GIFT OF
MICHAEL REESE

RESULTATS DES EXPLORATIONS
ZOOLOGIQUES, BOTANIQUES, OCEANOGRAPHIQUES ET 6EOLOGIQUES

ENTUEPBISES AUX
CNDES NEEELAlfDMSES ORIENTALES en 1899 — 1900,

a bord du SIBOQ-A.

SOUS LE COMMAXDElTEIiT DE

G. F. TYDEMAN

PUBLIES >AE
M A. X WEBER.

Chef de 1'eipedition.

•111.

IV.

V.

*VI.

VII.

•VIII.

*IX.

*X.

*XI.

•in.

*xm.

XIV.

xv.
*xvi.

XVII.

xvm.

XIX.
•XX.

•XXI.

XXII.

XXIII.

XXITi.

XXIV2.

•XXV.

•XXVI.

*XX\IiM.

xxvu.

XXVIII.
•XXIX.

•XXX.
•XXXI.

XXXII.
XXX111.

• xxxiv.

XXXV.

* XXXV I.
XXXVII.

XXXVIII.

XXXIX.

•XL.

XLI.

•XL1I.

•XLIII.

•XLIV.

•XLV.

XLVI.

•XLVII.

•XLVIII.

•XLIX'.

*L.

•LI.

•LI I.

LIH.

*LIV.

LV.

•LVI.

LVII.

LVni.

LIX.

*LX.
•LXI.

LXII.
LXIII.
LXIV.

LXV.
LXVI.

Introduction et description de 1'expedition, Max Weber.

Le bateau et son equipement scientifique, G. F. Tydeman.

Resultats hydrographiques, G. F. Tydeman.

Foramiuifer'a, F." W. Winter.

Xenophyophora, F. E. Schulze.

Radiolaria, M. Hartmann.

Porifera, G. C. J. Vosmaer et I. Ijima ').

Hydropolypi, A. Billard.

Stylasteriua, S. J. Hick son et M"« H. M. England.

Siphonophora, MU« Lens et van Riemsdijk.

Hydromedusae, O. Maas.

Scyphomediisae, 0. Maas.

Ctenophora, Mile F. Moser.

Gorgonidae, Alcyonidae, J. Versluys, S. J. Hick son et

Pennatulidae, S." J. H ickson. [C. C. Xutti ng ').

Actiniaria, P. Me M u r r i c h.

Madreporaria, A. Alcock ') et L. D5derlein.

Antipatharia, A. J. van Pesch.

Turbellaria, L. von Graff et R. R. von Stummer.

Cestodes, J. W. Spengel.

Nematomorpha, H. F. Xierstrasz.

Chaetognatha, G. H. Fowler.

Nemertini, A. A. W. Hubrecht.

jruidae, R. R. von Stummer.
laeta errantia, R. Horst.

Polycbaeta sedentaria, M. Caullery et F. Mesnil.
Gep'hyrea, C. Ph. Sluiter.
Enteropueusta, J. W. Spengel.
Ptcrobranchia, S. F. Harmer.
Brachiopoda, J. F. van Bemmelen.
Polyzoa, S. F. Harmer.
Copepoda, A. Sco
Ostracoda, G. W. Miller.
Cirrhipedia, P. P. C. Hoek ').
Isopoda, H. J. Han sen.
Amphipoda, Ch. Perez.
Caprellidae, P. Mayer.
Stomatopoda, H. J. Han sen.
Cumacea, W. T. Caiman.
Schizopoda, H. J. Han sen.
Sergestidae, H. J. Han sen.
Decapoda, J. G. de Man.
Pantopoda, J. C. C. Lorn an.
Halobatidae, J. Th. Oudemans.
Crinoidea, L. Doderlein1) et C. Vaney.
Echinoidea, J. C. H. de Meijere.
Holothurioidea, C. Ph. Sluiter.
Ophiuroidea, R. Kohler.
Asteroidea, L. Doderlein.
Solenogastres, H. F. Xierstrasz.
Chitomdae, H. F. Xierstrasz.
Prosobranchia, M. M. Schepman1).
Prosobranchia parasitica, H. F. Xierstrasz et M. M.
Opisthobranchia, R. Bergh. [Schepman.

Heteropoda, J. J. Tesch.
Pteropoda, J. J. Tesch.

Lamellibranchiata. P. Pelseneer et Ph. Dantzenberg.
Scaphopoda, M"= M. Boissevain.
Cephalopoda, L. Joubin.

Tunicata, C. Ph. Slniter et J. E. W. Ihle ').
Pisces, Max Weber.
Cetacea, Max Weber.
Liste des algues, M^e A. Weber.
Halimeda, JJUe E. S. Barton. (Mme E. S. Gepp).
Corallinaceae, Mm« A. Weber et M. Foslie.
Codiaceae, A. et M^e E. S. Gepp.
Dinofiagellata. Coccosphaeridae, J. P. Lots y.
Diatomaceae, J. P. Li
Deposita marina, 0. B. B'oggild.
Resultats geologiques, A. Wichmann.

Siboga-Expeditie

THE

IV. THE PLEXAURID^E

BY

C. C. NUTTING

Professor of Zoology', State University of Iowa
With 4 plates

Monographic XIII ^ of:

UITKOMSTEN OP ZOOLOGISCH,
BOTANISCH, OCEANOGRAPHISCH EN GEOLOGISGH GEBIED

verzameld in Xederlandsch Oost-Indie 1899 — 1900

aan boord H. M. Siboga onder commando van
Luitenant ter zee ie kl. G. F. TYDEMAX

UITGEGBVEN DOOR

Dr. MAX WEBER

Prof, in Amsterdam, Leider der Expeditie

(met medewerking van de Maatschappij ter bevordering van het Natuiirkundig
Onderzoek der Nederlandsche Kolonien)

BOEKHANDEL EN DRUKKERIJ

TOOUtUX

E. J. BRILL

LEIDEX

Public Mai 1910

Les numeros avec un asterique ont deja paru; ceux marques i) sculement en partie

Voor de uitgave van de resultaten der Siboga-Expeditie hebben
bijdragen beschikbaar gesteld:

De Maatschappij ter bevordering van het Natuurkundig Onderzoek der Nederlandsche

Kolonien.

Het Ministerie van Kolonien.
Het Ministerie van Binnenlandsche Zaken.

Het Koninklijk Zoologisch Genootschap >Natura Artis Magistra" te Amsterdam.
De >Oostersche Handel en Reederij" te Amsterdam.

De Heer B. H DE WAAL Oud-Consul-Generaal der Nederlanden te Kaapstad.
M. B. te Amsterdam.

CONDITIONS GfiNfiRALES DE VENTE.

i3. L'ouvrage du ,Siboga" se composera d'une serie de monographies. -
2°. Ces monographies paraitront au fur et a mesure qu'eUes seront pretes.

3°. Le prix de chaque monographic sera different, mais nous avons adopte comme base generale du prix de
vente: pour une feuille d'impression sans fig. flor. 0.15; pour une feuille avec fig. flor. 0.20 a 0.25;
pour une planche noire flor. 0.25; pour une planche coloriee flor. 0.40; pour une photogravure flor. 0.60.

4°. II y aura deux modes de souscription :

a. La souscription a 1'ouvrage complet.

b. La souscription a des monographies separees en nombre restreint.
Dans ce dernier cas, le prix des monographies sera majore de 25 °/0.

5°. L'ouvrage sera reuni en volumes avec titres et index. Les souscripteurs a 1'ouvrage complet recevront
ces titres et index, au fur et a mesure que chaque volume sera complet.

THE GORGONACEA OF THE SIBOGA EXPEDITION

IV. THE PLEXAURID./E

Siboga-Expeditie

XIII b1

THE

GORGONACEA OF THE SIBOGA EXPEDITION

IV. THE PLEXAURED^E

BY

C. C. NUTTING

Professor of Zoology, State University of Iowa

With 4 plates

(Aided by a grant from the ELIZABETH THOMPSON SCIENCE FUND)

LATE E. J.

PUBLISHERS AND PRINTERS

LEYDEN

&

THE GORGONACEA OF THE SIBOGA EXPEDITION

IV. THE PLEXAURID.E

BY

C. C. NUTTING,

Professor of Zoology, State University of Iowa.

With 4 plates.

(Aided by a grant from the ELIZABETH THOMPSON SCIENCE FUND.)

Family PLEXAURID^E Gray.

Plexaura Lamouroux. Exposition Methodique, 1821, p. 35.

Plexaurida Gray. Annals and Magazine of Natural History, Series 3, Vol. IV, 1859.

Eunicea + Plexaura Milne Edwards et Haime. Histoire naturelle des Coralliaires, 1857, Vol. I,

pp. 146, 152.

Eimiceidie Kolliker. Icones Histologicae, II, 1865, p. 137.

Plexaurida Verrill. Transactions Connecticut Academy of Science, Vol. I, 1869, p. 135.
Euniceidu! Ridley. Annals and Magazine of Natural History, Series 5, Vol. n, 1883, p. 253.
Plexaurid<z Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 135.
Plexaurida; Studer. Alcyonarien aus der Sammlung des Naturhistorischen Museums in Liibeck,

1894, p. in.
Plexaurida Brundin. Bihang til Svenska Vet.-Akad. Handlingar, Band 22, Afd., 17, N° 3,

1896, p. 17.
Plexaurida Thomson and Henderson. Ceylon Pearl Oyster Report, Alcyonaria, 1905, p. 304.

The original definition of the family, as given by GRAY, is as follows:
"Bark granular, persistent, cork-like, without any important grooves. Cells placed equally
on all sides of the branches".

SIBOGA-EXPEDITIE XIII £'. I

234629

VERRILL, as usual, was quick to discern the most important characters by which this
family can be differentiated from its allies. His definition is as follows :

"Corallum usually dichotomous or more or less arborescent. Axis horn-like, or more or
less calcareous, especially at base. Longitudinal ducts equal, arranged regularly all around the
axis. Ccenenchyma usually thick. Cells scattered over all parts of the surface, flat, or elevated
on prominent verrucae. Tentacles at base, and sides of the polyps stiffened with large fusiform
spicula. Spicula of the coenenchyma usually large, of various forms, most usually these are large
warty spindles mingled with clubs or crosses".

For the purposes of this work the following definition is offered:

Ccenenchyma thick, without evident grooves ; axis cylinder horny, or horny and calcareous,
but never jointed. Primary water-vascular canals in a regular series around the axis. Calyces
on all sides of the stem and branches, often entirely included. Spieules various, usually spindles,
clubs, butterfly-shaped or Blattkeulen.

As WRIGHT and STUDER remark: "The genera belonging to the family as it now stands,
certainly require revision".

The material secured by the Siboga Expedition that can be referred to the Plexauridae
is not sufficient in extent to justify the author of this report in undertaking a revision of the
family, and he therefore contents himself with recognizing the genera defined in the Challenger
Report, and the addition of a single new genus which seems necessary to accommodate a
remarkable species collected by the Siboga Expedition.

The most important feature in the diagnosis of genera in this family seems to be the
character of the axis cylinder, the forms of the calyces and spicules being however, of great
service in generic description in some cases.

The following artificial key may be of service in aiding the student to determine the
generic affinities of species.

Artificial key to the genera of PLEXAURHXE.

Stem, branches and horny axis distinctly flattened (Platygorgia) l

Calyces prominent and bilabiate (Eunicea)

Calyces moderately prominent, not bilabiate.

Spicules armed with long, truncate verrucae t (Anthoplexaura)

Spicules small, the outer layer club-shaped (Paraplexaura)

Calyces neither bilabiate nor decidedly prominent. Axis not distinctly flattened.
Axis entirely horny, except at base, or with calcareous particles deposited

in the central core.
.Spicules usually spindles, horizontally or longitudinally placed in outer

layer of coenenchyma.
Ccenenchyma thick. No very large, bar-like spicules .,..., Plexaura

1 Generic names enclosed in brackets indicate that such genera are not represented in the Siboga collection.

Coenenchyma thin. Large, bar-like spicules very prominent.
Spicules of outer layer clubs or "Blattkeulen" vertically placed.

Clubs large. Terminal branches long and slender

Clubs small. Terminal branches short

Clubs minute, their club-ends inflated and free

Axis with a central horny core, around which is a tubular casing containing

more or less calcareous matter.

