar results of a macroscopic examination induced me to cut out a sextant
of the animal for a closer study by means of sections, choosing that sextant of the
normal side which contained the directive septa, and which only departed from the
regular scheme of the Hexactiniz in the presence of two supernumerary tentacles. The
results were, that the mesenteries are grouped in pairs by the arrangement of their
muscles thus,—one pair of directive mesenteries, 2nd four other pairs, all of which reach
to the stomatodzeum. Of these four pairs I reckon one in the second cycle, two in the
third, the remaining pair being developed asymmetrically and repeating the irregularity
already noticed in the tentacles.

From the intra-mesenterial chamber of the directive septa are evaginated thre

12 THE VOYAGE OF H.M.S. CHALLENGER.

tentacles; besides the marginal, one oral tentacle and one intermediary are placed
on the disc. In the intra-mesenterial chamber of the second order the former (oral) was
wanting ; in those of the third order, the intermediary tentacle was also wanting, or
rather was replaced by a peripheral tentacle. From all the inter-mesenterial chambers,
and also from the supernumerary intra-mesenterial chamber, spring only marginal
tentacles.

Histologically our Corynactis is closely related to the Corallimorphi. The
mesogloea is homogeneous, branched stellate cells are richly scattered in it, while the
modified bladder cells, which occur in Corallimorphus obtectus, are wanting. Beneath
the endoderm runs a fibrous layer, sometimes closely under it, sometimes separated from
it by a homogeneous layer, giving off bundles which run to the endodermal surface.
The musculature of the oral dise and tentacles is weak and ectodermal; there is no
special sphincter, and the mesenteries are provided with only weak muscles on both sides.
On the other hand, I was surprised at the ocewrrence Y longitudinal muscles on the
outer side of the body-wall. They are not very strong, and are mostly composed of
short spindle-shaped fibres, the lamella being always slightly pleated here and there.
This discovery made it necessary to study Corallimorphus obtectus anew, with reference
to the body-wall. The epithelium having been preserved only at exceedingly few spots,
constituted the reason why I had not previously observed the muscle, but a renewed
study yielded figures by which I arrived at the following definite opinion, based on
numerous preparations from different parts of the body.

At the basis of each epithelial cell lies a small body, staining in carmine, and
resembling, in sections accurately transverse to it, a muscle fibril. If the section be
taken at an angle of about 30°, these bodies appear elongated and somewhat spindle-
shaped ; but I have seen no such obvious longitudinal fibres as in Corynactis. I am
therefore of opinion that Corallimorphus possesses longitudinal muscles, but that they
are extremely rudimentary.

The observation of ectodermal longitudinal muscles on the body-wall of Corynactis
is cn exceptionally teresting discovery. Among all Anthozoa, we know of a similar
condition in Cerianthus alone, and, as | may here mention, anticipating future
investigation, in Arachnactis, a genus very closely allied to Cerianthus: while in
the typical Anthozoa the ectodermal musculature is confined to the tentacles, the oral
disc, and the stomatodeeum. On the other hand, all Hydroids in the hydra-form (ze.
Hydroid-polypes and Scyphostomze) possess ectodermal longitudinal muscles of the
body-wall, which are prolonged directly into the tentacles and oral dise (peristome).
We have here, throughout the whole body, circular muscles on the endodermal side, and
longitudinal, z.¢c. radial, on the ectodermal.

On the ground of previous researches on the sexual organs, I have published the
view, since defended by Gotte, that the Scyphomeduse are ancestral forms of the

REPORT ON THE ACTINIARIA. 13

Anthozoa, the development of radial (mesenterial) folds which commences in the
former being further advanced in the latter. In this case the ectodermal longitudinal
musculature of Corynactis and the Ceriantha would be, as it were, heirlooms from the
Scyphostome. Both genera would thus retain an ancestral character no longer to be
found elsewhere among Anthozoa, with which would agree that both genera must on
other grounds be placed near to the original ancestor of the group. Of all Hexactinize,
the Corallimorphidee are, next to the Halcampe, the most primitive; the Cerianthidee
again must be derived from the extremely primitive Edwardsiee.

Family 2, ANTHEOMORPHIDs, Hertwig.
Genus Jlyanthopsis, n. gen.

Antheomorphidee with the tentacles in several rows; body-wall smooth; body
goblet-shaped, broadening upwards from the small pedal dise to the broad oral dise.

Tlyanthopsis longifilis,* n. sp. (Pl. IL. fig. 2).

Tentacles very long, pointed, with an obyious terminal pore, ranged in four circlets,
increasing in leneth from the centre outwards.

Habitat.—Reef of the Bermudas, June 1873. One specimen.

Dimensions.—Diameter of base, 4 cm., of oral disc, 7 em. ; height, 3°5 em.

The single specimen, which was well preserved but strongly contracted, in its
shape occupies a middle position between Azptasia and Anemonia. The base is
relatively small, the body not very high, but broadening out conically towards the
mouth. The body-wall being raised in goblet shape over the edge of the oral disc, the
animal possesses a “collar” in the sense of Angelo Andres, and consequently, owing
to the absence of cinclides and acontia, must be reckoned near the Ilyanthide. From
these it differs in the presence of a well-developed pedal disc, by which it undoubtedly
attaches itself to rocks.

The thin body-wall is smooth, except for transverse wrinkles due to the strong
contraction of the mesenteries. No sphincter is present. The circular muscle-lamella
is, in all parts of the body-wall equally, pleated into muscular laminz, which are low,
and either not at all or only slightly arborescent.

The tentacles are very numerous, and are arranged in four rows, the oral dise being
free from them in the immediate neighbourhood of the mouth. Since I counted but
160, not all the tentacles of the sixth order can as yet have been developed. The
longest of them were some 4 cm. in length, and 0°5 em. broad at the base ; the shehtly
truncated tip possessed a small pore. In studying the ectodermal muscle-lamelle,
peculiarities presented themselves which suggested the longitudinal muscles on the

outer surface of the body-wall in Cemanthus. The muscular pleats are generally

‘14 THE VOYAGE OF H.M.S. CHALLENGER.

slightly arborescent, as is shown in Pl. IIL. fig. 2, and arranged close to one another
like the leaves of a book. At the free edge of the pleat the musculature is
interrupted, since here the fibres of the mesoglcea, which serve as foundation: for
the muscle-pleat, radiate into the epithelium. For some distance they are united
in a bundle; they then part, and each fibre individually tends in the direction of the
epithelial surface. The nerve-fibre layer is consequently pierced by fine fibrils, arranged
parallel to and at equal distances from one another. I would have gladly determined
how far the connective tissue fibres reach, and whether they are connected with andi-
vidual epithelial cells or not; but in thin sections I could only follow them into the
dim granular striated layer of epithelial cells, im which they were no longer distin-
guishable from other fibres. Attempts to exhibit the isolated fibres by brushing and
agitating thin sections, or by maceration in alkali, yielded no result ; and staining with
picrocarmine was also unsuccessful. The latter generally stains the mesoglceal struc-
tures of a deep red, and is therefore peculiarly adapted for exhibiting the mesogloeal
lamina which carries the muscles, but it refuses to differentiate the fibrils. The red
tint is therefore only seen to extend so far as is expressed in the figure by shading ;
the fibrils probably do not stain, but only the cement substance uniting them. The
condition here described may be followed on to the oral disc, inasmuch as the sup-
porting laminee of the muscle pleats here also run out in fibres, and the individual
fibres radiate to the epithelium. I have only further to remark that radial furrows,
shallow and slightly expressed, run from the edge of the oral opening towards the
tentacles.

The stomatodzeum, in the only specimen which I could examine, was evaginated,
and consequently so tightly stretched that even the siphonoglyphes were almost
smoothed out, and hardly recognisable.

The mesenteries agree in number with the tentacles; all reach the stomatodzeum,
and bear generative organs. The younger mesenteries touch the stomatodzum some-
what further back, and are in other respects less developed than the older; but their
generative organs are more voluminous than those of the first and second orders.
Stomata in the mesenteries, and acontia, I have not been able to recognise.

Family 3, Actintpm, A. Andres.
Antheada, Hertwig.
Genus, Hormathia, Gosse.

Actinize with broad diffuse endodermal sphincter; smooth thin body-wall, and
parietal spherules (7.e. marginal spherules placed on the body-wall).

REPORT ON THE ACTINIARIA. 15

Hormathia delicatula,* sp. n. (PI. IIL. figs. 1, 3, IV. fig. 9).

More than 160 tentacles; parietal spherules tentacle-like, one of the latter to
about every four tentacles.

Habitat.—(?) (Inscription on the label completely soaked away). Two specimens.

Dimensions.—Diameter of the nearly spherical body, 2°5-3-0 em.

Gosse has conferred the name of Hormathia margarithe on an Actinian brought
up by the line of a deep-sea fishing-boat. Having obtained but one specimen, and that
not till some time after death, he could give but an incomplete description ; the most
important point of which is that on the delicate body-wall, at some distance from its upper
edge, are placed prominences resembling marginal spherules, the number of which is
about ten, and is essentially less than that of the tentacles. In his monograph treating
of the Actiniz, Angelo Andres has included the animal among the doubtful genera, as
being of uncertain systematic position. It was therefore very agreeable to me to find
in the Challenger material two Actinize obviously belonging to the genus Hormathia,
by the study of which I am enabled both to justify the creation of a new genus, and
also to define accurately its systematic position.

Goth specimens were so strongly contracted as to resemble an apple in shape.
The upper part of the body-wall, the pedal dise and the mouth being entirely drawn
in, and the latter covered over, one saw at first only the lower part of the body-wall,
the smooth surface of which was so little characteristic that I came near to ranking the
animal among the undeterminable forms. Only after dividing a specimen longitudinally
did the cirelet of parietal spherules come into view, their position being characteristic
of the genus Hormathia.

The pedal dise is strongly constricted and pleated by the violent contraction.
The body-wall is exceptionally delicate, so that the septa are plainly visible through it,
and is quite smooth. By a circular fold, which recalls to mind the boundary between
body-wall and oral disc, and marks the limit of retraction in a withdrawn specimen, is
bounded a separate invaginable region of the body-wall; close up to this fold, and on
the side nearest to the oral disc, is placed a circlet of 42 knobs, which are hollow and
beset with nematocysts, and which therefore recall the structure of the marginal vesicles
or “bourses marginales” (Pl. LV. fig. 9). They are of different sizes, the largest

generally longer than the marginal spherules; and are curved in a digitate manner at
the end, so as to present some resemblance to tentacles. The number of tentacles and
mesenteries being about 160, the parietal spherules, as I term these structures, are not
placed, like the marginal spherules, one on each inter- and intra-mesenterial chamber ;
but there is one spherule to about every four chambers, with one of which it is
always in communication, leaving the remaining two or three free.

The marked retractibility of the animal is effected by a sphincter muscle in a
definite region of the body-wall, which, commencing at some little distance from the

16 THE VOYAGE OF H.M.S. CHALLENGER.

parietal spherules, and reaching to the origin of the tentacles, extends therefore over a
fairly wide belt. Correspondingly to this broad extension, it is nowhere strongly
developed, and falls under the category of “diffuse” endodermal muscle, the lamella
being most markedly pleated in the centre. Its arrangement is very characteristic, as
a transverse section presents the appearance of numerous closely-packed acinose glands,
excavated in the mesogleea. In the more central parts—to continue the comparison—
the gland-like crypts are longer and more closely packed than in the upper and
lower parts (Pl. IJ. fig. 1).

The strongest development of muscles occurs on the ectodermal side of the disc,
where the supporting lamina rises into high plates, covered by strong fibrils and
richly arborescent. Here and there I have also noticed the plates fusing together, with
a resultant mesodermal inclusion of the muscle fibrils (Pl. Il. fig. 3). Towards the
tentacles the muscles become weaker. :

The tentacles are of a medium length, broad at the base, and drawn out to a fine
point, which is probably not provided with an opening at the tip. The siphonoglyphes
are hardly marked on the stomatodeum. To the latter, besides the mesenteries of the
first cycle, those of the second and third cyles at least are attached. Their musculature
is in no region strongly developed ; in the specimen investigated nearly ripe testicular
follicles occurred on them.

Family 4, Bunopip2,

Genus Aulactinia, Verrill.

Aulactinia,* sp. (*)

Habitat.—Simon’s Bay, Cape of Good Hope, December 1873; 10-20 fathoms.
One specimen.

Dimensions.—Height in a strongly contracted condition, 2 em. ; breadth of pedal
disc, 3 em.

In this place I will devote only a few words to a Bunodidan, of which I reserve
a detailed description till I shall have reviewed a rich supply of species of this
family which has been forwarded to me. The body-wall of the sole specimen lying
before me is thickly beset with thin-walled vesicular outgrowths, which are about
1 mm. in size, show a tendency towards arrangement into transverse and longitudinal
rows, and are so thickly set that the intermediate stouter parts of the body-wall have
a reticulate appearance. The three upper rows of these vesicles (about seventy in
number) are closely packed with nematocysts, and so take on the character of marginal
spherules ; they may be distinguished into a stalk, and a branching head like a cauli-
flower. They recall somewhat those external appendages of species of Oulactis, which

REPORT ON THE ACTINIARIA. 17

have been termed,—I do not know for what reason,—tentacles. The tentacles are
arranged in three rows, and more than 200 are present. The endodermal sphincter
is extraordinarily strongly developed, in the form of a ridge projecting into the
ccelenteron.

Family 5, Paractipa.
Genus Dysactis, Milne-Edwards.

Dysactis crassicornis, R. Hertwie.

Two additional examples of this Actinian, have reached me, dredged from a depth
of 55 fathoms at Station 313. One had died in an expanded condition, so that the
tentacles were in better preservation than in the specimens previously studied; from
this ] am enabled to determine some further characters of these organs.

In many cases terminal pores, which I was before unable to discover, were easily
recognised on a surface view; I have therefore re-investigated the older material, and
was able with some trouble to prove the existence of openings by injecting air into
them under water. ;

Further, in the well-preserved tentacles, comes strongly into view a characteristic
which I had previously figured (former Report, pl. vii. fig. 12), but had not introduced
into the text; the tentacles are longitudinally striated, so covered with longitudinal
ridges and furrows as to recall a fluted pillar; in section this is still more prominent.
At tolerably regular intervals the mesoglcea rises in high ridges (Pl. II. figs. 6, 7),
and at these pomts the mass of muscle lyimg in it is correspondingly increased.
The muscles therefore form in transverse section a continuous ring, which in the
region of the ridges of mesogleea is drawn out into cusps. At the base of an especially
strong tentacle I counted twenty-two longitudinal ridges, of which, however, some only
reach to the tip.

Family 6, Lironemip®, R. Hertwig.
Genus Liponema, R. Hertwig.

Liponemidze with weak endodermal sphincter; the body-wall marked by longi-
tudinal furrows, without marginal spherules ; stomidia very numerous.

Inponema multiporum, R. Hertwig (Pl. I. fig. 18, Pl. IT. fig. 4).

Stomidia, several hundreds in number, distributed in several cycles, and scattered
over the whole oral disc; body apparently cup-shaped, broadening out from the small
pedal dise upwards to the wide oral disc.

Habitat.—(a) Station 305, January 1, 1876; 120 fathoms. One specimen.

(6) Station 147, December 3, 1873; 1600 fathoms. One specimen.

(ZOOL. OHALL, EXP.—PART LXx111.—1888.) Dddd 3

18 THE VOYAGE OF H.MS. CHALLENGER.

Among the Actiniz with degenerate tentacles, I described in my former Challenger
Report a new species, in which the extent of retrogression of the tentacles can be
recognised in a degree attained by no other form. I was compelled to dispense with a
detailed description of its structure, since the only specimen at my disposal was on
the one hand much mangled, and on the other rendered so brittle by preservation in
chromic acid that it could not be methodically investigated. I am glad to be in a
position to fill up the deficiency by means of two specimens found in the supplementary
material, both well preserved, although considerably altered in shape by violent con-
traction. In both cases, as in the example previously described, the stomatodzeum is
so much evaginated as to take the place usually occupied by the oral disc, the latter
falling outwards from this point like a body-wall (PL I. fig. 13). On the other hand,
pedal dise and body-wall are alike deeply retracted on the lower side. The body-wall
forms a cup like the shell of a Patella, the pedal dise projecting into the cup somewhat
like the body of the Patella. In so marked a de-formation, dimensions can with
difficulty be given, and can serve only for approximate orientation. In the larger of
the two specimens (from 120 fathoms at Station 305), the pedal disc had a diameter
of about 2 cm., the distance between the edge of the oral disc and the mouth reached
2°5 em.; the length of the stomatodzeum was at most places 1°5 cm., and at the
siphonoglyphes more than 2 cm. ‘The corresponding dimensions of the smaller
example (Station 147; depth, 1600 fath.) are essentially less,—diameter of pedal dise,
0:07 cm. ; radius of oral disc, 1°2 em.; length of the stomatodeeum, 1°0 em. From the
nature of the contraction may be inferred that in both cases the dimensions of oral
disc and stomatodzeum are excessive, as the result of evagination, while those of the
pedal dise are too small.

On the pedal disc are about 160 radial furrows, of which, however, only a
proportion reach the centre, the rest dying out sooner or later. ‘ihe ridges between
the furrows are somewhat toothed, in the manner formerly described by me as occurring
in Polystomidium and Polysiphonia. In the centre of the pedal disc les a pit about
the size of a pin’s head, which cannot be proved to be an opening.

On the exterior of the body-wall also, similar ridges, alternating with furrows,
run longitudinally from pedal to oral disc ; their number is ereater, being close on 400 ;
they differ in size, some few of less considerable development rising between every two
of the stronger ridges. At the edge of the oral disc they all pass into a strong circular
ridge, which forms the sharp boundary between body-wall and oral disc.

The pedal disc and body-wall possess on their inner surfaces the circular muscle-
fibre layer occurring in all Actiniz ; on the body-wall this is strongly pleated, and the
more so, the nearer we approach to the upper edge. In the immediate neighbourhood
of the edge the pleating is so marked that one may term it a sphincter; it causes here
the circular ridge mentioned above as occurring at the upper edge of the body-wall

REPORT ON THE ACTINIARIA. 19

(Pl. IL fig. 4). This circular ridge appears in transverse section as a pushing out of
the body-wall, the circular muscle exhibiting a very different structure in the different
regions. At the base of the organ the pleating of the muscle-lamella is insignificant,
indeed weaker than at other points of the body-wall, but at both edges of the
evagination it is exceptionally strong, and more especially so at the boundary of the
oral disc. When the section comes to the actual spot on which one of the stomidia
is set, the inner sphincter—as we call the nearest muscular pleating—is beautifully
recognisable as a ridge projecting inwards, into the axis of which protrudes a mesogloeal
ingrowth. From this axial ingrowth are given off on both sides richly branching
mesogleeal lamellze, clothed by powerful muscle-fibres in transverse section. At the
remaining points, where the oral dise presents no stomidia, the sphincter is less clearly
bounded, and resembles more the outer sphincter, which is essentially nothing but an
approximation of muscular folds at two closely-adjacent points.

Relatively to the size of the animal, both sphincters are weak; a consequence of
this is the fact that they have not drawn up the body-wall over the mouth disc, but
that stomatodzeum and oral disc have rather been pressed outwards.

The oral disc recalls in appearance a toadstool, having a faintly flesh-coloured
surface, covered by whitish, slightly elevated spots. These spots are the stomidia or
tentacles, which are distributed nearly up to the mouth, leaving but a narrow strip
free. Between the stomidia the radial furrows run in undulating les. Their number
is difficult to determine, but may amount to about 400.

The stomidia are openings in the oral disc, surrounded by a slightly developed
ridge, and projecting a little above the surface ; roughly speaking, they are distributed
uniformly over the oral disc, or allow only of a vague distinction into several zones.
Of these zones one is peripheral, set close to the edge of the oral disc; one is
central, not far from the oral opening ; and two intermediate zones are placed between
them. The openings increase in size from without towards the centre, and at the same
time undergo an alteration of shape; in the peripheral zone they are like radially-set
slits, with a long axis of 0°7-1°5 mm. ; in the intermediate zones they are circular,
with a diameter of 1-2 mm.; and in the central they again form slits of 2°0-2°5 mm.
in the longer diameter, but are here placed at right angles to the radii.

The structure of the stomidia can best be exhibited by figures of transverse
sections. Hach stomidium completely occupies the intermediate space between two
neighbouring mesenteries, and forms a tube, opening peripherally by a wide mouth.
The walls of the tube appear in section to be direct continuations of the adjacent septa ;
morphologically their lower part is to be regarded as oral disc, their upper part as
rudimentary tentacle; accordingly, they exhibit below the numerous muscular pleatings
which at other points cause the radial ridges on the oral dise, while above these pleat-

ings are absent. A remarkable structure is a small cireular fold projecting below into

20 THE VOYAGE OF H.M.S. CHALLENGER.

the lumen of the tube, and constricting it like a diaphragm. This doubtless serves to
close the tube, since it is covered by a marked layer of muscle fibres, running circularly
round the opening.

Where no stomidium is placed, the oral disc exhibits on its ectodermal side a
thick layer of radial muscle fibres, arranged in simple lamelle, which, at most, branch
but once. The lamellee being higher midway between two mesenteries than elsewhere,
the radial ridge-like thickenings of the oral dise are the result.

With reference to the relations between the stomidia and the inter- and intra-
mesenterial chambers, in my former publication I expressed the opinion that a
intra-mesenterial chamber might carry more than one stomidium, Liponema thus
approximating to the Corallimorphide ; an opinion which I can now designate as
erroneous, on the ground of more accurate investigation. Hach intra-mesenterial
chamber possesses but one stomidium, which is the more closely approximated to the
centre of the oral disc, in proportion as its adjacent septa are of older formation.

The stomatodzeum is brownish-violet in tint, and 2 em. long; on it are placed
the marked siphonoglyphes, about 1°5 em. in breadth, projecting considerably at the
lower part of the tube, where they pass into the boat-shaped stomatodzeal cone. They
are bounded by two stout, transversely pleated, lips. Further, the stomatodzum is
marked by about 200 longitudinal folds, of which some 80, by their stronger build,
deserve the name of primary folds. Between every two primary folds lie, in many
cases, two secondary folds; but at some places one only may occur, or they may be
entirely wanting.

The number of mesenteries was determined by the method before mentioned, that of
cutting out a sextant of the animal and studying it closely anatomically. I found six
eycles, in all therefore 192 pairs of mesenteries. In the first four cycles all the
mesenteries reach the stomatodzeum, though those of the first two cycles only are
attached to it for its whole leneth ; they all possess wide openings near the edge of
the lip (internal mesenterial stomata), and their muscular nature so far preponderates
that only those of the fourth cycle carry generative organs. In this respect these
mesenteries of the fourth cycle agree with those of the fifth and sixth, but the muscular
development of the latter is considerably inferior to that of the others. The mesenteries
of the sixth cycle are practically nothing else than small genital folds, projecting but
slightly into the ccelenteron, and never provided with mesenterial filaments.

Of the generative organs I found exclusively the testicular follicles, containing
spermatozoa in parts ripe, in parts only commencing to develop.

It is possible that in this animal a further erowth takes place, with the formation
of new mesenteries; this I infer from the great number of stomidia. In the sextant
investigated they amounted to about 120, or to 700-800 for the whole animal. Since
only about 196 intra- and inter-mesenterial chambers are present, and each of the

REPORT ON THE ACTINIARIA, 21

former possesses but one stomidium, the latter apparently must be provided each with
two or three,—an inference confirmed by dissection. Since it is the rule amongst
Actinize that the development of tentacles precedes that of mesenteries, we can also
infer in this instance from the plentiful development of stomidia, an imminent addition
to the mesenteries.

Genus Aulorchis, n. gen.

Liponemide, whose generative organs are modified into a tube perforating the oral
to} to} P to}
lip; gonidial grooves on both sides drawn out into a long ear-like cone.

Aulorchis paradoxa,* sp. n. (Pl. I. figs. 9,10; Pl. IIL. figs. 2-6 ; Pl. IV. figs. 1-6).

Stomidia arranged in two alternating rows, approximately sixty in number.

Habitat.—Station 299, December 14; 1875; lat. 33° 31’ S, long. 74° 43’ W.;
depth, 2160 fathoms. One specimen.

Dimensions.—Height, 4 em. ; greatest breadth (measured about half-way up the
animal), 3 em.

Among the accessory Challenger Actinize occurs this form, of great interest as
enlarging by a new genus and new species the group of forms devoid of tentacles.
Unluckily, I have had but the one solitary specimen for study, and even this was badly
preserved, and had apparently suffered much from the dredge. It was exceedingly
contracted ; oral and pedal discs were externally unrecognisable, smce both ends of the
body-wall were closely drawn together. As a natural result of this condition, | have
not been able to clear up many important points of the organisation so well as I could
have wished. For investigation, I divided the specimen longitudinally, and dissected a
sextant with scalpel and scissors, arriving at the following results.

The strongly contracted, and therefore small, pedal disc exhibits indistinct radial
brownish wrinkles and furrows, and is sharply marked off from the body-wall, the
surface of which is smooth. The latter is of a whitish tint, and of inconsiderable thick-
ness, only here and there becoming more powerful, but never forming hooks or papillee.
Its consistence is less firm than that of cartilage, but considerably more so than that of
Medusan mesoglea. The tissue is of a fibrous nature, composed of very fine fibrils,
which are generally mterlacing and reticulate. At many points, however, they are
yavallel series, so that cords and lamelle are
formed, which, though staining brilliantly with carmine, are not sharply differentiated

thicker and bound together in more

from their surroundings. These lamelle are ranged parallel to the two surfaces, and
run constantly closer to one another till a firmly united mass of fibres is formed just
below the epithelium. At other points, however, the fibres are more loosely plaited, so
that spaces remain between them, which are filled up by homogeneous mesogloea
In some places I detected hollow spaces in the tissue, which were devoid of an epithelial

22 THE VOYAGE OF H.M.S. CHALLENGER.

lining. They occur also in the mesenteries, the stomatodzeum, and the oral disc, and
may perhaps be caused by inadequate preservation.

In the upper part of the body-wall lies, close under the endoderm, a mesodermal
sphincter muscle, its length amounting to about 1 cm., while its greatest breadth
reaches 5 mm. at the upper end, from which point it gradually thins out. It is of
interest from several points of view ; in the first place, the muscle-fibres are abnormally
strong; consequently the muscle-bundles are formed of but few elements, and consist
in many cases only of two to four. Again, the individual tracts are so far from running
parallel to one another that in a longitudinal section many bundles are cut absolutely
transversely, others obliquely, and others for long stretches superficially; thus an —
appearance of extremely entangled fibres is presented (PI. III. fig. 3a). .

Finally, Auvlorchis affords proof of the endodermal origin of the mesogloeal muscle-
bundles, as we find on the endodermal side every transition from the mesoglceal bundles
to the endodermal layer of circular fibres ; in one place the bundles he close under the
fibrous layer, at another are in communication with it by a broader or narrower band ;
finally, we find sheht infoldings of the endodermal muscle-layer (Pl. HI. fig. 3b).

The stomidia lie in two alternating rows between the edges of the mouth and of the
body-wall, somewhat nearer to the former ; they are about sixty-four in number (thirty-
two between two pairs of directive mesenteries). The stomidia of the inner row are
larger than those of the outer; the smallness of the latter producing the impression,
that they have just been formed, and that a further increase of their number is taking
place. Radial ridges on the oral disc start at the edge of the body-wall and run up
to the individual stomidia.

Transverse sections through the oral dise exhibit a strong mesodermal musculature ;
this is interrupted along the lines of mesenterial insertion, and falls therefore into
marked radial bands which cause the radial ridges of the oral disc. The individual
muscle-bundles contain a few strong fibres, and are so separated from one another by
mesoglceal sheaths, stout or slight, that the lines of mesogloea form dendritic figures
springing now from the ectodermal, now from the endodermal side (Pl. III. fig. 2).

The mesogloea sends into the ectoderm arborescent supporting offsets, on which
to my surprise I was unable to find muscle-fibres. It seems as if in Awlorchis
the ectodermal musculature is completely wanting; I would gladly have expressed
something definite on this point, had the histological condition of the animal not
been so indifferent; but the ectoderm, where present, was unfortunately reduced to a
detritus, in which no structure could be detected.

In order to demonstrate how the stomidia penetrate the thickness of the oral disc,
I have drawn two figures, in the one of which (PI. III. fig. 4) are seen the openings of
the tube to the exterior and to the cclenteron; in the other (fig. 5) the section passes
through a spot where the stomidial tube is closed at both ends, whence it may be

REPORT ON THE ACTINIARIA. 23°

inferred that its diameter is here considerably greater than that of the two openings.
The radial mesodermal muscle-fibres pass into its walls with a longitudinal trend.

On the stomatodeum are placed the two siphonoglyphes, which are of a very
characteristic appearance, as being more powerfully developed than in any Actinia
which I have as yet seen; each projects over the mouth edge and upwards with
two long ear-shaped cones. The groove itself is correspondingly deep and broad,
pleated, and of a cartilaginous consistence. Between the two siphonoglyphes run
on each side about ten strongly-marked longitudinal ridges, terminating in rounded
knobs on the lip.

In investigating the mesenteries, I could at least prove their arrangement in pairs,
but could not convince myself that the Hexactinian symmetry was carried out. Neither
by microscopic preparations of a sector, nor by dissection of individual mesenteries, could
I arrive at a definite law of arrangement; this point therefore requires investigation.

The mesenteries dissected bore no generative organs; these appeared to me to be
confined entirely to one mesentery, and to possess a tubular structure unparalleled in the
whole class of Anthozoa, a fact which decided me to choose for the genus the name
Aulorchis. Hven before dissection it had struck me that at a spot on the edge of the
lip, and by a pore specially present for the purpose, was the opening of a cylindrical
organ ; this organ had obviously once been longer, as at its end a fracture was clearly
recognisable. By splitting up the opening and the adjacent stomatodzeum, the organ,
which I will term in future, for reasons to be mentioned, the genital tube, could be
clearly followed into an inter-mesenterial chamber (Pl. I. fig. 9). It meets one of the
complete mesenteries, lies at this point embedded in the tangle of mesenterial coils,
and, as appeared later from sections, ends at the mesentery in a horseshoe-shaped curve.
The curved portion was firmly united with the mesentery. Transverse sections yielded
further conclusions relative to its structure ; but, unfertunately, owing to bad preserva-
tion, no exhaustive account of this is possible. For instance, I. have not been so
fortunate as to-determine how far the structure of the genital tube can be referred to
that of the ordinary Actinian ovary (Pl. LV. figs. 1-6).

The genital tube is superficially clothed by epithelium, which is limited exter-
nally by a border resembling a cuticle, but perhaps produced only by mucous
secretion ; then follows the mesogloea with the ova embedded in it; internal to these
lies a cavity, more or less spacious according to the mass of the ova. The mesogleea is
divided by a narrow granular layer into inner and outer zones, which here and
there, by failure of the intermediate layer, join together. The outer zone is narrow,
and exhibits what appear to me to be circular muscele-fibres referable to the
epithelium, which in longitudinal sections through the organ (fig. 3) resemble narrow
lamine placed close together. The state of preservation was inadequate for the
determination of the histological character of the granular median layer ; in transverse

24 THE VOYAGE OF H.M.S. CHALLENGER.

section it gave the impression of a disintegrated epithelium, in longitudinal, it resembled
a loose connective-tissue. This layer is important as containing small, spherical, deeply-
staining cells, which I regard as young ova. The masses of ova are in parts so con-
siderable as to present the appearance of mosaic, if part of the wall of the genital tube
be cut out, stamed, and viewed from the surface (fig. 2). Next comes the second zone
of mesogloea, the layer of most importance, since ova of various sizes are embedded in
it. Some of these are certainly connected with the superficial epithelium; this con-
dition, I believe, occurs in all ova, and is effected by the fibre-arrangement characteristic
of Actinian ovaries, of which remnants only could here be detected (fig. 1).

The lumen of the tube was mostly filled by a cell-detritus, but at some points was
lined by a clearly ciliated epithelium (figs. 4, 6); I reckon therefore the lumen as a
ciated canal, serving for the transit of ripe ova and perhaps also of embryos, and
opening to the exterior outside the oral dise. The ripe ova appear to lie on the floor of
the tube, since here I found compact masses of a finely granular substance, appearing
to me to resemble ova.

As to the distribution of the ova in the genital tube, I have the following facts to
add: the smaller ovules are met with in sections through the upper part of the tube,
forming a ring, on the one side of which the generative elements are more closely
packed than on the other. This lop-sided development of sexual cells is expressed
more obviously lower down, where on one side of the section they are entirely
wanting, the ripening ova being only present in the other half.

With regard to the connection of the genital tube with the body of the Actinia, I
have arrived at no positive results. At the pore, the organ merely perforates the oral
lip without being attached to it, as I can assert both from macroscopic dissection and
transverse sections ; while at the lower end I have discovered no intimate connection
with the mesentery ; what I saw there was only an epithelial adhesion, not a transition
from the mesoglcea of the mesentery into that of the genital tube. Such a connection,
however, must certainly occur at this point.

From my description it may be recognised that Aulorchis is one of the most
interesting Actiniz, and that it would be very desirable that a richer material of it
should be acquired by fresh Deep Sea investigations.

Family 7, PHELLID.

Genus Phellia, Gosse.

Phellia spinifera, n. sp. (Pl. II. figs. 8, 9).

The bark-hke part of the body-wall is bedecked with thorn-like pointed knobs,
distributed more richly on the upper than on the lower parts.

REPORT ON THE ACTINIARIA. 25

Habitat.—(a) Station 311, January 11, 1876; depth, 245 fathoms. Three speci-
mens. (b) Station 320, July 14, 1876; depth, 600 fathoms. One specimen.

Dimensions.—Length of the contracted animal, 2°5-3'2 em. ; breadth, 2°5-3°5.

At first I was inclined to refer the three specimens from Station 311, which were
seated on Molluscan shells, and the single specimen from Station 320, to Phellia
pectinata ; for they possessed the characteristic appearance of the body-wall, resembling
the tunic of Cynthia, while the upper indrawn part of the wall presented the ridged
surface which has been already figured. I was, however, persuaded to a closer study
by observing some points of divergence in the structure of the peripheral region of
the body-wall. The transverse and longitudinal ridges are wanting, instead of which
occur knobs, resembling those of Cereus spinosus; these start with a broad base, and
terminate in a slichtly truncated tip ; they are distinguished from the body-wall, which
is nearly white, by a brownish tint, and may amount to 200 in number, distributed
more abundantly on the upper than on the lower regions of the body-wall. The upper
knobs are as much as 0°25 cm. long, and are more strongly developed than the rest ;
they become gradually smaller below, and finally appear only as fine grains. Such an
arrangement of the knobs in series, as exists in Bunodes, does not occur.

The mesogloea of the body-wall is so extraordinarily stiff as to cause some trouble,
before good sections of the sphincter can be effected. The latter is essentially constituted
as in Phellia pectinata, so that reference to the description given under that species is
sufficient. In position it is considerably nearer to the ectoderm than to the endoderm.

The oral dise and stomatodeeum are of a brownish violet (partially altered in the
alcohol), the former lighter in tint than the latter. On the stomatodeum the two
siphonoglyphes, which are not pigmented, and are consequently of a whitish yellow,
strike the eye on opening the animal as two broad, sharply-marked, stripes. They are
only distinguished from their surroundings by this difference of colour, since they are
flush with the rest of the stomatodzeum. They are crossed by transverse folds regularly
arranged, which are continuous over the rest of the stomatodeum. Further, the
stomatodzeal cone is hardly expressed at all, and the longitudinal furrows, which so
commonly run parallel to the siphonoglyphes between the mesenterial insertions, are
wanting.

For the characterisation of the species the condition of the musculature of the oral
disc is also of importance ; it exhibits two methods of formation. In the one case it is
purely ectodermal and markedly pleated, the pleats running parallel to one another,
and only slightly arborescent (PI. Il. fig. 9). At other points (fig. 8) the arborescence
is very considerable, the individual branches anastomosing with one another; the
musculature thus becomes partly mesogloeal, and a very obvious and stout muscle-
layer arises. ‘The muscle-fibres are here, as in the sphincter and the powerfully
developed laminze of the retractors, of exceptional thickness.

(ZOOL. CHALL, EXP.—PART LXx1I1L—1888. ) Dddd 4

26 THE VOYAGE OF H.M.S. CHALLENGER.

All the mesenteries are unusually muscular; the primary mesenteries are sterile,
and reach to the stomatodeeum, while the secondaries are incomplete but bear generative
organs. I observed a few acontia ; cinclides, on the other hand, are wanting.

In conclusion, I might refer to the possibility that Phellia spinifera may be only a
variety of Phellia pectinata. In the sole example from Station 320, the spinose knobs
were developed only on the upper part of the bark-like body-wall, and even here not
abundantly ; so that its appearance is intermediate between the characters of Phellia
pectinata and Phellia spinifera. In spite of this, I have retained the separation of the
two species, because the musculature of the oral disc of Phellia pectinata does not yield,
on further study, the characteristic appearance drawn in Pl. Il. fig. 8. In this respect,
the transitional form agrees with the type of Phellia spinifera.

Family 8, AmpatantHip”, R. Hertwig.
Genus Amphianthus, R. Hertwig.

Amphianthus ornatum,* n. sp. (Pl. I. fig. 8).

Body-wall beset with numerous (about 26) longitudinal rows of papillee ; the latter
are for the most part recognisable by the naked eye, and are not arranged in transverse
series.

Habitat.—(a) Station 56, May 29, 1873; depth, 1075 fathoms. One specimen.
(b) Station 241, June 23, 1875; depth, 2300 fathoms. Three specimens. (c) Station
244, June 28, 1875; depth, 2900 fathoms. One specimen.

Dimensions.—Height, 0°2-0°5 em. ; length of the pedal disc, 0°3-2 cm.

The five specimens which I describe under the name of Amphicnthus ornatum
have on the one hand many points of resemblance to Amphianthus bathybium, on the
other to Cylista (Bunodes) minuta; with the latter they agree in the form of the
papillee, but differ from it in the divergent shape of the body and in characteristics of the
family Amphianthidee, as also in the absence of acontia; with the former, on the other
hand, they tally in general habits, but exhibit a divergent condition of the body-wall.
Amphianthus bathybium possesses small papille, recognisable only with the aid of a
lens, and arranged in small groups, with a tendency to transverse series. In Amphian-
thus ornatum, however, they are large, and comparatively isolated in position; they
form about 20-30 longitudinal rows, which die out sooner or later at some distance
from the lower end of the body-wall. The papillee are not all of one size; indeed, it
even happens that rows of larger and smaller alternate.

In the very young specimen from Station 244, only twelve rows of papille were
present, all most recularly distributed on the periphery of the body, and all of essentially
similar structure, since both in the size and number of the papille the individual

REPORT ON THE ACTINIARIA. 27

rows were closely identical. The number of the papille varies between six and seven.
From this observation it may be inferred that with increasing growth an addition to the
rows of papille occurs, proportional to the additions to the pairs of mesenteries. In
connection with this is the fact that the rows of papilla correspond to the intra-
mesenterial chambers.

Two examples of the present species were taken from the same locality as the one
example of Amphianthus bathybium, Station 241. This renders it necessary to weigh
the possibility that the differences which have been made of importance, are perhaps
only of secondary significance, and that all the specimens may be referred to one species.
Owing to the limited material, the question could not well be decided.

From the minuteness of the organism, anatomical investigation could only be
effected by means of longitudinal and transverse sections; to this purpose I devoted
two complete examples, the one from Station 241, the other from Station 244, besides
quadrants of specimens from Stations 241 and 56. It resulted that the papille were
proved to be solid outgrowths of the body-wall, and, like it, consist of an extremely
fibrous mesogloea. The fibres are generally interlacing, as is for the most part normal
among Actinie, so that the tissue appears finely granular; they also here and there
show a tendency to arrangement into bundles. In transverse sections, therefore, a
reticulate figuring appears round the endodermal lining; this can be rendered clearer
by staining, when it appears that small branches of the fibrils cross the course of the
rest of the fibrils in a longitudinal direction. Similarly, one sees numerous radial fibres
also in the peripheral parts of the body-wall, and a corresponding radial striation is
thus produced.

The sphincter is completely embedded in the connective-tissue of the body-wall,
and consists of small mesogloeal muscle-bundles composed of few, but powerful, fibres.
In some places only two or three fibres are united in a bundle, or a single fibre even
may run in the connective-tissue. The individual bundles are enclosed in such numbers
in the mesoglcea as to be separated from the two epithelial surfaces by only a narrow
layer. In transverse section, the muscle in most cases forms a club-shaped figure, being
of weak development below and broadening out strongly upwards; this merease in
breadth is so considerable that the whole upper end of the body-wall is strongly thickened.
Even in the youngest specimens the sphincter was completely formed, and inclosed in
the mesogloea. As it is separated from the endodermal circular musculature by the
insertion of a layer of connective-tissue, it seems that in the course of further growth
the bundles can only increase by division of the bundles of fibrils.

The musculature of the oral dise and tentacles is purely ectodermal, but very
markedly pleated. The number of tentacles corresponds to the number of mesenteries,
and this is different in the different individuals investigated. In the youngest specimen
from Station 244, the two first cycles were already formed, and of the third traces

i

28 THE VOYAGE OF H.M.S. CHALLENGER.

seemed to me to be recognisable in that inter-mesenterial chamber which is equidistant
from the ends of the transverse and sagittal axes: With this agreed the distribution
of the tentacles ; they were about equal in number to the mesenteries, and amounted to
more than twenty-four, z.e. the first three cycles and some tentacles of the fourth were
present, and those of the fourth cycle lay at pots corresponding to the inter-mesenterial
chambers above mentioned. In the other specimens, between forty and forty-eight
mesenteries were present in the whole circuit of the body-wall, so that here the fourth
cycle was nearly complete. The number of mesenteries was still greater in the angle
between pedal disc and body-wall, the pot where mesenterial erowth is first recognisable
in Actinie. This part beige very transparent, the number could be determined with
approximate accuracy, and reached to nearly a hundred.

From the fact that im places the mesenteries were discontinuous in transverse
section, I infer the existence of mesenterial stomata. On the other hand, I could not
demonstrate acontia ; generative organs (testicular follicles) I saw only in one specimen,
and, as they were at all points adherent to the mesenteries, I could not determine
whether they were present on all mesenteries, or were wanting on the primaries.

Directive septa and siphonoglyphes were distineuishable on all four specimens, but
only in two examples, namely the smallest and largest, could I accurately determine the
position which agrees with the typical attitude of Amphianthide. The sagittal axis
of this Actinian is at right angles to the long axis of the body on which it has fixed
itself, or, in other words, the lengthening of the animal takes place in the direction of
the transverse axis. ;

With tolerable certainty I can at length assert that only the mesenteries of the
first order are complete.

With the sole example of Amphianthus ornatum from Station 56 was associated
another Amphianthidan, externally so little characterised, that I decided not to describe
it. It possessed a smooth body-wall, which was pleated only as the result of contraction ;
the pedal disc was 1°5 cm. long, and the total height 0-4 em.

Family 9, IbyanTHID&, Gosse.
Genus, Halcampa, Gosse.

Halcampa kerguelensis,* n. sp. (Pl. I. fig. 5).

Tentacles devoid of longitudinal furrows, pointed ; circular muscles of the body-
wall weak; retractor muscles of the mesenteries powerfully formed.

Fabitat.—(a) Station 149 a, Betsy Cove, Kerguelen, January 10, 1874; depth,
25 fathoms. Ten specimens. (b) The same locality ; 25-30 fathoms. One specimen.
(c) Station 149, off London River, Kerguelen, January 29, 1874; 110 fathoms.

REPORT ON THE ACTINIARIA. 29

Three specimens. (d) Station 149 J, off Cumberland Bay, January 29, 1874; 105
fathoms. Three specimens. (e) Station 149 u, off Cumberland Bay ; January 29, 1874 ;
127 fathoms. One specimen.

Dimensions.—Leneth, 1°5-2°5 em. ; greatest breadth, 0°7-1°0 cm.