Spicules large, clubs, crosses and triradiate forms predominating.
Spicules small, short oval spindles and double spindles predominating.

Hicksonella

Plexauroides

(Paraplexaura)

(Eunicella)

(Plexaurella)
Euplexaura

The writer is unable to find any character in the definition of the genus Psammogorgia Verrill by which it can be differentiated
from others of the family. He therefore gives the definition proposed by the original describer, which is as follows :

"•Psammogorgia Verrill. Corallum dichotomous or subpinnate. with ronnd branches. Axis horn-like. Coenenchyma moderately
thick, the surface finely granulated with small rough spicula. Cells scattered, sometimes flat, more frequently raised in the form of rounded
verrucae. Polyps with rather large, elongated, slender warty spindles at the bases of the tentacles. Spicula of the Coenenchyma mostly short,
thick, and very rough, warty spindles and rough, warty clubs of moderate size".

(VERRILL, Transactions Connecticut Academy of Science, Vol. I, Part 2, p. 414).

Synoptic view of the genera and species of the Siboga

collection of PLEXAURID.E.

®The asterisk (*) denotes a new genus or species.

Plexaura.

*P. aggregata, *P. attenuata, *P. recta, *P.
platystoma, *P. pinnata, *P. flava.

Plexauroides.
P. praelonga, P. lenzii.

Euplexaura.
*E. rudra, *E. mollis, *E. reticulata.

*H. princeps.

P. arbuscula.

"Hicksonella.

Psammogorgia.

The above table indicates that of the thirteen species of the Plexauridae collected, ten
appear to be new, and nearly half of the total number belong to the type genus, Plexaura.
This genus has heretofore been unrepresented in the East Indian Region, with the exception
of one species which THOMSON and HENDERSON identify as a variety, (jlexuosa} of P. antipathes.
The present writer is of the opinion that this form is identical with the new species P. aggregata,
described beyond.

Systematic discussion of genera and species.
Plexaura Lamouroux (emended).

Plexaura Lamouroux. Histoire des Polypiers coralligenes flexibles, 1816, p. 424.

Plexaura Lamouroux. Exposition Methodique, 1821, p. 35.

Plexaura Milne Edwards et Haime. Histoire Naturelle des Coralliaires, Vol. I, 1857, p. 152.

Plexaura Duchassaing et Michelotti. Coralliaires des Antilles, 1860, p. 25.

Plexaura Kolliker. Icones Histologicae, II, 1865, p. 138.

Plexaura Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 137.

Plexaura Thomson and Henderson. Pearl Oyster Fisheries Reports, the Alcyonaria, 1905, p. 304.

The original describer, LAMOUROUX, gave a definition for this genus that needs little
change to fit it for modern use. It is as follows :

"Polypier dendroide, rameux, souvent dichotome ; ramaux cylindriques et roides; axe
legerement comprime; ecorce, dans 1'etat de dessication, subereuse, ou terreuse, tres-epaisse,
faisant peu d'effervescence avec les acides, et couverte de cellules eparses, grandes, nombreuses,
souvent inegales et qui ne sont jamais saillantes".

Eliminating non essential points, the difinition used for the present work will be as follows:

Coenenchyma thick, calyces included and distributed on all sides of the stem and branches.
Spicules in the form of warty spindles and clubs, usually in two layers. Axis entirely horny,
except at the base of the stem of large specimens.

The character of the axis will differentiate this genus from Plexaurella, which greatly
resembles it superficially, and from Euplexaura and Pseudoplexaura. The characters of the
spicules will separate it from Plexauroides and Hicksonella.

The type of this genus is Plexaura heteropora (Lamarck).

Owing to the superficial resemblance between Plexaura and Plexaurella, both genera
abundant in species, it is impracticable, without recourse to the types, to tell which of the
species originally .described should be placed in Plexaura. Both of these genera are but sparsely
represented in previous collections from the Western Pacific, or Indo-Pacific region. Hence it is
not surprising that the species in the Siboga collection are all apparently new.

i. Plexaura aggregata new species. (Plate I, figs, i, i#; Plate IV, fig. i).

Stat. 58. Anchorage off Seba, Savu Island. Up to 27 meters.

Stat. 65". 7°o'S., 1 20° 34'. 5 E. Flores Sea. Depth changing rapidly from 400 — 120 meters.

Coral bottom.

Stat. 213. Saleyer anchorage, and surroundings. Up to 36 meters.
Stat. 258. Tual anchorage, Kei Islands. Reef. 22 meters.
Stat. 315. Anchorage East of Sailus Besar, Paternoster Islands. Up to 36 meters.

Colony consisting of a dense clump of branches, 36 cm. in height. The branches all
spring from the base of the colony and almost immediately begin to subdivide. The base is
about 4.5 cm. broad, and the largest branches have a diameter of about 2 cm. The branches
divide irregularly, but ordinarily the division is not dichotomous, until ultimate branchings of
the 9th or ioth order are attained, the resul-t being hundreds of terminal twigs with a diameter
of about 3 mm. All of the branches are round and smooth, and distinctly enlarged at their
ends. The calyces are inserted on all sides of the branches, and are evenly spaced, averaging
about i mm. apart. The ccenenchyma is very thick.

The individual calyces are completely inserted, leaving the surface of the branch perfectly
even, except where pitted by the calyx apertures. These pits are quite small, in alcoholic
specimens, the pits being oval instead of round, their greater diameter being parallel to the

long axis of the branch and seldom attaining a length of over i mm. The margin appears to
be divided into shallow lobes lying horizontally. The polyps are small, with delicate fringed
tentacles, their bodies bearing eight longitudinal bands of very slender spindles. The tentacles
appear to be unarmed.

A cross section of a branch shows a horny axis surrounded by very large watervascular
canals symmetrically arranged on all sides of the axis, their cavities being larger than those
of the calyces.

S p i c u 1 e s. These are all very small and the prevalent type is a very deeply tuberculate
spindle with the tubercles arranged in definite series or zones. Clubs are also common. There
are no well-defined layers of spicules in the ccenenchyma.

Color. The colony is very light brown, in alcohol. The axis is almost black proximally,
and lightens distally. It has a slender, white core, which is not calcareous.

This species is probably identical with Plexaura antipathes var. flexuosa Thomson and
Henderson. Ceylon Pearl Oyster Fisheries Report, the Alcyonaria, 1895, P- 3°5-

It seems a very distinct species, however, differing from Plexaura antipathes in having
no violet spicules.

A specimen from Stat. 258 is much larger than the one described, being 90 cm. in
height, with a main stem 2 cm. in diameter. At the base there is a solid, flinty, calcareous
layer surrounding a horny core 7 mm. in diameter. The axis of the branches is entirely horny.

2. Plexaura attenuata new species. (Plate I, figs. 2, 2 a; Plate IV, fig. 2).

Stat. 162. Between Loslos and Broken Islands, West coast of Salawatti. 18 meters.
Stat. 164. i°42'.5 S., I30°47'.s E. Near New Guinea. 32 meters.
Stat. 285. 8°39'.iS., 127° 4'.4E. Timor Sea. 34 meters.
"Bay of Batavia. Professor StUITER leg.".

Specimen (incomplete) consisting of a straight, wand-like stem about 37 cm. long, from
which project three short, straight branches all of which have their distal ends broken off. The
greatest diameter of the main stem is 3 mm., tapering to 2 mm. near its distal end. The
calyces are evenly distributed on all sides of the colony, but are larger and further apart than
in Plexaura aggregata. Nearly all of the polyps are partly extended, and this gives the calyces
the appearance of being partly exserted and verruciform. In fact, however, the calyces are
hardly raised above the general level of the ccenenchyma when the polyps are retracted,
although there may even then be a slight swelling.

The individual calyces are about 1.7 mm. in diameter, and when the polyp is retracted
the calicular margin shows eight very plain scallops or lobes which are larger and deeper than
in the preceding species. The polyps are able to protrude their bodies considerable above the
calyces and still keep the tentacles folded within the body walls, where they form an acorn-
shaped mass, the individual tentacles being plainly seen within the transparent body wall. The
lower part of the polyp shows very delicate longitudinal bands of spicules.

A cross section of the stem shows a thick ccenenchyma in which the calyces are sunken
almost to the axis cylinder. The canals are not nearly so regular and distinct as in Plexaura
aggregata. The axis is horny, with a white noncalcareous centre.

Spicules. The spicules are all small, terete spindles with regularly disposed annular
rows of compound verrucae, giving a very symmetrical pattern. Definite layers of spicules can
not be made out, as they seem to pack the ccenenchyma from the surface nearly to the axis.
The spicules are those which KENT figures as characteristic of the genus Verrucella in the
Monthly Microscopical Journal, Feb. Ist, 1870, Plate XLII, fig. 3.

Color. The specimen is a light brown or tan color. The axis is dark brown and the
spicules are colorless.

3. Plexaura recta new species. (Plate II, figs. 3, 3*2; Plate IV, fig. 3).

Stat. 273. Anchorage off Pulu Jedan, E. coast of Aru Islands (Pearl Banks). 13 meters.
Stat. 299. Buka or Cyrus Bay, South coast of Rotti Island. 34 meters.
*Pulu Missa near Flores. J. H. DE SlSO don. 3 specimens.

Colony flabellate in form, not reticulate, attaining a height of 59 cm. About 2 cm. above
the base the main stem divides into two, and each of these divides often, but not usually, in a
dichotomous manner until twigs of the 7th order of division are attained. The ultimate branches
are long and slender, erect and parallel. They sometimes attain a length of 39 cm., are round,
and of approximately of the same diameter throughout. The main stem is i cm. in diameter
at its base, and the ultimate branches are from 2 to 3.5 mm. in diameter. The calyces are
evenly distributed on all sides and are entirely included when the polyps are retracted, leaving
but a slightly elevated border around the apertures. The apertures, in dried specimens, form
sharp oval openings.

The individual calyces are small and sunken almost to the axis. The margin is surrounded
by well-marked scallops as in the preceding species. The tentacles in the specimen described
often protrude through these apertures, although the polyps themselves are entirely retracted.
The tentacles are very long, with long delicate fringes. I am unable to find any spicules in
the body walls or tentacles.

A cross section of a branch reveals a condition much as in the last species. The axis
is noncalcareous, with a white centre around which are a number of light-colored strands, none
of which are calcareous. The canals are proportionally small and inconspicuous, and their
arrangement can not easily be determined.

Spicules. These are very short, stout, small densely tuberculate spindles, often so short
as to be almost globular. The tubercles are so closely crowded as to cover the whole surface
almost like the round cells of a morula. There is no division of spicules into definite layers.

Color. The colony is dark brown, in alcohol. Axis black, lightening distally. A specimen
from Stat. 273 is 64 cm. in height, and more profusely branched than the type described.

4. Plexaura platystoma new species. (Plate II, figs. 2, 2 a; Plate IV, fig. 4).

Stat. 43. Anchorage off Pulu Sarassa, Postilion Islands. Up to 36 meters.

Colony of irregular and straggling habit, 16 cm. in height. The main stem gives off
four branches of very unequal size, one of which arises about 5 cm. from the base. This
becomes the main part of the colony, bearing several short stubby branches very unequally
distributed, and one large descending branch producing a number of slender undivided branchlets
in an indistinctly pinnate manner. The diameter of the main stem and largest branch is 1.8 mm.
The calyces are entirely included and rather sparsely distributed on all sides of the stem and
branches. The polyps in retraction draw the calyx margins together so that the apertures are
almost obliterated. In the dried fragment of a branch, however, the apertures are really much
larger than in either of the preceding species.

The individual calyces, although hardly evident externally, are really considerably broader
than in the other species described. The apertures are oval, the long diameter being parallel
with the axis. The longer diameter of the calyx is about 1.5 mm. The polyps have eight
longitudinal bands of slender spindles, and the tentacles have a number of delicate spindles on
their dorsal surface. These latter are arranged in two longitudinal series on each tentacle, so
as to approach the en chevron arrangement on the proximal portions. The layers of the ccenen-
chyma are not well defined.

A cross section of a branch shows a moderately thick ccenenchyma. well-defined but not
numerous watervascular canals, and a horny axis with a white, noncalcareous core.

S p i c u 1 e s. These are rather slender, usually curved spindles of the same general type
as in Plexaura attenuata, but larger than any others thus far described in this report, some
of them attaining a length of i mm. The annular arrangement of the tubercles is not so well-
marked as in P. attenuata.

Color. Very pale gray, almost white, in alcohol. The axis is golden brown proximally
and very pale distally.

5. Plexaura pinnata new species. (Plate I, figs. 3, 30; Plate IV, fig. 5).

(The locality can not be given, as the label is missing).

Colony flabellate in form, 16 cm. in height and with a spread of 9 cm. The main stem
has been broken just above the origin of the first main branch, which thus constitutes practically
the entire specimen. This branch bears numerous branchlets in a pinnate manner, but they are
neither opposite nor regularly alternate. The calyces are regularly distributed on all sides of
the stem and branches, and are about i mm. apart.

The individual calyces are included, there being no external swelling except a slight
tumidity about the margin, as in other species of this genus. The aperture is quite small, usually
round, the tentacles being sunken below the eight-lobed fringe around the inner side of the margin.
The polyp is much compressed, when retracted, a longitudinal section being an oval whose width
is greater than the length. There are a few delicate spindles in the polyp body and tentacles.

8

A cross section of the stem shows a moderately thick ccenenchyma, a series of small but
well-defined watervascular canals, and an axis with a proportionally large white central core.

Spicules. These are all small, but of several types. Regular, terete spindles with
regularly disposed, very prominent verrucas are common. There are also many double clubs
such as KENT calls "laminatoclavate" spicules :, with a marked constriction around the middle.

A number of crosses are also found, the arms of the crosses being tumid and densely
tuberculate, forming a four-leaved rosette. While the ccenenchyma is divided into two layers
by the watervascular system, I can not determine any constant difference between the spicules
of these layers.

Color. The colony in alcohol is very light buffy brown. The axis is dark brown and
the spicules colorless.

6. Plexaura flava new species. (Plate II, figs, i, i#; Plate IV, fig. 6).

Stat. 19. Bay of Labuan Tring, West coast of Lombok. 18 — 27 meters.

Stat. 60. Haingsisi, Samau Island, Timor. Reef. 23 meters.

Stat. 142. Anchorage off Laiwui, coast of Obi Major. 23 meters.

Stat. 273. Anchorage off Pulu Jedan, East coast of Aru Islands. 13 meters.

A number of fragments of apparently more than one specimen were collected at Station 19.
The largest consists of a dense tuft of branches and branchlets, and is 37 cm. long. The main
stem is 8 mm. in diameter, and abruptly angulated 2.2 cm. from its base. After giving off
one compound, and a number of simple branches, it divides into two approximately equal parts
12.5 cm. from its base. These branches give off numerous compound and simple branchlets. On
their proximal portions both the main branches and their compound offshoots give off terminal
twigs from all sides. On their distal portions they give off usually simple twigs with a strong
tendency to a regularly pinnate arrangement, although occasional twigs are given off from both
the front and back of the distal parts of the colony. The pinnae are about 4 mm. apart, on
the average, and about 1.5 mm. in diameter. The main stem is flattened, but the branches
are round. The calyces are rather more prominent than in most species of this genus, and are
distributed on all sides of the branches, with a tendency to be more crowded on the sides
than on the front and back.

The individual calyces show externally as very low verrucae. The aperture is often
completely closed by the contraction of the calyx margin. The polyps are completely retractile,
but the tentacles do not sink below the level of the polyp walls. Thus there appears no lobular
margin around the calycular mouth, but the tentacles, in retraction, lie immediately below the
margin. The tentacles are very deeply fringed. There are a few very minute, bar-like spicules
on the body walls and basal parts of the tentacles.

A cross section of a branch shows a rather ill defined series of watervascular canals,
and an axis wholly corneous with a rather large central core which is white.

1 KENT. On the Calcareous spicuke of the Gorgonacea. Monthly Microscopical Journal, Feb. I, 1870, p. 76, plate XLII, figs. 38, 43.

Spicules. The spicules are mainly spindles, straight and curved, relatively large as
compared with most of the others in the Siboga collection of this genus, but not so as compared
with some other Plexauridae. A few club-shaped forms are present.

Color. The colony is a light naples yellow, probably brighter when fresh. The axis is
brown and the spicules colorless.

This species differs in general appearance from the other species of Plexaura in the
collection, but the writer is unable to find any structural difference, unless it be in the spicules,
which do not seem of a sufficiently different type to warrant its exclusion from the genus.

Plexauroides Wright and Studer (emended).

Plexauroides Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 138.
Plexauroides Studer. Alcyonarien aus der Sammlung des Naturhistorischen Museums in Liibeck,

1894, p. in.

Plexauroides Brundin. Alcyonarien des zool. Museums in Upsala, 1896, p. 19.
Plexauroides Kiikenthal. Japanische Gorgoniden, II. Teil, 1909, p. 27.

The original definition of this genus is as follows :

"Colony branching, mostly in the one plane. Stem and branches cylindrical. Axis horny
dense, with the central portion calcareous. Nutrient canals symmetrically arranged. Coenenchyma
thin, consisting of two very distinct layers of spicules, the one nearest the axis is composed of
irregular stellate forms, the outer layer of large Blattkeule, the broad foliar expansions of which
project beyond the surface of the coenenchyma forming a rough imbricated surface".

The polyps are numerous, fully retractile, with scarcely visible verrucse, the edges of
these latter being fringed with rows of the broad projecting folia of the Blattkeule.

KUKENTHAL re-defines the genus so as to exclude Plexauroides verrucosa Brundin, and
P . asper Moroff, which he places in a new genus Paraplexaura, which he differentiates from
Plexauroides mainly on account of short terminal branches and true calyces.

Aside from the original definition, there is no reference to the calcareous core to the
axis, and it is not referred to by BRUNDIN in his discussion of the genus. The specimens in the
Siboga collection do not show this character, but there is a white core to the axis which is
not calcareous. It may possible have deceived the describer of the genus, as it looks very
much like a calcareous core.

The spicules are the characteristic feature of the genus, which may be described as follows :

Plexauridae with a horny axis, long terminal branchlets inserted calyces, ccenenchyma
rather thin, but composed of two very distinct layers of spicules. The outer layer is formed of
spicules whose proximal part bears branched, warty radiating processes projecting downward
and outward ; and whose distal portions are composed of broad, leaf-like expansions standing at
right angles to the surface of the branch when in situ. The inner layer of spicules is composed
of smaller cruciform or stellate forms.

The type of this genus is Plexauroides pr&longa (Ridley). The other known species are
Plexauroides indica Ridley, P. unilateralis Studer, P. lenzii Studer, P. michelsoni Kiikth.,
P. rigida Kiikth., P. simplex Kiikth. and P. filiformis Kiikth.

SIBOGA-EXPEDITIE XIII *'. 2

10

This genus has much in common with the genus Eunicella Verrill, especially in the
form of the spicules.

1. Plexauroides prcelonga (Ridley).

Plexaura prcelonga Ridley. Report on the Zoological Collections of H. M.S. Alert, 1884, p. 339.
Plexauroides pralonga Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 138.
Plexaura pr&longa, var. elongata Thomson and Henderson. Ceylon Pearl Oyster Fisheries
Report, Alcyonaria, 1905, p. 305.

Stat. 273. Anchorage off Pulu Jedan, East coast of Aru Islands. (Pearl Banks). 13 meters.

Colony (dried) flabellate in form, 62 cm. in height and about 20 cm. in spread. The
main stem gives off a large branch 9 cm. from its base, and this bears several lateral branches
which are usually simple and attain a length of as much as 24 cm. The remainder of the
colony consists of the continuation of the main stem and its branches. These latter are roughly
alternate in position and tend to divide dichotomously until branches of the third order are
produced. The terminal twigs are very long and slender. The diameter of the main stem
is 9 mm., and of the branches about 3 mm. The calyces are entirely inserted, and are so
completely immersed that only their openings are seen. They are evenly distributed on all
sides of the branches, their mouths being about i mm. apart.

Nothing but the openings of the individual calyces are to be seen in the dried specimens.
These are oval and less than i mm. in their longer diameter. The polyps could not be seen
in the specimens at hand.

A cross section of a branch shows a very thick ccenenchyma with a superficial layer of
"Blattkeulen" standing at right angles to the surface, and an inner layer of colorless cruciform
or stellate spicules. The watervascular canals are large and conspicuous. The axis cylinder has
a white, noncalcareous core.

Spicules. These are mainly typical "Blattkeulen" with a branched and densely tuber-
culate basal portion and a distal, disk-like comparatively smooth part. This latter portion is
often inflated in appearance and approaches very closely the Echinogorgia type, as pointed out
by STUDER in his study of Plexauroides lenzii 1 besides these, which are by far the most
numerous, there are cruciform and stellate spicules of much smaller size.

Color. The colony is bright crimson. The axis is black, fading distally to a light
greenish brown. The spicules are bright red.

General distribution. The type was secured in Torres Strait. The Challenger found
it off Cape York at a depth of 8 fathoms. It was secured also from the Pearl Banks of Ceylon.

This is a very beautiful and well 'marked species.

2. Plexauroides lenzii Studer.

Plexauroides lenzii Studer. Alcyonarien aus der Sammlung des Naturh. Museums in Liibeck,
1894, p. 114.

Alcyonarien aus der Sammlung des Naturh. Museums in Liibeck, 1894, p. 114.

1 1

Stat. 258. Tual Anchorage, Kei Islands. 22 meters. Lithothamnion.

Stat. 273. Anchorage off Pulu Jedan. East coast of Aru Islands. (Pearl Bank). 13 meters.

Colony flabellate in form, 21 cm. in height and about 16 cm. in diameter. The main
stem forks about 2.5 cm. from its base, and one of the resulting divisions again forks, making
three main branches to the colony, which give off lateral branches in a very irregular manner,
often redividing until branchings of the 5th and 6th orders are attained. The diameter of the
main stem is 6 mm., of the main branches 5 mm. and of the slender, straight ultimate branches
2 mm. The calyces are evenly distributed on all sides of the stem and branches, their mouths
being ordinarily about i mm. apart from centre to centre.

The individual calyces are included, there being nothing visible externally except a very
slight swelling around the margins, this swelling fading insensibly into the general surface of
the ccenenchyma. The calyx walls are covered with the imbricating scales or foliar expansions
of Blattkeulen that form the distal portions of the superficial layer of spicules. The polyps are
completely retractile, the calycine apertures being in most cases obliterated. The retracted polyps
are very much flattened, being really reduced to disk-shaped bodies. There are a few slender
spicules on the upper surfaces of the tentacles, there usually being two longitudinally disposed
on each tentacle.

A cross section of a branch shows the two layers of spicules characteristic of the genus,
the outer with the scarlet foliar expansions standing erect, as if radiating from the axis. The
inner layer is composed of colorless spicules which are small and of various forms. The water-
vascular canals are not well differentiated, and the axis is horny, sometimes with a hollow centre.

Spicules. The Blattkeulen are like those oi \htEchinogorgia type found in the Muriceidae,
but the smooth, distal foliar expansions are aggregated into a knob-like head. Sometimes this
is much flattened so as to become disk-shaped. The proximal, immersed parts of these spicules
bear dense masses of tuberculated or branched processes reaching downward and outward.
Besides these there are a number of tuberculate spindles, crosses, butterflies, clubs, etc. which
are found in the inner layer of the ccenenchyma.

Color. The colony is bright scarlet, as are the Blattkeulen.

The specimens collected by the Siboga Expedition do not show the calcareous core to
the axis cylinder described by STUDER. They agree, however, so well in all other particulars
that the writer feels confident of the correctness of his identification.

Euplexaura Verrill (emended).

Euplexaura Verrill. Proceedings of the Essex Institute, VI, 1869, p. 143.
Euplexaiira Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 143.
Euplexaura Brundin. Alcyonarien des Zool. Museums in Upsala, 1896, p. 20.
Euplexaura Kiikenthal. Japanische Gorgoniden, II. Teil, 1909, p. 6.

The orginal description of the genus is as follows:

"In external characters it resembles Plexaurella, with rather large, open cells. The spicula
are mostly stout, blunt, warty spindles, and rarely small, irregular crosses".

12

WRIGHT and STUDER add to this description the character of the axis, which is really the
best diagnostic feature of the genus. After quoting VERRILL'S definition they add:

"To this may be added that in the structure of the axis there is a general resemblance
to that of Plexaurella '.