On an external inspection I was inclined to identify this species with Halcampa
clavus, which it strongly resembles. The preparation of tranverse sections, however,
caused me to abandon this view, and a more accurate study produced a number of
points of divergence, which I will briefly enumerate.

1. The tentacles, though twelve are also present in this species, are essentially
longer than in the other, and end in a fine point. The two longitudinal furrows which
occur on them in Halcampa clavus, can be recognised neither superficially nor in
transverse section.

2. The circular muscles of the body-wall are weakly developed ; the laminze which
they form are not so striking as in Halcampa clavus; and they project into the
ceelenteron at greater distances from each other. The sphincter-like enlargement of
the circular muscle-layer is wanting.

3. On the stomatodzeum the marked projections, which designate the insertions of
the mesenteries, are absent.

4. In the mesenteries the muscle-lamina is pleated in a most complicated manner,
so that in transverse section it exhibits an abundant arborescence. The centre of the
muscle forms a sort of tree (PI. Il. fiz. 5); a thin lamina starting outwards from the
mesentery, and branching like the top of a tree. This whole region is usually marked
off by an indentation from the adjacent parts, the mass of muscle being thus divided
into three sections.

Genus, Halcampella, Angelo Andres:

Ilyanthidze with six powerfully developed pairs of mesenteries, but with numerous
rudimentary mesenteries, and numerous tentacles.

Halcampella maxima,* n. sp.

Tentacles small, approximately 46; body devoid of longitudinal furrows; its
surface partly bark-like, partly somewhat incrusted ; the polyp of considerable size.

Habitat.—Station 209, Zebu, Philippine Islands, January 22, 1875 ; 100 fathoms.
Six specimens.

Dimensions.—Length, 8-15 em. ; greatest breadth, 2-3 em.; breadth at narrowest
point (near the pedal disc), 0°4-1°2 em.

In all the specimens the body is a lax thin-walled sack ; its diameter is least at the
posterior end, which is stalk-like and rounded off, but anteriorly it bellies out, contract-
ing again in the region of the oral dise. With the exception of the largest, all the

30 THE VOYAGE OF H.MS. CHALLENGER.

specimens are so contracted that tentacles, oral disc, and upper part of body-wall were all
drawn inwards together; in the largest, however, part of the tentacular crown protruded.

The surface of the body-wall is encrusted with sand-grains, so that at first sight
I was inclined to take the animal for a Sphenopus. ° The sand-grains are not, however,
embedded in the mesogloea, but adhere to the cuticle of the ectodermal epithelium, so
that they can easily be removed by scraping. At the anterior end they are more
sparse, and are practically absent on the upper third. This part of the body-wall
assumes a different appearance to the rest, being more leathery or bark-like, and
traversed by rough longitudinal furrows. The bark-like appearance is produced by
the cuticle, which is strongly developed, and of a brownish tint, resembling that of
Phellia pectinata and Tealia bunodiformis. A fairly sharp boundary marks off from
the rougher part of the body-wall a strip about 1 em. wide, which adjoins the oral
dise and wreath of tentacles, and which has a completely smooth surface. One can thus,
as in Halcampa clavus, recognise three regions of the body,—capitulum, scapus, and
physa ; but only the capitulum is marked off from the rest with any degree of sharpness.

Histologically the body-wall is composed of a strong fibrous connective-tissue.
The individual fibres are extremely fine, and are united in great numbers into tracts ;
they are not so sharply bounded, as, for example, in the connective-tissue of Verte-
brata, but, like them, have a curving course. Generally they cross one another and
interlace in every direction, and only under the endodermal surface does a longitudinal
arrangement preponderate, parallel to the endoderm. Here the. fibres stain exceedingly
deeply in picrocarmine, while at all other points fine cords alone retain the stain
after washing.

The endodermal circular muscle-layer is formed into lamellar pleats, arranged
closely like the leaves of a book, and seldom showing arborescence in section. A
muscular region specially developed for a sphincter is not present.

The tentacles are small conical stumps, measuring in the contracted condition about
0°5 em., and devoid of the two longitudinal ridges occurring in Halcampa clavus. On
the other hand, the termimal pores are obvious, and in many eases are recognisable
with the naked eye. The tentacles are arranged in several rows; their number in one
case amounted to forty-six, and was perhaps increasing, as I found several small tentacles
among the larger. The longitudinal muscle lamella is ectodermal, and but little pleated.

The oral dise is very small, and presents twelve radial ridges, produced at the -
edge of the mouth into the longitudinal ribs of the stomatodeum; the latter are
sharply-angled, with deep furrows between them. A specially differentiated siphono-
glyphe is not present. The length of the stomatodeum in the largest example
amounts to nearly 2 em. Correlated with the absence of a siphonoglyphe is that of
a stomatodzeal cone. The boundary between oral disc and stomatodzum is sharply
marked by the lip being elevated into a circular fold,

REPORT ON THE ACTINIARIA. 31

The radial muscles of the oral disc are ectodermal, and form a slightly pleated layer ;
a notable point is the presence of small bundles irregularly embedded in the mesoglea.

The number of mesenteries appears on macroscopic examination to be confined
to twelve, set at equal distances on the periphery of the stomatodeum; they are so
erouped in pairs according to the muscular distribution that one can distinguish two
pairs of directive and four pairs of intermediate mesenteries. They resemble thin
veils stretching between body-wall, oral disc, and stomatodeeum, unusually delicate, and
tearing at the slightest strain; below, they reach nearly to the posterior pole of the
body, but are here so weakly developed as to hardly project at all into the ccelenteron.

In these veil-like mesenteries are recognisable, as special thickenings, the following
organs :—1, the muscle pennons or retractors; 2, the muscles of the edge; 3, the
generative organs; 4, the digestive filaments.

The retractors are powerful swellings about 1-2 mm. wide, which are tolerably
sharply bounded, and appear as if glued to one side of the mesentery ; they commence at
the angle where oral dise and stomatodzeum are continuous, and run from this poimt in
a slight curve outwards and downwards to the boundary between the first and second
thirds of the body-wall, where they terminate, thus dying out disproportionately soon,
far sooner than even in Halcampa clavus. Transverse sections exhibit their structure
in greater detail; in the region of the muscle the supporting lamina is strongly
thickened, and is elevated, together with the muscle-layer resting on it, into lamelle
which are long, thick, and parallel to one another, but which either do not branch at
all, or only slightly. An arborescent or bushy appearance is occasionally produced by
a ridge of the mesogloeal mesenterial lamina bearing on both sides a complete series
of muscular lamelle. The sharp boundary of the muscular masses is referable to the
circumstance that on both sides the pleating of the muscular layer ceases abruptly.

The edge-muscles form a band of tendinous appearance running close along the
body-wall, and are most clearly expressed in the posterior parts of the body. Here
they constitute nearly the whole of the mesentery, and the mesenterial filament is
affixed almost directly to them.

The mesenterial filament is fairly obvious for the first two centimetres below the
stomatodeeum, and is arranged in a few coils. Afterwards it becomes finer, but is
wound into a mass of twisted loops, continuing thus for about the next four centi-
metres. The contortions then become gradually less marked, till, sooner or later, the
whole filament dies out ; in one mesentery it could be followed to within two centimetres
of the posterior pole. The first section of the filament is trilobate, possessing one
glandular and two ciliated lobes ; lower down it undergoes, as in other cases, a simplhi-
fication of structure by the dying out of the ciliated lobes.

Both the glandular and the ciliated lobes are of exceptionally strong development ;
the continuations of the mesogloeal lamina entering them broaden out in the shape

o

32 THE VOYAGE OF H.M.S. CHALLENGER.

of a wing, so that an accurately transverse section of the trilobate filament exhibits
the mesogloea in form of a cross, the arms of which are broad and wing-shaped.

The generative organs lie in the thin septum which is intercalated between the
retractor and the mesenterial filament, and were male in one specimen investigated, in
the other female. The testes are 1:5 cm. long, 0:2 cm. broad, composed of separate
follicles which are arranged in about thirteen transverse swellings. At the edge of the
organ occur small bodies, recognisable only in transverse sections, which I take to be
the first commencements of the follicles; the supporting lamina widens out, enclosing
a space in which are included roundish cells (spermatoblasts ?), fewer (five) or more
numerous according to the size of the cavity. The latter always opens towards the
epithelium by a small but obvious pore. The latter would argue, if there were any
question here of stages of development of the testis, for its derivation from endoderm ;
unfortunately, however, the mesenteries were not sufficiently well preserved for a close
histological investigation.

In the female organ the conditions were similar; the ova are irregularly scattered
in the mesentery as larger or smaller grains; those of fair size project above the surface,
while the largest of all stand out markedly beyond its plane, and are connected with
the mesentery only by means of a fine pedicle. The pedicle passes into a chorion which
surrounds the ovum on all sides, the latter being about 1 mm. in diameter. In this
condition the ovum appears to be already in segmentation.

In the mesenteries occur, finally, external stomata; they are oval, about 0°5 em.
long, and oceur rather to the outer side of the great mesenterial muscles, on a level
with the wreath of tentacles. Whether also internal mesenterial stomata exist just
below the oral lip, remains doubtful.

From the type of the true Halecampe, this Actinian diverges in exhibiting a
commencement of additional mesenterial cycles, although these are extremely weakly
developed. The accessory mesenteries are small projections, which, in the upper part
of the body alone, emerge from the angle between body-wall and oral disc; here
there occur pairs of mesenteries both of the second and third orders, readily dis-
tinguishable by difference of size. Since, as we have seen above, the number of the
tentacles also is larger than in the true Halcampe, the genus Halcampella leads up
to the remaining Ilyanthide, and through them to the true Actinie.

Haleampella, sp.* (2)

Habitat.—Shallow water; St. Vincent, Cape Verde Islands, July 1873.

To the genus Halcampella doubtless belongs another Ilyanthidan with numerous
tentacles, although too much mutilated for close investigation or systematic determina-
tion. It is to be distinguished from Halcampella maxima at once, by the absence of
incrustation on the body-wall.

REPORT ON THE ACTINIARIA. 33

If PaRacTiniaz.
Family 10, Stcyonmpa.
Genus Sicyons, R. Hertwig.

Sicyonis elongata,* n. sp.

The animal is elongated, with about 54 tentacular papille ; the genital mesenteries
project into the ccelenteron from between the oral disc and the body-wall.

Habitat.—Station 244, June 28, 1875; 2900 fathoms. One specimen.

Dimensions.—Height, 7 cm.; breadth about 3°5 cm.; diameter of the pedal
dise, 2 cm.

The sole specimen at my disposal was so strongly contracted that one could hardly
find the entrance to the oral disc. The pedal dise was also exceedingly small, due
partially, no doubt, to contraction. Had the specimen, which in other respects also
was but poorly preserved, not been so compressed in the packing, it would have had
the shape of a long sack sewn up at both ends.

The external appearance of the animal is therefore essentially different from that of
Sicyonis crassa, the body of which is flattened like a cake ; but in the ternal structure
there is considerable agreement between the two. The sphincter, the muscles of the
tentacles and oral disc, the cuticular consistence of the mesoglea, the differentiation of
muscular and genital mesenteries, the enormous folding of the siphonoglyphes, the
radial striation of the oral disc, the shape and arrangement of the tentacles, are in both
cases identical. I was therefore inclined to regard it as a new specimen of Sicyonis
crassa, had I not lighted on one distinguishing characteristic of great importance.

The genital mesenteries in Sicyonis crassa are thin lamelle, which bear only the
generative organs, and spring in the angle between pedal disc and body-wall; but in

“e

this new specimen the muscles are obvious, and are arranged in “ muscle-pennons ;”
the most noteworthy point, however, is, that the genital mesenteries belong to the
upper section of the body, lying in the angle between oral dise and body-wall, on the
former they reach as far as the oral opening, and on the latter, in the form of slight
folds, up to the pedal dise. Mesenterial filaments do not occur on them. Since the
specimens of both Sicyonis crassa and Sicyonis elongata were males, the different
position of the mesenteries cannot be due to the difference of sex.

Part of the animal was anatomically investigated with reference to the arrange-
ment of the mesenteries, and part of the body-wall, with the mesenteries in the
neighbourhood of the stomatodzeum, was utilised for transverse sections. | was able
to prove the normal arrangement of the mesenteries in pairs at some points; but at
certain spots irregularities oceur, owing to the alternation of isolated genital mesenteries-

(ZOOL. CHALL. EXP.—PART LXx111.—18838. ) Dddd 5

34 THE VOYAGE OF H.MS. CHALLENGER.

with isolated complete ones. It is probable that, here and there, the one mesentery
of a pair is formed, the other arrested. I was compelled to relinquish the determina-
tion of the number of the mesenteries, in order to spare the specimen. I counted,
however, the number of tentacular papille, amounting to fifty-three ; some of these, in
the neighbourhood of the single siphonoglyphe, were very small. I infer from this
that increase of the number of the tentacles was not yet concluded.

Ill, EpwarpDsi.
Family 11, Epwarpsip&.

Genus Hdwardsia.
Edwardsia, sp.* (2).

Habitat.—Station 168, July 8, 1874; 1100 fathoms. One specimen.

The sole example of the genus Hdwardsia which I met with in the Challenger
material, and which came from a depth of 1100 fathoms, was so strongly contracted
that the capitulum was concealed within the scapus, and in the posterior section was so
completely crushed that it was difficult to detect the rounded hinder pole.

The surface is extraordinarily rough and bark-like, probably in consequence of an
incrustation of mud on the cuticular layer; at the anterior end the entrance to the »
mouth is visible, and round it are eight radial furrows, which, owing to the indifferent
preservation, could be followed only for a short distance upon the body-wall. The
opening is slit-like; the wedge-shaped regions bounded by the furrows at the anterior
pole are dissimilar in size, and are so arranged that the broadest is at one end of the
slit, the smallest at the other, while the remaining six are symmetrically arranged right
and left. At the posterior end of the animal, only seven of these furrows, which
correspond to the mesenterial insertions, can be recognised.

I attempted to investigate the structure further by means of transverse sections,

but was reluctantly forced to the conviction that nothing remained of the mesenteries
and stomatodzeum.

lV. ZoantvHeE az.

As the result of researches instituted by G. von Koch and myself, I have in my
former Report separated from the hexamerous Actinie, the sharply marked group of the
Zoantheee, and have described as their representatives the genera Sphenopus, Zoanthus,
and Epizoanthus.

I conceived it to be eminently inappropriate that such discordance should exist
in the nomenclature of the individual species and genera of Zoanthez, a discordance

REPORT ON THE ACTINIARIA. 35

referable chiefly to the fact that the forms described had been quite insufficiently
studied, and that consequently the systematic characters had been referred to points of
secondary moment only. In this condition of affairs no alteration has been effected by
the monograph of Angelo Andres; the great abundance of forms cannot be compressed,
as he has attempted to compress them, into the three genera, Zoanthus, Palythoa, and
Sphenopus (the genera Verrillia, Bergia, and Antinedia having but a doubtful position,
so long as we possess such scanty information about them as at present).

I have therefore requested Dr. Erdmann, one of my students in Bonn, to undertake
a revision of the Zoanthez with reference to the following important anatomical
characters :—(1) condition of the ccenenchyme ; (2) arrangement of the mesenteries ; (3)
structure of the sphincter; (4) condition of the integument; (5) colony - formation.
His conclusions are as follows :—The Zoanthez may live solitary (Sphenopidee), or may
form colonies (Zoanthide) ; in the latter case the ccoonenchyme may either consist of
basal stolons more or less branching, sometimes even anastomosing, or of a connecting
lamella, or of a mass which unites the polyps almost for their whole height. The
integument either consists merely of an epithelium and cuticle, or else there occur
on it foreign bodies, which penetrate the mesogloea of the body-wall, and more or less
fill it. In the arrangement of the mesenteries two points are of importance: (1) that
the pairs of mesenteries, with the exception of the directives, consist of a macro- and a
micro-mesentery ; (2) that a dorsal and a ventral zone of mesenteries must be
distinguished. The two zones may approximate either with small (Microtype) or with
large mesenteries (Macrotype). Finally, the sphincter exhibits three modes of forma-
tion; it may be (1) endodermal; (2) mesoglceeal; (3) it may be mesoglceal, but
distinguished by a muscle-free region into upper and lower portions.

With reference to the points above mentioned, Erdmann has distinguished five
genera in the colonial Zoanthide, the characteristics of which may be followed without
further comment in the accompanying table :—

Genus. | Mesenuenal Sphincter. Ccenenchyme. | Intecument. Generative
arrangement. | : < organs.
| x =e p =
Zoanthus. Microtypal. © Mesodemnal, | Stolonar. | Soft. | Hermaphrodite.
duplex. |
Mammilifera. Microty pal. Mesodermal,.| Stolon-like, with a | Soft. (?)
simple. | tendency to form |
lamelle.
Hpizoanthus. | Macrotypal. | Mesodermal, | Connective, lamellar. | Incrusted. Dicecious.
simple.
Palythoa. Macrotypal. | Endodermal. | Resembling a ribbon | Incrusted. | Dicecious.
| or tongue. |
Corticifera. Microtypal. | Mesodermal, | Polyps sunk in the | Inecrusted. (2)

simple. ceenenchyme — to
their upper ends. | } {

36 THE VOYAGE OF H.M.S. CHALLENGER.

The material which I was able to place at Dr. Erdmann’s disposal was derived
partly from the Bonn Museum, partly from the Triton expedition, but chiefly from
the Challenger collection. For the descriptions of the Challenger Zoanthee 1
give here short extracts from his Memoir,’ for the accuracy of which I can vouch, as |
the whole investigation was carried out under my direction. I have achieved, what he
omitted, in identifying as far as possible the forms obtained with species previously
described, and, where that was impossible, have introduced new names, and have
reduced the diagnoses of species to shorter and more precise terms.

Family 12, ZoantH2.
Genus Zoanthus, Cuvier (pro parte).

Integument not incrusted ; coenenchyme stolonar, with an occasional tendency to
lamellar extension ; sphincter differentiated into upper and lower sections ; mesenteries
arranged on the microtype.

Zoanthus dane (?), Le Conte (PI. I. fig. 1).

Polyps with fleshy body-wall, the larger borne on a stalk-like extension, and
arranged closely together on reticulately branching stolons; approximately fifty
tentacles arranged in two cycles.

Halbitat.—Bermuda Islands ; shallow water.

Dimensions.—Of the individual polyps—height, 0°5-2°5 cm-; breadth, 0-3—0°5 em.

This animal, which I refer with considerable reserve to Zoanthus dane, is identical
with the Zoanthus which I have already described. To that description I can add the
following points, based on Erdmann’s researches :—

1. The colony grows on a foundation of rock in such a manner that the upper ends
of all the polyps lie in the same plane. As the foundation is irregular, the individual
polyps must be of unequal lengths, a result of which is that those animals which
co.respond to hollows in the foundation are produced posteriorly into a kind of stalk,
distinguished from the body proper by a constriction, and by the thinner consistence of
the body-wall.

2. A peculiar attachment of the cuticle to the body-wall, and one perhaps more
widely distributed among the Zoanthesx, is effected by mesogloeal processes which
perforate the epithelium and are inserted on the cuticle.

r . . =
3. The colony investigated by Erdmann was sexually mature ; ova and testicular
follicles occurred in the same mesentery.

+ Erdmann, Ueber einige neue Zoantheen. Ein Beitrag zur anatomischen und systematischen Kenntniss der
Actinien, Jenaische Zeitschr., Bd. xix, pp. 480-488, pls. iv. v.

REPORT ON THE ACTINIARIA. Si =

Zoanthus confertus,* Verrill (Pl. I. fig. 12).

Polyps with thin transparent body-wall, so closely packed as to be polygonally
flattened.

Habitat.—Simon’s Bay, Cape of Good Hope ; 10-20 fathoms.

Dimensions.—Of the individual polyps—height, 0:6—0°8 cm. ; breadth, 0°3-0°4 em.

The species is in general structure very close to the preceding, but differs in the thin
consistence of the body-wall, through which may be seen the mesenteries, and in the
compact arrangement of the polyps. The latter being consequently compressed
polyhedrally, a character of importance is afforded for the species, which is further
marked off by the transparence and delicacy of the body-wall.

Genus Epizoanthus, Verrill.

Integument incrusted, ccenenchyme (mostly?) lamellar; sphincter simple, meso-
gloeal ; mesenteries arranged on the macrotype ; colonies (mainly ?) parasitic.

Epizoanthus thalamophilus,* n. sp. (Pl. I. fig. 3; Pl. IV. figs. 7, 8).

Incrustation scanty, exclusively composed of Foraminiferal shells, which are
arranged on the individual polyps into 15-20 longitudinal rows, bifurcating
downwards ; body-wall transparent; tentacles 30-40, very long, and arranged in
two rows.

Habitat.—Station 299, December 14, 1875 ; 2160 fathoms; on Gastropod shells.

Dimensions.—Height of the contracted individuals, 0°2-1°3 cm.; diameter at the
base, 0°9-1°5 em.

“The colony of seventeen individuals has settled on a deserted Musus shell about
8 cm. long. The polyps are principally situated on the back of the shell, and only the
five young individuals at its apex are arranged in a whorl round it. The region round the
aperture of the shell is free from polyps ; they rise with elliptical bases from a common
ecenenchyme, and arch upwards like a dome. ‘The largest specimens have a base of
10-15 mm. in diameter, and are 13 mm. high ; but we find every transition to the smallest
specimens, which appear as flat elongated projections with a base of 5-9 mm., and a
height of 1-5-3 mm. The ccenenchyme is a continuous sheet, 0°3-0°5 mm. in thickness,
which covers the shell as far as the colony reaches. Towards its termination it becomes
constantly thinner and more transparent, till it ends as a very delicate pellicle, which
may be easily rubbed off. All the polyps were in a highly contracted condition ; and
at the dome-shaped summit lies, on a prominence which is bounded by a circular furrow,
the entrance to the interior; it is hardly recognisable as an opening, and is formed by
the indrawn parts of the body-wall. The latter is of slight thickness, so that the

38 THE VOYAGE OF H.MS. CHALLENGER.

mesenteries may be seen through it as clear stripes. In the external zone of its mesogloea
lie the deposits above mentioned, consisting exclusively of Foraminiferal skeletons.
They are evenly distributed over the coenenchyme ; but on the body-wall are ranged in
a most regular and elegant manner, the following facts bemg recognisable with the
aid of a lens. From the apex outwards run, in a well-grown individual, fifteen to twenty
looping rows of Foraminifera in clear elevated lines. Where the body-wall bends
downwards at right angles, each row bifurcates, and each branch so preduced runs
downwards on the body-wall in a straight line; a single row of Foraminifera is thus
situated over each mesentery, the insertion of the latter being externally clearly
recognisable, owing to the thinness of the wall. While therefore, from the apex of the
polyp outwards, the ridges agree in number with the pairs of mesenteries, in the lower
part of the body-wall there are present as many rows of shells as there are individual
mesenteries. Towards the base these become less plain, so that at the lowest part
of the polyps, as on the coenenchyme, the Foraminiferal coating is evenly distributed
all over” (Erdmann). The rows of shells are continued on to that region of the body-
wall which has been drawn inwards; and their arrangement can here be only understood
by referring to the point of transition from body-wall into oral disc. This occurs along
an undulating curve, since at one point the oral disc with its outer circlet of tentacles,
at another the body-wall with its rows of shells, projects the farthest. A horizontal
section therefore, through the region under discussion, meets alternately with rows of
Foraminifera and the origins of tentacles (Pl. IV. fig. 8). Further, at the point of
junction, the body-wall forms a strongly projecting fold in which lies the greater part
of the sphincter (PI. IV. fig. 7). The horizontal section represented in fig. 8 exhibits
this fold on the inner side, while on the outer lie the body-wall and oral disc, united
by mesenteries.

The fold of the body-wall bears, on both sides, rows of Foraminiferal shells,
supported on ridge-like processes of the body-wall, and appearing therefore in trans-
verse section as coronets ; they are, as we learn from longitudinal sections, discontinuous
at the free edge of the fold, so that the outer and inner rows of shells do not pass into
each other.

The sphincter embedded in the fold of the body-wall is mesogloeal and simple, and
forms here an evenly distributed complex mass of muscle-bundles, the latter being
variously shaped. It also overlaps a small strip of that region of the body-wall which
is not drawn inwards.

The tentacles are, as in other cases, in two alternating circlets, and are in part
produced into long pointed filaments, in part contracted into short stumps. Their
muscles are ectodermal and slightly pleated; the mesogloeal supporting lamina lying
at the base of the pleats sends processes into the epithelium.

The stomatodzeum is oval, and the siphonoglyphe only slightly expressed.

REPORT ON THE ACTINIARIA. 39

The number of mesenteries varied in the three specimens investigated between
twenty-eight and thirty-six, according to their size. The dorsal and ventral zones of
mesenteries approximate always with macromesenteries.

No channel filled with cells is present at the bases of the mesenteries ; the muscle-
pennons indistinct; the generative organs so abundantly developed as to fill the
greater part of the ccelenteron. These latter occur only on the macromesenteries,
and consisted of testicular follicles in the three specimens studied.

The ccenenchyme is extremely thin, and possesses internally smooth connecting-
tubes lined by endoderm; on the upper surface Foraminiferal shells are sparsely
embedded ; while on the other side, which covers the Gastropod shell, these are entirely
absent.

The name thalamophilus was chosen with reference to Thalamophora and Poly-
thalamia, names which have been applied to the Foraminifera.

Epizoanthus stellaris,* n. sp. (Pl. I. fig. 4).

“ Polyps of inconsiderable height, nearly saucer-shaped; body-wall vertical at the
sides, but strongly flattened above ; on its horizontal upper surface are numerous radial
ridges, separated by furrows, 15-20 in the adult animal; colour of the colony dark
greyish-brown ; deposits very various.” —

Habitat.—Station 202, off Samboangan, Philippine Islands.

Dimensions.—Of the individual polyps—height, 0:05-0°4 em.; diameter, 0°15-0°7 em.

“Of this species I possess a colony, covering the rooting spicules of a Hyalonema for
a distance of about 14 cm., and consisting of about 100 individuals. The coenenchyme
forms a tube open at both ends, and surrounds like a sheath the bundle of spicules, the
latter being about 5 mm. thick. The individuals spring from it at longer or shorter
intervals by an elliptical base, measuring in the largest polyps (3-4 mm. high) about
5-7 mm. in diameter. From these to the smallest, which hardly project above the
ecenenchyme, and are 1°5-3 mm. broad, by 0°5-1 mm. high, every transition is found.
All the animals are strongly contracted ; on the strongly flattened, discoidal, horizontal
surface of the body-wall may be dimly seen the entrance to the interior by a circular
pit. From this point outwards radiate over the surface of an adult specimen, about
15-20 ridges separated by furrows.

“The colour of the colony is a dirty dark-grey. The body-wall is of considerable
thickness, caused by the strongly developed mesogloea. The exterior surface of the
latter is charged with various deposits, consisting of irregular grains of sand and lime,
sponge spicules of very varied origin, and finally of the small dark crystalline bodies
which cause the dark tint of the colony. These deposits occur in additional quantity
on the radial ridges before mentioned. They are continued inwards as elevated ridges

over the edge of the covering fold without a break, and run even further, on the inner

40 THE VOYAGE OF H.M.S. CHALLENGER.

face of the indrawn part of the body-wall. Sections through the upper region of the
polyp yield appearances similar to those described under the preceding species, though,
owing to the abundant and various deposits enclosed, they are not so regular and
elegant.

“In those inner parts of the mesogloea which are free from adventitious accretions
there lie embedded in the homogeneous matrix—tl. fine radial fibres, penetrating
the whole thickness of the soft mesogloea, provided here and there with nuclei; 2. round
mesogloea-cells containing a large nucleus; 3. round or oval spaces packed with cells.
Hertwig, who has observed similar structures in the Hpizoanthus parasiticus described
by him, conjectures that these oval cell-islets are produced only by indifferent preserva-
tion, and result from the breaking down of a system of anastomosing cords, such as
the mesogloea of Zoanthus exhibits. 1{Erdmann]am inclined to regard these roundish
heaps of cells as primary structures, like the canals of Zoanthus, since I have been
able to recognise them in almost all my species of Hpizoanthus, which were without
exception in a very good state of preservation. As to their origin I have no data; but
there is no reason why they should not. be referred to an ectodermal origin as well as
the cell-canals of Zoanthus, the derivation of which from ectoderm is indisputable ;
besides, many of these cell-islets clearly exhibit an elongate outline, with here and
there even a slight tendency to branch, by which an external approximation to
Zoanthus is effected.

“The mesogloea of the mesentery is well developed, and on its inner edge is
thickened like a club. The micromesenteries project only slightly into the interior,
but, like the macromesenteries, clearly present marked muscle-pennons. On these
mesenteries there springs on the side opposite to the muscle-pennons a mesogloal
lamella, which is considerably elongated in order to carry the generative organs
and to form, centrally to these, the mesenterial filaments. The former are present
in considerable numbers; and, being cut more or less superficially owing to the con-
torted course of the mesentery, may be recognised in transverse section as roundish
balls enveloped in a thin mesoglceal lamella, pressed against the body-wall and generally
filling the adjacent chamber. All the specimens which I investigated were female, the
generative balls consisting of a large number of ova closely appressed together, but
separated by a fine mesogloea lamina.

“The body-wall is deeply drawn inwards, and conceals in this region a stronely
built sphincter, which has the shape described for the preceding species, but which
is distinguished by a greater complication in the branching of the bundles of fibrillee.

“The stomatodzeum is oval, with a clearly defined siphonoglyphe. The ensheathing
coenenchyme measures 1-1-3 mm. in thickness; in its interior run longitudinally
numerous connecting tubes. The mesogloea carries on its surface foreign deposits of
the same character and quantity as those on the body-wall, but the inner face, which lies

REPORT ON THE ACTINIARIA. 41

on the foundation, is completely free from incrustation. The soft mesoglcea of the
coenenchyme is, with reference to histological differentiation, in the same relation to the
body-wall as it is in Zoanthus, since here also, in addition to the other points of marked
agreement, the nucleated fibres are supplanted by mesogloeal cells.

“With a view to observing the mesenterial arrangement, | studied two examples,
one of medium size, and one fully grown ; both exhibit the regular macrotype. In the
younger specimen occurred a symmetrical arrangement of the pairs of mesenteries ; of
these there were sixteen, seven being regularly distributed on each side of the
directives. The other polyp possessed nineteen pairs, of which nine were situated on
the one side, and eight on the other.”

Epizoanthus elongatus,* n. sp. (PI. I. fig. 2).

“The individual polyps form elongated cylindrical tubes, the body-wall is flattened
above, with a marked indentation, but terminates without radial furrows; colour of
the colony a yellowish-grey.”

Habitat.—Station 322, off Monte Video; February 26, 1876 ; 21 fathoms.

Dimensions.—Height of the polyps, 0°05-1'0 em. ; breadth, 0°15—0°4 em.

“This species can only be externally distinguished from the preceding. The
colony is 10 em. high, consisting of about 100 individuals, and lives on a bundle of
the siliceous threads of a Hyalonema, about 3 mm. only in thickness. The largest
polyps are long cylindrical tubes, about 8-10 mm. high and 3-4 mm. broad ; in their
neighbourhood occur gradations to the youngest buds, which are small warts projecting
from the ccenenchyme, of 0°5-2 mm. in height, 1°5-2°5 mm. in breadth. All the
animals are in a state of the most marked contraction ; the horizontal upper surface of
the body-wall is more or less flattened, and exhibits a circular indentation. This part
of the body-wall is entirely free from radial ridges and furrows. The colour of the
colony is a greyish-yellow.

“The body-wall is thinner than in the preceding species, and possesses in its
outer zone the same deposits, though in smaller quantity. The remaining anatomical
and histological relations agree closely with those of the former species, but it is
important to observe that the sphincter is less strongly developed. The body-wall is
drawn inwards less deeply ; its sphincter is in transverse section correspondingly short,
but curved, and pointed at both ends. The generative organs consisted of ova in the

five specimens investigated.”

Epizoanthus cancrisocius,* Studer (P1. I. fig. 15).

Colony much inerusted, and consequently so brittle as to break readily in pieces ;
individual polyps slim, body-wall at the upper end bent outwards in the contracted

(ZOOL. CHALL, EXP,—PART LXx111.—1888.) Dildd 6

42, THE VOYAGE OF H.M.S. CHALLENGER.

condition into a plate-like expansion, from the indented centre of which run 15-20
furrows towards the thickened edge. ;

Habitat.—Station 49, May 20, 1873; 83 fathoms, upon a Gastropod shell
tenanted by a Pagurus, the shell entirely dissolved away by the coenenchyme.

Dimensions.—Length of the polyp, 0°6-1:0 em. ; breadth, 0°3-0°5 em. ; colour,
ereyish-yellow.

“This species forms a colony of eleven individuals, on a shell some 2°0 cm. high.
The calcareous substance of the latter is completely absorbed, and at all pots replaced
by the ccenenchyme, the latter having obviously taken its place, while preserving its
‘external form. Only the anterior side of this coenenchymatous structure, 2.e. the part
directed forwards in movement of the Crustacean, possesses polyps; the free posterior
side allows the coils of the former Gastropod shell to be clearly recognised. Of the
eleven individuals, eight large mature polyps occupy the edge of that side which is
directed anteriorly in the movement of the crab. They form long cylindrical tubes,
6-10 mm. high and 3-5 mm. broad. In the median space which they bound, stand
three very young polyps, projecting as vertical cylindrical warts from the coenenchyme,
with height and breadth alike of 1°5-2 mm. One may remark that the large polyps
bend forwards, z.e. their oral discs face upwards, in the direction corresponding to the
locomotion of the Pagurus, so that they are most favourably placed for the reception
of the food matters which stream against them. Owing to the curving just mentioned,
the large polyps are above strougly compressed laterally.

“The whole colony has a rough shagreen-like exterior, of a grey colour. The
otherwise smooth body-wall forms above a horizontal plate, which not only projects
like the capital of a column over the vertical part, but has also a characteristic sculp-
ture, and the appearance of a plate with raised edges and indented centre; in the
middle of the latter lies the entrance to the mterior, which is slit-lke, corresponds
to the lateral compression, and is always recognisable as an obvious opening. From
this median point outwards radiate over the plate-like surface 15-20 radial furrows,
which are continued outwards for a short distance over the marginal thickening,
appearing on it as deep notches.

“When a polyp is opened with scissors, one remarks that the mesenteries run
down the whole length of the body-wall, but do not pass over on to the horizontal
floor of the ccelenteron. In the lowest parts of the polyp, the mesenteries are visible
as shehtly projecting ridges, striking the eye by their clear colouring; at about one-
fourth of the total heioht, the macromesenteries form filaments; these are yellowish-
white contorted coils, which completely obscure the micromesenteries. One can
without damage remove the mesenteries from the body-wall, and study them indepen-
dently. The supporting lamina of the mesenteries is very thin, and runs simply to
the base without any excavation; the mesenterial filaments are of the customary

REPORT ON THE ACTINIARIA. 43

structure. 1 have been unable to detect generative organs im any. specimen
investigated.

“Owing to the abundant incrustation, the body-wall becomes as hard and brittle
as stone, and does not permit therefore of investigation by means of sections. In this
case therefore, and in the remaining forms with similarly strong incrustation, I made
use of the method of erinding tested and recommended by G. v. Koch in his researches
on Tubipora.

“The body-wall is of considerable thickness ; its mesogloea exhibits a structure very
different from the remaining species of Epizoanthus, as being penetrated by deposits
throughout its whole depth. These deposits consist of particles of sand with irreeular
angles, and are set ma strong circular fence, reducing the mesoglcea to thin lamellee ; but
there persists a very narrow internal lamella bounding the endoderm all round. In the.
homogeneous mesogloea-lamellz are situated roundish cells which give off fine radiating
processes, and fine fibres provided with nuclei; the presence of the cell-heaps, which
are to be met with in the remaining species of Kpizoanthus, I was unable to
demonstrate in this case. A transverse section through the wall of the shell exhibits
a similar condition in the ccenenchyme. This latter is also of considerable thickness,
and is internally traversed by the large endodermal tubes which connect the various
ceelentera together.

“The body-wall is, as has been already mentioned, bent above at a sharp angle,
thus forming a plate-like surface. In contrast to the remaining members of the
genus, where it turns deeply inwards vertically, it is here only slightly invaginated, a
difference resulting from the slighter development of the sphincter. The latter com-
mences to a certain extent on the horizontal part of the body-wall, and then thickens
oradually into a truncated muscular mass, which appears fusiform in section, and is
only slightly curved inwards. It lies enclosed in the innermost lamella of mesoglcea ;
the latter is thus much thickened, and is free from adventitious deposits. ‘The
sphincter is on both sides bounded by a layer of mesogloea, which extends inwards to
the commencement of the oral disc, is charged with the usual accretions, and is a direct
continuation of the outer sandy layer.”

So much for the anatomical description given by Erdmann, which sutticiently
proves that Lpizoanthus cancrisocius must be separated systematically from Lpizoanthus
parasiticus, the latter possessing larger and coarser polyps and far less incrustation. |
have identified the animal with the Epizoanthus cancrisocius of Studer, as he records
for his specimens similar dimensions, and a marked incrustation, at least for the basal
membrane. In other points his description is not sufliciently exhaustive, and this is
still more true of Gray’s account.’ Only the statement of the latter that the large

t Monatsber. d. k. Akad. d. Wiss. Berlin, 1878, p. 547.
2 Proc, Zool. Soc. Lond. 1867, p. 237.

44 THE VOYAGE OF H.MS. CHALLENGER.

polyps break up easily, and the reference to a figure of Gosse’s which recalls our
Epizoanthus cancrisocius, make it probable that his Hpizoanthus papillosus and the
Epizoanthus cancrisocius are identical.

Erdmann refers it in his Memoir to the expedition of H.M.S. “Triton.” I find,
howeyer, his specimen in a bottle from the Challenger collection, with the label given
above; some mistake must therefore have occurred in his manuscript.

Genus Corticifera, Lesueur.

Coenenchyme extending from the base upwards between the individual polyps, and
uniting them together almost as far as the upper edge of the body-wall; integument
incrusted ; sphincter mesogloeal ; mesenteries arranged on the microtype.

On the above diagnosis I may remark that, on the body-wall of each polyp may
be distinguished two regions, the one surrounded by ccenenchyme, the other projecting
freely above it. When the animal contracts, the latter is drawn inwards to the level
of the coenenchyme as in Madreporaria ; it partly serves to close over the anterior end,
and partly is invaginated inwards. A colony in contraction consequently forms a crust-
‘like covering, in which the individuals are only indistinctly marked off from each other.

Corticifera lutea,* Quoy and Gaimard (PI. I. fig. 6). ;

Individual polyps marked off by fairly obvious stripes on the ccenenchyme, and
recognisable as annular ridges on the common surface of ‘the colony ; they differ but
little from each other in size.

Habitat.—Bermuda, June 1873; smooth water.

Dimensions.—Height, 1 cm. ; breadth, 0°4-0°5 em. ; colour, yellowish-white.

“The colony at my disposal consists of a flat, quadrangular, crust-like structure,
about 16 cm. long and 7 cm. broad. It does not present a complete whole, but is
merely a piece torn off from a larger mass, carrying about 400 individuals ; the latter
reach a height of 10-15 mm., and are in diameter 4-5 mm. It must be insisted
that this external height of the polyps in no way corresponds to the internal, since the
ecenenchyme forms on the underside so thick an investment that of the total height
only about two-thirds belong to the coelenteron, the other third to the coenenchymatous
layer beneath. All the individuals are stronely contracted, and the body-wall is drawn
deeply inwards. The edge of the body-wall projects above the general surface as an
annular depressed ridge, in the centre of which lies, always clearly open, the aperture
to the interior. At the unmutilated edge the individuals stand out as slight swellings.

“In that part of the coonenchyme which borders on the ectoderm, are present
numerous accretions, producing a firm pellicle. The main bulk of the incrustation
consists of irregularly-shaped calcareous bodies; besides these occur more sparingly

REPORT ON THE ACTINIARIA. 45

Foraminiferal and Radiolarian skeletons, and finally, numerous sponge-spicules of
various kinds. In the ccenenchyme between the polyps, the accretions are present only
in small quantity, and fill here simple scattered cavities, which may be recognised after
decalcification as wide lacune. The rest of the coenenchyme~is soft; and in its
homogeneous matrix we meet with large canals, lined by pigmented epithelium and
traversing the ccenenchyme in every direction; they are especially numerous in the
lower coenenchymatous investment, which consequently presents a reticulate spongy
texture. As appears from longitudinal sections, these canals are direct continuations
of the ccelenteron from the base of the polyp outwards, and extend from this point
upwards through the whole of the coenenchyme ; they may consequently be homologised
with the endodermal connecting tubes to be found in all Zoanthidee. The mesoglcea of
the coenenchyme exhibits also numerous roundish cell-islets lined by epithelium, in which
we may perceive the origin of such ectodermal cell-heaps as have been described for
Epizoanthus. The whole of the endodermal epithelium is pigmented by dark granules,
as are also the large endodermal connecting-tubes. On the other hand, the roundish
ecll-acgregations just mentioned are free from pigment granules; this difference of
condition affords an indirect proof that the latter are by no means of endodermal
origin, but are purely ectodermal structures. Finally, the soft ccenenchyme exhibits
fine nucleated fibres starting from the endoderm, and, as is usual, numerous mesoglceal
cells provided with fine processes.

“The main bulk of the whole colony is to be regarded as ccenenchyme; the
individual polyps consist merely of a mesogloeal cylinder med internally by endoderm,
of moderate thickness and homogeneous consistence. The supporting lamina of the
mesenteries is of similarly weak development. Below, the latter enclose a canal filled
with cells, which in the case of the macromesenteries is frequently divided up by cross
anastomoses. ‘The muscle-pennons are well developed, and appear, especially in the
larger mesenteries, as branching processes, which extend over a wide stretch of the
mesentery. Nothing of interest can he said about the mesenterial filaments. In none
of the specimens investigated could I find generative organs. The stomatodzeum is
pear-shaped in section, with a well-marked siphonoglyphe.”

The sphincter is mesodermal, simple, and only slightly developed. It begins early,
as a narrow strip, in that part of the body-wall which is drawn horizontally inwards,
and extends without any thickening to the edge of the invaginated part. The number
of the meseuteries, which are arranged on the microtype, varied in five individuals
between thirty-four and forty.

Corticifera tuberculosa,* Klunzinger (PI. I. fig. 5).
Individuals closely appressed together and flattened polygonally, generally separated

by a deep furrow, and of very dissimilar sizes, so that the surface of the contracted

46 THE VOYAGE OF H.M.S. CHALLENGER.

colony appears to be irregularly covered with knobs. These knobs exhibit radial
furrows which run outwards from the indistinct opening.

Habitat.—Simon’s Bay, Cape of Good Hope; 10-20 fathoms.

Dimensions.— 0°6-0:8 cm. in height ; diameter, 0°2—-0°5 em.

Colowr.—Brownish.

The small colony of about forty individuals differs essentially from the above
described Corticifera lutea in its external appearance. From the small development of
coenenchyme, it results that the individual polyps press closely on one another, and
frequently become polyhedrally, generally hexagonally, flattened. They are separated
by deep grooves on the surface, which, at few points only, become shallower or dis-
appear altogether. The absence of the groove between two polyps possibly signifies a
genetic dependence, the one having arisen by gemmation from the other; and smaller
individuals are frequently adjunct to the larger polyps in this fashion.

The individuals of the colony are of most varying size; from the large dome-
shaped convex animals with a diameter of 0°6 mm. those of intermediate size lead to
the smaller, which measure only 0°1 mm. in the one direction and 0:2 mm. in the
other. Since the surface therefore exhibits smaller and larger knobs, I refer the species
to the Palythoa tuberculosa of Klunzinger, and have therefore retained the well-chosen
specific name.

In length there is but little difference between the larger and smaller animals, the
former measuring 0°6 cm., the latter 0-4 em. As they all diminish downwards in a
wedge-shape, the lower side of the colony is so much narrower thatthe polyps on the
edge are nearly horizontal.

All the polyps are so strongly contracted that the entrance to the interior is
recognisable only as an indistinct indentation, from which radiate outwards numerous
shallow furrows.