In spite of this "general resemblance", however, there is a very distinct difference between
the axis of Plexaurella and that of Euplexaura. In a cross section of a branch of a typical
species of Plexaurella the clear, horny core is surrounded by a thick envelope which is composed
of a number of long, vermiform, white calcareous bodies enclosed in a casing of chitin. In a
similar section of Euplexaura no such definite structure of the axis is seen; but there is a
central core of pure, translucent, horny material around which is a thick cylinder of horny
material extensively impregnated with lime salts. These latter sometimes seem to take the form
of fibres, but are not nearly so distinct and white as the vermiform bodies of Plexaurella.
The axis of the latter genus is excellently well illustrated by KOLLIKER, Icones Histologicae, II,
plate XIV, fig. 8. It has also been described and figured by the present writer *.

KUKENTHAL has emended the definition of this genus in so satisfactory a manner that
we may adopt his diagnosis, which is as follows :

"Kolonien in einer Ebene verzweigt. Polypen fast stets ohne gesonderte Kelche direkt in
das dicke Ccenenchym zuriickziehbar. Polypen stets mit konvergierenden Reihen von Spindeln
bewehrt, unter denen horizontal angeordnete liegen. Die Rinde enthalt an der Oberflache dicke,
meist ovale Spindeln und Doppelspindeln, die dicht mit grossen Warzen besetzt sind, darunter
liegen kleinere, schlankere Spindeln mit regelmassigen Dornengiirteln. Achse fast stets etwas
verkalkt und wenig biegsam. Die Farbung samtlicher Arten schwankt zwischen weiss, gelblich
und hellbraun".

The type of the genus Euplexaura is E^^plexaura capensis Verrill. The other known
species are Euplexaura pinnata Wright and Studer, E. rhipidalis Studer, E. parciclados Wright
and Studer, E. anastomosans Brundin, E. curvata Kiikth., E. robusta Kiikth., E. crassa Kiikth.,
E. abietina Kiikth., E. sparsiflora Kiikth., E. erecta Kiikth. , E. albida Kiikth., E. braueri Kiikth.,
E. parva Kiikth., and the new species about to be described.

i. Euplexaura rubra new species. (Plate III, figs. 3, 3^; Plate IV, fig. 7).
Stat. 164. i°42'.5 S., 1 30° 47'. 5 E. Near New Guinea. 32 meters.

Colony incomplete, about 8 cm. long. The basal part is lacking, and it appears that
we have but the terminal portion of the main stem, or large branch, giving off two small
lateral branches on one side, and one on the other. The stem and branches are round in section,
the diameter of the former being 2.5 mm. and of the branches about 1.5 mm. The calyces are
rather prominent for this family, and are equally distributed on all sides of the branches.

The individual calyces are coninal in form, a typical one measuring about i mm. in
height and 1.4 mm. across the base. The polyps are completely retractile, the summits of the

1 NUTTING, Anatomy of the Gorgonidje, Bulletin from the Laboratories of Natural History of the State University of Iowa,
Vol. I, N» 2, 1889, p. 129, plate II, figs. 8, 9 and 10.

13

calyces closing over them, but showing an eight-rayed margin. The polyps are very small, and
it is difficult to make out their characters of spiculation on account of the intimate cohesion
of the polyp and calyx walls. It seems, however, that there are a few spindles longitudinally
arranged on the walls and tentacles.

A cross section of a branch shows the ordinary features of this family, except the structure
of the axis cylinder. This has a very decided intercalation of lime salts, the axis appearing to
be composed of fibres between which are deposited the calcareous particles in such quantities
that the axis boils violently when immersed in dilute acid. The watervascular canals seem fewer
and more widely separated than is common in the Plexauridse.

Spicules. These are all densely tuberculated spindles which are so short as to become
oval in outline, and to resemble the disk-like forms of some species of Placogorgia. There is
little variation, except in size, probably due to age.

Color. The colony is scarlet throughout, except the polyps, which still show a yellowish
color in alcohol and were probably bright yellow in life.

2. Euplexaura mollis new species. (Plate III, figs. 4, 40; Plate IV, fig. 8).
Stat. 299. io°52'.4S., 123°!'. lE. Cyrus Bay, Rotti Island. 34 meters.

Colony incomplete, flabellate and reticulate. The proximal part is missing, the specimen
being 27 cm. in height and 15 cm. broad. The main stem, or branch, forks about 3 cm. from
its proximal end, and behind this forking a thick stump of a branch is directed backward and
a little downward. One branch of the fork is cut off 6.5 cm. from its base and is connected
by heavy anastomoses with the other branch. This latter forms the main part of the colony, a
central stem proceeding nearly to the periphery where it is dissipated in the reticulation. The
ultimate twigs are slender and but little over i mm. in diameter. The calyces are distributed
on all sides of the branches, their openings being about i mm. apart.

The individual calyces are almost entirely included in the ccenenchyma, and show externally
as low, dome-shaped verrucae with small round apertures, in the dried specimen. The polyps
are small and retracted so that their infolded tentacles are almost on a level with the calyx
margin in alcoholic specimen. The margin is lined with an eight-lobed membrane caused by the
infolding of the cesophageal region of the polyp. The infolded tentacles are provided with a
pseudo-operculum much like that of the Muriceidae.

A cross section of a branch shows a moderately thick ccenenchyma with two layers of
spicules imperfectly divided by the series of watervascular canals, but not showing two distinct
kinds of spicules. The axis cylinder is full of intercalated particles of lime salts, as in the last
species, and effervesces violently in weak acid solution.

Spicules. The spicules of this species are all small, even minute, in comparison with
others of the family. The most common form is a small terete spindle with relatively large tubercles
arranged in definite whorls. There are also minute globular forms, crosses and dumb-bells.

14

The small size of the spicules renders the surface much smoother than is usual, and the
coenenchyma is sponge-like in texture.

Color. The colony is dull, rather light, brown, or dust color.

3. Euplexaura reticulata new species. (Plate III, figs. 2, ia\ Plate IV, fig. 9).

Stat. 38. 7°35.4S., H7°28'.6E. Near Paternoster Islands. 521 meters. Coral.
Stat. 117. i° o.sN., 122° 56' E. Kwandang Bay, North Celebes. 80 meters. Sand and coral.
Stat. 144. Anchorage north of Salomakiee (Damar) Island. 45 meters. Coral bottom and
Lithothamnion.

The type of this species is a mere fragment, but is plainly different from others of this
genus in the collection. Colony flabellate and reticulate, the part preserved being evidently from
near the margin of the colony and showing the anastomoses of the branches. The fragment
is 3.2 cm. long, and consists of a main branch which gives off two branchlets from one side.
The lower of these gives origin to three short stubs of branches from its outer side and sends
forth another on the opposite side, which anastomoses with the main stem. The greatest diameter
of the stem, near the base is 2 mm., and the least diameter of twigs is 1.2 mm. The calyces
seem to be more unevenly distributed than in other species, being almost contiguous in some
places and as much as 2 mm. apart in others.

The individual calyces, while not much exserted, have sharply cut margins and are
therefore more pronounced than in other species of the genus in the collection. When open
they have the form of low truncated cones, and when closed they appear as low domes. When
the polyp is fully retracted a series of eight points are seen directed towards the centre. These
points constitute a pseudo-operculum on the dorsal side of the retracted tentacles. Each opercular
flap consists of several spindles arranged en chevron on the proximal part of tentacle, and
a number of longitudinal spindles on the distal part. There is also a well marked collaret.

A section of a branch shows the same features as have been described in the preceding
species. The axis contains a number of calcareous fibres that can be separated by boiling in potash.

Spicules. The spicules are mainly small, but hardly minute, terete spindles which are
densely tuberculate, the tubercles seldom appearing to be in definite whorls. The spindles are
quite uniform in character.

Color. The fragment is light grayish brown.

Two specimens of this species were found in the collection after the above description
was written. They are much larger than the type, but neither is complete. One of them is
1 2 cm. in length, and both are plainly reticulate.

Hicksonella new genus.

Plexauridae with a thick ccenenchyma, calyces included and on all sides of the branches,
horny axis cylinder, and two very different types of spicules. One type consists of very small,
short, warty spindles, and the other of comparatively large, slender, bar-like, smooth spindles
sometimes attaining a length of 1.2 mm.

15

The type species of this genus is Hicksonella princeps Nutting.

Just as the two types of spicules furnish the generic distinction that is most prominent in
the genus Plexauroides, so two very different forms of spicules are here used as the diagnostic
features of the genus Hicksonella, which the author takes pleasure in naming after the accomplished
naturalist Professor SYDNEY J. HICKSON who has done such important work in the Alcyonaria.

i. Hicksonella princeps new species. (Plate III, figs, i, \a\ Plate IV, fig. 10).

Stat. 240. Banda Anchorage. 9 — 45 meters. Sand and coral.

Stat. 315. Anchorage East of Sailus Besar, Paternoster Islands. Up to 36 meters. Coral and
Lithothamnion.

Colony densely arborescent, forming a profusely branched clump 17 cm. in height and
15 cm. in diameter. Immediately above the base the colony divides into two large trunks, each
of which divides in an irregular manner until branches of the seventh order are sometimes
attained. The larger branches tend to divide by sending off branchlets in the same plane, thus
forming a palmate structure of the main branch. Many of the secondary branches send off a
number of closely approximated branchlets from one side. The distal portions of the colony
consists of very numerous twigs in dense tufts, the ultimate branches being very short. The
diameter of the colony at base is 1.3 cm., of the main branches .5 cm. and of the ultimate
twigs 3 mm. Some of the larger branches are somewhat flattened, but the others are round.
The calyces are thickly implanted on all sides of the stem and branches. In alcoholic specimens
they are in the form of very low verrucae, which are much less pronounced in dried specimens.

The individual calyces are included, small, round, with their margins but slightly elevated
above the level of the coenenchyma. The openings are usually quite round, but are sometimes
oval. The polyp in retraction sinks far below the surface. Inside the calyx margin is a propor-
tionately small border with eight undulations surrounding a central aperture below which the
retracted tentacles lie.

A cross section of a branch shows a thick coenenchyma, large and regularly arranged
watervascular canals, and a horny axis cylinder with an exceptionally small central core of
white noncalcareous substance. No definite layers of spicules can be made out, although there
seems to be a distinct pellicle of ccenenchyma between the watervascular canals and the axis.

Spicules. These are of two very distinct kinds. By far the more numerous are quite
small, short, densely tuberculated spindles, so short as to be oval in outline and entirely covered
with verrucas. The second type is comparatively large slender, almost smooth, bar-like or terete
spicules attaining a length of 1.3 mm. Often one half is quite smooth and glassy, while the
other is finely tuberculate, the tubercles being very small. I am unable to find any definite
anatomical relations of these large spicules. In some cases their blunt smooth points were seen
projecting outward from the calyx walls. They are sparsely and irregularly distributed.

Color. The colony is light buffy brown. The spicules are colorless.

A specimen of this species labeled from Station 315 is 95 cm. in length. In the one from
Station 240 the large spicules are sometimes arcuate, but otherwise resemble those described above.

i6

Psammogorgia Verrill.

Psammogorgia Verrill. American Journal of Science and Arts, XLV, 1 868, p. 413.
Psammogorgia Verrill. Transactions Connecticut Academy of Sciences, Vol. I, Part 2, 1867 — 71,

p. 414.

Psammogorgia Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. LIX.
Psammogorgia Nutting. Alcyonaria of the Californian Coast. Proceedings of the U. S. National

Museum, Vol. XXXV, 1909, p. 719.

The original description of this genus by VERRILL is as follows:

"Corallum dichotomous or subpinnate, with round branches. Axis horn-like. Ccenenchyma
moderately thick, the surface finely granulated with small rough spicula. Cells scattered, some-
times flat, more frequently raised in the form of rounded verrucse. Polyps with rather large
elongated, slender, warty spindles at the bases of the tentacles. Spicules of the ccenenchyma
mostly short, thick and very rough, warty spindles and rough, warty clubs of moderate size".

As the author has remarked on another occasion (loc. cit.) this genus does not conform
very well to the accepted characters of the family Plexauridse, particularly in the absence of
regularity in the disposition of the watervascular canals.