With reference to the finer anatomy, what has been said for Corticofera lutea
holds good in this species. In the two specimens investigated there were respectively
thirty-four and thirty-six mesenteries, which followed the microtype.

Genus Palythoa, Lamouroux.

Integument strongly incrusted ; ccenenchyme little developed, ribbon- or tongue-
like; mesenterial arrangement on the the macrotype ; sphincter endodermal.

Palythoa anguicoma,* Norman (Pl. I. fig. 7).

Incrustation superficial, so that a thick layer of mesogloea remains free of deposit ;
ecenenchyme tongue-shaped ; individuals, when in a contracted condition, long, with a
terminal capitular enlargement, on which run 15-20 radial furrows.

REPORT ON THE ACTINIARIA. 47

Habitat.—Station 135 a, off Inaccessible Island; October 16, 1873; 60-90 fathoms ;
hard ground, shells, and gravel.

Dimensions.—Height of the polyps, 0°4-0°8 cm. ; breadth, 0°2-0°4 em.

Colour.—Brownish-yellow.

“ From the material at my disposal, which appears to have been carelessly detached,
the general form of the present species cannot with certainty be inferred. The greater
part of it consists of single individuals, in which one can recognise the forcible detach-
ment from the colony. One group, which to all appearance represents a complete
and intact colony, is composed of four individuals; they are situated, in a row and at
short intervals, on a thin coenenchyme which is extended lke a ribbon; their dimen-
sions are 4~8 mm. high by 2°5-4 mm. broad. All the polyps are strongly contracted ;
the body-wall forms above, in this condition, an obliquely-angled ridge projecting
outwards ; its upper surface presents an elevation, rendered obvious by a circular furrow,
in the centre of which the aperture to the interior is recognisable. From the middle
of this upper surface radiate outwards 15-20 furrows, which are continued over the
projecting ridge on to the vertical body-wall, where they then flatten out. The colour
of the polyps is a dirty yellow.

“The integument is furnished with accretions, and exhibits a rough shagreen-like
exterior. On rubbing away the thin sandy layer, there remains the thinner soft part
of the mesoglea, which is excellently fitted for the preparation of longitudinal and
transverse sections with a razor.

“The soft mesogloea is of considerable thickness, and consists of a homogeneous
matrix, in which come into view the large number of cavities charged with cells.
These may be simple, z.e. preserve their roundish or elliptical outline, or, as in most
cases, may branch to form a system of anastomosing canals which entirely recall
Zoanthus. Below the endoderm such a canal runs in an almost unbroken ring
through the whole of the body-wall; it lies so close under the epithelium as to be
separated from it only by a narrow lamella of homogeneous matrix. Its diameter is
not constant throughout its whole circuit, but is frequently constricted, and occasion-
ally such constriction produces an actual discontinuity. It is further of importance
that the canal invariably presents a considerable hollow expansion under each mesen-
terial insertion. At many points can be demonstrated a communication between
the smaller branching cell-canals and this large ring-canal, the latter being at such
places apparently expanded into a kind of funnel. Further, there are found in the
mesogloea numerous mesogloeal cells, giving off fine processes ; and, finally, delicate
nucleated fibres, the course of which, however, is here not radial, but in the main
circular.

“The structure of the eeenenchyme agrees in all respects with that of the body-
wall, except for the fact that it possesses endodermal connecting tubes.

48 THE VOYAGE OF HMS. CHALLENGER.

“The mesogloea of the mesenteries is strongly constructed, and on it can be
recognised well-developed muscle-pennons. The generative organs, borne in the
supporting lamina, consisted of ova in the individual which I investigated. The mesen-
terial filaments are of the customary structure.

“The mesenterial arrangement is to be referred to the macrotype: The specimen
investigated possessed thirty-six mesenteries, of which five pairs pertained to the dorsal
zone, and thirteen pairs to the ventral ; in the latter zone were ranged regularly, on each
side of the directives, six pairs, consisting of a macro- and a micro-mesentery.

“The body-wall is drawn inwards at a right angle; on the imner side of this
region a definite endodermal sphincter may be recognised. The pleatings of the
endodermal muscle-lamina are more clearly marked than in Palythoa aainelle ; and
produce on the mesoglcea prominent antler-like prones. The accretions are continued
on to the indrawn region of the body-wall, but die out at its lower edge, where the
oral disc commences.”

The identity of this animal with Palythow anguicoma is doubtful, as Norman, who
created the species, gave no figure of it. I was influenced by the circumstance that
eighteen rough radial furrows are ascribed to this form; besides which the incrustation
on it should be only superficial.

Palythoa, sp.* (?)

Habitat.—(a) Station 135 4, off Inaccessible Island, October 16, 1873; 60-90
fathoms. (6) Station 135 ¢, off Nightingale Island, October 17,1873 ; 100-150 fathoms.

In the same bottle with Palythoa anguicoma was another species of Palythoa, which
recurred in a second tube, the contents of which were dredged a day later than the
first, and at a greater depth. ‘The specimens in question could easily be distinguished
from individuals of Palythow angwicoma by containing black particles of hornblende.
Erdmann attempts to separate the two species, and gives the following description :—

“Tn this species also the larger part of the material consists of individuals torn away
from the colony ; one colony, which was undoubtedly not mutilated, was represented by
three individuals, ranged behind one another on a ribbon-like ecenenchyme. Hxternally
this species differs from the preceding in colour only, which is in this case a dull grey-
brown ; besides this, from the greater firmness and unevenness of the body-wall, it may
be recognised that the mass of accretions is greater. The body-wall presents, in contrast
to the former species in which the relations are reversed, a considerable zone charged
with accretions, opposed to a slightly-developed soft zone of mesogleca. In the latter
there passes close under the endoderm a cell-canal, frequently constricted, but rarely
interrupted ; external to this follow immediately the accessory deposits, so that of
the numerous canals and spaces observed in the preceding species only a few roundish
cell-islets are preserved.

REPORT ON THE ACTINIARIA. 49

Palythoa (2) sp.* (2)

Habitat.—Station 299, west of Valparaiso, December 14, 1875; 2160 fathoms.

I found a small Actinia, labelled “ Actinia on nodule,” which had settled on a piece
of pumice near an Ascidian. The animal, being incrusted with sand particles, probably
belongs to the Palythow, but its minuteness and the sandy incrustation forbade a
detailed study. The body, not so much as 1 mm. high, was flattened into a dise 5 mm.
broad. The number of mesenteries which, as in the Zoanthew, were very regularly
arranged, amounted to thirty-two.

Family 13, SPHENOPIDE.
Genus Sphenopus, Steenstrup.

Sphenopus pedunculatus,* nu. sp. (Pl. I. fig. 11).

Body marked off into an upper swollen trunk, an elongate narrow foot, and a
broad sole-like (?) “clasping-dise;” from the apex run, over the upper part of the
tvunk, about 10-12 indistinct rough furrows.

Habitat.—Station 203, off Panay, Philippine Islands, October 31, 1874; 12-20
fathoms. Three specimens.

Dimensions.—Leneth, 2°4—3°2 em. ; breadth, 2-2°4 em.

Colour.—Grey.

“This species differ in many respects from the already known Sphenopus marsu-
pralis (Steenstr.) and Sphenopus arenaceus (Hertw.). The fully-grown animal permits
of an external differentiation into three regions. The most obvious part of such a polyp
is formed by the upper bladder-like ‘body’ (Pl. I. fig. 11), which conceals within itself
the organs of nutrition and reproduction. On it is marked off, by a more or less
obvious cross-furrow, a hood-shaped anterior region, sculptured by coarse radial furrows.
The body passes into a long narrow ‘foot, from which it is sharply defined by a
marked furrow, and finally the foot broadens out at its base into a kind of ‘clasping-

?

disc.’ The three animals of this species which were at my disposal represented
stages of different ave. In the oldest individual the bladder-like body has been
irregularly contracted by preservation in spirit, its exterior is folded, and exhibits
besides a lateral compression. ‘The head region, defined by an obvious constriction, is
strongly tuberculate, and marked by twelve coarse radial elevations, separated by
discontinuous and incomplete furrows. The height of the body amounts to 2°5 em.,
its greatest width to 2°4 em. Sharply marked off from it by a circular furrow is the
eylindrical foot, the diameter of which reaches 1:2 em. Unfortunately this latter has
been broken away, so that I can give no accurate information either about the total

length, or about the clasping-dise of this animal. The second polyp was of medium
(ZOOL. CHALL EXP.—PART LxXx111.—1888.) Dddd 7

50 THE VOYAGE OF H.MS. CHALLENGER.

age ; its total lencth amounted to 3:2 cm., of which 2-0 em. belong to the body, and
1-2 em. to the foot. The former is on one side crushed inwards about the middle,
where it is of the greatest diameter (2 cm.), while on the other it is as strongly swollen
out. Above, it diminishes gradually into the head region, which is indistinctly
furrowed radially; and below, equally gradually, mto the foot. The latter is
cylindrical, and has a diameter of 0°5 em., while the sole-like clasping-disc has at its
base a breadth of 0°9 em. The third and still younger polyp consists mainly of the
‘body,’ which above is flat and discoidal, without differentiation of a head-region, but
as at the periphery pressed into folds; its height is 2°4 em., its breadth 20 cm. Below
it passes gradually into the foot, which is. rudimentary, round, only a few millimetres
high, and ends without a claspine-dise.

“For investigation I made use of the middle specimen, which was completely
preserved. A longitudinal section dividing the polyp into two halves yielded the
following results. The mesenteries run in the foot as clear narrow ridges on the body-
wall, scarcely projecting into the interior; they extend also on to the horizontal pedal
dise, and appear in this region as radiating lamelle, which meet at the centre of
the flat base. The filaments first appear on the mesenteries at the point of transition
into the broader ‘ body;’ they form a thick investment, which nearly fills the whole
celenteron and covers the mesenteries completely. The body-wall is fairly thick, and
even with the naked eye can be distinguished into two layers ; an outer, which appears
granular owing to the accretions, and an inner, which is soft, shining, and free from
deposits. It is further noticeable, that the quantitative relations between the incrusted
and the softer layers vary with the height of the part in question, and in such a
manner that, at the upper part of the body, both parts are about equally strongly
developed, while with increasing depth the harder constituents become more numerous,
till at last, in the foot, a complete obliteration of the softer zone is produced. Above,
the body-wall is drawn rather deeply inwards at a sharp angle. On to this infolded
region the accretions are uninterruptedly continued as far the point of origin of the oral
disc, the latter beg inserted just at the mner edge of the fold. The stomatodeeum
reaches far downwards, and is characterised by a siphonoglyphe of considerable depth.

“ A transverse section in the region of the stomatodeeum allows the mesenterial
arrangement to be recognised even by the naked eye. The longitudinal section having
been carried midway between two mesenteries on both sides, they were completely
intact, and the combination of the two sectional halves yielded a complete picture of
the mesenterial arrangement, which falls under the microtype. Sixty mesenteries in
all are present; of these, after deduction of the regularly formed dorsal pairs, there fall
into the ventral zone on each side of the directive macromesenteries, twelve pairs,
consisting each of a macro- and a micro-mesentery.

“For a study of the anatomical relations in more detail, I made use of von Koch’s

REPORT ON ‘THE ACTINIARIA. 5 eal

method of grinding. The integument is composed, as was stated above, of an internal
softer zone, and an external zone penetrated by accessory deposits. The latter consist
mainly of clear angular fragments of sand; but there occur also various indeterminable
mineral splinters of different colours, and finally, more sparingly, sponge - spicules
and Foraminiferal shells. All these particles lie confusedly mingled, and so closely
together as to form a stout external rind; between them they allow of only thin
mesogloea-lamelle, in which are embedded fine nucleated fibres, as well as a few
stellate mesogloeal cells. The zone of mesogloea which is soft and free from deposits,
consists of a homogeneous matrix, in which sharply circumscribed lenticular cell-
islets are embedded in large numbers and of various sizes. They are especially
plentiful in the neighbourhood of the endoderm; but, in passing outwards, every
gradation of size, up to fine fusiform structures, is met with. The plane of the
long axis of these cell-islets is always circumferential. The nucleated fibres are
extremely abundant in the mesoglea; they extend from the endoderm outwards,
their course being sometimes straight, but more generally undulating, with close coils
almost like a cork-screw. Besides the contents already mentioned, one observes also
the existence of stellate mesogloeal cells, which are sparsely scattered and emit fine
processes into the homogeneous matrix.

“The supporting lamina of the mesentery is well developed, and presents an antler-
like muscle-pennon. At its base passes a canal, filled with cells, and penetrating the
mesenteries for their whole leneth ; in transverse sections through the micromesenteries
this appears simple and cylindrical, but forms on the macromesenteries a longer cavity
divided up by cross anastomoses. This quite subordinate character accompanies the
microtype through all the genera, however different both externally and anatomically ;
no macrotypal form showing even a trace of this mesenterial canal.

“The sphineter of Sphenopus is mesodermal and simple, and is so far characteristic
that it commences incomparably deeper than in any other known Zoanthean ; it
extends so deeply downwards in the outer part of the body-wall, that, even in the
contracted animal, its lowest point lies in the same horizontal plane as the lower end
of the stomatodzeum. In longitudinal section one can see how, at its deepest point, the
bundles of fibrillxe, like small circles, ave laid so closely together that they appear
almost to form a continuous line. Above they are more extended, and place themselves
with the long axis perpendicular to the cndoderm, from which they are only separated
by a narrow lamina of homogeneous mesoglea. In this condition the sphincter forms a
system of bacillate fibrilla-bundles, which are arranged extremely regularly in the form
of a palisade. At the edge of the infolding of the body-wall the bundles begin to bay
out irregularly, and finally set themselves, on the indrawn part of the hody-wall, to form
the sphincter proper, a plait of delicately branching and anastomosing bundles. This

circular muscle increases in bulk downwards, and terminates below with a rounded
>

32 THE VOYAGE OF H.M.S. CHALLENGER.

end. It does not completely traverse the mesogloea, but leaves free on either side
a homogeneous layer, which in its turn is bounded by a stripe reaching to the com-
meneement of the oral disc, and carrying the usual hard deposits.”

Sphenopus arenaceus, R. Hertwig.

Habitat.—Station 187, Torres Strait, Australia, September 9, 1874; 6 fathoms.
Two specimens.

Sphenopus marsupialis, Steenstrup.

Habitat.—(a) Station 188, inthe Arafura Sea, September 10, 1874; 28 fathoms.
One specimen. (b) Station 208, Philippine Islands, January 17, 1875; 18 fathoms.
One specimen.

In the Challenger material I have found four further examples of the genus
Sphenopus; two of these I have determined as Sphenopus arenaceus on account of
their rusty red tint, and other two as Sphenopus marsupialis, in consequence of the
earthy-grey colour and the absence of a stalk. It seems to me, however, desirable that,
with an opportunity of more abundant and fresh material, a renewed study should be
undertaken to decide whether the received specific characters are variable, and
whether all three species should not be united in the single Sphenopus marsupialis.

APPENDIX TO THE ZOANTHE.
Genus Stephanidium, n. gen.

Among the Zoanthez I include with some reserve a genus which is represented
by a single species, and has thus been insutliciently investigated. It differs from the
characteristic forms of Zoantheze in the absence of incrustations, and the non-formation
of acolony. Both characteristics, however, may be absent in true Zoanthes, e.g. the
soft-skinned Zoanthus and the solitary Sphenopidee. Of more importance is the fact that,
in spite of careful study, I have not yet been so fortunate as to demonstrate beyond all
doubt the decisive characteristic of Zoantheze, namely, the regular distribution of micro-
and macro-mesenteries. I consequently omit to give separate diagnoses of the species and
genus.

Stephanidium schulza, n. sp. (Pl. I. fig. 14; Pl. II. figs. 1, 7).

Habitat.—Station 209, off Zebu, Philippine Islands, January 22, 1875; 95 fathoms,

Dimensions.-—Breadth, 1°5-2°2 mm. ; height, about 1-0 mm. 3

Some Actinize were forwarded to me by Prof. F. E. Schulze, found among the
Hexactinellidze entrusted to him for description ; they were mainly small, insufficiently
characterised forms, which I did not care to investigate ; but among them occurred five

REPORT ON THE ACTINIARIA. 53

specimens of one species, which I will here describe on account of the striking appearance
of the body.

The body of Stephanidium is in diameter 1°5-2°2 mm., and about 1 mm. high in
the contracted condition. The epithelium had been stripped off at most points, and
remained only on the lowest parts of the body-wall, the mesogloea thus being exposed
over a wide extent, and allowing the mesenteries to be seen through it. The resulting
appearance is drawn in Pl. I. fig. 14, and was originally interpreted as follows :—I
believed that the surface was indented by deep furrows corresponding to the
mesenteries ; the ridges lying between these furrows become narrower, from a definite
part of the body-wall outwards ; they are extremely unequal in breadth, a broader and
a narrower ridge alternating regularly with one another, and to every broader ridge
corresponds, at the upper edge of the body-wall, a special structure of the following
nature: the edge of the body-wall is elevated into a kind of battlement (PI. III. fig. 7),
on the outer side of which are situated roundish or oval bodies, which call to mind the
marginal spherules of Actinua mesembryanthemum. The longitudinal ridge of the body-
wall meets the spherule, splits into two forks, and surrounds the structure from below.

Sections through the animal, however, showed that the body-wall is smooth, and
that the appearance of furrows was caused by the insertions of the mesenteries. On
the other hand, the spherules are really present, and form evaginations of the body-wall,
above a spot which is marked by the position of the circular muscle (PI. III. fig. 1). The
latter, in spite of the contracted condition of the Actinian, is of weak development,
and is merely a part of that endodermal circular muscle-layer which is at other points
hardly recognisable, but is here elevated into small folds. It is most obvious at those
places where it traverses the thickness of a mesenterial insertion ; here the endodermal
muscle-layer is not recognisable, but mesoglceal muscle-rings are embedded in the
region of the sphincter, largest at the upper end, and becoming gradually less obvious
in a downward direction, till one meets with small groups of only two or three fibres,
or even with completely isolated fibres.

Of the tentacles and oral disc it can only be said that the ectodermal muscle-
layer is strongly pleated.

The mesenteries, the number of which may be learnt even by superficial observa-
tion, amount to twenty-six, and are differentiated, as in the Zoanthez, into macro-
and micro-mesenteries. Of their arrangement, despite much trouble, I have not yet
arrived at a completely clear comprehension, but I could demonstrate the probability
that the directives of the one side are macro-mesenteries, those of the other micro-
mesenteries, that dorsal and ventral mesenterial zones meet with micro-mesenteries, and
that one pair is more developed on the one side than on the other.

The mesenteries (probably only macro-mesenteries) bore ripe male generative
organs. I was unable to recognise a siphonoglyphe.

o

f

54

cm.

THE VOYAGE OF HMMS. CHALLENGER.

V. CERIANTHES.

Family 1, CERIANTHID&.
Genus Cerianthus, Delle Chiaje.

Cerianthus membranaceus, Spall.

Habitat.—Zebu, Philippine Islands, on the reefs.
Dimensions.—Length, in a contracted condition, 4°5-10°0 em. ; breadth, 1°5-1°8
Two specimens.

UNDETERMINED SPECIMENS.

1. Station 153, in the Antarctic Ocean, February 14, 1876; 1675 fathoms.

An Actinian, nearly as thin as paper, strongly contracted and folded together,
1°5 cm. in size.

2. Station 173, off Matuku, Fiji Islands, July 24, 1874; 310-815 fathoms.
An Actinian, firmly fixed on a Gastropod shell (probably an Adamsia).
3. Station 195, off Banda, October 3, 1874; 1425 fathoms.

An Actinian, about 5 em. long, very rotten.
4. Station 209, off Zebu, Philippine Islands.

An Actinian, 4 mm. broad, 2 mm. high, sessile, strongly contracted.
5. Zebu, 100 fathoms.

An Actinian, 6°0 mm. broad, 2 mm. high, of the usual structure ; 12 complete
pairs of mesenteries, two directives, 836 (=12+24) small pairs.

6. Station 219, North of Papua, March 10, 1875; 150 fathoms:

One small Actinian, 1°5 cm. high, 1°5 em. broad, slightly contracted (probably
no sphincter), about 30 short, plump, sack-like tentacles. Preservation
inadequate for study.

7. Station 244, North Pacific, Hast of Japan, June 28, 1875; 2900 fathoms.
One Actinian, 12 mm. broad, 3 mm. high, very strongly contracted.
8. Station 286, South Pacific, between Tahiti and Valparaiso, October 16, 1875;
2335 fathoms.
An Actinian, 1°4 em. broad, 0:4 cm. high, probably a Phellia.
9. Station 299, off Valparaiso; 2160 fathoms.

Actinian adhering to a Dentalium; one elongated specimen (3°5 cm.), flattened

by contraction, in shape recalling the Amphianthide.

TABLE OF CONTENTS.

PAGE

INTRODUCTION, : : 1
DescripTIoN OF GENERA AND SPECIES, 9
I. Hexactinia, . 9
Corallimorphide, 9
Corallimorphus, 9
Corallimorphus rigidus, 9
Corallimorphus obtectus, 9
Corynactis, : ; , : : . : j ee LeTO
Corynactis (2), sp. (4),* . : ‘ . , : ; : 10
Antheomorphide, . : aa : : : : : : : 13
Ilyanthopsis, . : d : : : é : ; 5 13
Ilyanthopsis longifilis,* . : ; i : } j : 13
Actinide, . : : : : F ; 5 ; j : 14
Hormathia, . : : ‘ : ; : ‘ ; . 14
Hormathia delicatula,* . : ; : ; : : 5 15
Bunodide, . : : : : : : : : : : 16
Aulactinia, : 3 ; : : ; : : : 16
Aulactinia, sp. (?),* : : ; i ; : : ‘ 16
Paractide, . : : j é : : : ’ , : 17
Dysactis, j : é j é ; : : : . 17
Dysactis crassicornis, : 6 : ; : : ; , 17
Liponemide, : : : : : ; : : : : 17
Liponema, : : é : : : : : : 6 17
Liponema multiporum, . : : ‘ : : : . 17
Aulorchis, : : : : : ; x " : : 21
Aulorchis paradoxa,* : . : , : : : : 21

Phellide, . i j : P : ‘ ; : ; F 24
Phellia, F ; ; , : . : : ; : 24
Phellia spinifera, . : : ; 5 : ; : : 24
Amphianthide, , ; : ae oat ; 5 : : : 26
Ainphianthus, . j : : é : : : : : 26
Amphianthus ornatum,* . : ; : : - ; : 26
Tlyanthide, : : : : : ; 2 5 : 3 28
Halcampa, : ¢ : : : : ; , : : 28
Halcampa kerguelensis,* . 5 4 2 : - : : 28
Halcampella, . : : : ‘ : : ; : - 29
Haleampella maxima,* . : 3 . : . . : 29

Halcampella, sp. (1),* : : : : 3 . : 32

56 THE VOYAGE OF H.MS. CHALLENGER.

F PAGE

II. Paractinig, . j : : : : j : : : : 33
Sicyonide, . ‘ : ; i ; : : : : : 33
Sicyonis, : : : : 3 : : ; ; : 33

Sicyonis elongata,* : : : : ‘ F ; : 33

III. Epwarpsia, . : : é : j : ‘ ‘ : : 34
Edwardside, : é : : shoes ae : : 34
Edwardsia, : ; : : 2 : ; : ; : 34
Edwardsia, sp. (2),* : 0 . : : : 4 j 34

IV. ZoantHEa, . s : : : : : : ’ - : 34
Zoanthide, . : : : : : : 3 3 b ; 36
Zoanthus, : : i : 4 é 3 ; : : 36

Zoanthus dane, . ; ; ; : : 5 : ‘ 36

Zoanthus confertus,* : : ; : f A 5 i 37

Epizoanthus, . : : . P i : : : 6 37
Epizoanthus thalamophilus,* : : ; 5 4 : Be te eh

Epizoanthus stellaris,* — . 5 : 5 : ; : : 39

Epizoanthus elongatus,* . x ; : 5 : ; ; 4]

Epizoanthus cancrisocius,* : : s é : 6 se All

Corticifera, . : 6 0 a : : : 5 5 44
Corticifera lutea,*. : : ; ; : : : 3 44

Corticifera tuberculosa,* . 4 : : 5 ; : : 45

Palythoa, : : 0 ; : : F : : é 46

Palythoa anguicoma,* . : : : : : ; ‘ 46

Palythoa, sp. (?),* . : 0 ; . 3 : ; 48

Palythoa (%), sp. (2),* 3 5 : Sn ee : : : 49

Sphenopide, : 0 : : : : 0 : : 0 49
Sphenopus, j 0 : 9 : : : 4 : : 49
Sphenopus pedunculatus,* . : 5 : : é 0 - 49

Sphenopus arenaceus, 0 . : : 5 3 6 : 52

Sphenopus marsupialis, . : : : é : ; 2 52

“Appendix to the Zoanthee, : : : : : 6 : : 52
Stephanidium, . : ; : : : 3 : : 3 52
Stephanidium schulzi, . : . é p ; ; : 52

V. CERIANTHEA, j ; j : 5 : : ; : ‘ 54
Cerianthide, : : : : : ; : ‘ : ‘ 54
Cerianthus, . : 3 : : i : f c ; 54
Cerianthus membranaceus, ; : j : : § ; 54

UNDETERMINED SPECIES, : ‘ ‘ 5 : ‘ R ‘ 5 : 54

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PLATE LI.

The lettering is the same in all the figures.

ew Cuticula. me Mesoglcea.
ec Ectoderm. | ms! Upper circular muscle,
en Endoderm. | ms* Lower circular muscle.
g Generative organs. | o Ova.
h Mesenteries. | r Marginal spherules.
am Intermediary layer. | sr Siphonoglyphe (cesophageal groove).
m Muscle-fibres. | t Tentacles.

All statements given as to magnifying powers have reference to Zeiss’s system,

Fig. 1. Zoanthus dane.
{ Fig. 2. Epizoanthus elongatus.

Fig. 3. Epizoanthus thalamophilus,

Fig. 4. EHpizoanthus stellaris.

Fie. 5. Corticifera tuberculosa.

Fig. 6. Corticifera lutea.

Fig. 7. Palythoa anguicoma.

Fie. 8. Amphianthus ornatum; x 4.

Fie. 9. Aulorchis paradoxa ; genital tube exposed by splitting the lip and the
stomatodzeum.

Fig. 10. Aulorchis paradoxa; siphonoglyphe, stomatodeum, oral disc, and
mesenteries exposed on removal of about one-third of the animal.
Fig. 11. Sphenopus pedunculatus.
Fig. 12. Zoanthus confertus.
Fig. 13. Liponema multiporum ; oral dise and stomatodeeum evaginated.
Fie. 14. Stephamdium schulzw; x 30.
Fig. 15. Epizoanthus cancrisocius.

(Figs. 1-7, 11, 12, 15 are after Erdmann.)

The Voyage of H.M.S’Challenger’

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PLATE ILI.

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me Mesoglea.
ms' Upper circular muscle.

o Ova.

r Marginal spherules.
sr Siphonoglyphe (cesophageal groove).
t Tentacles.

|
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All statements given as to magnifying powers have reference to Zeiss’s system.

Fig. 1. Portion of the circular muscle of Hormathia delicatula, D, Oc. 2, somewhat

jiminished.

Fig. 2. Ilyanthopsis longifilis ; musculature of the oral disc. */;., Oc. 1.

Fig. 3. Hormathia delicatula ; musculature of the oral disc. D, Oc. 2,

Fig. 4. Circular muscle and marginal spherules of Liponema multiporum. A, Oc. 1.

Fig. 5. Muscle-pennon of Halcampa kerguelensis. A, Oc. 2.

Fie. 6. Dysactis crassicornis ; transverse section through a tentacle. a*, Oc. 2.

Fig. 7. Portion of the tentacle represented in fig. 6, more strongly magnified.
AN, Oye, Ak.

Fie. 8. Phellia spinifera ; transverse section through the musculature of the oral
dise; H; Oe: 2:

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The lettering is the same in all the figures.

cu Cuticula. me Mesogleea.
ec Ectoderm. ms! Upper circular muscle.
en Entoderm. ms* Lower circular muscle.
g Generative organs. o Ova.
h Mesenteries. r Marginal spherules.
im Intermediary layer. sr Siphonoglyphe (cesophageal groove).
m Muscle-fibres. t Tentacles.

All statements given as to magnifying powers have reference to Zeiss’s system,

Fig. 1. Circular muscle of Stephanidium schulzi ;—1a, in the region of an inter-
mesenterial chamber and of a marginal spherule; 10, in the region of the origin of a
mesentery.

Aulorchis paradoaxa (figs. 2-6).

Fig. 2. Transverse section through the oral disc. A, Oc. 1, somewhat diminished.

Fig. 3. Parts of a transverse section through the circular muscle, showing the
connection of the endodermal and mesoglceal muscle-layers: 3a, with D, Oc. 1; 30,
with KH, Oc. 1.

Figs. 4, 5. Sections through the stomidia. a, Oc. 1.

Fig. 6. Transverse section through the mesogleeal musculature of the oral disc,

D, Oc. 1.

Fig. 7. Stephanidium schulzu ; upper edge of the body-wall, x 60.

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PLATE IV.

The lettering is the same in all the figures,

ow Cuticula. me Mesogloa.
ec Ectoderm. : ms! Upper circular muscle.
en Entoderm. | ms* Lower circular muscle.
g Generative organs. | o Ova.
h Mesentevies. r Marginal spherules.
um Intermediary laver. sr Siphonoglyphe (cesophageal groove)
m Muscle-fibres. t Tentacles.

All statements given as to magnifying powers have reference to Zeiss’s system.

Aulorchis paradoxa (sections through the genital tube, figs. 1-6).

Fig. 1. Connection of an ovum with the endodermal epithelium, probably by means
of a thread apparatus (‘“‘ Faden-Apparat”). E, Oc. 2.
Fig. 2. Surface view of the germinal layer. I, Oc. 2.

to)
Fig. 3. Longitudinal section through the germinal layer. , Oc. 2.
Fig. 4. Transverse section through the lower part of the genital tube. A, Oc. 2.
Fig. 5. Transverse section through the upper part of the genital tube, in the region

of the oral disc; the central detritus, which is probably produced by degradation of
epithelium, is omitted in the drawing. A, Oc. 2.
Fig. 6. Epithelial layer from the interior of the genital tube (cf. fig. 4). HE, Oc. 1.

Fig. 7. Hpizoanthus thalamophilus; section through the circular muscle (after
Erdmann).

Fig. 8. Horizontal section through the external and the invaginated portions of the
body-wall of Epizoanthus thalamophilus (after Erdmann).

fig. 9. Hormathia delicatula, Portion of the partly invaginated body-wall cut out
and magnified slightly. The invaginated part bears the parietal spherules.

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‘TheVoyage of HM.S “Challenger.”

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THE

NONE Gat OR OEE MS: CHALLENGER.

LOOLOGY.

REPORT on the Pennatutipa dredged by H.M.S. Challenger during the years
1873-1876. By Professor ALBerr v. Kérxixer, FMRS.. &e., &e.

Ty accordance with the request of Sir Wyville Thomson, I undertook the description of
the Prnnarutipa collected by the Challenger Expedition. With the exception of
Umbellula thomsoni, the whole collection came into my hands in April 1879. I devoted
the whole of the succeeding summer to the investigation, and sent my MSS. with a
number of plates drawn by Mr Rabus of Wiirzburg, to Sir Wyville Thomson in the begin-
ning of August of the same year,

Want of time, and the nature of the material forwarded to me, prevented me from
going deeply into anatomical details, and there was, perhaps, the less reason for my doing
so, as my monograph of the Pennatulida (Anatomisch-systematische Beschreibung der
Aleyonarien, Frankfurt, 1872) gives to those who have a special interest in this department
an opportunity of gaming a clear insight into the structure of the group.

The following is a description of all the Challenger PeNNarutma according to the
classification given at the end of this paper :—

Order voENNAD ULE DA:
Section lL. PENNATULES.
Sub-section I. PENNIFORMES.
Family 1. Prerormip2.
Pteroeides, Herklets.

1. Pteroeides esperi, Herkl,

This species is represented by five entire specimens of different ages, and a larger
number of fragments. All were collected at Station 212, lat. 6° 55’ N., long. 122° 15’ E.,
off Mindanao, one of the Philippine Islands, on the 28th ae 1875, at depths of 10,

_ 14, and 20 fathoms.

(ZOOL. CHALL, EXP.—PART 11,—1880.) Bl

2 THE VOYAGE OF H.M.S. CHALLENGER.

The larger and more fully developed specimens correspond pretty closely with my
Pteroeides esperi, var. latifolia, which was collected by Professor Semper at nearly the
same locality (near Bohol); but the Challenger specimens, like those of Professor
Semper, vary in the form of the leaves, which are also larger in some specimens and
smaller in others, in colouring, and in the number of the leaves and the number of
their spines.

The largest perfect specimen measures 132 mm. in length, of which 99 belong to the
pinnuliferous part, and 54 mm. in breadth. The broadest imperfect specimen is 80 mm.
broad, and the pinnuliferous portion 84 mm. long. The number of leaves in both speci-
mens is twenty-five, and that of their spmes eight in the first and ten to twelve in the
second.

2. Pteroides breviradiatum, Koll.

Two well-preserved specimens, with the label, “6th May 1875, Yokohama, Japan,
5-25 fathoms.”

The larger of these specimens measures 180 mm. in length and 100 mm. in breadth,
the other is 145 mm. long and 85 mm. broad. They are identical in structure, and
agree pretty well with my variety latifolia. The whole polypidom is colourless, with the
exception of the polypiferous border of the pinnee, which is pale blue.

Sarcophyllum, Koll.

Sarcophyllum grande, Gray. j ’

Three fragments with the label, “ Port J ackson, 6-15 fathoms.”

All three are colourless, and rich in small calcareous needles in the polypiferous zone
of the pinnules.

‘Family 2. PENNATULIDA.
Pennatula, L.

1. Pennatula naresi, n. sp. (Pl. I. figs. 1, 2).

Polypidom large, red and yellow in colour; pinnules triangular, hard, not transparent ;
polyp-cells alternating, numerous, with eight long spines; polyps with small calcareous
spicules in the tentacles and in the stomach walls ; zooids lateral and ventral, the latter
in sets beginning at the ventral borders of the pinnules.

Feather more than double the length of the stalk, and more than four times longer
than broad.

Pinnules twenty-nine, of which the lowest six or eight are rudimentary; the exact form
of these could not be determined, as this portion of the single specimen is defective. The
fully-developed pinnules are triangular, with a curved free end. The expanded base is

REPORT ON THE PENNATULIDA. 3

placed very obliquely on the rachis, so that its dorsal portion, which reaches the
middle line of the rachis, runs in a longitudinal direction. The ventral margin of the
pinnule is concave, thickened, and beset with irregular wart-like protuberances; whilst the
dorsal convex berder bears the closely set polyp-cells, thirty to thirty-four in number, which
alternate in such a manner as to give the appearance of two rows. Besides the more fully-
developed cells, each pinnule has at the dorsal end of its polypiferous margin from three
to five smaller or rudimentary cells, which are not to be confounded with the zooids. The
polyp-cells are in part well separated, and together with the eight strong spines at their
opening, 3 to 4 mm. long; in part shorter, more or less confluent; and some are as if
imbedded in the pinnules, and only free at their openings.

The rachis is nowhere free on the dorsal side of the feather, but on the ventral
aspect its middle line is not covered by the zooids. These are ventral and lateral.
The ventral zooids form thick prominent yellow spiny bands, which begin at the
ventral margin of the pinnule at a little distance from its attachment, run obliquely
upon the sides of the rachis, and end with a longitudinal streak, the point of
which reaches the next band of zooids, so that all the ventral zooids together form
one continuous line on each side, giving offsets to each leaf. The zooids them-
selves are crowded on each band, larger and smaller, and largest in the neigh-
bourhood of the pinnule. The lateral zooids fill the intervals between the leaves,
are numerous toward the ventral side of the rachis, where they reach the ventral
zooids, and run out with a single row at the outside of the dorsal attachnrent of the
pinnule ; they are all much smaller than the ventral zooids, but they are also armed
with projecting spines.

The stalk is thickened at the upper end, and seems to terminate inferiorly in a
rounded pomt. The colour of the whole polypidom is generally red, and darker on
the stalk, with the exception of its lower end which is pale red, becoming colourless
towards the tip. The feather is pale red, with the exception of the polyp-cells
and ventral zooids, which are yellow. The axes of the polyps and their stomach-walls are
also red. All coloured parts owe their colour to calcareous needles of characteristic form.
Uncoloured calcareous bodies are found at the lower end of the stalk.

Maximum length of the yellow needles of the polyp cells, . 1 mm.
Breadth, . : : f : 0:058
Maximum length of the red parentes of the pinnae, . ; : 0°85 to 0:90
Width, . 4 6 : : 0-021 ,, 0:027
Uncoloured bodies of the and of te stalk, ee or alipie: il, : ; 0-004 ,, 0-015
Length of the whole polypidom, 5 “ : 3 : 300

Length of the stalk, : , ; : : : 84

Breadth of the feather, . 5 : Z F 3 : 43

Breadth of the stalk, : : : : ; - 8

Breadth of the enlar; nent of the stalk, . : : : : 10°5

Breadth of the base of the pinnules, : : 5 : . 17-19

4 THE VOYAGE OF H.M.S. CHALLENGER.

Habitat.—A single specimen from Station 232, south of Yeddo, Japan, lat. 35° 11’
N., long. 139° 28’ E. Depth, 345 fathoms. Sandy mud. Bottom temperature, 5° C.
May 12, 1875.

Pennatula naresi at first sight somewhat resembles P. grandis, Ehrenberg (P.
borealis, Sars, Ptilella grandis, Koren and Danielssen), but on closer inspection the
differences are numerous and great. Before entering into this subject, I wish to say that
I cannot accept the genus Ptilella of Gray, which has been defined by him as follows :—
“ Pinnules membranous, broad, rounded, fringed with three close parallel series of short
polyp-cells on the edge. Rachis granular on each side behind without any spines.”
Koren and Danielssen have accepted the genus Ptilel/a, and define it as follows :—‘ Very

large sea-pens, with large, broad, semilunar fins bearing several rows of polyp-cells. The
ventral surface naked. The zooids lateral, extending towards the centre of the dorsal surface.
On the ventral margin of the fins strongly developed zooids. The sexual organs in the
fins. On the upper part of the stalk a fleshy enlargement. The axis is thick and round,
curved downwards in the form of an §, terminating in a hook, while in the upper part it
terminates in a volute.” With regard to this definition I have to add, (1) that Penna-
tula grandis, Ehrb., has very fully developed ventral zooids, which are tolerably well
represented in fig. 2 of Sars; and (2) that this species has also a row of zooids at the
dorsal end of the polypiferous margin of the leaves on the ridge, with which each leaf runs
out upon the rachis. Now, if we define, as I have done, the Pennatulidee as sea-pens with
well-developed leaves, which bear the zooids principally upon the ventral surface of the
rachis ; and the genus Pennatula as a pennatulid the leaves of which are beset in their
totality with calcareous needles, whilst these are found only in the polypiferous zone, in
the genera Ptilosarcus and Leioptilum, and are totally wanting in Halisceptrum,—
Pennatula grandis is a true Pennatula. At all events, | would rather unite the genera
Ptilosarcus and Leioptilum with Pennatula than subdivide the Pennatule on ground so
slight as the number of rows of polyp-cells, the size of the enlargement of the stalk, the
disposition of the zooids in each group, or even the presence or absence of zooids on the
ventral and dorsal margins of the leaves.

2. Pennatula pearceyi,’ n. sp. (Pl. I. fig. 5).

Small, of a reddish colour, with four to five polyps on the margin of the small
lanceolate pinnules. Zooids ventral and lateral, two to four in each set, small, all of
the same size. Feather more than double the length of the stem.

Pinnules thin, transparent, slender, obliquely attached to the rachis, 3 mm. broad at
their base. Ventral margin of the pinnule straight, dorsal margin with obliquely disposed
polyp-cells, and thus appearing serrated. Free end of the pinnule formed by one polyp-cell.

Polyps four to five on the dorsal margin of the pinnule, and two to three small

1 Named after Mr Frederick Pearcey, an excellent assistant attached to the Civilian Staff.

REPORT ON THE PENNATULIDA. 5

zooid-like individuals on that part of the margin which runs out upon the rachis.
Polyp-cells of the larger polyps united inferiorly, free at their ends, which are surrounded
by short spies.

Ventral zooids, three in number, longitudinally disposed at the base of each pinnule.
Lateral zooids, three to four, at the dorsal side of the ventral zooids along the base of the
pinnules. All the zooids are small, white, and surrounded by red spicules.

Rachis small, thicker than the stem. Colour of pinnules and rachis pale red, polyps
white. Stem white, with a small enlargement at each end. Calcareous needles of the
common type; the red needles of the feather measure 0°53 mm. by 0°028 mm. Colour-
less needles of 0°15 to 0°20 mm. in length, and 0-020 to 0°026 mm. in breadth, are
situated in the cutaneous layer of the upper part of the stalk, and the end bulb contaims
minute oblong and round calcareous corpuscles of 3 to 12 p. The Challenger collec-
tion contains two specimens of this Pennatulid, one pretty well preserved and a second

in a fragmentary state.

A. B.
Length of the feather, : : 5 : : ‘ 44 mm. 51
Length of the stalk, . : ; : : ; 5 21 20°5
Length of the pinnules, ; : : : : 5 11
Breadth, S F : : , ‘ : : 2:5—3:0
Breadth of the rachis, . : : 5 : : : 15

Habitat.—Station 235, south of Japan, lat. 34° 7’ N., long. 188° 0’ E. Depth,
565 fathoms. Bottom temperature, 3°-3C, June 4, 1875.

3 Pennatula murrayi, n. sp. (Pl. II. figs. 6, 7).

Small, yellow and red in colour. Pen twice and a half as long as the stalk. Pinnules
lanceolate, triangular, transparent, with nine to ten polyps on their margin ; calyces with
well developed spines. Zooids ventral and lateral, the ventral of two kinds, two large at
the base of each pinnule and many smaller, forming one longitudinal row on each side.

Pinnules lanceolate, thin, transparent, yellow, with a vermilion-coloured ventral
border; twenty-one to twenty-two in number, attached nearly parallel to the longitudinal
axis of the rachis, but so that the dorsal upper end of their base reaches the dorsal middle
line.

Polyps nine to ten on the more developed pinnules, placed in one single row on the
dorsal margin ; calyces the colour of minium, with eight well-developed spines.

Rachis yellow, with ventral and lateral zooids. The ventral zooids are of two kinds.
Larger spiny and reddish zooids, two in number, are situated at the base of each pinnule
just opposite the middle part ; smaller and whitish rudimentary polyps are disposed in
one single row on each side between the larger ones. Zooids of the same kind are also
placed laterally between the pinnules in a single or partly double row, so that they are
only visible from the ventral side of the feather. The lower part of the rachis of the only

6 THE VOYAGE OF H.M.8. CHALLENGER.

specimen of this Pennatula was evidently beset with small pinnules, of which remnants
were still visible ; the exact number of these could not, however, be determined, therefore
the number of twenty-one to twenty-two is only approximate.

The stem has an enlargement at the upper end, the upper part of which is of the
same sulphur-colour as the rachis, while the lower portion is colourless like the rest of
the stem. ‘This lower part diminishes in size till near the end, where there is a small
swelling or bulb covered with minute papillee only visible under the microscope.

The whole feather, with the exception only of the polyps, is furnished with a large
number of yellow and red calcareous needles of the form common in the Pennatulidee.
Yellow needles are also found in the stem where it is coloured yellow. The lower
part of the stalk is destitute of calcareous bodies with the exception of the end-bulb,
which contains very small round and oblong calcareous corpuscles.

The only polypidom at my disposal was of female sex, and the eggs were situated in
the pinnules.

Length of the whole polypidom, .. . : 0 ; : 140 mm.
Length of the whole stalk, . : 2 : : ; : 40
Length of the whole feather, 3 : : 0 : 0 100
Length of the longest pinnules, 6 ‘ 6 5 : : 17
Breadth of the pinnules at the base, : : : : é 53
Breadth of the upper enlargement of the stem, 3 0 : 3 3°30
Maximum length of the yellow needles, : : a : : 1:28
Maximum breadth, : j ' F : : ; 0-085
Maximum length of the red needles, y “ 0 5 . 0°85
Breadth of the red needles, . : ; : : ; : 0-041
Calcareous bodies of lower bulb of stalk, . : : : ; 0-007-0-011

Habitat.—Station 192, on the south-east of Ceram, west of New Guinea, lat. 5° 42’
S., long. 132° 25’ E. Depth, 129 fathoms. Mud. September 26, 1874.

4, Pennatula moseleyi, n. sp. (Pl. I. figs. 8, 9).

The Challenger collection contained only one specimen of this remarkable species,
consisting of a fragment of the pen 138 mm. in length; but this fragment showed |
characters sufficiently marked to cause it to be recognised as a good species. Polypidom
large, intensely red. Pinnules thick, not transparent, crowded, triangular and lanceolate,
curved at thew free end, and with thirty to thirty-four polyps in two or three rows on
their border. Polyp-cells with spines. Zooids of two kinds, the ventral beginning at the
border of the leaves, large and spiny, the lateral small.

Pinnules twenty-six in number on each side of the fragment, of which the upper end
is wanting. Form of the pinnules nearly triangular or lanceolate. Their broad basis
obliquely attached to the rachis, the polypiferous dorsal border convex and much longer
than the concave ventral margin, so that the free end of each pinnule is curved like a hook.

REPORT ON THE PENNATULIDA. 7

Polyps arrayed in two or three rows on the dorsal margin of the pinnules, with weli-
separated cells or calyces 3 mm. in length, the apertures of which are surrounded by
eight strong spines. Total number of polyps on a leaf 30 to 34.

Rachis of a medium thickness, with two kinds of rudimentary polyps or zooids.
One set, the ventral zooids, consists of a row of larger spiny zooids, which begins at
the ventral margin of the pinnules, at 3 to 4 mm. from their attachment, runs
obliquely towards the ventral side of the rachis, and there changes its direction so as to
become longitudinal. Each row has the aspect of a curved spiny ridge, and shows the
openings of the zooids as whitish points arranged in one single series.

The lateral zooids begin with a large crowded mass at the dorsal side of the ventral
zooids, but as soon as they reach the interspace of the pinnules their number greatly
diminishes, and they end with a double or single row near the dorsal attachment of the
pinnules. These zooids have only small spines or none at all, and look more like small
rounded or conical papillee.

The rachis has between the zooids on its ventral side a free space of 2°5 to 4:0 mm.
in breadth, and looks here as if it were beset with little papille or wart-like bodies. In
one part of the pen some two or three zooids seem to occupy a portion of the groove.
The dorsal side of the rachis is destitute of a free middle line, as the leaves somewhat
overlap each other.

The colour of the whole fragment, which is deep red, is occasioned by red spicules
lying in the integument. The greatest number of these is found in the polyp-cells, and
on both margins of the leaves, while the surfaces of the latter are pale red and whitish.
A whitish colour is also found on the ventral side of the rachis, but this is only produced
by the thick epithelium of this part, which contains many thread-cells, while the
subjacent cutis is red. The polyps themselves are not coloured, and the same holds
good of the whole interior of the pinnules and the rachis. The spicules are of the typical
form of those of the Pennatulide, with a maximum length of 1:14 to 1:2 mm., and a
maximum breadth of 0°058 mm. The minute and microscopic structure of this Pen-
natula corresponds, as far as I can judge, with that of the Pennatula rubra described
in my monograph; but I have to remark that in the Challenger example the calcareous
axis is wanting, having evidently been torn out of the fragment by accident.

The fragment belongs to a female polypidom, and the eggs are found in the pinnules.

Length of the pinnules measured in the curved state, 1
Breadth at base, - ; : : . : : 3 0-1
Breadth at their free end without the polyp-cells, . : : : : 3-4
Breadth of the rachis, : = 5-6

Habitat.—Station 164, off Sydney, Australia, lat. 34° 8’ S., long. 152° 0’ E. Depth,
950 fathoms. Temperature, 2°°2 C. Grey ooze. 12th June 1874.

8 THE VOYAGE OF H.M.S. CHALLENGER.

5. Pennatula sulcata, n. sp. (Pl. IL. figs. 3, 4).

General character of Pennatula rubra and Pennatula fimbriata ; colourless, with a
deep groove on the dorsal side of the rachis; the leaves are very numerous; ventral and
lateral zooids are present, the latter of which are also visible on the dorsal aspect of the
rachis. Besides these there is a long row of zooids at the dorsal end of the polypiferous
margin of the leaves.

Feather more than twice the length of the stalk.

Pinnules thin, transparent, closely set, twenty-six to twenty-seven in number,
lanceolate or triangular. Base of the pinnule attached transversly to the rachis. Ventral
and dorsal margin straight, the latter beset with one row of polyp-cells, alternating so as
to produce the appearance of two rows, especially near the dorsal end of the border.
The polypiferous margin of each pinnule ends in a long narrow ridge, which runs
obliquely upon the dorsal side of the rachis, as far as the base of the next pmnule. This
ridge is merely a single row of small zooids about twenty-seven in number, and of the size
of 0°10 to 0°12 mm., which I call the zooids of the dorsal margin of the pinnules.

Polyp-cells small, crowded, twenty-four to twenty-six on the larger pinnules; and
pretty well separated, with eight strong spines.

Rachis with a groove on its dorsal side, which begins shallow between the lowest
pinnules, assumes a depth of 3 mm. toward the middle of the feather, and runs out at its
upper end. This groove is narrow where it is deepest, and bordered by sharp whitish lips.
The calcareous axis lies inside at the bottom of the groove, and shines through the thin integu-
ment as a white streak. The ventral side of the rachis is covered on its sides by small zooids,
while the middle line is smooth. These ventral zooids are small wartlike or conical bodies,
0-2 mm. in breadth, all of one kind with this exception only, that those near the pinnules
have their calcareous needles projecting, and resemble small spines, whilst the others are
rather rounded protuberances. These zooids are continuous between the pinnules with very
numerous lateral zooids of rounded form, which run up to the dorsal aspect of the rachis, and
reach as far as the ridges of the pinnules described above, on the side of which they end
with a pointed train. The stalk is short, enlarged in its upper part, and pointed at the end.

With segard to the internal structure I have only to make the following remarks :—The
egos are found in the leaves, and, as it appears, also in the stalk, as in Pennatula rubra,
if we may judge from the fact that the stalk contains on both sides a crowded mass of
egos along the attachment of the pinnules. Calcareous corpuscles are found in the whole
integument. In the polyps short stout needles of 0°11 to 0°20 mm. he in the stem of the
tentacles. The polyp-cells contain needles of 0°86 mm. maximum length, and 0°032 mm.
breadth. Those of the lateral and ventral zooids are numerous but smaller, and those of the
zooids of the pinnules are smallest, measuring only 0:081 to 0°10 mm. in length. Besides
these needles the rachis contains none except at the ventral side, where needles of 0°050
to 0°080 mm. are found in the lips which border the longitudinal groove.

REPORT ON THE PENNATULIDA. 9

The stalk is very rich in flat elliptical calcareous corpuscles resembling those of
Veretillum, the maximum size of which is 0'1 mm., while the greater majority are not
more than 27 to 54 u long, and many measure only 5 to 10 p.

Length of the stalk, c 2 4 ; j c 5 : 29 mm.
Length of the feather, . . 6 : : : : é : 58
Length of the longest pinnule, : é : ¢ . : : 20
Breadth of the longest pinnule at base, ‘ : : 3 . ; 4:5
Breadth of the longest pinnule at rachis, : : ; é : 3 10:0
Breadth of the longest pinnule at stalk, . : : : : 5 5:0

Habitat.—Station 203, Zebu, Philippines, lat. 11° 7’ N., long. 123° 7’ E. Depth, 10
to 20 fathoms. Mud. October 31,1874. One single specimen.

Halisceptrum, Herklots.

Halisceptrum gustavianum, Herkl., var. parvifolia, mihi. -

Of this form the Challenger collection contains four fragments, from Station 212,
off Mindanao, one of the Philippines. Lat. 6° 55’ N., long. 122° 15’ E. Depth, 10,
14, and 20 fathoms. Sand. January 30, 1875.

Sub-section II. VIRGULARIEZ.
Family 1. VirGULARID&.
Virgularia, Lam.

1. Virgularia bromleyi, n. sp. (Pl. IIL. fig. 10),

Of this species the Challenger got only one small fragment.

Polyps nearly sessile, so that there is only a very faint appearance of pinnules, and
they must at all events be called very small. Pinnules nearly opposite, each group about
4 mm. distant from its neighbours. Polyps with their cells 2°5 to 2°8 mm. long, three in
each pinnule, with pretty well-marked cells, the margin of which has no spines nor pro-
tuberances of any kind.

Rachis small, of 0°37 to 0°42 mm., with lateral zooids disposed at the base of the leaves
in one single row of three individuals.

Axis round, 0°38 mm. in breadth, with well-developed radial fibres.

Caleareous corpuscles of the ordinary form of needles, 0°085 mm. maximum length,
are scantily found in the stalk, the rachis, and the tentacles of the polyps.

Habitat—Station 235, South of Japan, lat. 34° 7’ W., lone. 138° 0’ E. Depth, 565
fathoms. Bottom temperature, 3°3 C. Mud. June 4, 1875.

(ZOOL, CHALL, EXP.—PART 11.—1880.) B

9

10 THE VOYAGE OF H.M.S. CHALLENGER.

2. Virgularia gracillima, n. sp. (Pl. II. fig. 11).

A fragment of a Virgularia may be so named provisionally, as it seems to differ
from all known species.

Pinnules very small, about 0°85 mm. high, and 1:1 mm. distant from each other.

Polyps four on each pinnule, without well-marked cells.

Rachis small, with a breadth of 0°48 to 0°51 mm. in the middle part, and of 0°62 in
the region of the undeveloped pinnules.

Zooids.—(?)

Axis round, yellow, 0°42 mm., large in the lowest part of the rachis, with the typical
well-developed radiating fibres. Length of the whole fragment 77°5 mm.

Habitat.—Station 167a, Queen Charlotte Sound, near Long Island, New Zealand.
Depth, 10 fathoms. Mud. June 27, 1874.

Scytalium, Herkl.

1. Scytalium sarsi, Herkl. (Pl. IV. figs. 14, 15).

Of this remarkable species, the habitat of which has been hitherto unknown,
the Challenger got five more or less well-preserved specimens; these agree specifically
with the only two specimens known, which are preserved in the Leyden Museum. The
only remark I have to make is, that the colour of the polypidom, which depends upon
calcareous corpuscles of an opaque red colour, varies very much. One specimen had
the whole rachis uncoloured, and only the polyp-cells and stalk red. In a second the
rachis was uncoloured below; the colour then began at the base of the pinnules on both
sides, but more intensely on the ventral side; and on both faces of the rachis, more on
the dorsal side; at length the whole rachis became red, with the exception of small
patches here and there on the ventral border of the leaves.

The measurements of the three better preserved specimens are—

A. B 6.
Length of the entire polypidom, “ ; 5 343 mm. 400 324
Length of the stalk, . . 5 : . q 52 48
Breadth of the stalk, . 3 1:7 3
Breadth of the rachis, . 27 1:3 1-0
Length of the base of the pinnules, 6-8 4-5 4:2
Length of the ventral margin of the pinnules, 6-8 4-5-5 4:0

Habitat.—Station 212, Philippines, lat. 6° 55’ N., long. 122° 15’ EK. Depth, 10, 14,
and 20 fathoms. Sand. January 30, 1875.

2. Scytalium tentaculatum, n. sp. (Pl. III. fig. 12, Pl. IV. fig. 13).
General appearance of Scytaliwm sarsi, in every part larger, less coloured, with
a long simple tentacle at every, polyp-cell.

REPORT ON THE PENNATULIDA. 11

If this form did not present the very remarkable feature of the tentaculated polyp-
cells, of which fig. 13 representing a young leaf gives a very good idea, nobody would
entertain a doubt of its being only a stout form of the long-known Scytalium
sarst. But the tentacles, which are found on every polyp-cell, and, as the younger
leaves show, are developed before the polyps, make it necessary to describe it under
a new name, so long as no intermediate forms between it and Scytalium sarsi
are found. Besides this, the size of the most developed polypidom and the colour
deserve attention. The largest specimen was only coloured (1) in the region of the
polyp-cells, but not everywhere on all leaves, and not on all cells of the coloured leaves,
and (2) on the upper part of the stalk. A second specimen was nearly colourless, with the
exception of the upper end of the stalk. Two others, on the contrary, were pretty strongly
coloured on the stalk, the rachis, and the base of the leaves. As a difference between the
two forms I may also mention the form of the lowest undeveloped leaves. In Scytaliwm
tentaculatum these form a short series, and the leaves assume very near the end the form
given in fig. 13, whilst in Scytaliwm sarsi the row of these pinnules is longer, and
many of them are remarkable from the fact that the polyp-cell near to the ventral
surface is larger than the rest. The calcareous corpuscles are the same as those in
Scytalium sarsi, only their maximum length is a little less on the stalk, in Scytalium
tentaculatum 38 p, in Scytalium sarsi 53 pu.

Four well-preserved specimens were at my disposal, of which I here give the following

measurements :—

: A. B. © D.
Length of the whole polypidom, 2 : 620 mn. 340 330 90
Length of the whole stalk, , ; ; 92 71 17 33
Length of the base of the pinnules, 12-15 6-8 6-8 8-9
Length of dorsal border, . 7-9 5) 5-6 5
Breadth of the stalk, p . 3) 4 4 lg)
Breadth of the rachis, . ; : : 36 2 2 2:0
Number of pinnules, . : : 101 17

Length of the tentacles at the polyp-cells in adult leaves 0°58 mm.
Length of the tentacles at the polyp-cells in young pinnules 0°80 to 1:0 mm.

Habitat.—Station 203, Philippines, lat. 11° 7’ N., long. 123° 7’ E. Depth, 10 to 12
fathoms. Mud. October 31, 1874.

Section II. SPICATA.
Sub-section I. FUNICULINE®.
Family 2. STacHyPTILID&.
Stachyptilum, n. gen.
Small pens without leaves, polyps with cells in small rows of four on both sides, and
on the dorsal aspect of the rachis. Cells without stronger spines at their openings.

2

12 THE VOYAGE OF H.M.S. CHALLENGER.

Zooids ventral, lateral, and dorsal on all free surfaces of the rachis; all of one kind.
Stalk with a small zone of papille at the upper end. Axis pretty strong, round.
Calcareous corpuscles of different forms, needles on the cells and zooids, lenticular
bodies in the stalk, cylindrical corpuscles with three alternating ridges on each end in
the tentacles of the polyps.

1. Stachyptilum macleari, n. sp. (Pl. VII. figs. 24-26).

Feather a little longer than the stalk, uncoloured.

Polyp-cells in fourteen rows on each side, situated on the lateral and dorsal surfaces
of the rachis, the middle rows longer, with four cells, the inferior and superior shorter,
with three and even only two cells. All the rows oblique, and the dorsal cells a little
smaller than the ventral. Cells about 2 mm. in length, with strong needles 0°56 mm.
long and 0:037 to 0°043 mm. broad in their walls; these needles project more or less
at the openings of the cells, and form here and there regular spines, 1, 2, or 3 in
number.

Polyps with a strong band of calcareous corpuscles in the stem of each tentacle,
which are represented in fig. 26, and measure 0:027 to 0:060 mm. in length, and 0-016
to 0°028 in breadth.

The zooids are small bodies of 0°28 to 0°34 mm. in diameter, each of which is protected
at its lower side by a plate of strong needles of the same kind as those of the polyp-cells.
Besides these the mouth of each zooid has at its lower side a projecting two-lobed lip,
which might also be described as a divided short tentacle. These zooids cover every part
of the rachis which is not beset with the polyps, with the exception only of a very small
line on its ventral surface. The zooids go even further down than the polyp-cells, form
below the last of them about four regular rows on each side, and are also present in this
region on the dorsal and ventral surface of the rachis.

The stalk has at its uppermost part a zone of about 2 mm. in length, where it is
covered on its dorsal aspect, and on both sides by a crowded mass of small cylindrical
papillee of 0:17 to 0°19 mm. in length. The middle part of the stalk is whitish and the
end pointed. The end of the stem contains peculiar flat, oval, or biscuit-shaped calcareous
corpuscles of the length of 0°054 to 0°64 mm. :

Length of the feather, . : F : : : : : 42 mm.
Length of the stalk, j Rea niet te : ; i Dit : 32
Breadth of the feather, . : : 0 : 4 : : 8
Breadth of the stalk, : : 5 : ‘ : : ; 3°5
Breadth of the ventral side of rachis, j i F : : : 38

Habitat.—One single specimen from Station 192, south-east of Ceram, on the west

of New Guinea, lat. 5° 42’ S., long. 132° 25’ E. Depth, 129 fathoms. Mud. September
26, 1874.

REPORT ON THE PENNATULIDA. 13

Family 3. ANTHOPTILID&.
Anthoptilum, n. gen.

Polypidom without leaves, of the general appearance of Funiculina. Polyps in many
short rows on the sides of the rachis, large, without cells. At the lower end of the rachis no
prolonged streak of undeveloped polyps. Zooids lateral, ventral, and dorsal, all of one kind,
small, wart-like. Axis round. No calcareous corpuscles, except at the end of the stalk.

1. Anthoptilum thomsoni, n. sp. (Pl. V. figs. 16-18).

A large, magnificent sea-pen, with a short, thick stalk, long feather, and long polyps
crowded eight to ten in one row. Polyps often united at their bases. Zooids very
numerous. Rachis free only on the ventral side.

Stalk with a thick swelling at the upper part, and a smaller end-bulb, with short
pointed free end.

Polyps very long, without cells, and with long tentacles very seldom retracted.
These polyps are disposed in many oblique rows on both sides of the rachis, so as to
cover more or less completely its dorsal aspect. In the higher parts of the rachis it is
quite impossible to find a free surface on this side, whilst the reverse is the case below in
the neighbourhood of the stalk. On the other side the ventral surface of the rachis is
free in its whole length. With regard to the position of the polyps, I have further to
remark that very often the lowest parts of two, three, or more of them are united
_ so as to produce the appearance of very small pinnules, shorter even than those of
Pavonaria finmarchica, but in no place are all the polyps of one row united’in such a
manner. The tentacles of the polyps are very long, and provided with long, slender
branches (pimnules), which are remarkable from their moniliform appearance (fig. 18),
and the great number of small thread-cells situated in their single protuberances.

The zooids of Anthoptilum thomsoni are very numerous. The principal are lateral,
and lie between the rows of polyps; but these lateral zooids reach everywhere the
ventral surface of the rachis, and in many places the single lateral rows coalesce there
so as to form genuine ventral zooids. This coalescence, however, never takes place on
the greater part of the rachis, and generally coalesced lateral zooids alternate with
separated sets. On the dorsal side the zooids avoid the middle line where this line is
free of polyps, but where the polyps cover the whole dorsal surface the zooids are also
to be found everywhere. A peculiar feature of this sea-pen is that in many places little
groups of zooids reach as far as the base of the polyps themselves, and are also found
between the individuals of one row. The size of the zooids is from 0°40 to 0°58 mm.,
and their structure the ordinary one, inasmuch as they possess two well-developed
mesenteric filaments. With regard to the colour of Anthoptilum thomsoni, some specimens
are totally uncoloured ; others have all the polyps more or less brown, the stalk and
rachis on the contrary colourless,

14 THE VOYAGE OF H.M.S. CHALLENGER.

Caleareous corpuscles are only found very scantily in the muscular layer in the
lowest parts of the stalk. They are small oblong bodies of 7 to 22 p, which are
often united four together so as to form small star-like figures.

The axis is round, and of the common lamelliferous and fibrous structure. Its
radiating fibres are very numerous, but short.

The measurements of nine well-preserved specimens of Anthoptilum thomsoni are
as follow :—

A. B. G, D. E. F. G. H. ik
Length of the whole polypidom, 420mm. 560 530 362 422 410 400 360 440
Length of the stalk, . eg OD 87 75 63 67 75 65 61 57
Breadth of its enlargement, . 18 18 16 11 14 14 15 65 12
Breadth of the pen, . 0 25 a a
Length of the polyps with the

tentacles, . 19 WES © oan 20 13 18 17 12 16
Length of their tentacles 6-8... 7 @) :
Breadth of the rachis, . 8-9 10

Habitat—Station 320, Atlantic Ocean, south of Buenos Ayres, lat. 87° 17’ S., long.
53° 12’ W. Depth, 600 fathoms. Bottom temperature, 2°7 C. Hard ground.
February 14, 1876.

2. Anthoptilum murrayt, n. sp. (Pl. VI. figs. 19-21).

General appearance of Anthoptilum thomsoni, smaller, with smaller and less numerous
polyps, two to three in each row. Polyps all sessile, widely separated from each other.
Rachis without polyps in the middle line on both sides. Zooids more distant than in the
last species.

Stalk long, slender, without distinct enlargement.

Polyps disposed in oblique rows of two to three, seldom four, on both sides of the
rachis, which arrangement is not very apparent everywhere, all well separated from their
neighbours, and the dorsal smalJler than the ventral, with tentacles often far surpassing in
length the bodies of the polyps.

The zooids cover the whole rachis between the polyps, and leave only the middle part
of its ventral and dorsal aspect free. On the ventral side the zooids are situated on the
margin and form not more than one single row, which is even interrupted here and there
on the ventral side of the lowest polyps, whilst on the dorsal aspect they go nearer the
middle line, and leave only a small part of the rachis free. These zooids, which in no
case are situated on the bodies of the polyps as in A. thomsoni, measure 0°34 to 0°40 mm.
in width, and their distance from one another is equal to, or greater than, their diameter.
They have all two mesenteric filaments. The colour of the polypidom is pale red, the
polyps brown, while the rachis and stalk are usually colourless, and present only here
and there a light brown or pale rosy tint.

REPORT ON THE PENNATULIDA. 15

The axis is round, and tolerably strong.

Calcareous corpuscles in the end of the stalk oblong, of the same form and size as in
Anthoptilum thomsoni.

The measurements of the only specimen are—

Length of the whole polypidom, : . ; : 5 : : 510 mm.
Length of the whole stalk, : : : : , : 5 : 76
Length of the lower polyps, . : 5 5 ; ; : ¢ 6-10
Length of the tentacles, 0 : : : : : . ; 3-4
Breadth of the stalk, . : 3 : : : \ : ; 3-4
Breadth of the rachis, . - ; : - P : : : 4-55

Habitat—Station 50, North Atlantic, south of Halifax, lat. 48° 8’ N., long. 63°
39’ W. Onespecimen. Depth, 1250 fathoms. Bottom temperature, 2°°8 C. Grey ooze.
May 21, 1873.

3. Anthoptilum simplex, n. sp. (Pl. IV. fig. 22).

Polypidom colourless. Polyps sessile, widely separated, very large with a broad base,
two in each row. Rachis free on both sides in the middle line. Zooids numerous,
more elevated than in the other two species, and somewhat conical.

Stalk with an enlargement in the upper part.

Polyps long and large, resembling in size those of A. thomsoni, and measuring
without the tentacles 12 to 15 mm. in length, The tentacles, of which there exist only
traces on some polyps, seem to have been very long. A remarkable feature is the large
area of elliptical form upon which each polyp stands, and which may be regarded as a
broad base to the polyp.

The zooids are to be found in the same position as in the other species, and differ only
by their greater elevation on the surface of the rachis and their smaller size, as they
measure only 0°28 to 0°30 mm. in diameter. The ventral zooids form a single or double
series, and the dorsal a double or triple series.

Calcareous corpuscles as in the other species.

Measurement as follows :—

Length of the whole polypidom, . ; = : ¢ : : 400 mm.
Length of the stalk, d 5 ; 3 : 5 y : 5D
Breadth of the stalk, . : : ; : : : é 7
Breadth of the rachis, : , - ; A : : ; 4-5

Habitat.—One single specimen in a bad state of preservation, from Station 133, South
Atlantic, west of Tristan d’Acunha, lat. 35° 41’ S., long. 20° 55’ W. Depth, 1500 fathoms.
Bottom temperature, 1°3 C. Globigerina ooze. October 11, 1873.

16 THE VOYAGE OF H.M.S. CHALLENGER.

Sub-section II. JUNCIFORMES.
Family 1. KopHoBELEMNONID &.
Kophobelemnon, Absjérnsen.

1. Kophobelemnon ferrugineum, n. sp. (Pl. XI. fig. 43).

Rachis longer than the stalk, cylindrical and pointed at the upper end, of a clear brown
colour. Polyps short with broad base, retractile, at the oral side of the tentacles brown, and
dark brown in their inner cavities. Zooids large, numerous, of the form of pointed warts
or short spines, all obliquely directed upwards. Stalk with an end-bulb, externally of a pale
grey or greenish colour, internally brown. Calcareous bodies in every part of the structure,
in the form of shorter or longer slender needles, with warts and tubercles at the ends and
also in the middle. Those of the stalk shorter, thicker, and more warty and spiny.

The different species of Kophobelemnon are not easily distinguishable so long as their
structure is not thoroughly known; nevertheless, I think myself justified in separating
this form from those hitherto described. Fig. 43 is sufficient to show the external form and
the size of the species, and I have only to add that the longest calcareous needles of the
rachis and the polyps measure 0°57 to 0°71 mm. in length and 0°052 in breadth, and
the shortest on the stalk 0-09 to 0°10 mm. in length and 0°027 to 0°037 in breadth.

Habitat.—Station 232, south of Yeddo, Japan. One specimen. Lat. 35° 0" N., long.
139° 28’ E. Depth, 345 fathoms. Bottom temperature, 5° C. Sandy mud. May 12, 1875.

2. Kophobelemnon, sp. (Pl. XI. fig. 44).

A young Kophobelemnon, with only one polyp, and a pointed end to the rachis. It
resembles, by the occurrence of needles 0°54 mm. long and 0°070 mm. broad in the
tentacles, my KX. stelliferwm, var. durwm.

Zooids not numerous, in two rows on the ventral side of the rachis.

Habitat—Station 169, north-east of New Zealand, lat. 37° 34’ S., long. 179° 22° E.
Depth, 700 fathoms. Bottom temperature, 4°°2 C. Grey ooze.

3. Kophobelemnon burgeri, Herkl. (Pl. XI. fig. 45).

The Challenger brought home two specimens of this rare species, which I thought
right to represent in fig. 45, as their form is in some respects different from that
described and figured by Herklots.

Habitat—Station 209, Zebu, Philippines, lat. 10° 10’ N., long. 123° 55° 8. Depth,
95 to 100 fathoms. Bottom temperature, 21° F.C. Mud. January 22, 1875.

Family 2. UMBELLULID.
Umbellula, Cuv.
1. Umbellula durissima, nu. sp. (PI. VIII. figs. 32, 33).
Calcareous needles very numerous in every part of the cutis. Principal needles of

REPORT ON THE PENNATULIDA. 7,

the polyps and those of the tentacles of enormous length, 20 to 2°8 mm. Pinnules of
the tentacles brown. Zooids very numerous; the ventral forming a nearly continuous
plate. Rachis short, without a longer enlargement below. Stalk here and there very
light brown. Axis nearly cylindrical.

Of this very remarkable species I had only one young specimen at my disposal, and
it is, therefore, possible that the characters given are not fully sufficient. Nevertheless,
they are of such a kind that this form can be easily distinguished from all others at
present known.

The stalk has a long enlargement towards the lower end, with here and there a very
slight brown tint, the seat of which is in the longitudinal nutrient canals. Its calcareous
needles are extremely numerous, those of the upper part are 0°19 to 0°26 mm. long,
those of the lower half are shorter and broader, and measure 0°076 to 0°20 mm. in length,
and 0°019 to 0°045 mm. in breadth, all of them are warty, and have the typical three
edges, but those of the lower part show the first character better, while in the others
the edges are more prominent, and the surface less uneven. The breadth of the stalk
is 0°58 mm. in the upper part, and 1:0 to 1°4 and 2:0 mm. towards the base.

The rachis has the aspect of a flat rhomboid expansion of the stalk, which contains
the end of the axis in the middle, and bears on the dorsal side one large and two
undeveloped polyps. The whole ventral surface of the rachis, with the exception only of
a narrow middle line, is studded with wart-like zooids 0°28 to 0°42 mm. in size, which are
also found on the dorsal side of the rachis, on a small space below and between ‘the
polyps. Two or three zooids are also found on the end of the stalk in the neighbourhood
of the rachis, the lowest at a distance of 4 mm. from the great mass of zooids. All
the zooids are surrounded by calcareous needles, of the same size as the smaller needles
in the polyps, about 0°30 to 0°50 mm. in length.

This Umbellula is remarkable from the white colour of the body of its developed
polyp, and of the aboral aspect of the central stems of its tentacles, while all the pinnules
of the tentacles and their oral sides are of a deep brown. The white colour is occasioned
by calcareous needles, the largest of which, measuring more than 2°0, even 2°85, mm. in
length, and disposed in eight lines on the body of the polyp, are directly continuous
with those on the stems of the tentacles. The brown colour, on the contrary, lies in the
outer epithelium of the tentacles, and is brighter at the aboral side of the pinnulee, where
the epithelium is also strengthened by needles of about 0°30 to 0°34 mm. in length. The
undeveloped polyps are small, pyriform bodies of 2°0 to 2°5 mm. in length without
tentacles, but with large sized needles in eight rows.

The axis measures in the stalk 0°28 to 0°45 mm. in diameter. The length of the
whole polypidom including the polyp, 160 mm.

Habitat.—Station 234, North Pacific Ocean, south of Yeddo, Japan, lat. 34° 7’ N.,
long. 138° 0’ E. Depth, 565 fathoms, Bottom temperature, 2°°3C. Mud. June 4, 1875.

(ZOOL, OHALL, EXP,—PART 1.—1880,) B3

18 THE VOYAGE OF H.M.S. CHALLENGER.

2. Umbellula giintheri, n. sp. (Pl. IX. fig. 34).

Exquisitely bilateral. Calcareous needles very numerous in every part of the cutis,
none very large. Polyps disposed alternately, of a very light brown colour, very large,
with hard thick sarcosoma. Zooids very numerous, situated on the rachis and on the
stalk; those of the rachis cover every free part of it, with the exception of both middle
lines; and are, therefore, ventral, dorsal, and lateral. Those of the stalk are situated in
small numbers on irregular enlargements. Stalk strong, with well developed sarcasoma.
Axis quadrangular, with concave surfaces and rounded edges. Of this species also I had
only one imperfect specimen, which wanted the lower part of the stalk.

Stalk quadrangular, leneth 175 mm., broken below, where it measures 1°5 mm. in
diameter. It is beset with many irreeular but mostly spindle-shaped enlargements, where
it attains over 2°0 mm. in width, and shows invariably in these places a certain number of
zooids, of the form of those of the rachis but less prominent, all disposed irregularly, singly,
in pairs or more, even eight together, and in this case all in one longitudinal line. The
stalk, being broken in several places, it was impossible to make out on which side these
zooids were placed, only this, that they are situated on opposite aspects, and are probably
lateral. The needles of the stalk are of different sizes, longer in the upper, shorter in the
lower parts. All possess very distinct edges, and besides this a granular surface. Their
length is from 0°11 to 0°20 mm., and their breadth from 0°026 to 0°045 mm.

Rachis without inferior enlargement, and so evidently bilateral that it suggests a young
Kophobelemnon with only a few polyps. The ventral side shows a direct continuation,
a kind of keel, which ends with a bend or curvature where the uppermost polyp is situated.
Expansions at the sides of this keel, covered with zooids, are directly continuous with the
bases of the polyps, so that no other trace of demarcation exists, except that given by the
zooids. On the dorsal side the rachis shows a deep groove between the polyps, which is
totally covered with zooids, with the exception of a very small space in the middle line.
The polyps are very large, 44 mm. long, with the tentacles extended ; five well-developed,
and one rudimentary, and are disposed quite regularly on both sides of the rachis in the usual
alternating manner, so that the fifth developed polyp has its seat at the dorsal side of the
end of the rachis. The cutis of the polyps is studded with needles, which show this pecu-
liarity, that they are all about the same size in the same place. Those of the bodies of
the polyps measure 0°27 to 0°72 mm. in length, and 0°041 to 0°045 mm. in breadth, and are
in general disposed in a transverse direction. The same holds good of the needles of
the principal stem of the tentacles, only these are smaller, 0°38 to 0°62 mm. in length,
and 0:022 to 0°041 mm. in breadth. Those of the lateral branches or pinnules are
disposed lenethways on their aboral side, and measure 0°19 mm. in length, and 0:011
to 0:020 mm. in breadth. All these needles are three-edged, and slightly granular at
the end.

The zooids fill all interspaces between the polyps, and are in general conical bodies of

REPORT ON THE PENNATULIDA. 19

0-42 to 0°58 mm. in height and breadth at their bases. They are all surrounded with
needles, which frequently form a kind of cell ending with several points.

Habitat.—Station 106, Atlantic Ocean, a little north of the Equator, lat. 1° 47° N.,
long. 26° 46° W. Depth, 1850 fathoms. Bottom temperature, 1°°8 C. Globigerina
ooze. August 25, 1873.

3. Umbellula thomsoni, Koll.

(Von Willemoes-Suhm in Zeitschrift f. wiss. Zool., 1873; Kélliker in Wiirzburg.
Verhandl., Bd. viii., 1874, and in Die Pennatulide Umbellula und zwei neue Typen
der Aleyonarien, Wiirzburg, 1874, Festschrift, pp. 1-11, Taf. i. figs. 1-5.)

Indistinctly bilateral, colourless. Calcareous corpuscles in all parts of the sarco-
soma. Polyps forming a pendant bunch, with a distinct rachis containing the end of
the axis, which goes near the bases of the terminal polypi. Stalk quadrangular, with
a well-developed lower, but no upper, enlargement. Zooids on the ventral and dorsal
sides of the rachis; none on the stalk. Axis quadrangular, with excavated surfaces
and rounded edges.

For further details I refer to the paper above quoted, and only adjoin here the
measurements of the two specimens of this Umbellula.

A. B.
Length of the whole polypidom, . 6 : é : 895 mm. 270
Length of the lower enlargement of stalk, . . : . 80 55¢
Length of the polyps, . : . : : C 33-39 17
Length of the bodies of the polyps, . : . C , 18-2 10
Length of their tentacles, . of . : : ‘ 15-19 7
Breadth of the axis, : ; : , P ‘ 2°5 07
Number of polyps, . C : , : , : 13 5
Number of rudimentary polyps, : aC 5
Length of needles of tentacles, : C . 5 : 0:24-0°30
Breadth of needles of tentacles, ; : : : : 0:021-0:032
Length of needles of stalk at its lower end, : ; : 0-15
Breadth of needles of stalk at its lower end, 0-064

Habitat.—Station 7, North Atlantic Ocean, between Portugal and Madeira, lat.
35° 20’ N., long. 13° 47 W. Depth, 2125 fathoms. Bottom temperature, 2°°0 C. Mud.
January 31, 1873.

I add here some remarks on the Umbellule described by Joshua Lindahl (Om.
Pennatulid sleegtet Umbellula, Stockholm, 1874; Kongl. Svenska Vet. Akadem.
Handlingar, Bd. xii., No. 3). These Umbellule, ealled by Lindahl miniacea and
pallida, and brought together by me (loc. cit.) under the name of U. lindahli, come
very near my U. magniflora, but so long as we are unable to compare the different
forms, it will be impossible to decide whether they are identical or not, particularly
as the remoteness of the localities in which the Umbellule of Lindahl (in Baftin’s
Bay, lat. 70° 43’ N., long. 52° 3’ W., depth 410 fathoms ; and off the entrance of

20 THE VOYAGE OF H.M.S CHALLENGER.

Omenakfiord, North Greenland, lat. 71° 71’ N., long. 23° 58’ W., depth 122 fathoms)
and U. magniflora have been found militates a prior: against their identity.

The Crinillum siedenburgu of Van der Hoeven is, as I have shown, the basal
part of a Pennatulid, and no doubt of an Umbellula, as the axis has the same form as
that of most Umbellule.

Habitat.—Banda Sea, lat. 6° 40’ S., long. 126° 47’ E. Depth, 2700 fathoms.

4. Umbellula leptocaulis, n. sp. (Pl. IX. fig. 35).

Decidedly bilateral. Calcareous needles pretty numerous in every part of the cutis, none
very large. Polyps disposed alternately, of a light brown colour, large, with thin sarcosoma.
Zooids scanty, on the rachis only, ventral, lateral, and dorsal. Stalk quadrangular, thin,
with thin sarcosoma. Axis quadrangular, with concave surfaces and blunt edges.

Of this species I had at my disposal one smaller, perfect specimen (8), 150 mm. in
length, with three polyps; and the upper part of a larger one (a), with five polyps, con-
sisting of four fragments, and altogether 350 mm. in length.

The stalk is remarkable for its thinness. In A it measured 0°85 mm. in diameter
below, and 0°34 to 0°37 mm. in its upper part. In B there was an end-bulb of 0°42
mm., and the average breadth of the rest of the stalk was 0°42 to 0°28 mm.

In the polypiferous part the ventral side shows a small, keel-lke rachis, which bears
the polyps on both sides, so that there is no larger free ventral space as in Umbellula
durissima and Umbellula giinthert. The ventral zooids are, therefore, very few, and form
only a small series on both sides of the keel. The lateral zooids are represented by a
few individuals only, and the dorsal are also few in number, and disposed on a small
dorsal free space between the polyps. ;

The polyps, 27 to 30 mm. in length in 4, are thin in their sarcosoma, and show the
same arrangement of the calcareous needles as in Umbellula giintheri, with this excep-
tion, that the needles of the tentacles are all disposed parallel to the longitudinal axis of
the stems of the tentacles. The needles of the polyps in A measure 0°43 to 0°54 mm. in
leneth, and 0°027 mm. in breadth, and those of the tentacles 0:16 to 0°21 mm. Those
of the stulk measure in A 0°11 to 0°18 mm. in length, and 0°027 to 0°054 mm. in
breadth ; in B, 0'064 to 0°10 mm. in length, and 0°027 to 0°064 mm. in breadth. The
needles in the lower part of the stem are of the common type, the shorter granulated
and warty, and broader the shorter they are.

Habitat.—Station 181, South Pacific Ocean, south-east of New Guinea, lat. 13° 50’ S.,
long. 151° 49’ E. Depth, 2440 fathoms. Red clay. August 25, 1874.

5. Umbellula simplex, un. sp. (Pl. IX. fig. 36).
Decidedly bilateral. Calcareous needles numerous in every part of the cutis, none
very large. Polyps disposed alternately, colourless, small, rather hard. Zooids none.

REPORT ON THE PENNATULIDA. 21

Stalk cylindrical, thin, with a moderately thick sarcosoma. Axis quadrangular, with
concave surfaces and rounded edges.

The only specimen of this Umbellula brought home by the Challenger is evidently
young. Fig. 36 gives a clear idea of its appearance, so I mention only the following
details :—

The length of the whole polypidom is 108 mm., and that of the rachis with the polyps
23 mm. The polyps, four in number, are situated on both sides of a short and small rachis
in such a manner that the rachis with the axis seems to enter the uppermost polyp,
whilst the others lie on its sides, two on the left and one on the right side. The needles
in the bodies of the polyps are disposed transversely, and measure 0°5 mm. in length and
0:030 to 0:041 mm. in breadth. ‘Those of the tentacles are smaller, 0°27 and 0°21 mm.
placed longitudinally at the aboral side of their axes and pinnules, and transversely on
the oral face of the axes. All the needles are three-edged, and granulated only at their
ends. The calcareous bodies of the stem are short and broad, 0°10 to 0°18 mm. long, and
0:027 to 0:054 mm. wide oblong, slightly constricted in the middle, flat, and covered
with strong prominent warts.

Habitat.—Station 246, North Pacific Ocean, between San Francisco and Yeddo,
lat. 36° 10’ N., long. 178° 0’ E. Depth, 2050 fathoms. Bottom temperature, 1°°3 C.
Grey ooze. July 2, 1875.

6. Umbellula hucleyi, n. sp. (Pl. IX. fig. 37).

Indistinetly bilateral in the fully-developed state. Calcareous corpuscles none, except
in the end-bulb of the stalk. Polyps forming a cluster at the end of the stalk, with
traces of a bilateral arrangement, small, brown. Stalk with a long enlargement below,
ending in a kind of bulb, and a large thickening at its upper end, where it appears
flattened and curved in such a manner that the axis lies at the convex side. Zooids
numerous on the whole stalk and between the bases of the polyps, but none on the
dorsal side of the rachis between the polyps, all provided with one single tentacle.
Axis indistinctly quadrangular.

The Challenger brought home four specimens of this curious form, which being
different in size and age, gave me an insight into the development of the polypi-
ferous part. -

Two younger specimens had four and five polyps. One of these may be named
the terminal polyp, as the axis ends in its body, and in one specimen reaches even
as far as the line of attachment of the tentacles. Of the other polyps, two, which may
be termed the lateral polyps, are placed below and on the sides of the terminal polyp, and
the rest (one or two), which I call the dorsal polyps, on the dorsal side of the lateral
polyps.

Of the more developed specimens, one had seven more or less developed polyps,

22 THE VOYAGE OF H.M.S. CHALLENGER.

five small ones, and three wart-shaped and undeveloped. The terminal polyp was
bent in such a manner that it lay apparently at the dorsal side of the two uppermost
lateral polyps. Then succeeded three well-developed lateral polyps on the right side, and
on the left only one smaller. The dorsal polyps were six in number, five of which had
tentacles, but were small, the sixth being only rudimentary. Other two rudimentary
polyps were placed at the ventral side of the right lateral lower individuals.

The best developed polypidom of all (fig. 37) showed in the middle on its ventral.
side the terminal polyp in which the axis was not visible with the exception of its end.
Two large lateral polyps appeared on both sides, and between these and the terminal
individuals, but on the ventral side of the lateral, five young polyps and a rudimentary
one, the position of which is well shown by the figure. On the dorsal side four pretty
well-developed polyps lay between the lateral ones, two larger in the middle, one above
the other, and two smaller at the sides. Besides these, two very small polyps were
situated between the left dorsal, the left lateral, and the terminal polyp, and two rudimen-
tary ones at the same place on the other side.

Taken altogether, we may say that in the younger specimens the polyps show
a regular bilateral arrangement. A terminal and two lateral polyps are the first
expression of it. Then new buds arise, first on the dorsal, and then on the ventral
side, and these are in part also decidedly bilateral. But such buds seem likewise to grow
on the dorsal middle line, which fact would alter the symmetry. It may, however, be
supposed that these are also in reality lateral, and that the polyps of Umbellula are essen-
tially disposed in series on both sides of the rachis, which arrangement is veiled by
the shortness of their seat of attachment. :

The polyps of Umbellula huxleyi are dark brown in their upper parts and lighter
below; they have the tentacles shorter than the bodies of the polyps, and regularly beset
with short pinnule. A peculiar fact which was new to me is, that these polyps are
retractile, but this retraction takes place very seldom, and was only to be seen in one
specimen.

The stalk is somewhat rich in sarcosoma, especially at its enlargements, and shows
only faint traces of colour, both ends being pale. Its most remarkable feature is the
arrangement of the zooids, which are most numerous on the upper enlargement, which
they cover on every side, with the exception only of the dorsal and ventral -middle line.
From this point, the zooids throng to the polypiferous portion and pass on to the
terminal polyp nearly as far as the axis, whilst they end at the bases of the other polyps
entering for a certain distance in the spaces which separate them. In the interior of the
bunch of polyps no zooids are present.

The zooids just mentioned are visible to the naked eye, but the microscope is required
to ascertain that, as in the Umbellula giintherz, they are also present on the remainder of
the stalk and even on its lower enlargement. As far as I could ascertain without destroy-

REPORT ON THE PENNATULIDA. 23

ing the best specimen, they diminish gradually in number, and form a little below the
middle of the stalk, one row only on each side, the individuals of which are 1°5 to 1°7 mm.
apart.