The species grouped together by professor VERRILL under the name Psammogorgia seem
to be nearer this family, however, than any other thus far described, and the present writer
prefers to follow VERRILL in regarding it as an aberrant genus of Plexauridae rather than to
raise it to family rank.

The type of the genus is Psammogorgia arbuscula Verrill. The other known species
are Psammogorgia fusca Verrill, P. fucosa Verrill, P. gracilis Verrill, P. simplex Nutting,
P. spauldingi Nutting, P. teres Verrill and P. torreyi Nutting.

i . Psammogorgia arbuscula Verrill.

Echinogorgia arbuscula Verrill. Proceedings Boston Society of Natural History, Vol. X,

1866, p. 329.

Psammogorgia arbuscula Verrill. American Journal of Science and Arts, XIV, 1868, p. 413.
Psammogorgia arbuscula Verrill. Transactions Connecticut Academy of Arts and Sciences,

Vol. I, Part 2, 1867 — 71, p. 414.
Psammogorgia arbuscula Nutting. Alcyonaria of the Californian Coast, 1909, p. 719.

Stat. 262. 5°53'.8S., I32°48'.8E. Between Kei Islands. 560 meters. Mud.

Colony subflabellate in form, attaining a height of 22 cm. About 3 cm. from its base
the main stem divides into three branches, two of which are subequal and form the main part
of the colony. The third is smaller and bears two short, distant branches on the same side.
The other two are joined by the anastomoses of two branchlets, one from each. One of them
gives off two other branches from one side, and the other but one. The terminal branches are
all long and slender, in one case attaining a length of about 19 cm. They are of about the
same diameter (3 mm.) throughout. The calyces are unevenly distributed on all sides of the
branches, although there are long bare species on the back of some of the branches. Otherwise
they average about 2.5 mm. apart.

The individual calyces are very low verrucse, scarcely elevated above the general level
of the ccenenchyma and about 2 mm. in diameter. The verrucae are surmounted by an eight-
lobed margin. Their walls are filled with spindles which appear to be closely packed without
definite arrangement. The polyps are completely retractile, but are often seen, in alcoholic
specimens, with the tentacles resting above the margin and forming an acorn-shaped mass.

The body walls have eight longitudinal rib-like bands of parallel spindles which continue
over the dorsal surface of the tentacles.

The ccenenchyma is thick, and a cross section of a branch shows that the watervascular
canals are not regular in arrangement. The axis is entirely horny.

S p i c u 1 e s. Slender acute spindles predominate, often with a narrow but well defined
bare zone in the centre. A few clubs are seen, also short, bar-like forms quite distinct from
the numerous slender spindles.

Color. The colony is bright coral red, as are the spicules.

General distribution. Panama, and the Pacific Coast of Nicaragua, (VERRILL). The
Californian Coast, (NUTTING).

SIBOGA-EXPED1TIE XIII <5'.

DISTRIBUTION OF THE PLEXAURID^E COLLECTED BY THE SIBOGA EXPEDITION.

List of Stations

at which Plexauridae were collected by the Siboga Expedition, and a
List of Species collected at each Station.

STATION 19. 8° 44'.$ S., u6°2'.5E. West Coast of Lombok. 18 — 27 meters. River mud, coral, coral
sand. Plexaura flava.

STATION 38. 7°35'.4S., U7°28'.6E. Near Paternoster Islands. 521 meters. Coral. Euplexaura reticulata.

STATION 43. Anchorage off Pulu Sarassa, Postillion Islands. Up to 36 meters. Coral. Plexaura
platystoma.

STATION 58. Anchorage off Seba, Savu. .Up to 27 meters. Sand. Plexaura aggregata.

STATION 60. Haingsisi, Samau Island, near Timor. 23 meters. Lithothamnion in 3 meters and less.
Reef. Plexaura flava.

STATION 65". 7°o'S., I20°34'.5E. Depth changing rapidly from 400 — 120 meters. Coral bottom.
Plexaura aggregata.

STATION 117. i°o'.5 N., 122° 56' E. Kwandang Bay entrance, North Celebes. 80 meters. Sand and
coral. Euplexaura reticulata.

STATION 142. Anchorage off Laiwui, coast of Obi Major. 23 meters. Mud. Plexaura flava.

STATION 144. Anchorage North of Salomakie (Damar) Island. 45 meters. Coral bottom and Litho-
thamnion. Euplexaura reticulata.

STATION 162. Between Loslos and Broken Islands, West Coast of Salawatti. 18 meters. Coarse and
fine sand, with clay and shells. Plexaura attenuata.

STATION 164. i°42'.s S., I30°47'.5 E. Near New Guinea. 32 meters. Sand, small stones and shells.
Plexaura attenuata, Euplexaura rubra.

STATION 213. Saleyer Anchorage and surroundings. Up to 36 meters. Mud with sand. Plexaura
aggregata.

STATION 240. Banda Anchorage. 9 — 45 meters. Black sand, coral, Lithothamnion bank in 18 — 36
meters. Hicksonella princeps.

STATION 258. Tual Anchorage, Kei Islands. 22 meters. Lithothamnion, sand and coral. Plexaura
aggregata, Plexauroides lenzii.

STATION 262. S°53'.8S., I32°48'.8E. Arafura Sea. 560 meters. Solid bluish gray mud. Upper layer
more liquid and brown mud. Psammogorgia arbuscula.

19

STATION 273. Anchorage off Pulu Jedan, East coast of Aru Islands, (Pearl Banks). 13 meters. Sand
and shells. Plexaura flava, P. recta, Plexauroides prcelonga, P. lenzii.

STATION 285. 8°39'.iS., I27°4'.4E. Timor Sea. 34 meters. On the limit between mud and coral.
Lithothamnion. Plexaura attenuata, Euplexaura rubra.

STATION 299. io°52'.4S., i23°i'.iE. Cyrus Bay, Rotti Island. 34 meters. Mud, coral and Litho-
thamnion. Plexaura recta, Euplexaura mollis.

STATION 315. Anchorage East of Sailus Besar, Paternoster Islands. Up to 36 meters. Coral and
Lithothamnion. Plexaura aggregata, Hicksonella princeps.

Specimens of Plexaura recta from Pulu Missa near Flores. J. H. DE SlSO don.
Plexaura pinnata. Locality unknown, as the label is missing.

The list shows that Plexauridae were collected at 19 of the stations occupied by the
Siboga Expedition. As there appear to be somewhat more than 200 successful hauls from the
bottom it follows that members of this family were secured by about io°/0 of these hauls,
showing that the family is meagerly represented in this region in comparison with the Muriceidae.
No station yielded more than four species, while one Station (310) yielded no less than 17
species of the Muriceidee.

But two species of Plexauridae were secured at depths of over 500 meters. One of these
was Enplexaura reticulata, from a depth of 521 meters-, another was P sammogorgia arbuscula,
from a depth of 560 meters.

The family thus appears to be largely restricted to moderately shallow water, which may
in part account for the wide difference between the Atlantic and Pacific plexaurid faunae.

The genus Plexauroides is the only one in which species previously recorded are found.
Plexauroides prcelonga has been reported from Australian waters and Ceylon, and P. lenzii is
known to occur near Singapore. Neither of these localities is far from the East Indian region.

So far as the Siboga material bears testimony concerning the distribution of the Plexauridae,
that testimony is negative regarding the occurrence of species in both the Atlantic and Pacific.
It is also a notable fact that the genera Eunicea and Plexarirella, both furnishing numerous
species from the West Indies, are not at all represented in the Siboga collections.

As indicated above, the restricted bathymetric range of most of the known species of
this family may account for the correspondingly restricted geographic range. Caution must be
exercised, however, in drawing general conclusions from the limited information at our disposal.

Literature cited
in the Report on the Plexauridse of the Siboga collection.

BRUNDIN, J. A. Z. Alcyonarien aus der Sammlung des Zoologischen Museums in Upsala. Bihang til k.
Svenska Vet.-Akad. Handlingar, Band 22, Heft IV, N° 3. Stockholm, 1896.

DUCHASSAING et MlCHELOTTI. Memoire sur les Coralliaires des Antilles, Turin, 1860.

GRAY, J. E. On the Arrangement of Zoophytes with Pinnated Tentacles. Annals and Magazine of Natural
History, 3th. Series, Vol. 5, London, 1859.

KOLLIKER, A. Icones histiologicae, oder Atlas der vergleichenden Gewebelehre; 2te Abtheilung, der feinere
Bau der hoheren Thiere; istes Heft, die Bindesubstanz der Ccelenteraten, Leipzig, 1865.

KUKENTHAL, W. Japanische Gorgoniden, II. Teil; Die Familien der Plexauriden, Chrysogorgiiden und
Melitodiden. Munchen, 1909.

LAMOUROUX, J. F. V. Histoire des Polypiers coralligenes flexibles, Paris, 1816.

Exposition Methodique des Genres de 1'ordre des Polypiers, Paris, 1821.

MlLNE EDWARDS et HAIME. Histoire naturelle des Coralliaires, Vol. I, 1857.

NUTTING, C. C. Alcyonaria of the Californian Coast. Proceedings of the U. S. National Museum, Vol. XXXV,
Washington, 1909.

RIDLEY, S. O. The Coral Fauna of Ceylon, with Descriptions of New Species. Annals and Magazine of
Natural History, 5th. Series, Vol. II, London, 1883.

- Report on the Zoological Collections of H. M. S. "Alert", London, 1884.

STUDER, TH. Alcyonarien aus der Sammlung des Naturhistorischen Museums in Liibeck. Separatabdruck
aus den Mitteilungen der Geographischen Gesellschaft und des Naturhistorischen Museums in
Lubeck, II. Ser., Heft 7 und 8, Liibeck, 1894.

VERRILL, A. E. Review of the Corals and Polyps of the West Coast of America. Transactions of 'the
Connecticut Academy of Arts and Sciences, Vol. I, Part 2, New Haven, 1867 — 71.

Proceedings of the Essex Institute, VI, 1869.

— . — Critical remarks on the Alcyonoid Polyps in the Museum of Yale College, with descriptions of the
New Genera. The American Journal of Science and Arts, Vol. XLV, New Haven, 1868.

WRIGHT, E. P. and STUDER, TH. Report on the Alcyonaria collected by H. M. S. Challenger during the
years 1873—76. The Voyage of H. M. S. Challenger, Zoology, Vol. XXXI, 1889.

EXPLANATION OF PLATES

The photographs were made from nature by the author.
The spicules were drawn under the camera lucida by Mr. DAYTON STONER.

PLATE I.

Fig. I. Plexaura aggregata n. sp. Natural size, i a, part of branch X 5-
Fig. 2. Plexaura attenuata n. sp. Natural size. 2 a, part of branch X $•
Fig. 3. Plexaura pinnata n. sp. Natural size. 3 a, part of branch X 5-

SIBOOA-EXPEDITIE XIII ^ C. C. NUTTING. PLEXAURIDAE.

" * V b» B« „%•«*» * t- ***

b* C to ,v«- * * * * v ' -»

>\ : :>' t .-•; '-,.' ": : ..: ^.\ -..'

PLATE II.

Fig. I. Plexaura flava n. sp. Natural size. i a, part of branch X 5-

Fig. 2. Plexaura platystoma n. sp. Natural size. 2 a, part of branch X 5-
Fig. 3. Plexaura recta n. sp. Natural size. ?>a, part of branch >c 5.

SIBOOA-EXPEDITIE Xlll* C. C. NUTTING. PLEXAUR1DAE.

PLATE III.

Fig. i. Hicksonella princeps n. sp. Natural size. \a, part of branch X 5.

Fig. 2. Euplexaura reticulata n. sp. Natural size. 2 a, part of branch X 5.

Fig. 3. Euplexaura rubra n. sp. Natural size. 3^, part of branch x 5.

Fig. 4. Euplexaura mollis n. sp. Natural size. 4 a, part of branch X 5.

SIBOGA-EXPEDIT1E XIII «? C. C NUTTING. PLEXAUR1DAE.

Ill

PLATE IV.

Fig. I. Plexaura aggregate/, n. sp. Group of 5 spicules, a, b, c, d, e. X 112.

Fig. 2. Plexaura attenuata n. sp. Group of 3 spicules, a, b and c. X 112.

Fig. 3. Plexaura recta n. sp. Group of 3 spicules, a, b and c. x 112.