The zooids of this Umbellula are large, 0°22 to 0°34 mm. in diameter, and have all one
cylindrical tentacle, 0°28 to 0°58 mm. long, and 0°057 to 0°085 to 0-014 mm. broad. These
tentacles were found in a very good state of preservation on the largest specimen, whilst
the others did not show them at all, or only traces of them. I presume that they were
not yet developed in the younger specimens; or that they are easily lost or not easily seen
in certain cases because they are retractile.

Calcareous corpuscles of oblong form, with even surfaces, are only found in the
muscular layers of the lowest part of the lower enlargement of the stalk. Their maximum
length and width is 26 and 8 p.

Size of the four specimens in millimeters—

A. B. c. D.
Length of the whole, . : 0 : 5 107 mm. 153 160 180
Length of the polypiferous part, ¢ : : 12 ile 119 16
Length of the upper enlargement of the stalk, : 8 10 30 41
Breadth of the same, . j ; : : 15 1:5 3 2°5
Length of the lower swelling, . : : é 19 23 3l 34
Breadth of the same, . ‘ : : , 1 2°3 1:9 25
Length of the polyps, . a é : 5 Ol S60 17 13

Habitat.—Station 235, North Pacific Ocean, south of Yeddo, lat. 34° 71’ N., long.
135° 39’ E. Depth, 565 fathoms. Bottom temperature, 3°°3 OC. Mud. Jume 4, 1875.

7. Umbellula carpenteri, n. sp. (Pl. X. figs. 38-40).

Indistinctly bilateral in the fully-developed state. Calcareous corpuscles only in the
lowest part of the stalk. Polyps forming a rosette at the end of the stalk, long, colourless.
Stalk with an enlargement at its upper end, which is directly continuous with the club-
shaped rachis, and having a long enlargement at its lower end. Stalk here and there,
but not in all specimens, with brown-red streaks and patches. Zooids numerous on the
dorsal and ventral sides of the rachis, and along the whole stalk; all provided with
one singly branched tentacle. Axis quadrangular, with deeply excavated surfaces and
rounded edges.

Five specimens of this Umbellula showed a very interesting gradation from a bilateral
to an apparently irregular arrangement of the polyps. One terminal and two lateral
polyps are shown in fig. 39, A, B. Four polyps all lateral, with a free end of the rachis
are visible in fig. 39, C. A third specimen had one terminal polyp, two lateral on the right
and one only on the left side. In a fourth there were eight polyps, of different sizes, so
disposed that they formed a rosette surrounding a small dorsal area of the rachis of a stellate

1 Tentacles retracted. 2 Named after my old friend Dr W. B. Carpenter, C.B., F.R.S.

24 THE VOYAGE OF H.M.S. CHALLENGER.

form, but amongst these polyps the terminal one was easily recognisable, as the axis
ended in its base, and the other seven could be interpreted as lateral polyps arising
from a shortened rachis. ‘The fifth specimen finally showed eight polyps, arranged
in the form of a rosette, and surrounding like a cup a ninth middle polyp; but
this was not the terminal one in which the axis ended, one of the eight had this signi-
fication.

The stalk has at its lower end a small bulb, which is continuous with a long enlarge-
ment, the transverse section of which is very evidently quadrangular. At the upper end
the stalk begins again to enlarge at a certain distance from the polyps, and forms a club-
shaped swelling directly continuous with the rachis. At this point the ventral surface is
convex from right to left, whilst the dorsal aspect is flat or shghtly concave. The whole
upper swelling is also generally curved longitudinally, convex on the ventral, concave
on the dorsal side.

The zooids show the same arrangement as those of Umbellula hualeyi; the only differ-
ences are, (1) that zooid-like bodies are situated between the polyps of the dorsal side of
the rachis, (2) that their tentacles, the length of which is 0°3 to 0°5 mm., are generally,
but perhaps not in every case, provided with two to three branchlets, and (3) that the
zooids seem to be fewer on the lowest part of the stalk. The calcareous corpuscles of the
end-bulb are of the same kind as those of Umbellula hualeyr but smaller, scarcely sur-
passing 15 p in length.

A. B. ©. D. E.
Length of the whole polypidom, é : 51-5 mm. 105 280 393 485
Length of the polypiferous part, : : 5 16 as 47 Se
Length of the polyp bodies, 75 11 15 16 14
Length of the polyps with tentacles, 42 ae 83
Breadth of the upper swelling of the stalk, 3) 3 6
Breadth of the lower swelling of the stalk, 2°0 2°3 3°5
Breadth of the stalk in the middle, 0°6 1:0 1:3

Habitats—Station 156, South Polar Sea, south-west of Australia, lat. 62° 26’ S.,
long. 95° 44° HE. Depth, 1975 fathoms. Diatomaceous ooze. February 26, 1874.

Station 157, lat. 53° 55’ S., long. 108° 55’ E. Depth, 1950 fathoms. Diatomaceous
00ze.

8. Umbellula magniflora, n. sp. (Pl. XI. figs. 41, 42).

General appearance of Umbellula huxleyi. Polyps forming a bunch at the end of the
stalk, without any trace of bilateral arrangement, and no distinct rachis. Stalk with a
long swelling below, and a flattened and curved enlargement at its upper end. Zooids
numerous on the upper enlargement of the stalk at the bases of the polyps, and also on
the lower swelling of the stalk and in its neighbourhood. Calcareous bodies none. Axis
quadrangular, with concave surfaces and rounded edges.

i)

REPORT ON THE PENNATULIDA. 25

The only specimen of this Umbellula brought home by the Challenger is in a very
bad state of preservation ; nevertheless it is of great interest, as it is the only known
Umbellula which resembles the Umbellula of Ellis and Mylius so much that it seems to
be the same species, or at least to come very near it. The lower enlargement of the
stalk is cylindrical below, and ends in a small bulb, in which the pomted end of the axis
is contained. The upper portion of the lower swelling is quadrangular, of the same form
as the axis, and larger than the lower portion. From the top of this swelling the stalk
diminishes gradually in thickness, assuming its smallest diameter about the middle of the
whole length, and enlarges slowly upwards, forming finally the upper enlargement at a
short distance below the polyps. The upper swelling is flattened nearly to the point
where the polyps are attached, and only in their immediate neighbourhood becomes
more cylindrical, so as to form a kind of short peduncle for their attachment.

The polyps form a compact bunch, and seem to be placed all on one level. On a
closer inspection the axis is seen to run into the base of one of them, and here a kind
of short rachis is formed, which, however, is very different from the ordinary structures
of this kind. The real arrangement of the polyps is such that the nine polyps visible
from the outside surround a small inner area, which may be regarded as the dorsal side
of the rudimentary rachis, and from the middle of this space one single full-grown central
polyp arises, surrounded at its base by large wart-like zooids, which I am inclined to
interpret as rudimentary polyps.

The zooids are very numerous on the upper part of the flattened enlargement, and
leave only the two middle lines free. They then advance towards the bases of the
polyps in such a manner as to form four pointed areas corresponding to the interspaces
between them. These pointed areas, which are visible to the naked eye, appear to
have been seen also by Ellis, and are figured by him at letter N. On the lower part
of the upper enlargement. of the stalk the zooids become less numerous, and, so far as
I have been able to ascertain, they at length disappear, but they reappear on the lower
swelling of the stalk and in its neighbourhood, where they seem to be pretty numerous,
and to be arrayed in longitudinal lines. But I am not in a position to clear up totally
their relations, as I could not destroy the only specimen of this interesting form.

The colour of this Umbellula is different shades of brown.

Length of the whole, , : : : . Q : 740 mm.
Length of the polypiferous aon 5; f 3 : : : 50
Length of the upper swelling of the stalk, . 85
Breadth of the upper swelling of the stalk, if
Length of the lower swelling, 77
Breadth of the lower swelling, 5 : : : ; 5 ; 6
Breadth of the stalk in the middle, : : : , : 1°3-1°5
Length of the polyps, ; 5 ; ; ; : - 45
Length of the tentacles of the yay ps, : . : : : 5 19
Length of the bodies of the polyps, : : é . : ‘ 26
(Z00L, CHALL. EXP.—PART 11.—1880.) 34

26 THE VOYAGE OF H.M.S. CHALLENGER.

Habitat.—Station 147, South Sea, east of Kerguelen Island, lat 46° 16’ S., lone.
48° 97’ E. Depth, 1600 fathoms. Bottom temperature, 0°°8 C. Globigerina ooze.
December 30, 1873.

A fragment of an Umbellula in two pieces, dredged at Station 146—lat. 46° 46’ S.,
long. 45° 31’ E.; depth, 1375 fathoms; bottom temperature, 1°°5 C.; globigerina ooze—
seems to belong to Umbellula magiuiflora. The principal argument in favour of this
supposition, besides the habitat, is that the lower swelling of the stalk shows zooids as
in that species, which are so well developed that I thought it right to show them in
fig. 12. The upper part of the stalk is im so bad a condition that not a single polyp
is preserved, so that nothing can be said of these parts. The length of both fragments,
251mm.; breadth of the lower swelling of the stalk, 0°83 mm.; of the thinner part of the
stalk, 0°42 mm.; diameter of zooids, 0°17 to 0°19 mm.

Family 3. ProrocavuLip.
Protocaulon, n. gen.

Sea-pens of the group of the Protocauleze. Polyps sessile, without cells, disposed
alternately on each side of the rachis in one single row. No calcareous corpuscles.

1. Protocaulon molle, n. sp. (Pl. VII. fig. 23).

The whole pen 26 mm. long. Stalk, 15 mm. long, 8°28 mm. thick, with the exception
of the lower half, which has a maximum thickness of 0°57 mm. Rachis, 0°26 mm. Polyps,
fourteen im number, four of which are rudimentary, with the partially retracted polyps
not much longer than 0°58. Zooids(?). I think I have seen one zooid below each
polyp, but as I could not destroy the only specimen of this sea-pen, this point was not
ascertained. Axis round, 0°11 mm.thick, with shorter stout radiating fibres. Generative
organs in the more developed polyps.

Habitat.—Station 169, north-east of New Zealand, lat. 37° 34’ 8., long. 179° 22’ E.
Depth, 700 fathoms. Bottom temperature, 4°°2 C. Grey ooze. July 10, 1874.

Family 4. PRoTopriLip&.
Microptilum, n. gen.

Sea-pens of the family of the Protoptilidee. Polyps with cells, sessile, disposed alter-
nately on each side of the rachis in one single row. Cells triangular, with one strong
spine on their ventral side. Zooids small, one single individual at the base of each cell
on its ventral side. Axis round. Calcareous corpuscles in the rachis, the stalk, the cells,
and the tentacles of the polyps.

REPORT ON THE PENNATULIDA. 27

1. Microptilum willeméesi, n. sp. (Pl. VIL. fig. 27).

Small, rachis longer than the stalk. Stalk with very inconspicuous swellings. Polyp-
cells of two kinds, larger and smaller; the larger, 2°8 to 3°4 mm. in length, alternate
pretty regularly with the smaller, the size of which is about 0°8 mm., and which are to be
regarded as belonging to developing polyps. Number of larger cells 12; underneath the
lowest, three smaller cells follow, visible with the naked eye, and three or four zooid-like
undeveloped polyps, which are only to be seen with the microscope. The polyps are the
only coloured parts of the polypidom, and have brownish stomachs, while the rest of their
bodies has a yellowish tint.

Zooids flat, oval, 0°37 mm. long, without spines.

Caleareous corpuscles of the form of needles, 0°86 mm. long on the rachis, and
decreasing to from 0°080 to 0:14 mm. and less on the stalk.

Rachis broad, 0°70 mm.

Stalk 0°45 to 0°48 mm.

Length of the whole polypidom 65 mm., of the stalk 25 mm.

Habitat—One single specimen from Station 235, south of Yeddo, lat. 34° 7’ N., long.
138° 0’ E. Depth, 565 fathoms. Bottom temperature, 3°°3 C. Mud. June 4, 1875.

Leptoptilum, n. gen.

Sea-pens of the family of Protoptilidee. Polyps with cells, sessile, disposed alternately
in one single row on each side of the rachis. Cells cylindrical, with eight long spines.
No real zooids, but a certain number of rudimentary polyps between each pair of the full-
grown individuals. Axis round, pointed, and straight at both ends. Calcareous corpuscles
in the stalk, rachis, the cells, and the tentacles of the polyps

1. Leptoptilum gracile, n. sp. (Pl. VII. fig. 28).

Small, rachis longer than the stalk.

Stalk with a small enlargement at its wpper end, and a little end-bulb.

Polyp-cells 2 to 3 mm. long, and 0°85 mm. broad, with eight well-developed spines at
their opening, but disposed in such a manner that many of them appear to be opp: site, which
is in reality nowhere the case. Another peculiar feature is that the size of the polyp-cells
does not decrease regularly towards both ends of the rachis, as is usually the case, but
that in the centre smaller and larger cells are found without any rule in their distribution,

The polyps are the only coloured part of this sea-pen, their stomachs being brown, and
the other parts yellow. The axis of the tentacles bears a row of calcareous needles
0-11 mm. in length.

The rudimentary polyps lie two to five in number, and 0°16 to 0°32 mm. and
upwards in size, between each pair of developed polyps. They possess similar cells, but

28 THE VOYAGE OF H.M.S. CHALLENGER.

the tentacles are simple and have no calcareous needles. Between these rudimentary
individuals and the full-grown polyps many intermediate stages may be found, and I
have no doubt that this sea-pen grows not only at the end, but also by the formation of
new individuals between the old ones.

The calcareous corpuscles are very numerous in the cells, and in the integument of
the rachis, and have the form of long needles 0°35 mm. and upwards in length. On
the stalk the needles are also very numerous, but they diminish gradually in size, and
measure only 38 to 58 p in its lower parts. In the end-bulb itself the muscular
layer contains-the same small oval bodies of 3 to 15 y, which have been described in
the genus Anthoptilum.

In the axis radiating fibres are wanting, and are represented by the same oval plates,
which I have described in other Pennatulida.

Measurement of the largest specimen—

Length of the whole, : : : : ; : 75 mm.
Length of the stalk, : : : ; ; 23
Breadth of the stalk above and below : 5 ; ; 0:58
Breadth of the rachis, : : ; 3 : : 0:23-0:34
Breadth of the axis, ; ; : : ; : 0:20

Habitat.—Several well-preserved specimens from Station 169, north-east of New
Zealand, lat. 37° 36’ S., long. 179° 24° E. Depth, 700 fathoms. Bottom temperature,
4°-2 C. Grey ooze. 10th July 1874.

Protoptilum, Koll.

1. Protoptilum aberrans, nu. sp. (Pl. VIII. fig. 30).

General appearance of Protoptilum carpenteri, Koll. Polyps larger, disposed in one
row only on each side of the rachis. Polyp-cells truncate at their upper end, without
spines. Zooids dorsal, lateral, and ventral, larger than in Protoptilum carpenter.
Rachis with a swelling in which the sexual products are found, in the lower part, in the
region of the undeveloped polyps.

Polyps disposed, partly alternately, partly nearly opposite, forming in general a
single row on each side, but in some places showing a tendency to an arrangement in
series of two; polyp-cells of the form of a cornucopia, 2°85 mm. long, and 1:14 mm. wide
at the opening. Zooids of the form of the polyp-cells, 0°57 to 1:0 mm., with cells like
the polyps. The number of zooids is much more numerous than that of the polyps, and
they are placed without any apparent rule except at the lowest, thickest part of the rachis,
where the zooids alternate with the here rudimentary polyps in such a manner that one
dorsal and one ventral zooid is placed between two polyps.

Rachis, 0°85 mm. broad in the upper parts, increasing below to 1°7 mm. and 2°0 mm.

REPORT ON THE PENNATULIDA. 29

Colour of the cells of the polyps and zooids light red, and of the stems of the tentacles
of the polyps pale red, which colour is occasioned by red calcareous needles. Besides
these, colourless needles occur in all uncoloured parts of the rachis, and in the stems of
the tentacles at their ends.

Axis cylindrical, 0°37 mm.
Habitat.—One single specimen from Station 44, North Atlantic, south of New York,

lat. 37° 25° N., long. 71° 40’ W. Depth, 1700 fathoms. Bottom temperature, 1°°7 C.
Grey ooze. May 2, 1873.

2. Protoptilum, sp. :

A fragment of a Protoptilum differing from Protoptilum aberrans, (1) by the more
intense colour of the cells, (2) by the longer row of undeveloped polyps, (3) by the
occurrence of only dorsal and ventral zooids, (4) by the smaller size of the polypidom,
(5) by the more intense colour of the needles of the stems of the polyps, (6) by the
absence of a swelling at the lower part of the rachis.

The fragment in question consists of a stalk, which has an upper swelling, and a large
end-bulb.

Habitat.—Station 45, North Atlantic, south of New York, lat. 38° 34’ N., long.
72°10’ W. Depth, 1240 fathoms. Bottom temperature, 2°-4 C. Mud. May 3, 1873.

3. Protoptilum, sp.

A second fragment comes nearer to Protoptilum aberrans, and differs from it only in
the want of colour of the needles in the tentacles of the polyps, and in the absence of
generative organs in the swelling of the rachis.

Habitat.—Station 46, North Atlantic, east of New York, lat. 40° 17’ N., long. 66°
48’ W. Depth, 1350 fathoms. Bottom temperature, 2°°3.C. Mud. May 6, 1873.

Trichoptilum, n. gen.

Sea-pens of the family of the Protoptilide. Polyps with cells, sessile, disposed alter-
nately in one single row on each side of the rachis. Cells cylindrical, with eight strong
spines. Zooids dorsal, one to three between the polyps, small, without spines. Axis
quadrangular. Caleareous bodies numerous in the cells and tentacles of the polyps, very
searce in the sarcosoma of the rachis, abundant in that of the stalk.

1. Trichoptilum brunnewm, n. sp. (Pl. VIII. fig. 31).

Long and slender. Rachis more than five times the length of the stalk. Length of
rachis, 29 mm. of stalk, 5°33 mm. Stalk, with an upper enlargement of 1°6 mm. and
an end-bulb of 2°6 mm. diameter, with short calcareous needles of 42 to 68 pw, which are
very numerous in the upper parts, and diminish in number towards the end-bulb.

30 THE VOYAGE OF H.M.S. CHALLENGER.

The polyps begin below with a long row of undeveloped individuals the real length
of which cannot be ascertained owing to the bad state of preservation of this part of the
polypidom. The developed polyps measure 1:2 to 3:2 mm. in length, are rather crowded,
and so placed that smaller and larger are intermingled without any rule. Colour of the
polyps brown, with the exception of the tentacles which are colourless, and contain
calcareous needles of 0°15 mm. in length. Polyp-cells with strong colourless needles of
0°5 mm.

Rachis quadrangular, 0°76 mm. broad, brown on all four sides, from the colour of the
epithelium of the longitudinal canals. Sarcosoma in small quantity, with some needles
in its dorsal side.

Habitat.—One single specimen from Station 192, south-east of Ceram, west of New
Guinea, lat. 5° 42’ §., long. 132° 25’ E. Depth, 129 fathoms. Mud. September
26, 1874.

Y ef A
Scleroptilum, n. gen.

Sea-pens of the family Protoptilidee. Polyps without cells, sessile with broad bases,
disposed on each side of the rachis in a single row. Zooids dorsal, apparently in one row,
Axis round. Calcareous corpuscles of large size, abundant in the polyps and their ten-
tacles, and in the sarcosoma of the rachis; those of the stalk numerous, but smaller.

_1. Scleroptilum grandiflorum, n. sp. (Pl. VIL. fig. 29).

Calcareous corpuscles in the smaller branches of the tentacles very few in number.
Polypidom of medium size, uncoloured. Rachis longer than the stalk. Stalk, with an
upper swelling, and an end-bulb. Polyps usually disposed in pairs, apparently opposite,
while, on a closer inspection, it becomes evident that the two polyps of a pair never lie
on the same level; nevertheless, regular alternation does not take place, the more so
as In many places a single polyp is interposed between two pairs. The intermediate
polyps, which are smaller than the others, may be looked upon as indications of new
developing pairs, as we have seen that in several genera of the Protoptilide young polyps
are develcped between the old ones.

The single polyps are large and hard and stiff, from the great number of strong
calcareous needles in their sarcosoma. Their length is about 5 mm.,—with extended
tentacles, 6 mm.; and their breadth at the base 3 mm., and higher up, just below the
tentacles, 15 mm. Nearly all are curved in such a manner that the tentaculiferous
part is bent upwards; in some instances the curve is even stronger, and then the
tentacles look towards the stalk.

The zooids measure at their base 0°42 mm., and are small conical prominences, with
an elevation of not more than 0°2 mm. They are all dorsal, and form one single row,
- which is so disposed that one portion lies on the right, and the other on the left of the

REPORT ON THE PENNATULIDA. 31

dorsal middle line. Their number is so small that it does not much surpass that of the
polyps.

The rachis is cylindrical, with very little sarcosoma.

The axis is round, and measures in the lower part of the rachis 0°9 mm. in
diameter.

The maximum length of the calcareous needles is 0°70 to 0°74 mm., and the
breadth 0°14 mm. In the tentacles, needles of 0°40 to 0°45 mm. run up the aboral
side of the stem, forming a strong axis, and two or three smaller needles are found in
the base of each secondary tentacle. In the sarcosoma of the stalk and the rachis
itself the needles are shorter and more slender, and go down to a size of 0°085 to
0:14 mm. in length, and 0:028 mm. in breadth.

Of three specimens of this sea-pen only one was entire, the second wanted the stalk,
and the third the end of the rachis.

A. B. c
Length of the whole polypidom, : . : 100 mm.
Length of the rachis, . c : , ; 62 140 wat
Length of the stalk, : : : : : 38 tee 51°5
Upper swelling of stalk, : 6 ; : Uc7/ bd 2:0
Upper swelling of end-bulb, , ; : : 1:3 2°5

Habitat.—Station 241, North Pacific, east of Japan, lat. 35° 41’ N., long. 157° 42’
E. Depth, 2300 fathoms. Bottom temperature, 11°C. Red clay. June 23, 1879.

2. Scleroptilum durissimum, n. sp.

All smaller branches of the tentacles studded with calcareous corpuscles.

The Challenger collection contains only one imperfect specimen of this form, which
comes very near Scleroptilum grandiflorum. The principal differences are the following :—

a. The polyps are smaller.

b. The smaller branches of the tentacles possess in their whole length at their aboral
side a strong axis or train of needles of 0-054 mm. in length.

c. The needles of the sarcosoma of the polyps are a little shorter (0°28 mm. in length,
0:°085 mm. to 0°11 in breadth).

d. The needles of the sarcosoma of the rachis are more numerous and longer.

Habitat.—Station 235, North Pacific, south of Yeddo, lat. 30° 7’ N., long. 138° 0’ E.
Depth, 564 fathoms. Bottom temperature, 3°°3 C. Mud. June 4, 1875.

Section II—RENILLE.
Renilla, Lam.
1. Renilla miilleri, M. Schultze (Pl. XI. fig. 46).
‘reat number of this Renilla, of which I give in fig.

Oo
t=)

The Challenger brought home a

32 THE VOYAGE OF H.M.S. CHALLENGER.

46 amore characteristic representation than those contained in my monograph of the
Pennatulidee.

Habitat.—Station 321, off Buenos Ayres, lat. 35° 2’ S., long. 55° 15’ W. Depth, 13
fathoms. Mud. February 25, 1876.

Section. II]—VERETILLE/.
Family 1. CAVERNULARIDA.

Cavernularia, Val.

1. Cavernularia obesa, Val.

Habitat.—Station 163a, off Port Jackson, Australia. Depth, 30 to 35 fathoms.
June 3, 1874.

This Cavernularia, of which I had two specimens, is in its exterior forms so like
Clavella australdsie with which it was collected that it was necessary to investigate the
calcareous corpuscles in order to distinguish them.

Family 2. Lirvaripa.
LIntuaria, Val.

1. Lntuaria phalloides, Pall. (2)

One single specimen of a Lituaria dredged by the Challenger agrees pretty well with
Lituaria phalloides. Nevertheless, it differs in the following points, and may perhaps in
future, when both Lituarie are better known, be recognised as a new species :-—

1. The sarcosoma of the bodies of the polyps is much thinner than in Lhtuarva
phallordes, and contains some calcareous corpuscles.

2. The tentacles also contain some, but very few calcareous bodies.

3. The axis is provided with two excavations only at its uppermost part.

4. The calcareous bodies are furnished with longer excrescences and branches at
their ends.

Habiuat.—Station 233a, Kobi, Japan, lat. 34° 35’ N., long. 135 10° E. Depth, 8
to 50 fathoms. Mud, sand. May 17-19, 1875.

Clavella, Gray.

1. Clavella australasie, Gray.

Of this rare Pennatulid the Challenger brought home two well-preserved specimens
and several fragments. They agree with the typical form with this exception only, that
the axis passes in some specimens very nearly to the lower end of the stalk.

Habitat.—Station 163a, off Port Jackson, Australia. Depth, 30 to 35 fathoms.
Rock. June 3, 1874.

REPORT ON THE PENNATULIDA. 30

GENERAL Remarks.—After having described the Prnnarutia collected by the
Challenger, which consist of at least thirty-eight species and nineteen genera, amongst
which seven genera and twenty-seven species are new to science, I think it right to
conclude with some general remarks.

First of all I wish to propose a new systematic arrangement of the PENNATULIDA, as
the one given by me in my monograph (pages 14, 295, and 436) has become incomplete
in consequence of the newly-discovered forms and the addition to our knowledge derived
from their study. The system I now propose is the following :—

Order PENNATULIDA.

I. Rachis with a bilateral arrangement of the polyps.
A. Rachis elongated, cylindrical.
AA. With pinnules or leaves.
Section I. PENNATULES.

Pinnules well developed.
Sub-section I. PENNIFORMES.

Zooids situated on the pinnules.
Family 1. PrrroErpip2&.

Genera Pteroeides, Herkl.
Godefroyia, Koll.
Sarcophyllum, Koll.

Zooids on the ventral and lateral sides of the rachis.
Family 2. PENNATULID.

Genera Pennatula, Lam.
Leioptilum, Verr.
Ptilosareus, Gray.
Halisceptrum, Herkl.

Pinnules small.
Sub-section II. VIRGULARIEZ.

Pinnules without a calcareous plate.
Family 1. VireuLarm.
Genera Virgularia, Lam.
Scytalium, Herkl.
Pavonaria, Koll. (sp. P. finmarchica).
(Z00L. OHALL, EXP.—PART 11.—1880.) BE

o4 THE VOYAGE OF H.M.S. CHALLENGER.

Pinnules with a calcareous plate.
Family 2. STYLATULIDA.

Genera Stylatula, Verr.
Dubenia, Kor. and Dan.
Acanthoptilum, Koll.

BB. Rachis without pinnules, polyps sessile.
Section IT. SPICATAK.

a. Polyps on both sides of the rachis m distinct rows
Sub-section I. FUNICULINE.

aa. Polyps with cells.

a No ventral zooids.
Family 1. FuNIcULINIDA.
Genera Funiculina, Lam. (sp. F. quadrangularis).
Halipteris, Koll. (sp. H. christi).
B. With ventral zooids.
Family 2. SracHyPriLipé.
Genus Stachyptilum, Koll.

bb. Polyps without cells.
Family 3. ANTHOPTILIDA.
Genus Anthoptilum, Koll.

b. Polyps on both sides of the rachis in a single series or in indistinct rows.
Sub-section II. JUNCIFORMES.

aa. Polyps without cells.
a. Polyps large.
aa. Rachis elongated, cylindrical.
Family 1. KopHOBELEMNONID&.
Genera Kophobelemnon, Asb.
Sclerobelemnon, Koll.
Bathyptilum, Koll.

8B. Rachis short.
Family 2. UMBELLULID#.
Genus Umbellula, Lam.

REPORT ON THE PENNATULIDA. 545)

8. Polyps small.
Family 3. Prorocautis.
Genera Protocaulon, Koll.
Cladiscus, Kor. and Dan.

bb. Polyps with cells.
Family 4. Proroprinips.
Genera Protoptilum, Koll.
Lygomorpha, Kor. and Dan.
Microptilum, Koll.
Leptoptilum, Koll.
Trichoptilum, Koll.
Scleroptilum, Koll.

B. Rachis expanded in the form of a leaf.

Section II. RENILLEA.
Family 1. Renu.
Genus Renilla, Lam.

H. Rachis with a radiating arrangement of the polyps.

Section III. VERETILLE &.

Calcareous bodies long.
Family 1. CavERNULARIDA.
Genera Cavernularia, Val.
Stylobelemnon, Kall.

Calcareous bodies short.
Family 2. Lrruarm..
Genus Lntuaria, Val.
Veretillum, Cuv.
Policella, Gray.
Clavella, Gray.

With regard to the GrocrapuicaL Disrrieurion of the Pennatulida the new forms of
the Challenger Expedition are of great interest, and confirm and extend the conclusion
at which I arrived in my monograph.

As to their horizontal distribution, I wish to point out first of all the interesting fact
that the Challenger Expedition seems to prove that the Pennatulida are not distributed

36 THE VOYAGE OF H.M.S. CHALLENGER.

over all seas in a regular manner. Over great tracts the Challenger did not find a single
specimen of this order; for instance, in the Atlantic, between Buenos Ayres and Cape
Finisterre (Stations 322 to 354), between the Canaries and the West Indies (Stations
1 to 42), between Bermuda, Madeira,’ and the Cape de Verde Islands,’ till near the
Equator (Stations 58 to 105).

One Umbellula was found at Station 106,’ and then nothing across the Atlantic to Cape
St Roque, along the coast to Bahia, and again back across the Atlantic to Station 132, near
Tristan d’Acunha. Nothing again on the way to the Cape of Good Hope, and up to
Stations 146 and 147, where two Umbellule were found. From Station 147 to Melbourne,
through the South Polar Sea, two Umbellule were dredged at Stations 156 and 157. No
Pennatulidee were found between Australia and New Zealand (Stations 164 to 168), none
between these islands, past the Fiji and New Hebrides groups, to New Guinea (Stations
170 to 180), none between the Philippines and New Guinea, and thence to Japan (Stations
213 to 231), only two forms, an Umbellula anda Scleroptilum between Japan and the
Sandwich Islands, and nothing from Hawaii through the whole Pacific Ocean to Valparaiso,
through the Straits of Magellan, past the Falkland Islands to near Buenos Ayres (Stations
237 to 239).

It seems, therefore, reasonable to conclude, so far as our present knowledge goes, that
the deeper portions of the Pacific and the Atlantic Oceans, and the South Polar Sea,
contain very few or none at all of the Pennatulida at a certain distance from the shore.

I may add that Professor T. H. Studer, of Bern, who went with the German ship
“Gazelle” round the world, and dredged in a good many places, found only six
Pennatulida, which is the more worth mentioning as he dredged especially 1 in shallow
water and along the shore.

As to the horizontal distribution of the families of the Pennatulida, the following
may be remarked :—

As I showed in my monograph, the Prrrormip# have a well-defined centre in the
south-east coasts of Asia, the Sunda Islands, and the Philippines, from which they
spread, with few forms, as far as Japan, Australia, New Guinea, New Caledonia, the
Carolines, the west coast of Africa and the Red Sea; Pteroeides grisewm of the Mediter-
ranean being quite an exception. The results of the Challenger confirm these data, as
they make only three Pteroeidide: from the Philippines, Australia, and Japan.

The PeNNATULIDa, on the contrary, have a wide distribution along the coast of
Europe, the west coast of North America, the coasts of China, Japan, India (south-east
coast), Australia, New Guinea, Africa (east coast). No Pennatulidee are known from the
east coast of North America, the west coast of South America, nor the west coast of

1 Studer found at Madeira, Cavernularia madeirensis.
* Studer found here Veretillum cynomorium, var. astyla.
3 Studer found an Umbellula and Pavonaria africana, Stud., near Station 97.

REPORT ON THE PENNATULIDA. 37

Africa. The Challenger found five new forms of Pennatulide from Australia, New
Guinea, the Philippines, and Japan, amongst them four species (Pennatula moseleyi,
murrayt, naresi, and pearceyi) which are nearer the known European types, and only
one species with the soft leaves of the typical Asiatic and west American forms (P.
sulcata).

The knowledge of the VircuLarip& has been augmented by the discovery of the
habitat of Scytaliwm sarsi (Philippines), and the discovery of a new Scytalium from the
same locality. The Virgularide, as I now define them, are widely distributed in the
European seas (three species of Virgularia, two of Dubenia), the east and west coasts of
America (all the species of Stylatula and of Acanthoptilum), the east coast of Africa
(Pavonaria africana, Stud.), and the south-east Asiatic seas, as far as Australia (eight
species of Virgularia, two of Scytaliwm).

The Sracuypririps, Prorocaunips, and Proropriips, belonging to the simplest
forms of the Pennatulida, have two centres, one in the Pacific Ocean, on the coasts of
New Guinea (Stachyptilum, Trichoptilum), New Zealand (Protocaulon, Leptoptilum),
and Japan (Scleroptilum, Microptilum), and one in the North Atlantic (Protoptilum),
and North Sea (Lygomorpha, Cladiscus).

The ANTHoPTILID# are limited to the east coast of America, but have a wide range
from Halifax to Buenos Ayres and Tristan d’Acunha.

With regard to the KopHopetemNnonip#®, the VERETILLIDA, and the RENILLIDA, little
new has been added to our knowledge through the investigations of the Challenger, with
the exception of a new Kophobelemnon from Japan. Nevertheless, it is interesting to
know that the limited distribution of these families has been confirmed. Professor Studer
has lately found a Veretillum at the Cape de Verde Islands, and a Cavernularia at
Madeira.

The distribution of the UMBELLULID# is most remarkable. After having known for
more than a century only one locality, the North Polar Sea, near the coast of Green-
land, we have now learned that this form is far and widely distributed. Uimbellule have
now been obtained from the North Atlantic Ocean (between Portugal and Madeira); from
the North Polar Sea, coast of Greenland; from the Atlantic Ocean, under the Equator,
between Africa and America, and from the west coast of Africa, north of Sierra Leone
(Stud.) ; from the South African Sea, west of Kerguelen Island; from the South Polar
Sea; from the coasts of New Guinea and of Japan; and from the middle of the North
Pacifie Ocean (Station 246). Umbellula has, therefore, of all genera of Pennatulida the
widest distribution.

Our knowledge of the vertical distribution of the Pennatulida has made great
progress through the explorations of the Challeneer. When I published my monograph
s g g J is
I was justified in sayine that the ereat majority of the Pennatulida were shallow-water
g g y

38 THE VOYAGE OF H.M.S. CHALLENGER.

animals, living in the vicinity of the coasts, at a depth of 6 to 10 or 20 fathoms; but
now the number living at great depths has so increased that it is nearly equal to that
of the shallow-water forms. —

If we compare the two groups, it is obvious that the great majority of the higher
forms of the families PreroEIpID&, PENNATULIDA, VIRGULARID®, and REniLLIp& live in
shallow water. The only species gomg deeper than 100 fathoms, are—

Fathoms.
Pennatula grandis, Ehrenb., : ; : : é . 150-200
P. phosphorea, var. aculeata, Koll., : ; : : ; 30-300
Dubenia abyssicola, Kor. and Dan., j : : : : 100-120
Pavonaria africana, Stud., é : ‘ . : : 360-
P. finmarchica, Sars, ; : é : : : : 240-300
Virgqularia bromleyi, Kall, : : ; : : : 565-

Of the lower groups of the Pennatulida, only the Veretillidee seem to live in shallow
water (V. cynomorium, var. astyla was found by Studer, at the Cape de Verde Islands,
in 115 fathoms). All the others are, with very few exceptions, deep-sea forms, as shown
by the following list :—

FUNICULINIDA. Peas
Funiculina quadrangularis, Blainv.., : : 4 : : 20-350
Halipteris christii, Kor. and Dan., ; : : : : 200
STACHYPTILID&.
Stachyptilum macleart, KOoll., : : : : : ‘ 129
ANTHOPTILIDA.
Anthoptilum thomsoni, Koll., : : : : : : 600
murrayt, Kell, : 0 : : : b 1250
simplex, Koll, : : : : : : 1900

KoPHOBELEMNONID.

Kophobelemnon stelliferum, var. durum, Miill., A 5 : : 40-300
stelliferum, KOll., . Wak : : i : 458-690
Serrugineum, Koll., : : : ; E 345
(sp.), : : ; ; ‘ : : 700
Bathyptilum carpenteri, Kol.., : : : : , ‘ 650
UMBELLULID®.

Umbellula giintheri, Koll, . : ; 5 ; f 5 1850
simplex, Koll, . é : : x : ; 2050
leptocaulis, KOll., : : ; 4 : ‘ 2440
durissima, Kél., : : : : 5 : 565

hueleyt, Koll, . : : ; A é : 565,

REPORT ON THE PENNATULIDA. 3

Fathoms.
Umbellulu magniflora, Koll, : 5 5 : : : 1600
magnifiora (1), Koll, : ; : : : 1375
carpenteri, Koll., : : : 3 % F 1950-1975
thomsoni, Koll., . ‘ : 5 : : : 2125
lindahli, Koll, . ; : , : : : 122-410
(sp. Studer), i : : : ; : 360
PRoTOCAULID®,
Protocaulon molle, Kol ae : : ; ; : : 700
Cladiscus gracilis, Kor. and Dan., 5 40
PROTOPTILID.®.
Protoptilum thomsoni, Kill. ; ; i 3 ; ; 322
carpenteri, KOll., A : : : : : 690
smitt?, Koll, 223
aberrans, Koll., : 2 3 : . 1700
aberrans, var. Koll, . : : : ; ‘ 1240
aberrans, var. Koll, : : : : 1350
Lygomorpha sarsi, Kor. and Dan., : : : : : 80-100
Microptilum willembesi, Kall, : : : 2 F 3 565
Leptoptilum gracile, K6l., 4 ; ; : : : 700
Trichoptilum brunneum, Koll., . . : : : - ~ 129
Scleroptilum grandiflorum, Koll, . : : ; : : 2300
durissimum, Koll. : : E : : 965

It follows from all these facts, as I have already pointed out in my monograph
(page 449), that the simpler forms of the Pennatulida, especially those with sessile
polyps, inhabit great depths. The presence of their less complex representatives in
deep water has also been shown in other invertebrate groups. These simpler forms are
probably also the oldest, and may be regarded as the last remnants of an extinct primary
creation. The Protoptilidee and the Umbellulidee are the principal representatives of these
old forms, and of these two families especially the Challenger Expedition has discovered a
large number of species with a wide distribution. This addition to our knowledge
makes it possible to gain a better insight than formerly into the development of the
whole group. On this point I may refer the reader to my often-quoted monograph, in

which the phylogenetic development of the Pennatulida is treated on the 449th and
following pages,

SHOONaAnAR WD He

—

eet oe
@s Ro ES

RORY TD) RS) RE RS) (PS) he) Rot aS eS SS
oanrTy oumnbpwWoNrF COO ON DS

EXPELANATION (Ot TE Ei ADEs.

Pennatula naresi, Koll., from the ventral side.
The same from the dorsal side.

. Pennatula sulcata, Koll., a, from the dorsal; b, from the ventral side.
. A part of the dorsal side of Pennatula sulcata twice the natural size.
. Pennatula pearceyt, Koll., twice the natural size.

. Pennatula murrayt, Koll., from the dorsal side.

The same from the ventral side.

. Pennatula moseleyi, Koll., from the dorsal side.
. A part of Pennatula moseleyi, from the ventral side.

Virgularia bromleyi, Koll., fig. 1, natural size; fig. 2, from the ventral aspect
fig. 3, from the sides,—four times the natural size.

. Virgularia gracillima, Koll.
. Scytaliwm tentaculatum, Koll., d, dorsal; v, ventral side.
. A young leaf of Scytaliwm tentaculatum magnified ; (*) the tentacles at the end of

the not yet developed polyp-cells.

. A smaller but developed leaf of Scytaliwm sarsi.

. Undeveloped leaf of Scytaliwm sarsi.

. Anthoptilum thomsoni, Koll, v, ventral side.

. A part of the same from the side, the polyps cut to show the lateral zooids.
. A tentacle of Anthoptilum thomson.

. Antnoptilum murrayi, Koll.

. Part of the same from the ventral side, three times the natural size.

. The same from the dorsal side.

. Anthoptilum simplex, Koll., v, ventral; d, dorsal side.

. Protocaulon molle, Kéll., three times the natural size.

. Stachyptilum macleari, Koll., A, ventral; B, dorsal aspect.

. A part of the dorsal side of the same, three times the natural size.

. Calcareous corpuscles of the tentacles of Stachyptilum.

. Microptilum willemési, Koll., A, natural size; B, three times the natural size.
. Leptoptilum gracile, Koll., A, natural size; B, three times the natural size.

Fig.
. Scleroptilum grandiflorum, Kéll., A, natural size ; B, a part of the rachis three times

. Protoptilum aberrans, Kéll., A, natural size ; B, three times the natural size: 1

REPORT ON THE PENNATULIDA. 41

the natural size.

>

dorsal, 2, ventral side.

. Trichoptilum brunneum, Kall., A, natural size; B, part of the rachis three times the

natural size.
Umbellula durissima, Koll., A, dorsal ; B, ventral side.

. The same, upper part, three times the natural size.
. Umbellula giintheri, Koll., A, ventral aspect of the whole fragment ; a, swelling of

the stalk with zooids ; B, dorsal side of the upper part.

. Umbellula leptocaulis, Kéll., fragment from the ventral side.

Umbellula simplex, Koll., from the ventral side.

Umbellula husleyi, Koll, A, natural size; B, upper part three times the natural
size.

Umbellula carpenteri, Kéll., A, dorsal aspect ; B, ventral side of the upper part.

. Three young forms of Umbellula carpenter’, Koll., A and B from the ventral side,

C' from the dorsal side.
Umbellula carpenteri, part of the stalk, about twelve times the natural size, to show
the ramified tentacles (¢) of the zooid. The shorter tentacles are in part broken.
Umbellula magniflora, Kéll., upper part, natural size.

. Part of the lower swelling of the stalk of Umbellula magniflora, from Station 146,

to show the zooids, three times and a half the natural size.

. Kophobelemnon ferruginewm, Koll., from the dorsal side.

. Kophobelemnon, sp., from the side.

» Kophobelemnon burgeri, Herkl., A, from the dorsal ; B, from the ventral side.

. Renilla miilleri, M. Sch., part of frond ten times the natural size ; p, polyps

retracted ; g, groups of zooids.

(Z00L. CHALL. EXP.—PART 11,—1880.) B6

,

The Voyage of H.M.S."Challenger. Pennatulida, Pl.I

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THE

VOYAGE OF H.M.S. CHALLENGER.

ZOOLOGY.

REPORT on the Crrerrepia collected by H.M.S. Challenger during the
years 1873-76. By Dr. P. P. C. Horx, Member of the Royal
Academy of Science of the Netherlands.

ANATOMICAL PART.

INTRODUCTION.

One of my principal reasons for wishing to inyestigate the Cirripedia dredged during
the cruise of H.M.S. Challenger was the hope that I should be able by the aid of the

‘deep-sea material to enlarge our knowledge of the morphology of the order. It was

possible that among the forms from considerable depths there might be some which on
account of their great size, or for other reasons, would be especially favourable for
anatomical research, as was the case with some of the Pyenogonids from the abysses.
It was possible also that among them a new form might occur, the investigation of
which would cast light on details in the organisation which had not hitherto been suffi-
ciently understood, In this respect, however, the study of the deep-sea material has
somewhat'disappointed my expectations ; the new forms for the most part are represented
by single specimens only, or are too small to be dissected advantageously. I have
therefore been obliged to limit my researches entirely-to such forms as were previously
known and had served for the researches of former investigators. They belong to the
genera Lepas, Conchoderma, and Scalpellum of the pedunculated Cirripedia, and to the
genus Balanus of the sessile Cirripedia. What I have been able to work out does not
form a connected whole, but may conveniently take the form of separate chapters in the
morphology of the group.

(ZOOL, CHALL. EXP.—PART XXVvul.—1884.) Ee l

2 THE VOYAGE OF H.M.S. CHALLENGER.

I. THE COMPLEMENTAL MALES OF SCALPELLUM.

Since 1851, when Darwin issued the first volume of his Monograph on the Sub-class
Cirripedia, nothing has been published on the so-called complemental males of Scalpellum,
though the subject was far from exhausted by his treatment of it. The truth of this
assertion in no way diminishes the respect which we feel to be due to the labours of the
great master in this department of investigation as well as in so many others. For when
we consider that the methods of microscopic research have been greatly improved in the
thirty years which have since elapsed, and that'the male of Scalpellwm vulgare, which
Darwin investigated, has a size of only 0°7 mm., we can only wonder at the thoroughness
of the information which he has given, and:2t the soundness of the conclusions at which
he arrived.

When dissecting Scalpellum vulgare, Leach, Darwin observed one or more very
minute parasites on the margins of both scuta, close to the umbones. He dissected one
or two specimens and at first concluded that they belonged to some new class or order
amongst the Articulata. By repeated and more careful dissection he was able to make out
the general appearance of the animal, the form of the thorax and abdomen, the generative
system, the antenne and the mode of its attachment; he found that the prehensile
antennee of the little parasite showed an absolute correspondence with the same organs
of the hermaphrodite Scalpellum vulgare, and that it belonged exclusively to the male sex.
From this knowledge, together with its fixed condition and its short existence, he thought
himself justified in provisionally considering the little parasite as the complemental male
of the Cirriped to which it was attached. f

The results of Darwin’s investigation of the complemental males of the other species
of Scalpellum known to him are, shortly, the following :—The complemental male of
Scalpellum ornatum, Gray, sp., shows a close general resemblance to that of Scalpellum
vulgare; but as Darwin had only dried specimens of that species, his description is not
so exhaustive ; he found males of Scalpellum rutilum, Darwin, also, but in so extremely
decayed a condition that they could not be examined. What Darwin considered to be
the complemental male of Scalpellum rostratwm, Darwin, is a little animal constructed
like an ordinary Cirriped and furnished with a mouth, thorax, and cirri, enclosed in a
capitulum (with a carina and a pair of scuta), and supported on a peduncle of moderate
size. Specimens were found attached to the integument of the hermaphrodite in a
central line between the labrum and the adductor scutorum muscle. The complemental
male of Scalpellum peroni, Gray, sp., is a pedunculated Cirriped with a capitulum of
six valves, firmly cemented to the integument of the hermaphrodite in a fold between
the scuta, in the middle line a little below the adductor scutorum muscle. Finally,
the complemental male of Scalpellum villosum, Leach, sp., is attached in the same
position as that of Scalpellum peronw; it is also six-valved and it has a close general

REPORT ON THE CIRRIPEDIA. 3

resemblance to that of Scalpellum peronii. Whereas the parasites in the first three
species (Scalpellum vulgare, Scalpellum ornatum, and Scalpellum rutilum) are in such
an extraordinarily modified and embryonic condition, that they can hardly be compared
with other Cirripeds, those of the other three (Scalpellwm peronu, Scalpellum rostratum,
and Scalpellum villosum) are pedunculated Cirripedia, remarkable for their smallness.
These are the facts which were known to Darwin; he then enters into a masterly
discussion of the evidence that these parasites are really the males of the Cirripedia to
which they are attached. Curious and novel as was the fact, his reasoning was so con-
vincing that this theory has been generally accepted.
With respect to the occurrence and the structure of these complemental males, I believe
I have been enabled to augment our knowledge not inconsiderably. Though the princi-
pal result of my investigations has been to convince me of the exactness of Darwin’s
theory, I think the question is important enough to justify me in giving all the informa-
‘tion which I possess in the following pages.
I observed the complemental male in nineteen out of the forty-one new species of
Scalpellum described in my Report.’ I found them all in or about the same place,
viz., at or near the occludent margin of the scutum at the interior side of this valve, a
little above the adductor muscle. As arule they are placed in a pouch formed by the
mantle ; very often, but not always, I found them on the left as well as on the right
hand scutum. In five different species I took either from one or from both scuta two
or more specimens, in the other species each, or one only, of the two scuta was furnished
with asingle male. In one species (Scalpellum marginatum) the male was seated at a
considerable distance from the occludent margin of the scutum, and hence it happened that
at first I did not find it out. In one species (Scalpellum recurvirostrum) the only male
~ observed was still in the Cypris-larval or pupa stage ; in three other species (Scalpellum
“ regium, Scalpellum eximium, and Scalpellum velutinum) males in the pupa stage were
attached along with full-grown males. The male of Scalpellum brevecarinatum could
‘not be studied, being in a very unsatisfactory eondition.
In eighteen out of the nineteen cases I was able to form an-opinion as to the condition
‘ of the male when the testis was ripe, and the little creature therefore full-grown or nearly
so. In five of these eighteen cases the condition can be said to correspond with that of
the male of Scalpellum vulgare. In thirteen the males are still more degenerate. These
five are Scalpellum tritons, Scalpellum intermedium, Scalpellum parallelogramma,
Scalpellum elongatwm, and Scalpellum triangulare. 1 thimk they correspond with
Scalpellum vulgare in as far as there are rudimentary valves visible in them. The
thirteen remaining species all, no doubt, belong as regards the structure of their males
1 Zool. Chall. Exp., part xxv. The small species represented by single specimens have not been investigated so

thoroughly as would have been necessary to make out whether a male really occurred or not. 1 often found myself unable
to do so without spoiling the specimen.

$ THE VOYAGE OF H.M.S. CHALLENGER.

to. one and the same division of the genus. I have been able to study the male of one
of these (Scalpellum regium, Wyv. Thoms., Hoek) more in detail; in all essential
respects the males of the other twelve agree with it.

The twenty-four species of Scalpellum, the males of which are known at present, may
be classified with rega “to the structure of these males in the following way.

A. Species, the males of which show a distinct capitulum and peduncle :—

Scalpellum peroni, Gray, sp. Scalpellum rostratum, Darwin.
Scalpellum villosum, Leach, sp.

All these are shallow water species.

B. Species, the males of which do not show a division of the body into a capitulum:
and a peduncle, but yet are furnished with rudimentary valves :—

Scalpellwm vulgare, Leach. Scalpellum parallelogramma, Hoek.
rutilum, Darwin. elongatum, Hoek.
ornatum, Gray, sp. tritonis, Hoek,
intermedium, Hoek. triangulare, Hoek.

Species occurring in depths varying between shallow water and 700 fathoms.

C. Species, the males of which do not show a division of the body into a capitulum
and a peduncle, and are not furnished with rudimentary valves :—

Scalpellum marginatum, Hoek. Scalpellum gigas, Hoek.
strémit, Sars. reguum (Wyv.Thoms.), Hoek.
compressum, Hoek. darwin, Hoek.
nymphocola, Hoek. tenue, Hoek.
velutinum, Hoek. dubiwm, Hoek.
exrmmum, Hoek. flavum, Hoek.

Scalpellum pedunculatum, Hoek.

With the exception of three (Scalpelluin pedunculatum,.. Scalpellum, strému, and
Scalpellum nymphocola), these species occur in depths of upwards of 1000 fathoms,
The depths at which Scalpellum strémii and Scalpellum nymphocola were collected are
less considerable ; these species, however, belong to the arctic fauna, which, as is well
known, shows numerous instances of deep-sea animals occurring in rather shallow water,
Scalpellum pedunculatum was taken from a depth of 150 fathoms only.

REPORT ON THE CIRRIPEDIA. 5

a. DESCRIPTION AND COMPARISON OF Cypris-LARVz.

At first I experienced great difficulties in identifying the parts of the body of the
complemental male; however, I believe I have solved the problem by comparing the
full-grown male with a younger stage of its development, and the latter with the
corresponding stage of an ordinary species of Lepas. The occurrence of a Cypris-larva
between the two complemental males at the ordinary place enabled me to make this
comparison ; from its structure as well as from the place whence it was taken there can
be no doubt, I believe, that this latter creature was destined to develop (retro-
gressively of course) into a complemental male.

The species of Lepas, the Cypris-larvee of which have served me for comparison, was
the Lepas australis, Darwin. It is not only very characteristic on account of its great
size, but it is also the best known Cypris-larva, as it served first for the investigations of
Darwin, and again some years ago for the studies of Claus. The latter has given a very good
figure of the internal structure of this larva as seen in a sagittal section. My figs. 1
and 2on PI. Il. very closely correspond to that of Claus. My fig. 1 was drawn from a
preparation made by dividing the body of the Cypris-larva of Lepas australis into two
nearly equal halves by means of a sagittal section. The rounded spot (A J) is the
adductor muscle of the two valves of the Cypris-larva; the straight lme at the under
side of the valve represents the ventral side, the convex one the dorsal side; the
extremity on the left of my figure the frontal (cephalic), the one faemg it the hinder
(abdominal) extremity of the body ; from the way in which the spines of the legs are
stretched out at the ventral side itis clear that there is a slit-like opening between the
adductor muscle and the hinder extremity of the body. In fig. 2 of Pl. LI,
representing a longitudinal section parallel to and at a little distance from the ventral
margin, this orifice is also distinct. This is the only place where the interior of the sack
or mantle (as Darwin calls it) is in open communication with the surrounding water.

The body of the future Lepas is enclosed within the sack and has also a wall of its
own; on one side (the right hand side of the figure) this wall is very distinct, and it
passes over near the middle of the dorsal margin into a transverse invagination which
almost reaches up to the ventral side. It is by this invagination that the division of the
body into a capitulum and a peduncle is brought about; what in fig. 1 of Pl. Il. is
placed on the right hand side of the invagination (Jnv.) is the capitulum, what is placed
on the left: hand side the peduncle. As the invagination of the dorsal wall does not reach
as far as the ventral side, a direct communication remains between the capitulum and the
peduncle. Through this commissure, which is very narrow in the full-grown animal, pass
the oviducts and the nerves destined for the peduncle.

On the ventral side an invagination is seen at a distance of about one fourth of the
total length from the peduncular extremity; at the bottom of this invagination, when

6 THE VOYAGE OF H.M.S8. CHALLENGER.

studied in a sagittal section as figured, the compound eyes—which, according to Darwin,
are attached to the basal joints of the antennee—are visible.

The structure of the interior of the body can easily be made out by the aid of the
figure. WM. is the mouth; it is surrounded by darkly pigmented parts, the exact shape of
which is not very distinct ;.the mouth gives entrance to the esophagus (4); the latter
has a horizontal direction, is furnished with a pair of coeca (C), and leads into a very
eapacious stomach (S}, from which a narrow intestine (Jnt.) is seen to start. Cisophagus,
cooca, stomach, and intestine are all very darkly pigmented. The six pairs of cirri and
the caudal appendages present nothing particularly interesting ; the different cirri have
only to shed their skin to change into the cirri of the Lepas; the caudal appendages will
have to undergo a very marked retrogressive metamorphosis to change into the
rudimentary, uniarticulate, and smooth appendages of the full-grown Lepas australis. The
nervous system is already quite distinctly visible; it consists of the supracesophageal,
ganglion (GS), and the six thoracic ganglia (@I-G VI). The first is situated very close
to the ececa of the cesophagus and has a simple eye (e), represented by a small triangular
spot of pigment attached to it (fig. 2, e). The chain of thoracic ganglia is on the right
hand side of the stomach, between this organ and the ventral wall of what is properly
the body. The ganglia are not yet separated by commissures, but are placed close to one
another ; the first has an oval shape and is much larger than the following ones The
ganglionic cells which cover the surface of the different ganglia are extremely small.

In the peduncular part of the body nearly all the room is filled up by a mass of con-
nective tissue with very large meshes; between this mass of reticular connective tissue
and the layer of cells which represents the mantle a double layer of muscular fibres may

be discerned. The fibres of the two layers are at right angles to each other, and both
layers run parallel to the surface of the body and the valves of the Cypris; in the figure,
one of these layers is represented by the lines running parallel to each other, and also to
the curved frontal line of the larva. This layer is composed of rather broad fibres (each
fibre has an oval, not very elongate nuclei) and a breadth of 0°012 mm., which will develop
into the layer of longitudinal muscles of the peduncle of the Lepas. The other layer
is situated between the former and the mantle, and shows much narrower fibres, with very
narrow and elongate nuclei (each fibre has a breadth of only 0°003 mm.) ; this latter
layer forms the circular muscular layer of the peduncle in the full-grown Lepas. The
cells which constitute the mantle are relatively small and are furnished with large nuciei
(0-01 mm.); at different places they are richly pigmented.

Between the fibres and nuclei of the connective tissue numerous fatty bodies are
visible which are more like vesicles than grains; they have an elongate shape, are
pointed at both extremities, and belong to what still remains of the yolk.

The c¢ell-masses which Claus! describes as the cement-glands were very strongly

1 Claus, C., Die genealogische Grundlage, &., Wien, 1876, p. 87.

REPORT ON THE CIRRIPEDIA. 7

developed in the larvee of Lepas australis which I studied. Claus says that these glands
consist of groups of cells which have either still the form of a sinuous string (“eines
gewundenen Stranges”) or which lie scattered by the side of one another; the latter is the
case in Lepas australis. Claus has not observed the communication of these glands with
the cement-duct which he figures; at least in his figure they are at a very considerable
distance from one another. I have not been more fortunate; I even failed to observe
the cement-duct. The different cells (Pl. II. fig. 5) do not show much resemblance to
the cement-glands of the full-grown animal; yet I think that Claus’ supposition as to the
nature of these elements is right. As regards the place they occupy in the Cypris-larva,
it quite corresponds to the place they occupy in the full-grown animal, viz., in the
most posterior (when the animal changes its position, the most superior) part of the
peduncle. The Cypris-larva which furnished the drawing fig. 2 is a little older than
the one figured in fig. 1. In the former the cement-cells are much more separated from
one another than in the latter ; moreover, their nuclei are much more easily distinguish-
able, and many of them are not so richly furnished with fatty granules as was the case in
the younger condition. Very delicate and flat fibres in the later Cypris-stage are visible
between the cement-cells; probably they represent the canals figured by Claus and
considered by him as branches of the cement-ducts.
A pair of club-shaped bodies is situated near the ventral wall of the animal, the
thickest part of which is directed towards the front of the Cypris and the narrower part of
which can be traced as far as under the cceca of the cesophagus of this larva. These are
described by Claus as the ovarium (figs. 1 and 2, Od). I observed these bodies also, and
I think it very probable that they represent the female genital apparatus ; they are

especially distinct in the longitudinal section of the body shown in fig. 2. In this
figure the valves of the Cypris are not represented; the clear margin round the body
represents the chitinous wall of the future Lepas; the cells of the mantle serve as a
matrix for its formation.

When we look now at the figure of the Cypris-larva of Scalpellum regium which is
destined to develop into a complemental male, we observe great analogy as well as
considerable difference. Pl. Il. fig. 3 represents a larva which has probably attached
itself lately, and which therefore is exaetly in the same stage as the larva of Lepas
australis which I have just described. It is somewhat different from the latter in
general outline, being more elongate and not so high. At the hinder extremity the Cypris
of Lepas australis is obliquely truncated and bluntly pointed, and that of the male of
Scalpellum almost entirely transversely truncated. Like the former it is enclosed within
a shell consisting of two valves of a very brittle constitution. The antenne (A n) are
stretched forward out of the ventral slit between the two valves; they have in all essential
respects the same structure as those of the full-grown complemental male which will be
_ described further on. At their base in the interior of the body of the larva a cellular

8 THE VOYAGE OF H.M.S. CHALLENGER.

body is visible which, I think, must necessarily represent the cement-gland. However,
neither the place it occupies nor its structure shows any resemblance to the same glands—
or what we must consider as such—in the Cypris of Lepas australis. Nor have these
glands in the male of Scalpellum regium great conformity with those organs in the younger
Cypris-stage of another species of Scalpellum (Scalpellum triangulare) which I figure in
Pl. IL. fic. 4. In this stage the antennze (Am) are still totally hidden within the valves,
and the cement-glands (C. g/) form very large cellular masses situated on both sides of the
thoracic part of the body between it and the valves. I think it is in this stage that the
Cypris-larva leaves the mantle cavity of the mother.

What we called the mantle in the Cypris of Lepas australis takes in the male Cypris
of Scalpellum regium the form of a bag closed on all sides, with only a very small opening
at the hinder extremity. This opening no doubt corresponds to the slit-like opening at
the ventral side of the Cypris of Lepas. It also serves the same purpose. We see the
very delicate and slender spines placed at the extremity of the legs come forth from this
opening. For want of material I have not been able to study in detail the structure of
the mantle, nor its musculature. I can only say that the mantle is composed of
flat and pale rounded cells of 0°01 mm. in diameter, with a small clear nucleus, and that
these cells are placed at a little distance from each other; that the muscular fibres form
a single layer only, and are built up of elongate oval cells placed in longitudinal rows and
each furnished with a distinct nucleus (Pl. L fig. 7). Besides the body the interior of
the mantle contains a mass of connective tissue with little grains and small fatty corpuscles
scattered irregularly throughout its meshes. With regard to the body it is not difficult to
observe the mouth (Pl. II. fig. 8, 7), the cesophagus (C1), and the stomach (St); the
nervous system consisting of a supracesophageal ganglion (G S) and a single, rather large
thoracic ganglion (G 7’); six pairs of very slender cirri with delicate spines at their
extremities; a pair of long and well developed caudal appendages (C'A). A dark-
coloured mass consisting for the most part of yolk-fragments makes up a great deal of the
rest of the true body of the embryo Scalpellum.

\s for details, I can only say that the parts which surround ‘the mouth are not very
distinct, and that the very long cesophagus leads into a blind pouch of an oval shape, and
that this pouch represents the stomach. The two branches of each cirrus are indistinctly
divided into four segments; the shape of each segment is cylindrical, with the exception of
the last joint, which is conical and slopes into the very long spines placed at the extremity.
The first two pairs of cirri are somewhat different from the following pairs, in as far as in
the first two the lower two segments are the only ones which are filled up with a mass of
cellular structure ; so, when the cirri have shed the exuvize which now cover them, the
cirri of the first two pairs undergo a considerable loss of length. The very long caudal
appendages in this stage are also only represented by the chitinous skin. After the last
casting of skin they will no doubt have disappeared.

‘REPORT ON THE CIRRIPEDIA, 5

- The supracesophageal ganglion is well-developed; in one of the specimens two nerves
were indistinctly visible starting from the ganglion and directed towards the antenna;
if my observation be correct there can be little doubt that these are the antennal nerves.
I have not observed the commissures which unite the supracesophageal ganglion with
the thoracic ganglion; the latter is large and oval, and probably only represents the
first larger ganglion of the thoracic chain of Lepas. Neither the small eye near the supra-
esophageal ganglion nor the large compound eyes at the base of the antenne are present ;
the pigment which is so richly distributed over all the organs and parts of Lepas australis
is totally wanting in the male Cypris of Scalpellum. This no doubt finds its explanation
in the circumstances under which the little animal is destined to live.

Of great importance is the fact that the dorsal invagination, which as we have seen
causes the division of the body of Lepas into a capitulum and a peduncle, is totally
lost in the metamorphosis of the Cypris of the male of Scalpellum; hence there is no
trace of this division to be observed in the full-grown males. This want of a peduncle
together with the smallness of the orifice of the mantle and the total absence of valves,
form the most characteristic features of the male in question.

The metamorphosis of the Cypris-larva, in its latest stage (as figured), into the full-
grown male is now | think easy to understand. In this respect at least it quite
corresponds to the metamorphosis of Lepas. The difference between the latest stage of
the Cypris of Lepas australis and the young Cirriped of that species is not greater, nor
less either, I think, than that between the attached Cypris of Scalpellum regiwm and
the young male; to say that the complemental male of Scalpellwm is in its Cypris stage
or thereabouts, is not in accordance with the facts.

The valves of the Cypris are first of all shed. The cells of the mantle or sack soon
develop a distinct membrane of chitin at their surface, which no doubt is as efficient a
protection as the shell was, but which contains no carbonate of lime and therefore is not
so brittle. When the wall of the male is quite intact, its impenetrability makes it
absolutely unfit for transference from absolute alcohol into oil of cloves ; the alcohol leaves
the little body faster than the oil enters it, whence the body wall becomes shrivelled.
As the internal structure is best studied in a specimen placed in oil of cloves, and as for its
investigation by transverse sections the passing through oil of cloves was also necessary,
I found it very useful, when the specimens were quite sound, to make a little opening in
the wall before transferring them into the oil. For the rest, this internal structure is
very simple. The antennze and the very delicate thorax with the legs are the only parts
which show that the little body belongs to an articulate animal; the whole interior of
the body is filled with a mass of connective tissue with very wide meshes, serving to
keep the different organs in their places,

(ZOOL, CHALL, EXP.—PART XXvIII.—1884,) Ee 2

10 THE VOYAGE OF H.M.S. CHALLENGER.

b. ANATOMY OF THE MALE oF Scalpellum regiwm.

I will now proceed to give an anatomical description of the complemental male of
Scalpellum regium (Wyv. Thoms.), Hoek. I choose this species because it is represented
by numerous specimens, and also because it is one of the largest species in the Challenger
Collection.

Form and dimensions.—The complemental male of Scalpellum regium has an
elongated oval shape. Its length varies from 1°6 to 2°4 mm., its breadth is 0°63 to
0:71 mm. The difference in length corresponds to differences in some of the internal
parts, especially of the testis. Whether it is occasioned by the growth of this organ I
cannot say. The third dimension, the thickness, is nearly equal to the breadth. We
may call the extremities of the longer axis the poles of the body, and I propose to call
one the peduncular, the other the capitular pole (PI. I. fig. 1).

The Antenne.—The only. appendages externally visible are the small antenne,
situated close to the extremity of the body corresponding to the peduncle of other
Cirripedia ; they are seated at a. little distance from the extremity, on that side of the
body which represents the ventral surface. They have two segments; one cylindrical,
and about twice as long as the other, which is flat and triangular. What Darwin calls
the third and ultimate segment of the antenne is very distinct in the case of this little
creature (PI. I. fig. 3). It is articulated to the upper surface of the disk and directed
rectangularly outwards. Whereas the main segments of the antenne are not furnished
with spines, this latter segment bears five spines at the end, and three very slender ones
at a notch a little beneath the extremity of this segment. i

With the aid of these antennz the little creatures are attached to the inner surface
of the scutum of the hemaphrodite or female. The triangular terminal segment of the
antenns, in all the cases I observed, surrounded the extremity of a transparent mass, which
I think can safely be considered as the product of the cement-glands which are in relation
with the antenne. It is by means of this cement that the attachment of the triangular
disk takes place. In the case of Scalpellum regium the males are attached a little above
the adductor muscle, and as a rule, three of them are implanted so closely together as to
touch eachother. What I think very peculiar is, that in three different cases observed
by me, two of the three males attached to the scutum were much further developed than
the third ; the first contained a fully developed testis and a well-filled vesicula seminalis,
the third was still in the condition of a Cypris-larva (Pl. II. fig. 3), probably only lately
attached to undergo its final metamorphosis.

The wall of the body is a chitinous skin which is comparatively thin and delicate, _
when a transverse section of the body is made, the chitinogenous epithelium beneath the

REPORT ON THE CIRRIPEDIA. 1f

chitinous outer wall is easily observed. The external surface of the body-wall is clothed
with microscopic spines, having a length of about 0°0235 mm., and placed in transverse
rows (not quite so regularly as shown in fig. 1 of Pl. I.). As a rule, these spines are
narrow and pointed at the extremity which is attached to the wall of the body and
broadest at the other extremity. Here the free margin is deeply toothed, which gives
the spines a certain resemblance to the scales of the Lepidoptera. In other places the
incisions of the spines are so deep as to divide the scale into two or three narrow spines. A
small circular space at the peduncular pole is left free from spines, and at the other
extremity the terminal part is so completely covered with minute particles of mud and
sand, that it is impossible to distinguish the little spines there. This latter part of the
body is the only one which is visible when the little male is in its ordinary place, viz.,
between the mantle or ‘“‘sack” (as Darwin calls it) and the scutum of the hermaphrodite.
A small rounded part at the capitular extremity of the body is covered by a chitinous
membrane of greater thinness. The nuclei of the chitinogenous epithelium are placed
here much more closely and are more easily visible owing to the thinness of the
chitinous wall. A narrow slit-like opening (fig. 1,0) divides this little circular space; it
corresponds with the orifice of the capitulum of the pedunculated Cirripedia. It is not
easy to distinguish the edges of this slit-like opening, owing, as Darwin suggested for the
same orifice of Scalpellum vulgare, to their extreme thinness.

The chitiogenous membrane which is found beneath the chitinous outer wall shows
the ordinary structure of very flat cells with indistinct limits and with rather distant but
conspicuous nuclei. These nuclei are very close to one another at the. small circular
part at the capitular extremity (Pl. IL. figs. 2 and 3). The slit which indistinctly divides
this part gives entrance to a cavity which contains the thoracic part of the little male.
This cavity is not lined by an epithelium; it is only surrounded by a somewhat more
solid layer of the same connective tissue, which fills up the whole interior of the
body of the male. This cavity is seen in transverse section in Pl. III. fig. 4. In all the
specimens of this species which I investigated the thoracie part was always retracted
high up into the interior of the body, so that even the very long spines at the end
of the slender limbs never reached the slit-like orifice at the capitular pole. In the
males of some of the other species (Scalpellum intermedium, Scalpellum tritonis)
the spines at the end of the thoracic limbs extend beyond this orifice. This was
often also the case in the males of Scalpellwm vulgare as observed by Darwin,
which always showed the whole thorax forced outwards through the orifice, a cireum-
stance which perhaps was owing, according to Darwin, to the action of the spirits of
wine and consequent endosmose.

Muscles of the body-wall.—Under the cells of the hypodermis a well-developed layer
of muscular fibres is everywhere present; these muscular fibres are indistinctly trans-
versely striated ; in some of my preparations however the transverse striation is some-

12 THE VOYAGE OF H.M.S. CHALLENGER.

what more distinct. Perhaps the indistinctly striated condition of the fibres is the
consequence of their being nearly functionless and rudimentary.*

From their position close to the body-wall one feels inclined to compare these muscles
together with the outer wall of the body with the “ Hautmuskelschlauch” of worms, as
the Germans call it. The muscular fibres form.a single layer only ; they have an irregular
oblique direction, which in some parts approaches to a transverse, in other parts to a
longitudinal position; their course is imperfectly parallel. Their structure is very simple
and can be best studied in Canada balsam preparations; when seen in oil of cloves
their transverse striation is so indistinct as to be hardly visible. It is from such a
preparation that the fig. 6, Pl. [V. has been made. When making a preparation of them by
means of needles they present themselves like flat bundles of delicate fibrillee, each bundle
having a breadth of about 0°01 mm.; they sometimes show a clear wall as a kind of sheath
and are furnished with nuclei.at intervals; the latter are elongate and—as appears on a:
transverse section of the muscle—cylindrical ; they have a length of about 0°02 mm. and
atransverse diameter of about 0:005. Ina transverse section of the wall of the body,
as in all the figures of Pl. IIL, the nuclei of the matrix are seen between the chitinous
outer wall and the transverse sections of the muscles. In these sections the latter show
a very curious structure (Pl. IV. fig. 5); whereas that side of the muscle-fibre which is
directed towards the anterior of the animal is smooth and arched and shows the sheath
in the form of a distinct margin; that side of the same fibre which is directed towards
the exterior is deeply toothed; here the fibrillee which compose the fibre seem to part in
different ways. As I could observe this phenomenon only in very thin sections, there can
be no doubt that this structure does not agree with the natural condition of the fibre.
The nucleus of the muscle-fibre is sometimes placed near the outer wall, sometimes almost
in the centre of the fibre. As to the development of the muscle-fibre, when comparing
it with the condition of the muscular fibre in the Cypris-larva, we may suppose that the
oval contractile cells which compose the larval fibre grow out into long fibres, the pointed
extremities of which are no longer placed in a longitudinal row but have been pushed
aloug each other.

The connective tissue is composed of fibres, but also of extremely delicate and finely
granulated membranous plates which form the partitions between the large meshes. _ Its
nuclei are round and flat and have a diameter of 0°008 mm. The fibres are more robust
where they form the wall of the cavity in which the thorax is situated; we find also
stronger fibres where they run in a straight direction from the organs to the wall of the
little animal.

I have not observed a true body-cavity in these little males, and.before I had
studied the bodies of other Cirripedia by means of transverse sections, I was much.

‘t Leydig (Zum feineren Bau der Arthropoden, Arch. fiir Anat. wnd Physiol., 1855, p. 394), says that the muscle-
fibres of young individuals of Coccus hesperidwm are distinctly transversely striated, those of full-grown individuals which.
almost lost the function of locomotion are totally rudimentary (and smooth 2).

REPORT ON THE CIRRIPEDIA. 13

puzzled by this fact. A part of the body of this male corresponds to the peduncle of the
pedunculated Cirripedia, and as this is also filled up with connective tissue—with the
exception of a rather narrow tubular cavity towards the rostral side—I at first endeavoured
to homologize the connective tissue of the male with that of the peduncle. Extending
my researches also over the body of the hermaphrodite or female Scalpellum, over Lepas
and other genera of Cirripedia, | found that the occurrence of a well-developed mass of
connective tissue between the different organs within the body is the rule in all the
Cirripedia. In the interesting essay on the ccelom-theory by the brothers Hertwig! we
read that all the Arthropoda possess a very capacious body-cavity, and that in the full-
grown animal the intestinal tract passes freely through this cavity, a dorsal mesentery
uniting the intestine to the wall of the body being observed only in a younger stage of
the development. Whether the plurality of typical forms of Arthropoda have been
sufficiently investigated so as to allow of this conclusion to be drawn, I will not decide.
Doubtless, however, the Cirripedia have a very rudimentary body-cavity, and a well-
developed mass of connective tissue nearly fills up all the space left open between the
wall of the body and the internal organs. So the complemental males in this respect also
correspond in structure to the female and hermaphrodite animals.

The internal organs consist of the well-developed genital apparatus, the nervous
system, the cement-glands, and the totally rudimentary and evidently functionless
cesophagus and stomach.

Fig. 1 of Pl. I. shows these parts in their normal position ; fig. 2 represents part
of these organs more strongly magnified. Testis (¢), vesicula seminalis (vs), and
vas deferens (vd), can easily be made out in all the specimens. Neither do the other
organs (the nervous system, and the cesophagus with the stomach), present any further
difficulties after comparison with the structure of the Cypris-larva (PL. II. fig. 3).

Digestive tract.—The cesophagus and the stomach have nearly preserved their original
condition ; the mouth has grown totally functionless; its place is indicated by the
presence of a group of cells (Pl. I. fig. 2 m), which are placed in the connective tissue
bordering the cavity in which the thorax is situated. The cesophagus is a narrow tube
which imperceptibly widens and passes over into the stomach. The latter is a pyriform
pouch closed on all sides, having a rudimentary intestine at the extremity opposite
to the cardia. It has a double wall, as can be best studied in the transverse sections
(Pl. III. figs. 6 and 7). Probably the internal wall represents a chitinous cuticle which
has been shed, but which could not be removed, the mouth being closed. Perhaps the
internal wall represents the chitinous tube, or model of the stomach filled with excrement,
Darwin describes in the alimentary canal of Cirripedia.? In the full-grown male the
stomach is almost empty ; in a younger condition (Pl. IV. fig. 1), the stomach is filled

10. and R. Hertwig, Die Coelomtheorie, Jenaische Zeitschr., Bd. xv., p. 76, 1882.
? Darwin, Balanide, p. 86, 1854.

14 THE VOYAGE OF H.M.S. CHALLENGER.

with a yellowish-brown coloured mass of a fatty nature. Between the two walls of:
the stomach, nuclei of nearly the same size as those of the connective tissue are visible.

Nervous System.—The supracesophageal ganglion, also, has nearly kept its original
position; it is situated against the cesophagus, a little anteriorly to the place where it
communicates with the stomach. In Pl. I. fig. 2 it is figured in its natural position
and condition; in Pl. III. fig. 5, and Pl. I. fig. 4, it is seen in transverse section ;
numerous rounded ganglionic cells are placed at the periphery, and the whole interior of
the ganglion is occupied by the medulla. Pl. L. fig. 4 distinctly shows the commissures
which serve to unite the ganglion with the large thoracic ganglion. In the preparation
which is figured (Pl. I. fig. 2) these commissures could not be made out, nor has this been
possible in any of the other preparations I made by the aid of needles.

This thoracic ganglion represents alone the whole ventral nerve-cord ; together with
the thorax, it has changed its place and has been transposed in a direction towards the
front of the animal, so as to be now attached before the supracesophageal ganglion ; it
has an elongate oval shape with numerous ganglionic cells at the periphery. In a trans-
verse section such as that figured (Pl. I. fig. 5), we observe that the ganglionic cells form
a much thicker layer on the side which is directed towards the thorax than on the other
side; the lateral symmetry of the ganglion is very distinct, the medulla forming two
rounded portions which meet in a straight line in the middle of the ganglion. The nerves
given off from this ganglion as well as those from the supracesophageal ganglion are
extremely delicate and are hardly recognisable as such; two somewhat stronger nerves
start from the commissures very close to the supracesophageal ganglion, and a distinct
nerve is attached terminally to the thoracic ganglion, but as for other nerves, I
found it impossible to distinguish them with certainty from the fibres of the connective
tissue.

There are no organs of sense; even the sense of touch can be only very slightly
developed, as the whole body is enclosed within a chitinous- bag bearing only chitinous
spines on its surface. The hairs on the antenne (PI. I. fig. 3) no doubt once per-
formed the function of organs of touch, but after the antenna has attached itself the
function of these hairs can no longer be of any importance. Close to the supra-
cesophageal ganglion I always observed two little bodies which from their position I at
first felt inclined to consider as belonging to the nervous system. They are kept in
their places by the connective tissue, and they are situated near the corner between the
stomach and the supracesophageal ganglion. Their structure is that of an oval bag
slightly poimted at one or both extremities, lined by an extremely delicate mem-
brane and filled with a granular substance of a brownish-yellow colour, having
numerous nuclei scattered throughout its interior (Pl. I. fig. 2, gl.). Most probably
these organs represent the remains of the appendages of the oesophagus (Pl. IL.
figs. 1, 2, C) of the pedunculated Cirripedia, which are very distinctly developed in the.

REPORT ON THE CIRRIPEDIA. 1d

Cypris of Lepas, and which probably correspond to the salivary glands of Cuvier; that
they are here as rudimentary and as functionless as the cesophagus and the stomach itself
is an argument, though a negative one, in favour of my interpretation.

In some of the sections and preparations I observed globular elements which I think
are blood-corpuscles. | have figured some of them PI. IV. fig. 7. They have very distinct
dark coloured nuclei and their size varies from 0°015 to 0°02 mm. ; by their size alone
they can be easily distinguished from the nuclei of the connective tissue.

From the condition of the mouth and the alimentary canal there can, I believe, be
no doubt that these little animals never take food at all. For this reason it is necessary
not only that the whole of the body with its well-developed genital apparatus develops
from the yolk-mass in the Cypris-larva, but it must be supposed also that the little
body can only furnish so much of the male genital product as may develop from the
testis after it has once arrived at its full size and maturity. Probably therefore each
male only once, or in one season with short interspaces, takes part in the act of
propagation. And as it is highly probable that the species of Scalpellum like most other
animals spawn only once a year, the male which has once furnished its quantum of the
male genital product is to be replaced by another. The objection may be made that it
is possible that only one part of the spermatozoid mother-cells develops into sperma-
tozoids in one season, and a second part in a following year; but then it is difficult to
understand, with our present knowledge of animal life, in what way the little animal is
supplied with the material necessary for its maintenance.

The Male Organs.—The testis is heart-shaped with the incision directed towards the
hinder or capitular extremity. Its length in some of the specimens was about 0°5 mm.,
in others, which themselves were longer, no less than 0°8 mm. In the latter case
the incision was more than half as long as the organ.’ This incision is remarkable,
I believe, because it is the only sign of the original duplicity of the male genital gland.

The histological structure of the testis presents no points of special interest; the
spermatozoid mother-cells have a size of 0°021 mm. and fill up the whole interior of the
gland. They split into extremely small transparent cells with a dark-coloured little
body for a nucleus. These small cells are 0°004 mm. in diameter and I think each of
them develops into a spermatozoid. The wall of the testis is built up of connective
tissue with nuclei of 0°01 mm. in diameter; the wall of the vesicula seminalis presents
about the same structure. It is an irregularly globular vesicle, having in the full-grown
and mature males a diameter of 0°3 mm. ; it is very closely pressed against the testis.’
In younger specimens I did not observe this organ; the vas deferens in them only
presented a very small swelling at the place where it communicates with the testis; the

‘ The testis of Scalpellwm darwiniit when young does not show an incision ; in older specimens, however, traces of
an, incision are present. Other species (¢.g. Scalpellum tenue, Hoek) have the testis triangular with a heart-shaped foot.

2 In other species (Scalpellum tenwe, Scalpellum darwinii, &c.) the testis is separated from the vesicula seminalis
by means of a duct of not inconsiderable length.

16 THE VOYAGE OF H.M.S. CHALLENGER.

vesicula seminalis is no doubt only a dilatation of the vas deferens at the place where it
corresponds with the testis. The vesicula seminalis in all the larger specimens was filled
with a dense mass of very small spermatozoids; they have the shape of threads, each
having a length of about 0°02 mm., and each furnished at the extremity with a very
small vesicle (Pl. I. fig. 6). Between the spermatozoids in the vesicula seminalis small
empty vesicles are seen, as also others which quite resemble the very small cells of the
contents of the testis, probably each one of them contains a spermatozoid.

The length of the canal acting as a vas deferens is not very considerable ; it passes
freely through the connective tissue for about 0°25 mm. and then enters into that part
of the body which represents the thorax of the Cirriped. Figs, 10 and 11 on Pl. II]. show
sections of the duct before it reaches the thorax, but in the figs. 5 to 8 of Pl. III. the
same canal is represented in the middle of each transverse section of the thorax. In
fig. 9 the form of the section of the thorax is nearly quadrangular ; this is its shape near
the place where the vas deferens enters it; in the sections, however, which more approach
the other extremity of the canal the thorax is exactly cylindrical, and then its wall is
parallel to the wall of the genital canal. The diameter of the thorax itself is about
0°08 mm.; the canal which runs through it longitudinally has a width of 0°03 mm.
Whether it be preferable to designate the eylindrical terminal portion of the thorax as
“penis” is I think difficult to say ; morphologically it is hardly to be distinguished from
the appendix of that name in the hermaphrodite Cirriped, which is called by some authors
a penis, by others an abdomen. j

The nuclei of the cells which surround this canal (PI. I. fig. 5) are slightly larger
than those of the connective tissue placed between the canal and the chitinous wall of

the thorax ; as far as I could distinguish in any of the sections, these cells of the wall of
— the canal have no distinct shape and do not compose a true epithelium. From the place
where it enters into the thoracie part of the body the vas deferens is seen in all the
sections which pass transversely through the thorax; it may be traced for about half a
millimetre, it then ends abruptly; probably, though this could not be distinctly
observed, it now opens into the cavity (Pl. III. fig. 4 ca) lined by the connective tissue,
which has an outward opening at the capitular pole of the body. The communication
with this cavity must be about at the height of the supraocesophageal ganglion. The
whole thoracic part of the body can be stretched forward in a direction towards the
eapitular pole ; though I do not believe that the opening of the vas deferens ever reaches
the opening at the surface of the body, this stretching forward of the thorax is no doubt
brought about in order to approach the opening of the vas deferens as much as possible
to the slit at the extremity of the body. Well-developed musculi retractores serve for the
retraction of the thorax within the body of the male. I have figured one of them on
Pl. I. fig. 1, mr. In the transverse section figured on Pl. HI. fig. 10 these muscles are
also represented,

REPORT ON THE CIRRIPEDIA. 17

The Appendages.—As far as the number and the shape of the appendages. of the
thorax are concerned, it has proved rather difficult to get any certainty; in the first place,
because the limbs with their thin chitinous wall refract the light in the same way as the
thorax, and are pressed so closely against the body of the thorax as to make it
impossible, even in a well-stained preparation, to make out their respective outlines,
and in the second place, because of the smallness of the parts in question. After a
eareful study of sections, as well as from preparations made by dissection with needles, I
believe the following facts may be safely relied upon. Only four pairs of legs are
relatively well-developed; these’are the four posterior pairs, and each of them is
composed of two branches. Of the first two pairs of cirri only one very short branch is
left. Each branch of the double-branched ones is relatively long and narrow, and
terminates in two or three very long spines. In a transverse section each leg is
represented by its chitinous wall and by the nuclei of its matrix, which are more or less
elongate (PI. I. fig. 5).

The Cement-Glands.—Finally, I must describe in a few words the structure of the
cement-glands. They may be best studied ina section of a not quite full-grown specimen,
as shown in Pl. IV. fig. 8. Each male contains a pair of these glands; they are situated
a little above the vesicula seminalis (Pl. I. fig. 1 ¢. gl.); they have an oval shape and
measure about 0°15 mm, They are composed of very large cells with granular contents
and a large nucleus, kept together by an extremely delicate network of connective tissue
with a single rather small nucleus here and there between its fibres. Between the large
cement-cells cavities are left open here-and there in the connective tissue ; each cell has
the shape of a wedge, and is placed so that the broader part is directed towards the
periphery, the narrower on the contrary towards the centre of the gland. The
structure of the contents of each cell is rather remarkable, since the larger granules
are placed at the periphery, and the contents are much more homogeneous towards the
narrower extremity of the cell. In one of the preparations the ducts which run from the
gland to the antenne were rether distinct ; they are attached as thread-like appendages
to one of the narrower extremities of the gland.

Summary.—l think I have given herewith a full description of the so-called
complemental male of a species of Scalpellum. With this description and with the
figures on Pls. I-IV. it is possible not only to prove that this male has a highly degenerated
organisation, but also to demonstrate in what this degeneration consists, and how it affects
some of the organs very greatly, whilst others suffer less from it, and some are not influ-
enced by it at all.

The state of things in the male under consideration may be summed up as follows :—

1. The external characteristic shape of the species with its capitulum and peduncle,

its valves and scales, is lost. The microscopic body consists of an elongate bag closed on
(ZOOL. CHALL, EXP.—PART XXVuII.—1884. ) Ke 3

18 THE VOYAGE OF H.M.S. CHALLENGER.

all sides. A very small slit represents the opening between the two scuta. The
antennse are the only extremities which still show their original condition; the cirri
have grown straight and functionless; the parts of the mouth have disappeared.

2. The cement apparatus is well developed as long as the male is young; when
mature it is no longer so distinct.

3. The intestine has become functionless and is quite rudimentary ; circulatory and
respiratory organs may be passed by, as they have no distinct organs even in the herma-
phrodite Scalpellwm. :

4, The nervous system consists of a relatively small supra-cesophageal ganglion, of a
not.very stout cesophageal ring, and of a large thoracic ganglion. It is probably the
latter which alone regulates the functions of the genital apparatus. The peripheral part
of the nervous system is not much developed. The eyes (and other organs of sense) have
been lost.

5. The genital apparatus is the only well-developed system of organs. The female
apparatus, however, is totally lost, and even the male organs show a great deal more
concentration than do the same organs in ordinary hermaphrodite Cirripedia. In the
first place the testis is single, and has become a rather compact gland, whereas in other
Cirripedia it is double and scattered throughout almost the whole interior of the body.
In the second place, the vesicula seminalis is also represented by a single vesicle only,
hermaphrodite Cirripedia on the contrary having always two of them.

In all these respects the little males of other deep-sea species of Scalpellum which I
have been able to investigate exactly correspond to the male of Scalpellum regvum.
So does the male of Scalpellum vulgare (from specimens from the Mediterranean) with
the exception of the presence of rudimentary valves, which in that species, as in some of
the deep-sea species (vide p. 4), represent the so-called primordial valves of the young
capitulum of pedunculated Cirripedia.

ce. GENERAL OBSERVATIONS.