Fig. 4. Plexaura platystoma n. sp. Group of 3 spicules, a, b and c. X 112.

Fig. 5. Plexaura pinnata n. sp. Group of 4 spicules, tf, £, £, d. X 112.

Fig. 6. Plexaura flava n. sp. Group of 4 spicules, «, £, c, d. X 112.

Fig. 7. Euplexaura rubra n. sp. Group of 3 spicules, «, £ and c. ; 112.

Fig. 8. Euplexaura mollis n. sp. Group of 4 spicules, «, £, c and */. X 112.

Fig. 9. Euplexaura reticulata n. sp. Group of 4 spicules, a, b, c, d. ) ; 1 1 2.

Fig. 10. Hicksonella princeps n. sp. Group of 6 spicules; «, £, c, d, e and £•. X "2.

a and * represent one of the two general types, and the rest the other, or tuberculate type.

SIBOGA-EXPEDITIE XIII/>'. C. C. NUTTING. PLEXAURIDAE.

IV

a

8

10

THE GORGONACEA OF THE SIBOGA EXPEDITION

V. THE ISID/E

Siboga-Expeditie

XIII b2

THE

GORGONACEA OF THE SIBOGA EXPEDITION

V. THE ISIIXE

BY

C. C NUTTING

Professor of Zoology, State University of Iowa

With 6 plates

(Aided by a grant from the ELIZABETH THOMPSON SCIENCE FUND)-

. J. BRILL

PUBLISHERS AND PRINTERS

LEYDEN

The earlier writers usually included the species now allotted to the family Melitodidce
in the old genus Isis, thus involving the classification of the I sides in considerable confusion.

KOLLIKER (1865) with his usual clear insight, separated the " Melithceacea" and Isidinae
as distinct subfamilies of his Gorgonidae, using the characters of the axis cylinder.

GRAY (1870) established the families Isidce, Mopseadce, Acanelladce and Keratoisidce, all
of which are now included in the single family Isidce.

STUDER (1887) gave a careful diagnosis of the family Isidce, and divided it into the
subfamilies Ceratoisidints, Primnoisidince and Isidince. Later (1889), in the Challenger Report,
WRIGHT and STUDER defined the family as follows :

"Colony consisting of a simple or branched axis. The axis consists of calcareous and
horny (internodal and nodal) regions; the branches when present arising from either the nodal
or internodal regions, sometimes anastomosing; the axis solid or hollow, smooth, fluted or
echinulate. The base of the axis calcareous and attached".

To avoid any confusion of certain species of the Melitodidce with the Isidce, this definition,
although substantially correct, may be modified for the purposes of the present work as follows :

Gorgonacea with an axis composed of alternating calcareous and horny segments, the
former being amorphous and not composed of a mass of agglutinated spicules, and the latter
entirely horny without the admixture of definite calcareous spicules.

Several authors have proposed breaking up this family into subfamilies; but with the
increase of our knowledge of the group this becomes increasingly difficult. GRAY (1870) went
to the extreme of placing the species now included in the Isidce into four distinct families,
viz. Mopseidce, Acanelladce, Keratoisidcz and Isidce.

VERRILL (1883) separates all but the genus Isis into a family Ceratoisidce, which therefore
includes GRAY'S Keratoisidee, Acanelladce and Mopseidce. STUDER (1887) divides the family into
the subfamilies Ceratoisidints^ Primnoisidince (including Mopseidce) and Isidince. In their Report
on the Alcyonaria of the Challenger Expedition (1889) WRIGHT and STUDER substitute the name
Mopseince for STUDER'S subfamily Primnoisidinee, and base the subfamilies of the Isidce on the
characters of the spicules.

The trouble with this arrangement is the intergrading features between the Mopseince
and Ceratoisidince . In his discussion of the genera Ceratoisis and Primnoisis, which belong to
the Ceratoisidince and Mopseince respectively, HICKSON (1907) holds that these genera are not
distinct, and proposes including both in the genus Ceratoisis. He says:

"The study of many specimens belonging to this family has convinced me that this
subdivision is unnecessary and inconvenient. The many variations of spicule characters that are
found in the species of a single genus render these structures unsatisfactory for the purpose of
wide systematic differentiation. If we take a single species from each of two of the subfamilies
and compare them, the differences observed in the character and arrangement of the spicules
may seem to be of a higher rank than the usual differences between genera; while, on the
other hand the examination of a large number of species of the same two genera will reveal
so many of the intermediate conditions as to render the separation of the genera, on spicule
characters alone, impossible. This kind of difficulty is particularly well seen in the case of the

genera Ceratoisis and Primnoisis which were placed by Professors WRIGHT and STUDER in the
subfamilies Ceratoisina and Mopseintz" J.

This view is supported by an argument which should be read carefully by those interested
in the discussion, but is too long to be quoted here. The present writer believes, however, that
the family Isida was ably handled by WRIGHT and STUDER, and finds himself unable to agree
with the eminent authority quoted above.

The intergradation of spicules is very wide spread among the Alcyonaria, and yet there
are often certain dominant forms of spicules that are quite characteristic of definite groups, and
therefore available for systematic purposes and form good zoological characters 2.

The spicules of the Ceratoisiditue are of two general types. Ist. True spindles, either with
verrucse or comparatively plain or needle-like. These may be slightly forked or bifid at one end,
but this does not alter their essential character. 2nd. Flattened spindles which are often bar-like with
rounded ends, or with ends enlarged forming a lengthened hour-glass, or biscuit-form. These may
approach the form of scales rather than of spindles. Even in such cases their edges are smooth,
not ctenate nor with branched processes, although they may be beset with minute thorny points.

These spicules seem to me to be quite distinct from those found in the genus Primnoisis,
which has the characteristic scales of the primnoid gorgonians, with branched processes or finely
ctenate edges, often imbricating on the calyx walls.

This difference is strikingly shown in Plate IX of the Challenger Alcyonaria, where
figures i to 5 represent spicules of Acanella, one of the Ceratoisina ; and figures 6 to 1 1 all
representing species of Mopseince. Or compare Plate Va, figures i to 9, all of Ceratoisidince ,
with Plate IX, figures 6 to 1 1 , of spicules of Mopseintz. It seems to the writer that it would
be difficult to show greater contrasts than are found not only in these figures, but also in slides
of spicules from specimens of Ceratoisiditue on the one hand, and Mopseiruz on the other.

It is true that HICKSON'S Ceratoisis spicata (loc. cit., p. 7) at first seems to form an
intergrading link between these subfamilies; but it appears to me that this is more seeming
than real. This writer describes the spicules, in part, as follows:

"The calyces are covered with an armature of overlapping scales, some of which are
triradiate, others irregular in form".

According to this description and the figures none of these spicules show any real
approach to the form of the characteristic spicules of Ceratoisis. Moreover the writer says:

"In the character of the axis it is closely related to Primnoisis".

The calyx spicules resemble closely some of the thorny scales of the primnoid genus
Caligorgia, for instance.

The present writer, therefore, would place HICKSON'S Ceratoisis spicata in the genus Prim-
noisis, calling it Primnoisis spicata (Hickson), and retain the subfamilies adopted by WRIGHT
and STUDER, modifying, however, their subfamily diagnoses as follows:

I s i d i n ae : - - Coenenchyma thick ; calyces inserted ; spicules densely tuberculate spindles, oval
radiate forms, heads, double heads, etc.

1 National Antarctic Expedition. Natural History, Vol. VII, Coelentera Alcyonaria, 1907, p. 4.

* See the discussion of this point by the writer in his Report on the Muriceicbe of the Siboga Expedition, 1910, p. 5.

Ceratoisidinae: - - Ccenenchyma thin; calyces inserted, long, usually cylindrical; characteristic
spicules in the form of spindles, or flattened bar-like of hour-glass forms which are smooth
or with minute spiny points, never with true verrucae; colony not profusely branched.

M o p s e i n se : - - Ccenenchyma thin ; calyces usually exserted ; often club-shaped ; characteristic
spicules flattened scales, often profusely branched or ctenate on their edges.

Systematic relationships of the family ISID^E.

The closest affinities of this family seem to be with the Primnoida, a fact which has been
commented upon by several writers, the calcareous internodes of the former being apparently
very similar in composition and structure to the calcareous axis of the latter. The ccenenchyma
is usually thin in both families.

In the polyps and calyces of certain Isida we have a very striking similarity to those of
the Primnoidcz, and this is particularly true in the case of the new genus Peltastisis described
in this Report. Here the form of the calyx, the form and arrangement of the spicules, the
reduction in the number of adaxial scales, and the essential character of the operculum (a scale
to each segment) are all typically primnoid in their nature. Were it not for the jointed axis
of Peltastisis I doubt if any one would hesitate in putting it in the family Primnoidcz.

Indeed the character of the axis alone can be successfully used in separating these two
closely related families.

On the other hand, the Isida show many characters in common with the sclerogorgian
family Melitodidee. These families can not be separated on the characters of the spicules, for
those of the Isinfs show the same general characters as are common in the Melitodida. The
nodes and internodes are superficially much alike in the two families, and the calcareous inter-
nodes are in some cases, particularly in the older parts of the colony, apparently almost as
completely calcareous and amorphous in the Melitodida as in the Isidte. It was formerly held
that both nodes and internodes of Melitodidtz were penetrated by solenia ; but this is now
denied a. Here, again, the characters of the axis seem to afford the only reliable means of
family differentiation, the horny nodes of the Melitodida being always more or less mixed with
calcareous spicules, while those of the Isida are purely horny, without spicules.

The writer desires to emphasize an opinion elsewhere expressed 2 as follows :

"Our knowledge of the lower invertebrates is still far too fragmentary to permit us to
indulge the hope that our work as systematists will really serve to express in final form the
actual relationships of any large group of animals.

While a natural classification is a 'consummation devoutly to be desired' we are not yet,
it seems to me, in sight of it".

The main service of classification, in our present state of knowledge, is to facilitate
identification of groups, the final result being facility in determination of species.

1 BOURNE. A Treatise on Zoology, Part II, Chapter VI, p. 28, 1900.

2 The Gorgonacea of the Siboga Expedition, III, The Muriceida;, 1900, p. 9.

Key to the genera of the ISID.E.

(Generic names enclosed in brackets indicate that such genera are not represented in the Siboga collection).

Isidinse :

Spicules densely tuberculate spindles, calyces included Isis

Ceratoisidinae:

Calyces not uniserial, and with a crown of points formed by large, needle-
like spicules.

Colony simple ; or, if branched, with branches springing from the calcareous
internodes.
Calyx with an external layer of flattened, bar-like spicules with

rounded ends (Lepidisis)

Calyx with spindles or needles only Ceratoisis

Colony branched, branches arising from horny nodes Acanella

Calyces sometimes uniserial, without a crown of points.

Colony unbranched ; calyces uniserial (Bathygorgia)

Colony branched, branches from calcareous internodes.

Coenenchyma with spicules (Callisis)

Coenenchyma without spicules (Sclerisis)

Branches from horny nodes (Isidella).

Mo psei nse :

Calcareous internodes with serrated ridges (Acanthoisis)

Calcareous internodes without serrated ridges.

Calyces uniserial, with true opercula Peltastisis

Calyces not uniserial, no true opercula.

Spicules of calyx ctenate scales, or with thorny points .... Mopsea
Spicules of calyx spindles, with true verrucae (Chelidonisis) l

Synoptic view 9f the genera and species of ISID.E secured by the Siboga.

* The asterisk (*) denotes a new species.

Is idinae.
Isis.

/. kippuris, L *reticulata.

M o p s e i n ae.

Mopsea.
M. *flava, M. *alba.

Peltastisis.
P. *uniserialis, P. *cornuta.

Ceratoisidinas.
Ceratoisis.

C.paucispinosa, C. philippinensis, C.*wrighti,
C. s.'r

Acanella.

A. *sibog&, A. *weberi, A. sp.1

1 This form shows affinities with the fsidin<z in the form of its spicules, which are much like those of Isis hippuris; but has
a rather thin crenenchyma and evident calyces, characters which allie it with the Mopseina. See STUDER, Alcyonaires provenant des
Campagnes de 1'Hirondelle, 1901. p. 39 and Plate Iv, fig. 9.

It will be seen from the table that of the thirteen species collected, three were
previously known, two are represented by material insufficient for identification, and eight are
described as new.

Systematic description of genera and species of ISID/E
of the Siboga collection.

Isidinae. (See the definition of this subfamily on p. 3).

Isis Linnaeus.

Isis (in part) Linnaeus. Hortus Cliffortianus, 1737, p. 479.
Isis (in part) Linnaeus. Systema Naturae, 1758, p. 1287.
Isis (in part) Pallas. Elenchus Zoophytorum, 1766, p. 220.
Isis (in part) Ellis and Solander. Natural History of Zoophytes, 1786, p. 104.
Isis (in part) Esper. Die Pflanzenthiere, Vol. I, 1791, p. 27.
Isis Lamouroux. Hist. Polypes coral, flexibles, 1816, p. 4687.
Isis Lamouroux. Exposition Methodique, 1821, p. 39.
Isis Lamarck. Hist. Nat. Anim. sans Vert., 1836, p. 473.

Isis (in part) Milne Edwards et Haime. Hist. nat. des Coralliaires, Vol. I, 1857, p. 193.
Isis Gray. Proceedings Zool. Society of London, 1857.
Isis Kolliker. Icones Histiologies, II, 1865, p. 140.

Isis Dana. Synopsis Report on Zoophytes of the Wilkes Expedition, 1859, p. 144.
Isis Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 46.
Isis Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. XLV.
Isis Thomson and Simpson. Alcyonarians of the Indian Ocean, II, Alcyonarians of the Deep
Sea, 1909, p. 1 80.

The original genus Isis included not only all of the present Isidce, but also certain of
the Melitodidee, and resulted in the same confusion as in the synonymy of the family Isida.
LAMOUROUX (1816) appears to have used the name in almost its modern signification; but
subsequent writers included many other forms, until GRAY (1857) restricted the genus. KOLLIKER
(1865) was the first to carefully describe the spicules and use them in his generic definition,
and subsequent writers have used the name as understood in the present work.

This being the only genus of the subfamily Isidina, the definition already given for the
Isidincz will serve for the genus.

The type species of this genus is Isis hippiiris Linn., and the only other known species
in the Isis reticulata described beyond.

i. Isis hipp^lr^s Linnaeus. (Plate I, figs, i, i a, \b\ Plate V, fig. i).

Isis hippuris (in part) Linnaeus. Systema Naturae, i2th Edition, p. 1287.

Isis hippuris (in part) Pallas. Elenchus Zoophytorum, 1766, p. 233.

Isis hippuris Ellis and Solander. Natural History of Zoophytes, 1786, p. 105.

Isis hippuris (in part) Esper. Die Pflanzenthiere, Vol. I, 1791, p. 279.

Isis hippuris Lamouroux. Histoire Polypiers coralligenes flexibles, 1816, p. 476.

Isis hippuris Lamouroux. Exposition Methodique, 1821, p. 39.

Isis hippuris Lamarck. Histoire Naturelle des animaux sans vertebres, 1836, p. 475.

Isis liippuris Milne Edwards et Haime. Histoire nat. des Coralliaires, Vol. I, 1857, p. 194.
Isis kippuris Steenstrup. Om slaegter og de under Isis hippuris Linn, sammenblendede Arten,

1848, p. I.

Isis hippuris Kolliker. Icones Histiologicse, II, 1865, p. 140.
Isis hippuris Thomson and Simpson. Alcyonarians of the Indian Ocean, II, 1909, p. 180.

Stat. 71. Makassar and surroundings. Up to 32 meters. Mud, sand with mud, coral.

Stat. 133. Anchorage off Lirung, Salibabu-Island. Up to 36 meters. Mud and hard sand.

Stat. 142. Anchorage off Laiwui, coast of Obi Major. 23 meters. Very fine hard sand, mud.

Stat. 144. Anchorage North of Salomakiee (Damar) Island. 45 meters. Coral bottom and

Lithothamnion.

Stat. 149. Fau Anchorage and lagune. West coast of Gebe Island. 31 meters. Coral.

Stat. 258. Tual Anchorage, Kei Islands. 22 meters. Lithothamnion, sand and coral.

Stat. 279. Rumah-Kuda Bay, Roma Island. 36 meters. Mud and sand.

Stat. 301. io°38'S., I23°25'.2E. 22 meters. Mud, coral and Lithothamnion.

Stat. 303. Haingsisi, Samau Island. Up to 36 Meters. Lithothamnion.

Colony (incomplete) 28 cm. in height, growing in a densely aggregated mass of branches
which are individually composed largely of tufts of branchlets. Main stem, or branch, round in
section, about i cm. in diameter. The main branches are lateral in position, often flattened
prpximally in the plane of ramification. The secondary branches are usually lateral in position
and often bear terminal twigs which are swollen, round and pointed at the ends.

The ccenenchyma is very thick and fleshy, and does not show any external evidence, in
alcoholic specimens, of the jointed axis. The calyces are entirely included, and are distributed
on all sides of the stem and branches, much as in the P lexaurida . Their openings are almost
completely concealed, appearing only as minute depressions in the general surface of the branches,
the openings being no larger than pin holes. In color and appearance the colony greatly
resembles a profusely branching Millepora, the fine pits closely resembling the gastropores of
the latter. The polyps are very minute and entirely retracted, so that little of their structure
could be ascertained without sectioning. The surface is quite smooth, the spicules not being
evident on account of their small size.

A cross section of a branch reveals a very thick ccenenchyma in which the relatively
small calyces are embedded. The ccenenchyma is filled with a dense mass of small spicules.
Around the axis is a series of very large watervascular canals, their number being very often
eight in the smaller branches. The axis is composed of alternate horny and calcareous joints,
the latter being the longer and larger, being i cm. in diameter in the specimen described. Their
length is about i cm., and this does not vary greatly even in the distal branchlets.

These calcareous internodes are strongly fluted longitudinally, the grooves being the
impressions of the primary watervascular canals. The horny nodes are much shorter, not exceeding
3 mm. in the specimen described, and having a diameter of 5 mm. where the adjacent calcareous
joints are i cm. long. The branches usually arise from the calcareous nodes, but bifurcations
usually take place upon the distal ends of horny joints.

A cross section of a calcareous internode about 5 mm. in diameter shows a central
amorphous area surrounded by a darker line, like a line of growth, enclosing a figure with
eight concave sides, beyond this, at varying distances, are other similar lines enclosing figures
of more than eight concave sides, the outer lines being closer together than the others. While

8

the calcareous substance of the axis shows a crystalline appearance, there are no indications
that it is composed of fused spicules. The concave sides of the cross section correspond, of
course to the grooves for the primary canals, and the number eight seems significant as being
the original number of these canals, corresponding to the eight intermesenterial chambers of
the primary polyp of the colony or branch. The central area is marked by an axial nuclear
spot, from which many lines radiate toward the periphery of the area

The horny nodes are hour-glass shaped, in longitudinal section, their ends being concave
for the insertion of the convex ends of the calcareous internodes. At the line of juncture there
is an irregular mass of horny projections alternating with the calcareous material, giving an
anchorage that binds the node and internode together. There are no calcareous spicules in
the nodes.

Spicules. These are all quite small, and of several forms. All are modifications of
short tuberculate spindles. Double spindles, dumb-bell shapes, double heads, crosses and densely
tuberculate oval forms predominate. All are closely tuberculate, and most of them show a
median, constricted smooth girdle. There are a few double crosses and spindles with regular
whorls of tubercles.

Color. The specimens in alcohol are a tan brown, the dried specimens being darker
brown. Axis white, with the horny nodes dark horn brown.

General distribution. This species has been reported from the Indian Ocean, and
parts of the tropical eastern Pacific. The form reported from the Mediterranean is in all
probability not this species or genus.

This species is quite variable, and specimens differ much according to size and age, the
larger stems and branches having the "moniliform" appearance that has led some authors to
describe several species on the basis of what appears to be merely varietal differences.

Many of the dried specimens were originally much larger than the one described ; but,
owing to their excessive brittleness, they are so badly broken up that the original dimensions
can not easily be ascertained.

2. Isis reticulata new species. (Plate I, figs. 2, 2#; Plate V, fig. 2).

Stat. 273. Anchorage off Pulu Jedan, East coast of Aru Islands. 13 meters. Sand and shells.

Colony much broken up, the specimens consisting of large and small fragments all from
the same station. General habit loose and straggling, much less inclined to the formation of
dense tufts than in Isis h^pp^lris. The thickest stem found is 7 mm. in diameter, and the horny
internodes are almost entirely obliterated, being indicated by darker color alone. The longitudinal
grooves are continuous over the calcareous and horny joints, the latter being but slightly con-
stricted. The first calcareous internode is i cm. long, the next 1.6 cm., the next 2 cm., and
bearing a branch a little above its middle. Further up the horny nodes are sharply constricted,
clearly defined and about 2 mm. in length. The branching is straggling, and there are occasional
anastomoses of branches. There is a distinct tendency toward a flabellate form of colony. The

distal branches are much longer and more slender than in Isis hippuris, sometimes attaining
a length of as much as 17 cm., while their diameter is only 2 mm. The terminal twigs are
not swollen at the ends, in marked contrast to 1. hippuris.

The calyces are entirely included, very small, and sparsely and irregularly distributed on
all sides of the branches. The polyps are partially expanded in the specimen described, making
it difficult to ascertain the form and size of the apertures. Where the polyps are fully retracted
the surface of the branch is perfectly smooth, with little or no indication of the calyx openings.
The polyps themselves are small and appear to be devoid of spicules, both in body walls
and tentacles. Consequently they are very soft and flabby, and are usually prone against the
coenenchyma of the branches when expanded in alcoholic specimens.

Spicules. The spicules are minute, smaller than in Isis hippuris, and distinctly different
in shape, being much more delicate spindles with tubercles often symmetrically disposed around
the main axis. Irregular branched forms are common. Crosses are more rarely seen, and also
a few curved spindles with large tubercles. A comparison of a slide of spindles from /. reticulata
with one from /. hippuris shows a very distinct difference in the assemblage of forms of the
two species.

Color. The entire colony, in alcohol, is reddish brown. The polyps are more distinctly
reddish than the coenenchyma, sometimes approaching a maroon.

The species seems quite distinct from Isis hippuris, from which it differs in manner of
branching, reticulation, slenderness of twigs, color, and most of all in the character of the spicules.

Ceratoisidinae. (For definition of subfamily see p. 4).

Ceratoisis Wright.

Keratoisis E. Percival Wright. Annals and Magazine of Natural History, 4* Series, Vol. II,

1868, p. 427. (Name only).

Keratoisis E. Percival Wright. Annals and Magazine of Natural History, 4th Series, Vol. Ill,

1869, p. 23.

. Keratoisis Gray. Catalogue of Lithophytes in the British Museum, 1870, p. 18.

Keratoisis Studer. Monatsbericht der Konigl. Akademie der Wissenschaften zu Berlin, 1878^.662.
Ceratoisis Verrill. Bulletin Museum of Comparative Zoology, Vol. XI, 1883, p. 10.
Ceratoists Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 26.
Ceratoisis (in part) Hickson. National Antarctic Expedition. Natural History, Vol. Ill, Coelentera

Alcyonaria, 1907, p. 5.
Ceratoisis Nutting. Hawaiian Alcyonaria, 1908, p. 570.

The original description of this genus is as follows :

"Coral branched, irregularly furcate; axis jointed, composed of horny and calcareous
portions; the latter are hollow, smooth, varying considerably in length, and maintaining their
form after maceration in caustic alkalies ; the branches are given off from the calcareous portions.
The so-called "barky layer" (coenenchyma) is well developed, and contains a large number of
calcareous spicules. The polyps are irregularly and somewhat densely grouped all around the

SIBOGA-EXPEDITIE XIII h*.

10

axis ; they are of large size and are completely covered with spicules, which are closely packed
side by side. A variable number (nine to eleven) of long fusiform spicules
surround the apical portion of the polype, forming a calyx. Tentacles eight,
pinnately lobed".

VERRILL includes in this genus all of his family " Ceratoisida" that have the ccenenchyma
and calyces filled with large fusiform spicules and the calyx armed with a crown of spines.
This definition is somewhat misleading, as the small spicules often found in the calyces and
ccenenchyma are often not fusiform but lenticular or "biscuit-shaped", sometimes fiddle-shaped,
or even oval.