In the case of Scalpellum vulgare, Leach, Scalpellum rostratum, Darwin, Scalpellum
peronii, Gray, sp., and Scalpellum villosum, Leach, sp., Darwin observed what he
considered a penis; in Scalpellum vulgare, Leach, and in Scalpellum villosum, Leach,
sp., he ascertained moreover the presence of vesiculz seminales and testis in the
apecimens which were also furnished with ovaria. These specimens, therefore, were
hermaphrodites, and as little males were found attached to their scuta, these male
specimens got the very characteristic name of “‘complemental” males. On the other
hand Scalpellum ornatum, Gray, sp., did not show a trace of a proboscidiform penis
in the four specimens which Darwin examined, and he, therefore, supposes that the
animals studied by him were females, although it was impossible, as the specimens were

REPORT ON THE CIRRIPEDTA. 19

dried, to demonstrate the absence of the vesicule seminales and testes, The male animals
were lodged in a pouch on the under side of the scutum, in that case should not bear the
name of “complemental” males. From the state of the specimens of Scalpellum rutilum,
Darwin, which Darwin examined, it was quite impossible to ascertain whether the
individual was a hermaphrodite or a female; from the analogy of its nearest congener
Scalpellum ornatum, the latter, Darwin says, is the most probable.

Darwin's supposition as to the unisexuality of some species of Scalpellwm proves to
be in a very striking accordance with the facts. What I at first considered to be the
hermaphrodite form of Scalpellum regium (Wyv. Thoms.), Hoek, is not furnished with
a penis and does not show a trace either of a testis or a vesicula seminalis. To
have full certainty in this respect, | divided the whole thoracic part of the body of a
specimen of this species into a series of sections, and in none of them did even the smallest
trace of a part of the male genital apparatus appear. The body was stained in toto by means
of aluminium carminate, a most brilliant staining for the testis and for the sperma-
tozoa within the vesicula seminalis when present. I then repeated the examination of
Scalpellum vulgare, Leach; I found the animal a true hermaphrodite; it is furnished with
a well-developed penis, and the vesiculee seminales have exactly the structure of these
organs in species of the genus Lepas. The only difference is shown in their small size.
Slightly more developed testes pour out their products into the vesiculee seminales.

The specimen of Scalpellum vregium, of which I examined a series of sections, was a
full-grown animal; it was furnished with males and there were ova in the ovigerous
lamelle. I got the same results when making a series of sections of Scalpellum
parallelogramma, Hoek (PI. IV, fig. 9), and Scalpellum nymphocola, Hoek (PI. IV. fig. 10).
So I think that we may safely draw the following conclusions :—

There are species of the genus Scalpellum, Leach, which show a very characteristic
dimorphism. Some of these consist of large hermaphrodite and small rudimentary
male specimens ; others have large female and small rudimentary male forms.

However, I do not believe that these are the two most divergent cases in the sexual
relations of the genus Scalpellum. I think there is still a third category of species in
this genus, viz., those which are as true hermaphrodites as other Cirripedia, and in
which no complemental males are developed. As a supposed species of this third
division I will point out Sealpellum balanoides, Hoek. In the descriptive part of my
report I have communicated the fact (p. 130) that one of the specimens contained eggs,
though no complemental male was present at the place it ordinarily occupies. Though I
have studied some more specimens of this species with great care, I have not once observed
a male; yet they were nearly all furnished with eggs. I then studied the body of one
of the specimens by the aid of transverse sections (Pl. IV. fig. 8, af); I found that
the specimen was furnished with a very largely developed testis greatly surpassing the
same organ in Sealpellum vulgare. The penis of this specimen was also of considerable

“20 THE VOYAGE OF H.M.S. CHALLENGER.

‘size. Suppose I had observed this same organisation in a species of another genus of
Cirripedia, then I should never have thought the existence of a complemental male in
that species possible, and now in the case of a species of Scalpellwm I think I may safely
infer that in this species the absence of a complemental male is not an accident, but indeed
the rule! I think, therefore, that there is sufficient reason to conclude..that the genus
Scalpellum presents the three following stages of sexual differentiation :—

Ist. True hermaphrodite species: all the specimens develop male genital products
as well as female. Whether these species are also “ autogames,”? 2.e. whether
the spermatozoa of a specimen as a rule fertilize the ova of the same
specimen, is a point, which I do not wish to discuss at present. I will only
say that in case “autofécondation”’ should be proved in the case of other
Cirripedia (which at present has not, I think, been done) we can also safely
admit it in the case of these species of Scalpellum.

Example :—
Scalpellum balanoides, Hoek.

2nd. Large hermaphrodite specimens and small unisexual (male) ones in the
same species.

A. Male specimens with a capitulum and peduncle, with a mouth
and stomach.

Examples :-—

Scalpellum villosum, Leach, sp. | Scalpellum peronu, Gray, sp.
(Scalpellum trispinosum, Hoek.*)

B. Male specimens with or without rudimentary valves, without. a
peduncle, a mouth and stomach.

Examples :—

Scalpellum vulgare, Leach. | Scalpellum rostratum, Darwin.
(Scalpellum acutum, Hoek.*)

} Robin, Ch., Article “Sexe” in Dictionn. encyclopéd. d. sci. med., Paris, 1880.

3 The body of this species has not been investigated; so my conclusion is based only on the presence of a well-
developed penis, and on the great resemblance of the species to Scalpellum villosum, Leach.

3 This species has not been investigated either ; the supposition as to its hermaphroditism is based only on the:
presence of a well-developed penis. ‘

REPORT ON THE CIRRIPEDIA. 24

3rd. True unisexual species; the females are large, the males very small and
(probably) short-lived.

Scalpellum ornatum, Gray. Scalpellum vitreum, Hoek.
regium (Wyv. Thoms.) Hoek. moluccanum, Hoek.
parallelogramma, Hoek. eximium, Hoek.
nymphocola, Hoek. darwini, Hoek.
tritonis, Hoek. carinatum, Hoek,’ &c.

Of all the genera of Cirripedia, Scalpellum is no doubt the one which presents the
greatest amount of variety as far as the sexual relations are concerned. In this regard
it even surpasses the genus [bla, Leach, of which we know, through the aid of Darwin,
that it presents two instances of sexual differentiation only, viz., unisexuality in the one
species and hermaphroditism with accompanying rudimentary males in the other. It is
well known that the genus Scalpellum, by means of Scalpellum villosum, Leach, sp., and
by means of Scalpellum trispinosum, Hoek, blends with the genus Pollicipes, Leach,
and also that the latter genus is one of the oldest, if not the oldest, of the genera of
Cirripedia. All the known species of Pollicipes are true hermaphrodites as are
other Cirripedia, and moreover, Pollicipes seems to be a genus which only contains
shallow-water species. With a little imagination it does not appear to be very
difficult to trace the way in which sexual differentiation took place in the genus
Scalpellum. Originally there were only hermaphrodite species, inhabitants of shallow-
water. They resembled more or less the species of the genus Pollicipes. In some of
the species specimens attached themselves to each other? as well as to other objects, and
they developed all into ordinary. hermaphrodite specimens. In one of these species,
however, young specimens attached to full-grown older ones, though developing into
animals of the ordinary shape with a capitulum and a peduncle, did not acquire the size
of the older specimens and lost their female genital apparatus. In a following stage,
we see that the little creatures which by their smallness are enabled to hide within the
valves of the older hermaphrodite specimens, lose their valves and are reduced to a
rudimentary ‘state in all respects, except so far as the male organs are concerned.
Finally we observe in the latest stage that. the original hermaphrodite specimen loses
its male genital apparatus and becomes unisexual. In the latter species we have large
and relatively long-lived female specimens, and small and short-lived males.

I feel sure that some’ serious objections may be advanced against this reasoning, and

1 The bodies of Scalpellum tritonis, Scalpellum vitrewm, Scalpellum moluccanum, Scalpellum eximium, Scalpellum
darwinti, and Scalpellum carinatum, have not been investigated by means of transverse sections. Their unisexuality is
based only on the total absence of a penis and on their general resemblance to the investigated unisexual species.

2 Specimens of Scalpellum vulgare are attached to various horny corallines, and occasionally to the peduncles of
other individuals. Darwin, Lepadide, p. 226, 1851.

22 THE VOYAGE OF H.M.S. CHALLENGER.

one of these I will point out myself. Those species which are unisexual and have very
small and rudimentary males, which, therefore, according to the sketch given above, are
the youngest of the hypothetical course in which the different stages of sexual differenti-
ation have developed, are at the same time those which closely resemble the species from
the oldest geological strata from which species of Scalpellum are known. But I think this
objection is weakened by admitting that the sexual differentiation in the genus Scalpellum
was already achieved at the period from which these fossil remains date. The somewhat
aberrant shape of Scalpellum balanoides—the species in the supposed original condition
of true hermaphroditism—is also difficult to explain at first sight. We might have
expected to observe the original condition (hermaphroditism without complemental males)
in a species as closely resembling Pollicipes as possible, as for example in Scalpellum
villosum, Leach, sp.; or Scalpellum trispinosum, Hoek.t| The condition of the genital
apparatus and the external shape of the valves (the whole capitulum), however, are two
factors which need not necessarily stand in so very close a relation to each other. So it
may be easily imagined that the original condition of the sexual apparatus is left in a
form in which the external shape of the capitulum has been altered, and on the other hand
there is no reason why the sexual relations of a form should not become altered without
the external shape undergoing considerable changes at the same time.

When, however, all these considerations are weighed I do not believe that there are
trustworthy grounds for doubting the exactness of the hypothesis that in the genus
Scalpellum the hermaphrodite condition is the original, and the unisexual, the secondary
stage in the development.

1 I did not observe the male of Scalpellum trispinosum. I suppose that this species is furnished with a comple-

mental male with capitulum and peduncle from its resemblance to the species Scalpellum villosum, 1 did not study its
genital apparatus. I can only say that it is furnished with a well-developed penis.

REPORT ON THE CIRRIPEDIA. 23

TL SEGMENTAL ‘ORGANS IN THE CIRRIPEDIA.

~ Cirripedia are rich in organs of an unknown or at least problematic function. One
‘instance of these is found in the “olfactory organs” or sacs of Darwin. ‘In the
outer maxille,” Darwin says,’ “at their bases where united together, but above the basal
fold separating the mouth from the body, there are, in all the genera, a pair of orifices ;
these are sometimes seated on a slight prominence, as in Lithotrya, or on the summit of
flattened tubes projecting upwards and towards each other as in bla, Scalpellum, and
Pollicipes. In Ibla these tubular projections rise from almost between the outer and
inner maxille. It is impossible to behold these organs, and doubt that they are of high
functional importance to the animal. The orifice leads into a deep sack lined by pulpy
corium, and closed at the bottom. The outer integument is inflected inwards (hence
periodically moulted) and becoming of excessive tenuity, runs to near the bottom of the
sack, where it ends in an open tube; so excessively thin is this inflected membrane, that
until examining Anelasma, I was not quite certain that I was right in believing that the
outer integument did not extend over the whole bottom. I several times saw a nerve of
considerable size entering and blending into a pulpy layer at the bottom of the sack of
corium ; but I failed in tracing to which of the three pair of nerves, springing from the
front end of the infracesophageal ganglion, it jommed. I can hardly avoid concluding that
this closed sack, with its naked bottom, is an organ of sense; and, considering that the
outer maxille serve to carry the prey entangled by the cirri towards the maxille and
mandibles, the position seems so admirably adapted for an olfactory organ, whereby the
animal could at once perceive the nature of any floating object thus caught, that I have
ventured provisionally to designate the two orifices and sacks as olfactory.”

This supposition of Darwin’s has, however, been accepted with great reserve. As far
as my knowledge of the literature of the group goes, the same organs have not been
studied, nor has another opinion been published about their function since Darwin’s.?
I first tried to get a good insight into the structure of this apparatus by isolating the
outer maxille. I arrived at the same conclusion as Darwin, viz., that it was composed
of a duct with an outward orifice and an internal portion, a kind of sac lined by a layer
of cells different in structure from those of the duct. In some of the figures representing
parts of the mouth of species of the genus Scalpellwin (e.g. Scalpellum parallelogramma,
Scalpellum strémiu, &c.), in the systematic part of my report, the long and very
characteristic tubes at the extremity of which the orifices are found have been represented.

I then studied the apparatus by the aid of transverse sections of the thorax of the
) Darwin, Lepadide, 1851, p. 52.
2 Claus (Lehrb. d. Zool. 3 Aufl. 1876, p. 456, says :—“ Gehor- und Geruchsorgane sind nicht mit Sicherheit nachge-
ewiesen, da die von Darwin als solche in Anspruch genommenen Bildungen eine andere Deutung (Oviducte, Driisen-

offnungen) erfahren haben.” 1 do not know where this opinion has been published, so far as Darwin’s olfactory organ is
concerned.

24. THE ‘VOYAGE. OF H.M.S. CHALLENGER.

animals, and I then became certain that Darwin’s description was not correct in one
very important regard. The sack is not closed at the bottom, but gives entrance to the
body cavity of the animal.

For want of material I have been obliged to limit my researches to the pedunculated
Cirripedia ; in the sessile Cirripedia, however, there cannot be the slightest doubt that the
apparatus will prove to have about the same structure ; the orifices are here never pro-
duced nor tubular. I got by far the best preparations from specimens of Scalpellum
vulgare, Leach, which I received from the Zoological Station at Naples. The figures on
Pl. V., as well as the description, are based upon preparations of these specimens.

Fig. 1 of Pl. V. shows a complete transverse section through the thorax of
Scalpellum vulgare a little below the first cirrus. The large cavities (A) separated in the
figure from one another by the band of connective tissue (B) represent parts of the body
eavity. An epithelial clothing (a true ccelomic epithelium) cannot everywhere be made
out distinctly; yet I think its presence may be safely concluded from the cellular
remains which here and there adhere to the connective tissue, in the shape of elongate
and rather flat nuclei. The section passes longitudinally through the long and flattened
tube which belongs to the right outer maxilla; the duct on the interior is clothed by a
thin chitinous tunic, with a chitinogenous epithelium everywhere beneath it; both the
chitinous tunic and its matrix are the continuation of the outer body-wall and are no
doubt true epiblastic products. Vig. 3 of Pl. V. represents a longitudinal section. of
one of the segmental organs. From the outer wall of the flattened tube thin transverse
fibres of connective tissue run towards the wall of the duct. Having passed longitu-
dinally through the tube, the duct may be traced for a short distance beneath the surface
of the body; it then passes over into a very narrow channel which passes through a
compact mass of cells. The whole mass of cells has the shape of a bell; the limits of
the different cells are not very distinct, but the different nuclei are. They are oval and
their longest diameter is about 0°005 mm. (fig. 2, Pl V.) The surface of the cells
bordering the narrow channel is markedly protuberant, so as almost to meet that of the
opposed cells; in very favourable sections only can the presence of the channel be made
out. To judge from the great number of nuclei, the cell-mass, at least on one side, is
formed of more than a single layer. Whereas the cells of the duct have their nuclei with
their longer axis parallel to the surface of the wall of the duct, those of the bell-shaped
cell-mass are rather perpendicular to the surface of the very narrow channel. Moreover, the
latter are very characteristic on account of their staining much more intensely than do those
of the chitinogenous cells or of the surrounding connective tissue. ‘Towards the interior
of the body-cavity the thick cell-coating of the narrow channel slopes and soon terminates ;
from the body-cavity the entrance of the narrow channel is distinctly funnel-shaped. The
chitinous membrane which clothes the interior of the duct is not present at the surface of

1 Darwin, Balanide, 1854, p. 97.

REPORT ON THE CIRRIPEDIA. "25

‘the cells which border the narrow channel. (Probably we have here the explanation: of
-what Darwin means, when he says that the outer integument is inflected inwards, and
‘ends in an open tube).

I propose to call the duct which opens at the extremity of the tubes the segmental

“duct, and the bell-shaped cell-mass with its very narrow channel the segmental funnel.

I think we can hardly hesitate to consider these organs as true segmental organs, but
before entering into a discussion of the arguments in favour of this suggestion, I will
finish the description. To the apparatus belongs also a well-developed set of muscles
attached round about to the external surface of the bell-shaped cell-mass, and especially
those directed to the external side of the body, are very strongly developed; they form
towards the interior of each organ a nearly triangular mass, the apex of which’ is
directed towards the interior of the body, the broad basis being placed against the
outer surface of the bell-shaped cell-mass (Pl. V. fig. 2). The muscle-fibres of the
external side of the cell-mass are distinctly divergent, and a part of them continues
in a rather strong bundle of muscle-fibres running towards the border of the body-
cavity. In my most successful, thinnest, and best stained preparations the muscle-
fibres did not show transverse striation; those especially of the external side were
remarkable for their clearness and smoothness, resembling thin elastic fibres of the
connective tissue. Between these fibres interspaces may be seen everywhere, and in
these numerous pale small round cells were visible, which I think were blood-corpuscles.
‘Probably the function of the muscle-fibres is not in the first place to move, but to form
a labyrinth of small cavities in which the blood accumulates.

What may be the morphological significance of this organ? Considering that it
constitutes an“open communication of the body-cavity with the exterior, there can be no
doubt that it must be compared with the segmental organs of the Annelida. The high
development in the genus Scalpellwm of the flattened tube at the end of which the orifice
is found, shows, I think, that we have not before us a rudimentary organ, but an
apparatus of an important. functional significance. From a phylogenetic point of view
its importance increases with our knowledge of the great age of Cirripedia, of which e.g.
the present genus is already represented in the Lower Greensand. Where the shell has
remained exactly the same, we can safely admit that the structure of the animals is sure
to have changed very little or not at all since that remote geological period.

A rather curious circumstance is found in the fact that in Cirripedia only one pair of
segmental organs has remained. In the oldest Tracheate Arthropoda we know of
(Peripatus), according to Balfour,’ there are found nephridia or segmental organs in all
the legs ; in Crustaceans these same organs have not been observed with certainty ; the
only instance mentioned in literature is that of terrestrial Isopods, where M. Huet?

1 F. M. Balfour, The anatomy and development of Peripatus capensis, Quart. Journ. Micr. Sci., vol. xxiii.
pp. 213-259, 1883.

7 Huet, Sur l’existence d’organes segmentaires chez certains Crustacés isopodes, Comptes Rendus, 1882, No. 12, p. 810.

(Z00L. CHALL. EXP.—PART XXVUL—1884.) Ee 4

26 THE VOYAGE OF H.M.S. CHALLENGER.

believes he has observed segmental organs in each of the seven body segments. Whether
M. Huet be right in considering these organs “‘organes glandulaires . . . qui s’ouvrent &
la partie supérieure des épimeres, de chaque cdté, par une ouverture en crible” as segmental
organs, I will not discuss. To judge from his description they have not the typical
structure of true segmental organs which are to form an open communication between the
body-cavity and the exterior.

Two other sets of glands of Arthropoda, and more especially of Crustaceans, are
perhaps more nearly related to the segmental organs; they are the antennal glands of
the larvee of many Entomostracans and of the full-grown Malacostracans ; and the shell-
glands of full-grown Copepoda and Phyllopoda. According to Grobben’ they have
nearly the same structure and must be regarded as homologous organs (homodynamous
they are called, more accurately I think, by R. and O. Hertwig’); both are com-
posed of a little terminal sack (Hndsiickchen), and a channel (Harnkanilchen) which
opens at the surface of the body. Moreover, the cells covering the interior of the little
sack in the antennal and shell-glands show a complete resemblance. An open communi-
eation with the body-cavity has, however, never been observed in the. case of these
organs®; if they really are to be compared with segmental organs, there can be no
question that they have degenerated from their original condition. |

Should there ever be discovered an intermediate form between a true segmental organ
such as that of Scalpellum and a shell-gland as observed in the Copepoda, then in the
first place the homology of the apparatus may be accepted; but in the second place it
will then also be possible to give a more solid basis for demonstrating the homologies of
the extremities of Cirripedia and Copepoda than has been the case hitherto. When treat-
ing of the female genital apparatus and its orifice at the base of the first cirrus I hope to
point out that there is sufficient reason for admitting that a second pair of segmental
organs, though in a slightly modified condition, is present in the Cirripedia also.

Finally, I will not take leave of this subject without stating as my opinion that the
segmental organ which I have described is physiologically an organ of an excretory
nature * The condition of the material at my disposal did not allow of my attempting a
chemical investigation of the contents of the cells, and so it is only from analogy that
this conclusion has been arrived at. It is fairly supported, I think, by the presence of
muscle-fibres with numerous cavities between them, such as have also been observed
by Grobben (loc. cit., p. 105) in the neighbourhood of the antennal glands of the
Decapoda.

1 ©. Grobben, Die Antennendriise der Crustaceen, Arb. Zool. Inst. Wien. Ba. iii. 1880.

2 R. and O. Hertwig, Die Coelomtheorie, Jenaische Zeitschr. Bd. xv. pp. 1-150, 1882.

3 According to Sedewick (Quart. Journ. Micr. Sci., vol. xxiv. N.S., pp. 46, 47, 1884), the nephridia of the Inverte-
brata are developed from solid masses of cells derived from the wall of the celom; a communication with the body-
cavity in that case would represent a secondary stage.

REPORT ON THE CIRRIPEDIA. 27

Ill. THE CEMENT APPARATUS.

The cement apparatus and the genital organs of the Cirripedia are in general
tolerably well known; in detail, however, our knowledge often proves to be very
insufficient. © Darwin has the merit of having discovered the presence of the cement
apparatus, but he failed to understand its organisation, partly because he confounded its
elements with those of the female genital apparatus.

Krohn! gives a much more accurate description of the cement apparatus of Lepas
anatifera and Conchoderma virgatum. He was the first to observe the true cement-
glands. In Lepas anatifera they are, according to him, situated in the most superior
part of the peduncle and scattered through the connective tissue which envelops the ovary ;
they are very numerous and they have the shape of long oval, vesicular little bodies,
which are attached to very delicate and richly ramified canals in the same way as berries
to their stems. These canals open, before the inferior extremity of the ovary is reached,
into the two cement-ducts, the commencements of which are swollen into ampulle.
These cement-ducts have been already observed by Darwin; they run downwards at a
considerable distance from one another, one at the right, the other at the left hand side
of the peduncle, and they are situated close to the innermost layer of longitudinal muscle-
fibres. Finally they penetrate into the chitinous wall of the peduncle near the place
where it is attached ; they pass through this wall, becoming narrower and narrower, and
are then lost sight of. In the deeper layers of the chitinous wall of the peduncle the
cement-ducts are invested with rounded swellings of different sizes, which are hollow
and which are doubtless in open communication with the ducts; these swellings act
as reservoirs to retain the cement before it is evacuated. In Conchoderma virgatum the
cement-apparatus differs from that of Lepas anatifera in the cement-glands being
for the greater part placed in the parenchymatous tissue of the mantle and for a very small
part only in the superior extremity of the peduncle. The two cement-ducts with their
swollen ampulle reach very close up to the place where the capitulum communicates
with the peduncle. The two ampulle in this genus communicate with one another
by means of a transverse and tortuous canal.

I studied the cement apparatus in Lepas, Conchoderma, and Scalpellum. As
regards the histological structure of the apparatus my researches are far from satisfactory,
the condition of the material at my disposal being, in part at least, the cause of this.
The peduncle of the Cirripedia is very difficult to preserve ; even in specimens freshly
sent over by the Direction of the Zoological Station at Naples, the condition of the
tissue has suffered much.

The little bodies which were considered by Krohn as the true cement-glands must

1 A. Krohn, Beobachtungen tiber den Cementapparat und die weiblichen Zeugungsorgane einiger Cirripedien, Archw.
f. Naturgesch. Jahrg. xxv. Bd. i. pp. 355-364, 1859.

28 THE VOYAGE OF H.M.S. CHALLENGER.

indeed be regarded as such. Krohn has not given a description of these glands, nor is
such a description to be found in the literature of the group. For Balanus I myself
published figures of these glands some years ago,’ when it was my opinion that the
ovarian cceca might perhaps develop from these bodies—a serious error pointed out by
Claus. My excuse was firstly that these bodies, scattered everywhere between the
young ovarian coeca, had never been observed in a sessile Cirriped before, and secondly
that Darwin had led me into error by describing the cement-glands as adhering to the
basal membrane or basal calcareous plate of the Balanine. I should have paid more
attention to a foot-note in Krohn’s paper (p. 357) in which he states his opinion, that
the true cement-glands of the Balanidze might also be found between the ovaries or in the
connective tissue surrounding the mantle.

» The cement-glands of Lepas anatifera, of Conchoderma virgatum, and of Scalpellum
vulgare are nearly the same shape and size. Those of Lepas anatifera are a little larger,
the longest diameter measuring 0°15 to 0°2 mm., whereas those of Scalpellum vulgare are.
smaller, having a diameter of about 0125 mm. (The largest diameter of one of the
cement-glands of Balanus umprovisus is not quite 0°2 mm.). The interior of the cells
is filled with a plasmatic mass, which shows the curious property of staining rather
intensely with aluminium carminate. At the same time the large nucleus, which
occupies nearly the centre of the cell and which measures half the length of the cell
itself, is coloured also and much more intensely. In many preparations the body of
the cell shows an extremely delicate granular structure, whereas the nuclei are coarsely
granulated, or appear to have a fibrillar structure. In Lepas nucleoli have not
yet been observed. Pl. II. fig. 5 shows the condition of the cement-cells im the
Cypris-larva. I do not quite understand in what way the pear-shaped gland
develops from these cells. The size of the latter is about 0°03 mm., at least in the
ease of Lepas australis. Towards one side, and as a rule in the longer axis of the
cell, its wall is produced so that the cell becomes the shape of a pear; this produced part
slopes into a long and narrow duct (Pl. V. fig. 5). The structure of this duct is very
simple ; here and there small cells are visible in its wall (measuring about 0°005 mm.),
which ca the exterior is lined by a kind of thin cuticle. |

The ducts of the different cement-glands unite together to form a much more
capacious duct; a little before the place where the junction is observed, a transverse
short duct often runs from one branch to the other; all the ducts together form an
irregular network, the thickest branches finally pour out their contents into two
longitudinal ducts. The ducts (fig. 5, d), which communicate directly with the glands,
have a diameter of about 0°025 mm.; the two longitudinal ducts im which the
contents of the narrow ducts are evacuated, measure about 0°05 mm. in width. In a

_ 1 P. P. C. Hoek, Zur Entwickelungsgeschichte der Entomostraken, I. Embryologie von Balanus, Niederlind.
Archiv. f. Zool., Bd. iii. pp, 47-82, 1876.

REPORT ON THE CIRRIPEDIA. ; 29

large series of sections of the peduncle of Lepas anatifera, the presence of the’ principal
cement-ducts can everywhere be ascertained; in the most superior part of the peduncle
they run at a somewhat greater distance from the innermost layer of longitudinal muscle-
fibres than is the case in the more inferior sections of the peduncle. The ampullee which
would represent the commencements of the cement-ducts I have not observed. The two
ducts run in a zig-zag line, whence in many sections parts of them 0°3 mm. in length are
represented. I have not been able to follow the cement-ducts quite up to the inferior
extremity of the peduncle. The wall of the duct itself is irregularly folded in all my
preparations of Lepas anatifera ; towards the interior of the canal it seems to be invested
with a thin cuticle, for, when a transverse section is studied, its interior is always
limited by a sharp smooth line; for the rest, I have not a very clear notion of
the cellular structure of the canal. The condition of the specimens of Conchoderma
virgatum at my disposal has only allowed of my making a preparation of the glands.
They are very small, measuring not quite 0°06 mm. ‘Their nuclei are nearly circular
and have a diameter of about 0°024 mm. In one of the glands a little nucleolus was
visible, though not very distinctly. The thin cuticle which invests the canal that-passes
away from the gland in Conchoderma virgatum was visible also round the glands them
selves. I found Krohn’s statement as to the occurrence of the cement-glands for the
main part in the parenchymatous tissue of the mantle to be quite correct.

In Scalpellum I studied the cement-apparatus in two species in greater detail; viz., in
Scalpellum vulgare, Leach, and in Scalpellum regium (Wyv. Thoms.), Hoek. In these
two species this apparatus is, curiously enough, not quite built up after the same type.
That of Scalpellum vulgare has been described already by Darwin.’ In young specimens,
Darwin says, the attachment is performed by cement:.proceeding exclusively from the
antenn of the larva; in older and full-grown specimens the cement is poured: out
through a straight row of orifices along the rostral edge, thus causing a narrow margin
to adhere firmly to the thin and cylindrical branches of the coralline. ‘At each period
of growth the corium (the soft flesh, the mass of connective tissue with the muscles of
the peduncle) recedes a little from the attached portion of the peduncle ; of which portion
the greater part is thus left empty, &c. . . . The two cement-glands are seated high up on
the sides of the peduncle; the two cement-ducts proceeding from them, are z;%59ths of
an inch (0'039 mm.) in diameter and run in a zig-zag line ; at the point where they pass
through the corium to enter the lower attached portion of the peduncle they become
closely approximated, and partially imbedded in the membrane of the peduncle. Together
they run along the rostral edge, giving out through each orifice a little disk of brownish
cement, and finally they enter the larval antennz.”

The specimen of Scalpellum vulgare, whose cement-apparatus I have investi-
gated, had a pedunole of about 9 mm. in length, and was attached by its under surface

1 Darwin, Lepadide, 1851, p. 226.

30 THE VOYAGE OF H.M.S. CHALLENGER.

to the rather broad stem of a horny coral. In order to be able to make transverse
sections of the peduncle I have removed the chitinous wall of the peduncle with its
calcareous seales. I stained the peduncle am toto by means of aluminium carminate.
The ovary in this specimen was very strongly developed and its cceca extended as far
as the most inferior part of the peduncle. The true cement-glands have nearly the same
shape and structure as in the other genera; in size they are larger than those of Concho-
derma, but not so large as those of Lepas. They are rather numerous in the superior part
of the peduncle but become scarce lower down (PI. V. fig. 6). On opening a peduncle
of Scalpellum vulgare in alcohol, the glands appear as little white grains and are visible
even with the naked eye. Often the glands are not unicellular but composed of two or
three cells combined ; in that case the body of the gland is larger and the two or three
nuclei of the original cells are distinctly visible. In many of the glands a dark coloured
oval nucleolus was present within the circular nucleus (PI. V. fig. 6*); the size of the
gland was 0°11 to 0°125 mm. in diameter, that of the nucleus 0°04, whereas the nucleolus
measured 0'013mm. Theducts at the end of which the glands are observed are very narrow,
their diameter being about 0°007 mm. ; those of adjoining glands often anastomose, so as .
to form together a network of ducts. I know these anastomosing canals from a prepara-
tion stained with picrocarmine and isolated by the aid of needles. In the transverse sec-
tions of the peduncle only very small parts of the ducts are seen attached to the glands.

All the narrow ducts pour their contents into four rather wide canals which at the
rostral side run longitudinally through the peduncle. Immediately below the place in
the superior part of the peduncle, where the two oviducts terminate, the first longitudinal
cement-duct begins (Pl. V. fig. 6,d). It is closed at its superior extremity, the cement
being shed in the canal by means of lateral openings. The blind extremity of the canal
is placed a little more towards the centre of the peduncle; the canal slightly changes its
direction so as to run parallel with and close to the elongated cavity (fig. 6,a) which
is visible at the rostral side of most pedunculated Cirripedia (Lepas, Conchoderma,
Scalpellum) and which is a continuation of a part of the body cavity of the animal within
the capitulum. The width of the cement-duct is about 0°3 mm. It is surrounded by a
chitinous wall—perhaps the chemical composition is different from that of chitim—and
it shows traces of an epithelial (or rather endothelial) cell-layer on the internal surface.
About half-way along the peduncle a second longitudinal canal begins; it has when seen in
transverse section a long oval shape, and is divided by a partition into two halves which
soon become independent. A little lower a third—properly speaking a fourth—canal
begins (Pl. V. fig. 7). It has an oval shape; its largest diameter is 0°4 mm., its shortest .
0°28 ; its wall is composed of a chitinous (?) outer layer and a recularly developed inner
epithelial layer of very small cells with distinctly coloured nuclei. 1 do not quite under-
stand why this epithelial cell-layer is well developed (at least distinctly visible) in the one
duct, whereas it can scarcely be made out in the other ducts.

REPORT ON THE CIRRIPEDIA. 31

After the four canals have run independently of one another for about 13 mm.,
the first duct unites with one of the two ducts into which the second canal has divided,
whereas the other half of the second duct terminates by uniting with the third. In the
lowest sections of the peduncle of Scalpellum vulgare which I have been able to
investigate, two ducts only are present. They run close to one another, and are
placed within the wide canal which in the peduncle represents the ccelom. Of course
higher up in the peduncle they were situated in this canal also; but at the place where
they commence with a blind extremity, as a rule, they are not within this cavity. All
the canals have very irregularly folded walls, and are filled up with a solid mass of a
granular structure. Probably this is the cement after it has been affected by alcohol and
reagents. At many places, part of the chitinous (?) and irregularly folded wall is stained
also by the aluminium carminate.

The way in which the cement is poured out into the canals has not been observed by
me. Hverywhere round the canals a dense layer of connective tissue with numerous nuclei
is observed, and at the places where the wall of the ducts is open, a spongy mass of this
tissue penetrates within the opening. Most probably the connective tissue is charged with
the duty of conducting the cement till it comes within the canals. The communication
of the microscopic canals, at the end of which the glands are placed, with the cement-
ducts—or with the connective tissue surrounding these ducts—has not been observed. I
think it impossible to observe this without the aid of very rich and fresh material.

The cement-glands of Scalpellum regiwm (Wyv. Thoms.), Hoek, are not numerous,
but they are relatively large. They are placed in two groups in the superior part of the
peduncle to the right and to the left side (Pl. V. fig. 8). As a rule, each gland is composed
of three or four glandular cells (Pl. V. fig. 11). I measured a gland which appeared to me
to be unicellular, and its greatest diameter was 0°5 mm.; another composed of three cells
had alength of ‘7 mm. The nuclei in the glands of this species have a very characteristic
fibrillar structure ; it is, of course, possible that the reagents have caused this. The ducts
going off from the cells are narrow (their diameter being 0:016 to 0°02 mm.); the nuclei of
the cells forming their walls are verydistinct. The walls of these ducts are not quite smooth;
globular vesicles adhere to them as small excrescences, and so give the duct, especially
when studied in transverse section, a very curious aspect (Pl. VI. fig. 3). The ducts
unite together so as to form groups of nearly parallel ducts, but often many of them
retain their independence. Often two groups of ducts reunite, to become isolated again
after a short time. About the middle of the peduncle I counted more than twenty
groups of these ducts; some were composed of three or four single ducts, others of more
(Pl. V. fig. 10). In the centre of each group of ducts often a much wider duct is visible ;
especially wide is a duct which runs at the rostral side of the peduncle close to the
innermost layer of muscular fibres (Pl. V. fig. 10; Pl. VI. fig. 3).

This wide duct may be seen to continue as far as the uppermost part of the peduncle,

ay THE VOYAGE OF H.M.S. CHALLENGER.

and is nothing else but the cavity (A) which we observed also in the peduncles of the
other Lepadide, and which can be traced as a continuation of a part of the ccelom. In the
superior part of the peduncle (PL. V. fig. 8) this wide canal (measuring here 0°9 by 0°56 mm.)
has an oval shape, and is completely filled with a very delicately granulated mass,which I
think more resembles blood serum than any other substance. The connective tissue
surrounding this canal, and especially the interior of the peduncle, has a very spongy
structure ; as I shall point out again when treating of the development of the ovaries
within the peduncle, I think the contents of the duct and the tissue which surrounds
it serve to nourish the ovaries.

At a short distance—about 3 mm.—from the superior extremity the duct begins to
get narrower; the space occupied by the delicately granulated substance measures now
only 0°22 mm. in diameter. The spongy mass of connective tissue has grown much
thicker, and forms especially towards the interior of the peduncle a very thick wall; for
the first time here cement-ducts are seen within this thickened portion of the wall of the
duct (PI. V. fig. 9). Between this wall and the central mass of the granulated substance
a layer of vesicles can be distinguished. I think they are formed by the cement poured
out into the canal and pressed between the wall and the central mass. One millimetre
and a half farther down the duct becomes still narrower ; it now has with its wall a diameter
of 0°43 mm. only. The granulated substance has almost. totally disappeared, but the
interior of the wall is everywhere covered with large and small cement vesicles. Below
the middle of the peduncle at numierous places, larger cement-ducts pour out their contents
into this canal, which eventually has in all respects the shape of one of the wider cement-
ducts such as are found also in the interior of the peduncle. In the undermost part of the
peduncle it runs no longer close to the rostral side, but is observed in the centre of the
peduncle. It there quite resembles two other larger cement-ducts which run longitudinally
through the peduncle. Probably these ducts are open at their inferior extremities, which,
as far as I could make out, are not continued up to the base of the peduncle; the latest
sections I prepared of the peduncle do not show the ducts in the connective tissue.

So we see that in Scalpellum regium, the cement-ducts do. not run within the ccelom-
eavity, or what I feel inclined to consider as its homologue, but that this cavity in its
most inferior part is itself changed into such a cement-duct. The other ducts stand in open
communication with the one at the rostral side. A second difference is seen in the
structure of the wall of the ducts; the smooth-lined sheath of the ducts in Scalpellum
vulgare, which made me compare the substance of which that wall is built up with chitin,
is nowhere to be observed in Scalpellum regium. No doubt the investigation of other
species of Scalpellum and of other genera of Cirripedia will show that the cement-
apparatus of this group of Crustaceans presents many more variations than would have
been expected beforehand. The knowledge of these variations is no doubt of great
interest, yet it would be of much more importance still, if the morphological significance:
of the apparatus were more apparent.

BEPORT-ON THE CIRRIPEDIA. 33

IV. DARWIN’S “TRUE OVARIA.”

Darwin’ observed in the Cirripedia two glandular masses resting on the upper edge of
the stomach, and touching the cceca where such exist ; these were thought by Cuvier to be
salivary glands. They are of an orange colour and form two parallel “ gut-formed” masses.
Darwin was not able to ascertain whether the two main ovarian ducts coming from the
peduncle expanded to envelop these glandulee or what the precise connection was. He
says “the state of these two masses varied much ; sometimes they were hollow, with only
their walls spotted with a few cellular little masses ; at other times they contained or
rather were formed of more or less globular or finger-shaped aggregations of pulpy matter ;
and lastly, the whole consisted of separate pointed little balls, each with a large inner cell,
and this again with two or three included granules. These so closely resembled in
general appearance and size the ovigerms with their germinal vesicles and spots, which
I have often seen at the first commencement of the formation of the ova in the ovarian
tubes in the peduncle, that I cannot doubt that such is their nature. Hence I conclude
that these two gut-formed masses are the true ovaria. I may add that several times I
have seen in the two long unbranched ducts, connecting the true ovaria and the ovarian
tubes in the peduncle, pellets of orange-coloured cellular matter (v.e., ovigerms) forming
at short intervals little enlargements in the ducts, and apparently travelling into the
peduncle.”

In the second volume of Darwin’s Monograph,’ the same opinion as to the nature of
these glandular bodies was given for the sessile Cirripedia. This opinion, however, was
not only opposed to that of Cuvier’ but also to that of Martin-Saint-Ange and of Karsten.
Martin-Saint-Ange* describes “ une espéce d’appendice stomacal, un véritable prolongement
renflé et bilobé, communiquant avec la premiére cavité de l’estomac par un pédicule étroit
et fort court. La structure, la forme générale, la coloration et la disposition mamelonnée
de la surface extérieure de cette partie sont tout d fait semblables 4 celle de l’estomac,
et doivent étre regardées comme faisant partie du méme organe.” Martin-Saint-Ange,
therefore, cannot be said to have considered these bodies as salivary glands, since he
points out in his Memoir as well as in the explanation of the figures that these organs
communicate with the stomach. So Darwin’s objection “that salivary glands have not
been positively recognised in any Crustacean” cannot be considered of any consequence.

Krohn,’ describing the direction followed by the oviducts, says that they approach very

1 Darwin, Lepadide, 1851, p. 57.
2 Balanid, 1854, p. 100.

3 Cuvier, Mémoire sur les animaux des Anatifes, Mém. Mus. Hist. Nat., t. ii., 1815.
4 Martin-Saint-Ange, Mémoire sur l’organisation des Cirripedes, Mém. Inst. Savans. Etrang., t. vi., 18365.
6 Krohn, Ueber d. Cement-und Zeugungsapparat d. Cirripedien, Wiegmann’s Archiv, t. xxv., 1859.

(ZOOL, CHALL. EXP.—PART XXVIII.—1884.) Ke 6

BY THE VOYAGE OF H.M.S. CHALLENGER.

close to those organs “die seit Cuvier fiir die Speicheldriisen gelten.” For the rest he
does not say what is his own opinion in regard to the nature of these bodies.

I do not think that since the publication of Darwin’s Monograph these organs have
been investigated ; so I was most anxious to study them, and if possible to make out
their structure. They occurred in all the genera in which I sought for them; I studied
them in greatest detail in the genera Lepas and Scalpellum.

Near the place where the esophagus communicates with the stomach, the outer surface
of this latter organ is invested with a pair of oval masses; they are placed at rather a
considerable distance from one another, one being found at the right, the other at the
left hand side of the stomach. Pl. VL fig. 7 shows their situation in Lepas anatifera when
seen laterally, fig. 8 when seen from the anterior (dorsal) side. In both figures GZ. repre-
sents the cesophagus and G. S. the supracesophageal ganglion ; p. n. are the two strong
peduncular nerves which start from the supracesophageal ganglion ; oc. is the curious eye
discovered by Leidy, placed close to the surface of the stomach and separated from the
external surface of the body by a very darkly pigmented integument and a thick layer of ©
muscles, which are both left out in the figures, The oviducts (ov) are also distinct in both
figures. They come from the peduncles and for some distance run parallel to the pedun-
cular nerves; a little beyond the eye they are seen to diverge and then may be followed
running transversely over or at least close to the surface of the stomach. Dorsally from the »
oviducts (in fig, 7 beneath them) the most anterior parts of the testis (¢) can be distin-
guished. That part of the surface of the stomach which is nearest to the oesophagus is
covered all over with rounded and dark-coloured tubercles (7) which cause the “ disposition
mamelonnée” of Martin-Saint-Ange, and which when studied in ‘a transverse section
appear to be the arborescent ceca of the surface of the stomach. The internal surface of
these coeca is darkly pigmented and this causes the blackish colour of the rounded
swellings at the exterior.

The glandular bodies in figs. 7 and 8 are marked gl. They are not always the
same shape and size. Sometimes they are rather regularly oval and compact, having a
length of about 4mm. and a breadth of not quite2 mm. In other cases, however, finger-
shaped excrescences (as observed by Darwin) give the gland a much more irregular
appearance, In both cases the surface of the body is uneven owing to the presence
of globular swellings; whilst the whole body represents an acinous gland, each of the
globules being a distinct acinus.

Before giving a description of the microscopic structure of the gland in Lepas I will
describe its structure in Scalpellum. My best preparations are from Scalpellum paral-
leloyramma, Hoek. In this species the gland is relatively small, having a length of little
more than one millimetre. It is pyriform; at the narrow extremity it communicates
with the interior of the stomach by means of a very narrow duct ; at the other extremity
its body is rather blunt and rounded, The greatest transverse diameter of the gland in

REPORT ON THE CIRRIPEDIA, 35

one of my series of sections measured 0°6 mm. In another series, however, it was more
oval and measured 0°9 by 0°5 mm. The gland is not situated near the cardia but at
a considerable distance, about half-way between the cardia and the dorsal surface of
the body. The gland is a true tubular one ; its wall consists of a single layer of cells
only. The shape of these cells may be seen in Pl. VI. figs. 4 and 5. Each cell is
cylindrical or rather conical, its base always being greater than the other extremity,
which is direeted towards the interior of the gland. The bases of the different cells
are parallel to the nearly smooth outer surface of the gland; the other extremities of
the cells, however, are as a rule not flat but convex, or even protuberant towards
the interior of the canal which runs through the gland. In thin sections the outer
surface of the gland is marked by a double line; the outer one is here and there
distinctly sinuous, and between the two lines small nuclei are visible, which are rather
flat; they are placed in the cavities between the inner and the outer margin.
There can be no doubt that in this way a rudimentary membrana propria is formed.
The connective tissue surrounding the glands has smaller meshes and is very rich in
nuclei.

The dimensions of the glandular cells are about 0°1 mm. in length and 0:03 mm.
in breadth. Lach cell has granular plasmatic contents and a very large oval nucleus. In
preparations stained with aluminium carminate the body of the cell as well as the
nucleus has taken up the colour. The first is beautifully lilac-coloured, the latter darkly
violet. Hach nucleus is coarsely granulated and measures 0:036 by 0°02 mm. __ It contains
a smooth and brilliant nucleolus of 0:°009 mm. in diameter. In each nucleus the nucleolus is
situated in the centre of a clear space, which, as a rule, is placed towards that side of the
nucleus which is directed towards the internal surface of the gland. The clear space—
which gives the impression of a clear vesicle with fluid, but which has no distinct contour
of its own—is on one side separated from the surface of the nucleus only by a very
narrow layer of the granular substance which fills the nucleus. The nucleus has a
distinct external contour,

All the cells are built after the same type; but there are very characteristic differences
between the cells of two different specimens of Scalpellum parallelogramma. In the
first place there is a very marked difference in size; the length is nearly the same (0°09
mm.); the breadth, however, measures only 0°013 mm. and the nuclei are not, as in the
first specimen which I investigated, placed close to the internal surface of the glandular
cells, but beyond the middle: they are nearer to the external than to the internal]
surface. The structure of the nuclei is the same; they are more elongate and slightly
pointed towards the outer extremity.

In a series of sections through the cephalic part of the body of Scalpellum nympho-
cola, these glands which I propose to call “pancreatic glands” are also represented. In
this species the form of the gland is the same as in Scalpellum parallelogramma, the

36 THE VOYAGE OF H.M.S. CHALLENGER.

transverse sections are circular or nearly so. The nuclei of the cells of ‘the gland are“all
situated at the periphery close to the membrana propria which envelops the body of the
gland.

The structure of the gland in Lepas will now be easily understood. Let the wall of
the gland in Scalpellwm develop excrescences, so that the interior of each excrescence
communicates with the interior of the original or main part of the gland and the tubular
gland will have changed into an acinous one. The excrescences have as a rule the shape
of globules, but they may also be elongated so as to form finger-shaped appendages. When
the gland is divided by transverse and parallel sections in a series of preparations the
shape and size of the cells are by no means so uniform as in the case of Scalpellum. This,
of course, is partly in consequence of the sections not always cutting the cells in the
same direction, though parallel, In some of the sections the cells are cylindrical, having
a length of 0°1 mm. and a breadth of 0°026 mm. _ If these same cells had been cut
transversely to their longest axis, their length would have appeared much shorter. The
size of the oval nuclei is 0°016 mm. In the more tubular parts of the gland the cells are
not so high and their walls not so parallel; in the sections, therefore, they are almost
triangular or flattened quadrangularly ; between them I observed here and there larger
cells with very capacious nuclei. I measured one of the cells, the length of which
was 0°13, whereas its breadth was 0°9 mm. It was furnished with a nucleus 0°05
mm. in diameter The only difference which I could make out between the different
cells of each gland was, however, in size; in regard to their staining with aluminium
carminate, I must point out a very striking correspondence of these cells to those of
the cement-apparatus of the peduncle, viz., the body of the cells is always beautifully lilac-
coloured, the nuclei appearing dark violet. The latter are remarkable, in the same way
also as those of the cement-glands, since coarse granules and even fibres fill their
interior. A distinct membrana propria surrounds the body of the gland in Lepas as well
as in Scalpellum.

The gland communicates with the interior of the stomach by means of a narrow duct
which opens close to the cardia in an interspace between two of the so-called hepatic
excrescences.

As to the function of these glands a few words may suffice. That they are not true
salivary glands needs no further proof. At the same time it can hardly be doubted that
their function is that of a digestive organ which pours its secretion into the alimentary
canal. Whereas the recent interesting researches of Max Weber! have cast light upon
the structure and function of the digestive glands (Verdauungsdriisen) of the higher
Crustacea (Isopoda, Amphipoda, Decapoda), we are still almost entirely ignorant of their
occurrence, functions, structure, &c., in the different orders of Entomostraca. The
supposition of Claus, that the name of liver in invertebrate animals has often been used

+ Max Weber, Ueber den Bau u. die Thiatigkeit der sog. Leber der Crustaceen, Arch. f. Mikr, Anat. Bd. xvii. 1879.

REPORT ON THE CIRRIPEDIA. 37

where in reality a pancreatic or a chyle-producing gland should be spoken of, has proved
to be very important. Weber, however, tries to demonstrate that in the Crustaceans
which he studied, the digestive glands are built up of two kinds of glandular cells, and
therefore are at the same time liver and pancreas, both modified so as to be accommodated
to the organisation of the Crustacean body. Now no doubt is left that the glands of the
Cirripedia are built up of one kind of cells only, and I think we can safely admit that
these belong rather to the pancreatic than to the hepatic type. Whether the excrescences
of the wall of the stomach (which are very strongly developed in Lepas and which are
coated in the interior by a cylindrical epithelium with very small cells,’ the nuclei
of which are almost entirely hidden by a dark-brownish pigment). represent a kind
of liver, I cannot undertake to say. It is indeed a curious fact—one, however, observed
by Darwin thirty years ago—that these excrescences are large and well developed in
some genera (Lepas, Conchoderma), and almost totally wanting in others (Scalpellum).
1 The height of these cells is 0:03 mm., their breadth only 0-006 mm.

38 THE VOYAGE OF H.M.S. CHALLENGER,

V. THE EYE OF LEPAS.

I believe Leidy was the first who observed in an adult Cirriped an organ of vision.’
In Balanus there are, according to him (and Darwin has confirmed the correctness of
his observation), two small eyes which stand apart from each other laterally and, owing
to this discovery of the American naturalist, Darwin’ was led to look for them in
Lepadide. In Lepas fascicularis he found an elongated almost black eye composed
of two eyes united together. The eye is innervated by two nerve-chords which extend
from the front of the two supracesophageal ganglia, and which before reaching the eye
run into two small, perfectly distinct, oval ganglia. From the opposite ends of these
two ganglia smaller nerves run, and, bending in at right angles, enter the elongated eye
beyond the middle.

I do not think that any description of this organ has been published since Darwin's.
I made preparations of it in Lepas anatifera and in Lepas fascicularis. The place it
occupies in the first species may be seen on Plate VI. figs. 7 and 8. On removing
the ligament between the two scuta as well as the muscles which are here placed between
this ligament and the widened stomach, the surface of the latter with its black (hepatic ¢)
excrescences and the white pancreatic glands appear. At a distance of about 6 mm.
from the supracesophageal ganglion in an adult Lepas anatifera, a small oval black spot
is seen attached by means of connective tissue to the surface of the stomach. This is
the eye. Morphologically it represents the small pigment spot which, in the Cypris-
larva (Pl. II. fig. 2, e), is attached to the upper surface of the supracesophageal ganglion,
and which is the remainder of the simple eye of the Nauplius-larva. In an adult
Lepas anatifera it measures 0°25 mm. only in length, its breadth being not quite 0°15
mm. I believe its function to be of no consequence, in Lepas at least, for I do not
understand how a ray of light can ever reach it, but the little organ beautifully illustrates
the persistence of an old larval structure.

Most curious, however, is the fact that this rudimentary organ is indeed furnished
with a kind of special ganglia (Pl. VI. fig. 9). Between the two broad (antennal)
peduncular nerves, four thinner ones separate from the supracesophageal ganglion. Their
thickness is not quite the same ; the two outer ones are slightly stronger than the other two
which lie very close to one another, almost exactly midway between the two other
nerves. These four nerves can be traced up to a very short distance (about 0°6 mm.)
from the small eye. Here the two stronger nerves of the four bend shghtly outwards
so as to approach a little more nearly to the peduncular nerves and show a distinct
swelling, in the interior of which two elongate ganglionic cells are to be observed. I

1 Leidy, Proc. Acad. Nat. Sct., Philad., No. 1, vol. iv., January 1848.
* Darwin, Lepadidee, 1851, p. 49.

REPORT ON THE CIRRIPEDIA. 39

think they can safely be described as bipolar, for their body can be followed up as a very
pale process in the direction of the supracesophageal ganglion as well as in the direction of
the eye. In both directions these processes are placed, like the ganglionic cell itself, quite
in the interior of the nerve. Close to the eye the nerve shows a second swelling which
contains also a distinct ganglionic cell, and it'is by this swelling that the nerve is laterally
attached to the eye. Each of the two other slightly thinner nerves, which run between
the two stronger ones, has also a swelling at about the same distance from the eye. The
two nerves unite together where this swelling is thickest and where each contaims a
ganglionic cell; they then part again and separately run towards the eye, which they
reach at its frontal extremity, ze. that extremity which is directed towards the supra-
cesophageal ganglion. I have not been able to study the way in which the nerves enter
or are attached to the pigment spot. Round about the spot a network of fibres of greater
or less capacity can easily be made out; yet it is extremely difficult, not to say impos-
sible, to ascertain with certainty the nature of these fibres. Some of them are no doubt
nerve-fibres, while others belong doubtless to the connective tissue.

The way in which the ganglionic cells are placed in the interior of the nerves slightly
resembles what Leydig observed in the case of the sympathetic nerve-fibres of insects.
He observed! (in Bombus terrestris) in single fibres of the so-called sympathetic nerves,
a nucleus here and there with a granular mass surrounding it, forming a kind of bipolar
ganglionic cell “in der Anlage.”

Neither in Lepas anatifera nor in Lepas fascicularis could I distinguish the two
little lenses which Darwin says he has observed. Nor do I think that this is owing
to any fault in my observation. Darwin may have observed living, or at least fresh,
animals, and the lenses may have disappeared under the influence of the alcohol. But I
think it is more probable that Darwin, who used only a feeble magnifying power, has
mistaken the ganglionic cells for lenses. What he calls the two small perfectly distinct
oval ganglia, are probably the swellings: of the optic nerves which in Lepas anatifera
contain two distinct ganglionic cells.

As regards the sessile Cirripedia, and especially different species of Balanus, the
experiments of different naturalists have shown that they are sensible to a difference
between light and shadow. Ido not know whether similar experiments have ever been
made on pedunculated Cirripedia. Should they give the same result, and I think they very
probably would, even then I should hesitate to consider the rudimentary simple eye placed
on the external surface of the stomach as the organ of this function.

1 Leydig, F., Bau des thierischen Korpers, Tubingen, 1864, p. 205.

40 THE VOYAGE OF H.M.S. CHALLENGER.

VI. THE FEMALE GENITAL APPARATUS.

According to Darwin, the female genital apparatus consists of the true ovaria, or
glandular bodies seated on each side, not far from the basal edge of the labrum; the
main or unbranched ovarian ducts; and the ovarian branching tubes and ceca. The
latter in the pedunculated Cirripedia are placed high up in the peduncle, and in all sessile
Cirripedia lie between the calcareous or membranous basis and the inner basal lining of
the sack. After the most careful and repeated examination of various Lepadidee
and Balanidee, Darwin became convinced that there were no oviducts ; he therefore
supposed that the ova were brought to the surface by the formation of a new membrane
round the sack underneath them, and by the subsequent exuviation of the old membrane.
This supposition of Darwin’s has proved to be erroneous. What Darwin called the main
or unbranched ovarian duct is in reality the oviduct ; it does not run up to the glandular
bodies (which I have described in one of the foregoing chapters), but it passes at some
distance beneath them (Pl. VI. figs. 7 and 8); it describes a curve and then enters the basal
egment of the first cirrus, at the foot of which it opens." Krohn was the first to describe
the female genital apparatus accurately ; Kossmann, though in the main agreeing with
Krohn, differs from him with regard to the significance of the little shoe-shaped sack
which is placed in a swelling of the oviduct near its opening. I studied the female genital
apparatus in Lepas, Scalpellum vulgare and Scalpellum regiwm, in Conchoderma
virgatum and in Balanus. In all essential points the results of my researches tend to
confirm those of my predecessors ; in detail I think I am able to add to our knowledge.

From the existence of two oviducts we may conclude that there are also two ovaries
present. In the full-grown animals their numerous and strongly ramified cceca are
united so intimately that they seem to form a single mass only. The cceca of the
right side, however, communicate with the right oviduct, the others with that on the
left.

A study of the way in which the ova are formed has given the following results.
The oviduct itself is lined by a very distinct and well-developed epithelium ; where the
limits of the cells are not distinct, which may be due to the condition of the material
at command, the nuclei are placed so regularly along the wall that even the dimensions of
the epithelial cells can still be made out. Where the oviduct passes over into a coecum of
the ovary, the epithelium of the wall is no longer so distinct, and in its place nuclei
are seen rather irregularly along the wall; of the true body of the cell there are only
traces here and there. The ovigerms or future ovarian eggs are seen in the interior along
this wall. When the ovary is mature or nearly so, we observe in the first place the large
ovarian eggs, each having a nucleus with a sparkling nucleolus (Pl. VI. fig. 2) about

foto ie)
1 Zool. Chall. Exp., pt. xxv. p. 12, pl. i. fig. 2.

REPORT ON THE CIRRIPEDIA. 41

the centre of the égg, and in the second place, rounded groups of very small ovigerms,
forming together what the Germans call the ‘‘Keimlager.” One or two of these ovi-
germs are often slightly larger than the rest, and these will be the first to develop into
ovarian eggs after those which are already mature are evacuated.

In a ripe or nearly ripe ovarian egg of Scalpellum vulgare which had a diameter of
0°3 mm., a nucleus of 0°036 mm. was present, having a nucleolus of 0°009 mm. The
nuclei of the cells placed along the wall of the ovary are oval and measure about
0°01 by 0°005 mm.; the small ovigerms are nearly circular and have a diameter of
about 0°013 mm. Their nuclei, of course, are a great deal smaller than those of the ripe
ovarian eggs. One of the ovigerms was considerably larger; it was rounded oval, its
diameters being 0:03 and 0023 mm.; its nucleus was about 0°012 mm. A ripe ovarian egg
-of Scalpellum vulgare is filled with a coarsely granulated vitelline mass (Pl. VI. figs. 14,
2a). Between the larger granules, which in the microscopical preparations appear lke
vesicles, a much more delicately granulated mass of plasma is here and there visible ;
sometimes a layer of this is placed in the centre round the nucleus. The wall of
the ovarian egg seems to be a very thin and structureless membrane, and neither
in the case of Scalpellum, nor of any of the other genera observed, was a follicular
epithelium present. The mature ovarian eggs of Scalpellum regium are about
06 mm. in diameter. They are very coarsely granulated; they do not quite fill
the interior of the ovarian cceca, but between them, and also between each egg and
the wall of the ccecum, a layer of a much more delicately granulated mass of plasma is
visible (Pl. VI. fig. 3). Here the ovigerms form groups of little cells, the dimen-
sions of which nearly correspond to those of Scalpellum vulgare, In one of these groups
I counted about 20 of these ovigerms. Here again one of these ovigerms was developed
into a young ovarian egg. The wall of the cceca shows the same cellular elements as in
Scalpellum vulgare ; its outer surface is formed by a distinct membrana propria, which
may be composed of stronger fibres of connective tissue, but which often looked as if
composed of circular muscular fibres. The wall of the oviducts, however, did not show
the same stronger outer wall; it is composed of a distinct epithelium and a very narrow
or thin membrana propria.

Whereas in Scalpellum vulgare each oviduct gives off a egecum only once, and this
ececum, which starts from the oviduct at the superior extremity of the peduncle, divides
again and again, the oviduct in Scalpellum regium penetrates into the interior of the
peduncle for about one-third of its whole length. In different places each oviduct in this
species gives off cceca, and these form together so voluminous a mass that the peduncle is
filled with it up to its inferior extremity.

The oviduct of Scalpellum vulgare appears in a transverse section as an exceedingly
narrow slit, and 0°2 mm. in length. The oviduct of Scalpellum regium (Pl. V.

figs. 8 and 9), in a transverse section shows an irregularly folded wall; its largest
(400k. OHALL. EXP,—PART XXvI1].—] 884.) Ee 6

ey) THE VOYAGE OF H.M.S. CHALLENGER.

diameter is about 0°55 mm., its smallest 0°15 mm. I calculated that for Scalpellum
regium the surface of the lumen of the oviduct was about 0°09 square millimetres, whereas
a section of one of the nearly ripe ovarian eggs was not less than 0°28 square millimetres.
Therefore, it is either necessary that the walls of the oviducts be very elastic, or that the
egos pass through the oviduct when it is much distended. Perhaps both circumstances
favour the passage of the ova.

The number of eggs laid by Lepas is immensely larger than by Scalpellwm. In
some of the species of the latter genus it is not even a hundred; in Lepas anatifera it
amounts, on the contrary, to many thousands and tens of thousands. In accordance
therewith, the eegs of Lepas are very small; I measured eggs from an egg mass of this
species, and their length was only 0°24 mm. The cceca which form the ovary are very
narrow and elongate, and contain rows of numerous and relatively small eggs. The
ovarian egg when ripe is not so elongate as after its fecundation ; | measured eggs in the
oviduct, the length of which was only 0°14, their breadth beng 0°1 mm. The nuclei of
the eggs in the ovary are again nearly circular, and have a diameter of about 0°02 mm.;
they may be seen as a rule in the centre of each ovarian egg, and contain a single very
distinct nucleolus. In the cceca of younger specimens of this genus, the groups of
ovigerms can be very distinctly made out. ‘The number of ovigerms composing such a
group in this genus, however, is much larger than in the genus Scalpellum ; their dimen-
sions do not show any considerable difference.

In Conchoderma virgatum the form of the cceca corresponds to that in Lepas. The
eggs are numerous and small. I do not think it of much use to give any details as te
their dimensions. j

When comparing young ovarian cceca, such as are observed in the peduncles of younger
specimens, with those which are gorged with numerous and larger eggs, one feels
convinced that a considerable increase in bulk has taken place. This can only have been
brought about by a regular and abundant supply of food. Yet it is not so very easy to
understand in what way the nourishment of the peduncle is brought about. The only way
is, of course, that the blood—or the fluid which in Cirripedia acts as blood—passes through
the narrow band which in the pedunculated Cirripedia runs from the capitulum to the
peduncle, at the rostral side near the place where the two scuta meet with their occlu-
dent margins. The two strong peduncular (antennal) nerves and the oviducts pass
through this narrow commissure ; ‘but so does also a rather wide cylindrical tube which
has no distinct wall of its own, and therefore is lined only by connective tissue, and
which here represents the body cavity. In those cases in which I found the ovarian eggs
ripe or nearly ripe, I always found this canal totally filled up by a delicately granulated
mass, which much resembled blood plasma. I therefore think it highly probable that by
means of this elongate canal a regular nourishment of the peduncle and the organs placed
in it is carried on. In Scalpellum parallelogramma I have been successful in tracing

REPORT ON THE CIRRIPEDIA. 43

this canal, or cylindrica! cavity, to within the body of the animal. When a transverse
section of the body is made near the mouth, the alimentary canal in the middle of its
dorsal surface is found attached to the wall of the body by means of a rather strong band
of connective tissue. Towards the hinder extremity of the body*this band grows broader
still, and then it appears to be perforated by a central cavity. Towards the anterior end of
the body the band grows narrower, yet it may be followed up: in all transverse parallel
sections, as long as these contain a section of the stomach. “Those sections which pass
through that part of the body contained between the stomach and that stripe of the
mantle which unites the two scuta, only show the band of connective tissue as a loose
band attached only on one side, viz., on the dorsal internal surface of the body wall.
The two large cavities which were separated from one another by means of this band,
are now united. An excrescence of this cavity penetrates this part of the body in a direc-
tion vertical to the original dorsal surface, and this part of the body cavity has one of
the two sections of the oviducts on each side. It advances considerably towards the
original ventral surface of the body and now meets the two sections of the oviducts on the
dorsal aspect ; after having described a curve it runs longitudinally close to the rostral
surface of the narrow part between the two scuta. The two oviducts are now on that
side of the cavity which is directed towards the interior of the mantle-cavity, and in the
same place they remain visible in the superior part of the peduncle.

The course of the oviducts through the true body of the Cirripedia can be followed up
by making a dissection of it by the aid of needles. To make out its position with
regard to the place occupied. by the other organs a series of sections serves the purpose
still better. In Scalpellum transverse sections through the cephalic part of the
body show the oviducts on both sides about midway between the intestinal tract and the
wall of the body (Pl. VI. fig. 4). It is surrounded on all sides by the connective tissue,
and as a rule one of the larger cavities of the connective tissue is separated from the
duct only by a very narrow.strip of the tissue. In Scalpellum as well as in Lepas and
Balanus (the three genera in which the course of the oviducts has been investigated),
the oviducts pass beyond the first pair of cirri. They then run upwards, 7.e., towards
the ventral surface of the body, and bending outwards, 2.e., towards the lateral surface
of the body, and forwards, they enter what Darwin considers the basal articulation of the
first cirrus. In some of the genera (e.g., Lepas, Alepas), this swelling belongs doubtless
to the first cirrus; from analogy we may safely conclude that it belongs also to that
pair of extremities in those cases in which (as in Scalpellwm) no distinct relation to it can
be made out. The oviduct enters this articulation at a considerable distance upwards
from its base ; it now describes a curve for the last time and leads into the curious sack
which Darwin considered an acoustic organ, and which opens by means of a transverse
slitlike orifice at the proximal part of the basal articulation.

'The structure of the wall of the oviduct may be briefly described as epithelial ;

44. THE VOYAGE OF H.M.S. CHALLENGER.

the limits of the cells are never very distinct, and their height is’inconsiderable ; the
contents of the cell are a nucleus about 0°005 mm. in diameter and quite clear protoplasm.
A very thin membrana propria covers the outer surface of the oviduct.

The way in which the oviduct corresponds with the sack in the basal articulation
of the first cirrus in Scelpellum is different from Lepas. In Scalpellum vulgare (Pl. VI.
fig. 10), and Scalpellum parallelogramma, the oviduct, once arrived in the basal articula-
tion, expands so as to form a kind of funnel, which with its wide opening embraces a large
portion of the curious sack which opens at the base of the swelling. The wall of this
funnel closely resembles that of the oviduct. In some of my preparations the funnel is
placed exactly opposite to the genital opening, in others it is attached to the sack in a
more oblique direction. The curious sack, in Scalpellum, communicates with the genital
opening by means of a long duct, the length of which equals and sometimes even surpasses
that of the sack itself, At the other extremity the sack is open also and its wall round
about the opening turned outward, the opening of the funnel closing exactly on the margin
of the part which is turned out. In one of my series of preparations of Scalpellum vulgare
the funnel-shaped widening of the oviduct is in close relation with a bag of connective
tissue surrounding the whole sack, so that it may be traced up to where the sack goes
over into the duct; at first it was my opinion that the eggs passing through the oviduct
and the funnel arrived in this bag and then passed into the duct by a lateral opening
situated beneath the sack, without entering the curious sack at all; but I failed to,
make out the existence of this opening, and since I afterwards observed the direct
transition of the oviduct into the curious sack in the genus Lepas (Pl. VI. fig. 11), [have
given up this supposition, which I must confess was rather hazardous.

The structure of the cells which compose the wall of the curious sack is that of a high
cylindrical epithelium. In Sealpellum vulgare their dimensions are 0°02 by 0:006 mm. ;
each cell has a very distinct oval nucleus which, in the full-grown specimens, measures
0-006 by 0°005 mm., and which is seated very close to the free extremity of the cell.
The outer surface of the sack is lined by a membrana propria with very flat nuclei. The
shape of the sack in Scalpellum is that of a pear, the part which communicates with the
duct being as a rule narrower than the other extremity. In Scalpellwm vulgare the duct
shows a small swelling near the place where it communicates with the sack, and the
length of the duct is exactly equal to that of the curious sack. The wall of the duct
has the same structure as the outer wall of the body, as an inflected part of which it
must be necessarily considered. The limits of the cells which compose it are not distinct,
its nuclei are relatively oval and large, their longest diameter being 0:009 mm. The
surface of the duct is covered by a thin chitinous cuticle.

In none of the species of the genus Scalpellum in which | investigated this curious sack
did I find it empty (Sealpellum vulgare, Scalpellum parallelogramma, Scalpellum nympho-
cola, Scalpellum regium, and Scalpellum balanoides have been investigated by means of

REPORT ON THE CIRRIPEDIA. 45

sections). I always observed in its interior the “ flattened sack of singular shape” which
Darwin called the acoustic sack. As long as I knew this sack only from preparations of
Lepas anatifera, young specimens of which I cut into series of sections some years ago,
I really considered it with Darwin and Krohn’ as a sack. Guided by this opinion, I
wrote the passage on page 12 of my Report on the Challenger Cirripedia, in which
I gave it as my opinion that the interpretation of Krohn was more in accordance with
the facts than Kossmann’s; for Kossmann called the sack a ‘‘Klumpen,” ze, an
irregularly-shaped mass, which is sometimes quite solid, sometimes is only furnished
with very uwregular cavities. A glance at Pl. VI. fig. 10 will easily convince the
reader that Kossmann’s suggestion is now indeed mine also; the curious body looks
like a compact mass, being composed of smooth layers which have probably been
more or less parallel to the wall of the sack, and a granular substance binding these
layers together. All the cells bordering the sack, as also those forming the part which is
turned outward, participate in the act of secreting the fluid, which hardens to compose
the compact body. Hence it is suspended as by two short arms in the opening which
leads from the funnel of the oviduct into the curious sack. The compact body must be
evacuated before the eggs can pass through the curious sack and the narrow duct, and I
think that this is done by the retraction of the margin of the opening which leads from
the funnel into the sack. In one of my series of preparations of Scalpellum vulgare the
opening of the sack is as wide as that of the funnel; the arms of the compact body form
a transverse partition between funnel and sack, the remaining part of the compact mass
being suspended in the middle of this partition, Regarding the structure of this
same apparatus in other genera of Cirripedia I have little to add. In Lepas anatifera
and Lepas halliz the structure of the oviduet is the same as in Scalpellum. The funnel
at the end of the oviduct where it communicates with the sack seems to be wanting; in
a very complete series of preparations of Lepas hill the oviduct can be followed up to
where it communicates with the sack. Its structure is very markedly different from
that of the sack, so that the place where the one ends and the other begins can easily be
seen (Pl. VI. fig. 11). It widens only very inconsiderably to meet the opening of the
sack. The wall of the sack is composed of very high and narrow cells (0°05 mm. high
and 0-003 mm. wide), having an oyal nucleus about half way up. The length of the
sack itself in Lepas hillii is about 0°8 mm. In Lepas anatifera it is a great deal more ;
in a specimen, the capitulum of which measured 38 mm., the greatest diameter of the
sack was 3 mm., the shoe-shaped mass in its interior measuring about 2 mm. _ I observed
the curious sack at the end of the oviduct also in Balanus corolliformis, Hoek, and in
Balanus tintinnabulum, Linné. _ Its size in the first species is about 0°5 mm.; the way in
which the oviduct communicates with the sack in this species is very like that in
Scatpetlum,—the oviduct is considerably swollen at the extremity which meets the sack,
1 Krohn, loc. cit., p. 361.

46 THE VOYAGE OF H.M.S. CHALLENGER.

The sack of Balanus tintinnabulum was studied in transverse sections ; its diameter was __
about 0°9 mm. I have been unable to investigate the way in which the oviduct L
communicates with it. i

If Kossmann’s explanation as to the presence of the irregular mass in the interior of the ,
curious sack at the end of the oviduct be right (and I have no sufticient ground to doubt
its correctness), the function of the cells which form the wall of the sack is to produce a
viscous fluid which envelops the eggs. The thick mass which sometimes, and even very
often or as a rule, is found in the interior of the sack is formed because the secretion
continues incessantly, even when no eggs pass through the oviduct. The quantity of this
viscous fluid which is secreted by these cells must indeed be rather large ; for when a
Lepas is furnished with ovigerous lamelle and the interior of its sacks studied, large
masses of the secreted substance are present. This must necessarily have been formed
after the eggs passed through it, and cannot have been very long before, as in the
Cirripedia the evolution of the eggs in general does not take long. The very regular
shape of the mass in some genera, as e.g. in Lepas, where it is shoe-shaped and has
a very smooth surface, must be ascribed to its being modelled, at least in part, after the
internal surface of the sack; it remains, however, in my eyes a curious fact which,
perhaps, has an analogy in the presence of a chitinous bag within the stomach in this
same group of Cirripedia. I observed it in the stomach of all the Cirripedia of which I
prepared transverse sections; according to Darwin it is a model of the stomach, filled
with excrement and expelled by the rectum entirely in a single piece, as he observed in
some living specimens of Balanus balanoides.

To understand the physiological meaning of the apparatus at the end of the oviducts,
a second difficulty arises from the circumstance that we do not know the place where, and
the way in which, the eggs are fecundated. If Kossmann’s supposition be correct, the
eggs are evacuated after being united together by means of the fluid secreted by the
cells of the curious sack. These eggs, however, are ovarian, not yet fecundated eggs!
I think itis difficult to understand how they are fecundated after they are united together
by a fluid viscous glue. Of course, the only way of investigating successfully physio-
logical questions of this kind is to study fresh and living material. But this study can
only give trustworthy results when the anatomical structure is sufficiently well known.
{ think I have contributed to a more accurate knowledge of the anatomical structure.

I will not take leave of this subject without pointing out the great probability
that the apparatus at the end of the oviduct morphologically represents a second seg-
mental organ. Krohn’ has already shown that, of all Crustaceans, the female genital
openings are placed nearest to the cephalic part of the body in the Cirripedia ; and even
at present, though our knowledge of Crustaceans has been considerably increased since
the year 1859, it is still true that they are the only Crustaceans which show this

1 Loc. cit., p. 360, note at the foot of the. page.

REPORT ON THE CIRRIPEDIA. 47

peculiarity in their structure. The curious animal which Prof. Lacaze-Duthiers has
described as Laura gerardie, and which according to him belongs to a distinct group of
abnormal Cirripedia, has the female genital openings also in the basal segment of the first
pair of legs. The peculiar position of these openings in this group would, however,
not be so strange, if it could be shown that the female genital apparatus in the case of
Cirripedia made use of a segmental organ. Now, I think everybody, who will study
preparations of the curious sack and the oviduct in relation to it, will be struck by the
totally different structure (1) of the oviduct, (2) of the sack itself, and (3) of the canal
or duct, short in Lepas and long in Scalpellum, at the end of which the genital opening
is placed. To call the sack a widened part of the oviduct is not in accordance with
the condition of these parts at the place where they are in communication with each
other. Even in Lepas, where the communication is much more gradual than in Scal-
pellum, the place where the oviduct terminates and the sack commences is very distinct.
Since the duct by the aid of which the sack opens is a true epiblastic product, and is
lined by a thin chitinous cuticle, the sack, which is placed between it and the oviduct,
probably represents the funnel of the original segmental organ, Of course, this
suggestion is based on the occurrence of the other pair of segmental organs opening
at the base of the second maxille described on p. 23 of this Report.1_ The first pair of
segmental organs furnishes a direct communication of the body-cavity with the surround-
ing medium, the second serves for the evacuation of the female genital products. The
cells of the funnel of the first pair, probably, have an excretory function; those of the
second pair have a more special function,—that of producing a viscous fluid for uniting
the eggs into egg masses.

I hope I shall soon be able to continue these investigations and if possible to enlarge
them with the aid of fresh material.
1 Zool. Chall. Exp..part xxv,

‘

oh

rt

PLATE I.

An, stands for antenne. mr. stands for retractor muscle of the thorax,
e.gl. Re cement glands. 0. 3 orifice of the sac.

f. . muscular fibres. @. 50 cesophagus.

gt. - thoracic ganglion. r. yy cesophageal ring.

gs. 5p supracesophageal ganglion, st. mn stomach.

gl. gland of unknown nature. t. iy testis.

b 59 thoracic appendages, vd. 50 vas deferens.

mM. RS mouth, US, i yesicule seminales.

Fig. 1. Male of Scalpellum regium (Wyv. Thoms.), Hoek ; magnified 94 diameters.
Fig. 2. Nervous and alimentary systems of this male; magnified 275 diameters.
Fig. 3. Antenna of the male ; magnified 275 diameters.

Fig. 4. Transverse section of the supracesophageal ganglion where it is in relation with
the cesophageal ring ; magnified 275 diameters,

Fig. 5. Transverse section of the thoracic ganglion and the thorax with its appen-
dages ; magnified 275 diameters.

Fig. 6. Spermatozoa and spermatozoid mother-cells ; magnified 575 diameters.

Fig. 7. Epithelium of the sac and muscular fibres in a young stage of development ;
magnified 275 diameters,

The Voyage of H.M.S.”Challenger” Cirripedia. Suppl. Pl.1.

@ sees—

PP C.Hoek Del

MALE OF SCALPELLUM REGIUM.

may
Nias

ai@anine tals

PLATE IL.

AM. stands for adductor muscle. Int. stands for intestine. i
An. an antenne. LUO sy invagination dividing the body into a capita,
C. NS ceca attached to cesophagus. lum and peduncle.
Cr-C VI. thoracic appendages. f M. rs mouth.
CA. 0 caudal appendage. Ma. ,, mantle.
C.gl. Me cement glands. Od. A ovarium with oviduct.
E. i, the large compound eye. @. 8 esophagus.
€. in the simple eye. Op. A orifice of the mantle.
G1-G VI. thoracic ganglia. Sh. 30 shell.
Gs. ny supracesophageal ganglion. S or St. stomach.
GT. ae thoracic ganglion. See

Fig. 1. Cypris-larva of Lepas australis, Darwin, sagittal section ; magnified 70 diameters.
Fig. 2. Same larva in a slightly older stage, longitudinal section ; magnified 70 diameters.

Fig. 3. Cypris-larva of Scalpellum reqgium (Wyv. Thoms.), Hoek, which is destined to
develop into a male; magnified 94 diameters.

Fig. 4. Cypris-larva of Scalpellum triangulare, Hoek, which is also destined to become
a male; magnified 94 diameters.

Fig. 5. Group of cement-cells with their ducts and pale yolk-elements of the Oyen
larva of Lepas australis, Darwin ; magnified 275 diameters.

The Voyage of H.M.S.”Challenger’ Cirripedia. Suppl. Pl. Il.

I Int ew gy

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PRE C. Hoek Del. A S Wendel Lithogr

CYPRIS-LARVAE OF CIRRIPEDIA.

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PLATE III.

va. stands for cavity in which thorax is lodged. o. stands for orifice of thoracic cavity.

gs. mp supracesophageal ganglion. st. on stomach,

gt. nh thoracic ganglion. t. s testis.

4. i thoracic appendages. th. ie thorax.

m. Me longitudinal muscles of body-wall, vd. Bs vas deferens.

mr. ute retractor muscle of the thorax. VS. a vesicule seminales.

Eleven sections out of a series of about eighty through the body of the male of

Hig.) 1
Fig. 2.
Bio, 73
Vig. 4
Janae, 5)
Fig. 6
Fiz. 7
Fig. 8
Fig. 9
Fig. 10.
Fig, 11.

Scalpellum regiwm (Wyv. Thoms.), Hoek.
Transverse section near the capitular pole,

Second section. The outer wall is covered by particles of mud ; where it is taken
away, the nuclei of the chitinogenous epithelium are distinctly visible.

. Third section. To the left the orifice is visible surrounded by a dense mass of

cells of the chitinogenous epithelium ; to the right the connective tissue is
visible with its small nuclei and with the longitudinal muscles of the body-
wall.

. One of the following sections, passing transversely through the cavity in which

the thorax of the little body is lodged, and which opens outwards by means °
of the orifice in figs. 1 and 2.

. One of the following sections about the place where the vas deferens opens into

the cavity of the foregoing figure.

. Section passing through one of the lobes into which the testis is divided at its

capitular extremity, through the stomach, the supracesophageal ganglion,
the thoracic ganglion, the thorax with its central canal, the vas deferens,
and the appendages.

. In this section both lobes of the testis are represented.

. Between the two sections of the testis the narrow blind sack of the stomach

which represents the intestine is visible.

. The two lobes of the testis have united; the thoracic ganglion is only indis-

tinctly represented.
Section passing through the upper extremity of the thorax.

Section passing through the vesicula seminalis and vas deferens before the
latter enters into the thoracic part of the body.
All the figures are magnified 94 diameters.

Cirripedia. Suppl. Pl. II.

The Voyage of H.M.S. “Challenger”

Ad Wendel Tnthogr.

PPC Hoek Dal.

MALE OF SCALPELLUM REGIUM.

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PLATE IV.

an. stands for anus. mf. stands for muscular fibres.

c iy chitinous wall of the peduncle. n. Af nuclei of the chitinogenous epithelium.
ca, "0 caudal appendages. p- A penis.

Op wy connective tissue fibres. s. oF St. ,, stomach.

ct. - connective tissue nuclei. t. a testis.

cg. A cement glands. th. BS thorax.

g-9'-9" ,, first and second thoracic ganglion. vd. eH vas deferens.

Gia.) female genital aperture. vs. a vesicula seminalis.

gl. a glands of unknown function. x. is widened portions of the oviducts near the genital
gt. ms thoracic ganglion. aperture.

te is intestine. I-VI. ,, first to sixth cirrus.

Figs. 1-7. Anatomy of the male of Scalpellum regiwm (Wyv. Thoms.), Hoek.

Fig. 1. Transverse section through a male of Scalpellum regium, which is in a young
stage ; stomach filled almost entirely with nutritive yolk.

Fig. 2. Section passing through the vesicula seminalis and a narrow portion of the
testis.

Fig. 3. Section passing through a younger male at the level of the cement glands.
Figs. 1-3 magnified 94 diameters.

Fig. 4. Section of one of the cement glands ; magnified 275 diameters.
Fig, 5. Section of the wall of a male; magnified 575 diameters.
Fig. 6. Muscular fibres; magnified 575 diameters.

Fig. 7. Supposed blood-corpuscles ; magnified 575 diameters.

Figs. 8a-8f. Six out of a series of transverse sections through the body of Scalpellum
calanoides, Hoek; magnified 41 diameters.

Fig. 9. Part of a section through the body of Scalpellwm parallelogramma, Hoek, at the
base of the first pair of cirri; magnified 26 diameters.

Fig. 10. Part of a section through the body of Scalpellum nymphocola, Hoek ; magnified
41 diameters.

Cirripedia. Suppl. Pl. IV.

The Voyage of H.M.S. “Challenger”

rh.
So
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A.J Wendel Lithogr.

P.PC.Hoek Del.

1-7 MALE. OF SC. REGIUM. 8 SC. BALANOIDES. 9 SC. PARALLELOGRAMMA. 10 SC. NYMPHOCOLA.

1

oon. HALL. ‘eX? —PART xxy11.—1684,)—Ke.

ie ’
fe J *

PLATE V.

A. stands for body-cavity. e. stands for darkly pigmented epithelium.
a. . outer layer of (longitudinal) muscles. im. a intestine.
B. a band of connective tissue. M. Be outer maxilla.
b ; second layer of (circular) muscles. m. my muscle masses.
C. a organ of unknown function, nN. es nerve cords,
c. a inner layer of (longitudinal) muscles. 0. 43 ovarian cceca. a
Cighk-) cement glands. od. ua oviduct. E
Ch. 5 chitinous outer wall of peduncle. t. IK testis.
; ee main cement duct. Ss. 5s segmental organ.
D'-D'" ,, branches of the main cement duct. Sd. a segmental duct.
d, is initial cement ducts. x. es (elastic) fibres of the connective tissue.

Figs. 1-3. Segmental organ of Scalpellum vulgare, Leach.

Fig. 1. Transverse section of the body of Scalpellum vulgare, Leach, about the second
pair of maxillz ; magnified 27 diameters. The band of connective tissue (B)
contains cceca of the testis.

Fig. 2. Section of the segmental funnel ; magnified 305 diameters.

Fig. 3. Section of the segmental organ; magnified 106 diameters.

Figs. 4,5. Anatomy of the peduncle of Lepas anatifera, Linn.

Fig. 4. Transverse section near the upper extremity ; magnified 84 diameters.

Fig. 5. Part of a section near the upper extremity ; magnified 58 diameters,

F igs. 6, 7. Anatomy of the peduncle of Scalpellum vulgare, Leach,

Fig. 6. Part of a section at about 5 mm. from the upper extremity; magnified 33
diameters. The chitinous outer wall with the scales removed.
Fig. 6*. One of the cement glands ; magnified 192 diameters.

Fig. 7. Part of a section near the lower extremity ; magnified 33 diameters.

Figs. 8-11. Anatomy of the peduncle of Scalpellum regqium (Wyv. Thoms.), Hoek.

(The chitinous outer wall with the scales removed.)

Fig. 8. Part of a section near the upper extremity ; magnified 83 diameters.
Fig. 9. Section at about 1 cm. from the upper extremity ; magnified 84 diameters.
Fig. 10. Section about half the length of the peduncle ; magnified 83 diameters.

Fig. 11. Group of cement glands in the upper extremity of the peduncle; magnified 58
diameters,

RP.C. Hoek Del

Cirripedia. Suppl. PLY.

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A.J Wendel Lithogr

1-3 SCALPELLUM VULGARE. 4-5 LEPAS ANATIFERA. 6-7 SC. VULGARE. 8-11 SC. REGIUM.

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PLATE VI.

A. (in fig. 1) stands for matured ovum. O. stands for ovarian ceca.

A. (in fig. 3) oF body-cavity. oc. 1 eye.

A, (in fig. 6) Fe musculus adductor scutorum. Od. or ov. oviduct.

B. stands for ovum, not fully matured. Oe. i esophagus.

C. (in fig. 1) stands for young ovarian eggs. 0.n. 0 four optic nerves,

C. (in fig. 10) __,, outer sac of connective tissue. P. ap pancreatic gland.

c. stands for inner layer of longitudinal muscular fibres. p.N. peduncular 1 nerve.

Die 8 genital duct. 8. (in figs. 4 and 6) stands for stomach.

d. (in fig. 1) stands for epithelium of ovarian wall. S. (in fig. 10) stands for funnel at the end of the oviduct.

d, (in fig. 3) nh cement ducts. S’. stands for curious sac.

gl. stands for pancreatic gland. t. 6 testicular cceca.

GS. or G. supracesophageal ganglia. WV. 90 body-wall.

GA. ,, genital aperture. X. (in fig. 2) stands for yolk-elements of egg.

L. Nes labrum. X. (in figs. 10 and 11) stands for unknown mass.

L Ke cceca of the so-called liver. I.-III. stands for small optical ganglia.

M. iS, mouth. E

Fig. 1. Part of one of the cceca of the ovarium of Scalpellum vulgare, Leach ; magnified
685 diameters.

Fig. 2. Nucleus with nucleolus of a nearly ripe ovarian egg of Scalpellum vulgare,
Leach ; magnified 685 diameters.

Fig. 3. Part of a section of the peduncle of Scalpellum regium (Wyv. Thoms.), Hoek,
in its lower half; magnified 33 diameters. Body-cavity, acting as the main
cement duct.

Figs. 4, 5. Pancreatic gland of Scalpellum parallelogramma, Hoek.

Fig. 4. Part of a transverse section through the cephalic part of the body ; magnified 33
diameters.

Fig. 5. Section of the gland where it has its greatest diameter; magnified 106
diameters.

Fig. 6-9. Anatomy of Lepas anatifera, Linné.

Fig. 5. Sagittal section of the body; magnified 1°5 diameters.

Fig. 7. Lateral view of the upper and front part of the stomach, after the muscles have
been removed ; magnified 8 diameters.

Fig. 8. Frontal view of a part of the stomach with the suprawsophageal ganglia;
magnified 8 diameters.

Fig. 9. The eye and its innervation ; magnified 58 diameters.

Fig. 10. The apparatus by means of which the oviduct opens in Scalpellum vulgare,
Leach ; magnified 106 diameters.

Fig. 11. Same apparatus of Lepas hullir, Leach ; magnified 58 diameters.

Cirripedia. Suppl. PL VL.

The Voyage of H.M.S."Challenger’

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