STUDER (1887) practically adopts the original definition of WRIGHT. WRIGHT and STUDER
(1889) point out the difficulty of distinguishing between the unbranched species of Lepidisis
(Verrill) and the unbranched forms of Ceratoisis. This point seems to the present writer to be
well taken, and should result in the combination of the two genera, as suggested by WRIGHT
and STUDER.

Their definition of the genus Ceratoisis is as follows :

"The colony is simple or branched, in the latter case with the branches arising from
the calcareous internodes. These latter are long and hollow when young. The ccenenchyma
contains long smooth spindles or needle-like spicules. In the polyps, which are nonretractile,
there are large needles. One row of these spicules is so disposed that one lies at the base
between each pair of tentacles and projects beyond them, the result being a circlet of diverging
spines around the oral region".

This definition is dificient in the fact that it makes no mention of the oblong, compara-
tively smooth, oval, or lenticular spicules found both in Ceratoisis grayi (the type species) and
in the species of VERRILL'S genus Lepidisis. This point, however, is covered in their more
elaborate definition of the genus on page 26 of the Challenger Report, Alcyonaria, 1889.

The genus Ceratoisis, as used in the present work, may be defined as follows :

Ceratoisidina whose calyces are armed with a crown of needle-like spicules. The axis is
simple or sparingly branched, the calcareous internodes hollow, at least in the younger portions
of the colony. Ccenenchyma, and often the calyces, with oblong, lenticular, fiddle-shaped, or
oval scales with comparatively smooth surfaces.

The type species of this genus is Ceratoisis grayi Wright. Other species are C. (Lepidisis)
caryophyllia (Verrill), C. flabellum Nutting, C. gracilis Thomson and Henderson, C. grandiflora
Studer, C. grandis Nutting, C. (Lepidisis) inermis (Studer). C. japonica Studer, C. (Lepidisis)
longiflora (Verrill), C. nuda Wright and Studer, C. ornata Verrill, C. palmce Wright and Studer,
C. philippinensis Wright and Studer, C. ramosa Hickson, C. siemenensis Studer, C. (Lepidisis)
vitrea (Verrill), and the new species described in the present work.

i. Ceratoisis paucispinosa Wright and Studer.

Ceratoisis paucispinosa Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 28.
Stat. 52. 9°3'.4S., 1 19° 56'. 7 E. 959 meters. Globigerina ooze.

II

Specimens consisting of two fragments, probably from the same stem. The largest of
these includes the base of the colony consisting of large thin, plate-like calcareous lobes, but
one of which is complete. This is 2.6 cm. long. The fragment has an entire length of 26 cm.
The first internode above the base is the shortest, being 3.5 mm. long. The next is 1.7 cm.,
the next 3.1 cm. the next 4.3 cm., the next 4.5 cm., and the remaining three gradually diminish
in size. The diameter at base is 3 mm., at distal end 1.5 mm. The longest horny node is the
third, which is 3 mm. long, and their length diminishes to the distal node which is 1.4 mm.
The surfaces of the internodes are marked by shallow longitudinal furrows. The other fragment
is nearly 18 cm. long, much more slender than the first, and the length of the internodes varies
from i cm. to 2.9 cm. The specimens are so mutilated that the arrangement of the calyces can
not be determined, further than that they appear to be borne on all sides of the stem.

The individual calyces are excessively long and slender. It is possible that the specimen
has been dried at some time, and that the polyps have been shrivelled so as to be more
slender than they were originally. A typical calyx is 8 mm. long to the top of the marginal
spines, 2.2 mm. in diameter at margin, and i.i mm. at the narrowest part of the pedicel, near
the middle. There are a few slender, needle-like spicules on the proximal part of the calyx,
especially on the abaxial side, and a series of 8 very long, sharp smooth spindles with their
points projecting far beyond the margin, forming a crown of points. There are a few needle-like
spindles in the ccenenchyma near the polyp bases. Otherwise the ccenenchyma is rather leathery
and almost devoid of large spindles. But there are numerous comparatively minute bar-like
spicules near the surface of the ccenenchyma, and a few minute spicules in the tentacles.

Spicules. These are long sharp needles, and small bar-like forms. The former sometimes
attain a length of 5 mm., and are usually sharp at both ends. Their surface is studded with
numerous small sharp thorn-like points. The largest of these needles form the marginal crown
of points. The bar-like forms in the coenenchyma are minute, rather short bars, with their ends
somewhat expanded and rounded.

Color. The colony is ivory white (in alcohol), and the polyps are very light brown.

General distribution. The type locality is off the Hyalonema Grounds, Japan,
343 fathoms.

A comparison with polyps of the Challenger type shows that the Siboga specimens
have nore slender calyces, due probably to drying. The original description says that the
ccenenchyma is without spicules. These are minute, and might escape observation.

2. Ceratoisis philippinensis Wright and Studer.

Ceratoisis pliilippinensis Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 27.

Stat. 52. 9° 3'-4 S., ii9°56'.7E. 959 meters. Globigerina ooze.

Stat. 122. i°s8'.5N., 125° o'-5 E. 1264 — 1165 meters. Stone.

?Stat. 173. 3° 27' S., 131° o'.s E. 567 meters. Fine yellow grey mud.

? Stat. 178. 2° 40' S., I28°37'.5E. 835 meters. Blue mud.

Specimens consisting of two unbranched fragments, the longest being 13.6 cm. in length.

12

The longest calcareous internode is 6.1 cm. long, while the horny nodes are but i mm. long.
The shorter fragment has a thicker axis than the other, their diameters being 2 mm. and
1.8 mm. respectively. Both are largely denuded of ccenenchyma, but retain this and the polyps
in places. The calyces are rather closely set in irregular spirals, being on all sides of the
stem or branch.

The individual calyces are columnar in shape and usually project at a wide angle from
the stem. A typical one is 4.5 mm. in height and 2.5 mm. in diameter. The walls are nearly
straight. There are a few transversely disposed spindles near the base, and a row of about
eight long spindles extending perpendicularly from the transverse spicules to beyond the margin,
around which they form a crown of points. Shorter spindles support the larger ones near the
base, as if propping them. The dorsal surfaces of the tentacles are armed with two or three
rows of bar-like spicules longitudinally disposed.

The ccenenchyma of the stem is thin and stripped from most of the specimens. It contains
a few spicules in the form of spindles.

Spicules. These are nearly all slender spindles, pointed at the ends and attaining a
length of 3. mm. They differ from the others described in having their surfaces almost perfectly
smooth, without verrucae or projecting points of any kind, thus resembling most of the spicules
of the pennatulids. The largest of these spicules are those forming the crown of points around
the calyx margins. Besides these spindles, there are a few bar-like forms with rounded ends,
found in the tentacles.

Color. The specimens are ivory white, in alcohol. The nodes are dark brown, and the
polyps very light brown.

General distribution. The type locality is Challenger Station 201, off the Philippines;
depth 82 fathoms; bottom, stones.

This species is also found in the Japanese waters. (NUTTING, Mss.).

The specimen described is labeled * Ceratoisis philippinensis" . This was very likely written
by Dr. VERSLUYS during his preliminary studies of the Gorgonacea of the Siboga Expedition.
Through his kindness the writer has been permitted to examine fragments of the Challenger
types of this species. These agree fairly well with the above description ; but differ considerably
from the description in the Challenger Report, having calyces in some instances 5 mm. in height,
and with the spiculation as described above. The small spicules are more numerous than in
the Siboga material, and the color of the calyces is much darker. The calcareous internodes
are longer in the Siboga material than the descriptions of the type would indicate.

3. Ceratoisis wrighti new species1. (Plate II, figs, i, i«; Plate V, fig. 3).

Stat. 87. o°32'S., H9°39'.8E. 655 meters. Fine grey mud.
Colony over i meter in length (113 cm.), unbranched. The base consists of two very

i Named in honor of E. PERCIVAL WRIGHT who first denned the genus Ceratoisis.

13

long, expanded, lobular limestone processes, extending laterally from the bottom of the stem.
One of these processes is nearly 5.6 cm. in length, and 5 mm. wide at its broadest point. The
greatest diameter of the axis, near base, is 3.3 mm. The shortest (basal) internode is 3.5 mm.
long, and the longest (4th from base) 3.3 cm. The horny nodes are short, and the longest (basal)
one is 3 mm. in length. Average length about i mm. The polyps are biserially arranged, in
general, although this is occasionally interfered with by one situated on the front or back of
the colony. They all curve upward toward the distal end of the colony, with their adaxial sides
almost contiguous with the ccenenchyma of the stem ; the summit of one reaching to, or slightly
beyond, the base of the one next above.

The individual calyx is columnar or cylindrical in form, but many are swollen with ova
in their proximal portion. A typical one is 6 mm. in height to the end of the crown of points,
and 2.5 mm. broad at the slightly expanded margin. There is usually one conspicuous, needle-
like spicule placed vertically in the abaxial side of the calyx, reaching nearly from the base to
the summit, but ordinarily not projecting beyond the margin, and attaining a length of 5 mm.
There are also eight vertical spicules in the distal part of the calyx wall, whose points form a
conspicuous crown, as in C. paucispinosa. Aside from these there are very few if any spicules
in the calyx walls. Spicules appear to be wanting both in the tentacles and the general ccenen-
chyma of the stem, which is quite thick and fleshy.

Spicules. I find but the one kind, the slender, needle-like form described above as
occurring in the calyx walls. Their surface is covered with regular, but rather sparsely disposed,
minute, thorny points.

Color. The colony, when the ccenenchyma and the calyces have not been stripped
from the stem, is a rather bright reddish brown. The axis is pure white, except at the nodes,
which are dark brown.

This fine species differs from C. paucispinosa, its nearest ally, in length of calcareous
internodes, size and disposition of polyps, and in the spiculation, being without spicules in the
tentacles and ccenenchyma. It differs from C. nuda Wright and Studer in size of spicules, and
in having no tentacular spicules, as well as in size of internodes.

4. Ceratoisis sp.^.

Stat. 122. i°58'.5N., i25°o'.5E. Between Menado and Biaru Island. 1264 — 1165 m. Stony bottom.

A fragment of denuded axis from Station 122 differs from all the other species in the
collection in the length of the single calcareous internode which is 9.9 cm. long and has a
diameter of 2.5 mm. The surface is regularly but not deeply furrowed or fluted longitudinally.
The horny node is 23 mm. long.

The axis approaches the characters of Ceratoisis grandis Nutting from Hawaiian waters x,
which has internodes up to 14 cm. in length. The writer, however, does not feel justified in
identifying species on the characters of the axis alone.

1 Proceedings of the U.S. National Museum, Vol. XXXIV, p. 570, 1908.

14

Acanella Gray (emended by Verrill).

Acanella Gray. Catalogue Lithophytes in British Museum, 1870, p. 16.

Acanella Verrill. Bulletin Museum of Comparative Zoology, Vol. XI, N° i, 1883, p. 13.

Acanella Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 44.

Acanella Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 29.

Acanella Nutting. Hawaiian Alcyonaria, 1908, p. 572.

VERRILL'S definition of the genus is as follows:

"Coral either simple or variously branched. Axis with long calcareous joints and very
short horny ones. The branches, where they exist, arise from the horny joints, either singly,
or two or more together, often forming a whorl. Ccenenchyma very thin, containing, more or
less abundantly, elongated fusiform spicula, usually of large size. Calicles large, elongated,
composed of large fusiform spicula, often obliquely arranged ; the margin is armed by eight long,
spine-like, projecting acute spicula. Tentacles stiffened by abundant spicula. Base, in most cases,
divided into large, flat, palmate lobes, which descend into the mud and serve as supporting
roots or anchors".

STUDER (1887) gives a condensed definition, retaining the essential points as given
by VERRILL.

WRIGHT and STUDER (1889) retain the definition of VERRILL, somewhat condensed, with
the additional point that the basal internodes are much shorter than the distal. For the purposes
of this work the following definition is offered for the genus Acanella :

Ceratoisidince, simple or branched, with branches arising from the horny nodes, often in
whorls. Calyces prominent, with a crown of marginal points. Tentacles with minute spicules.
Ccenenchyma thin, with fusiform spicules. All spicules have thorny points, but are without
true verrucae.

The type species of this genus is Acanella arbuscula (Johnston). Other known species
are Acanella eburnea (Pourtales), A. chiliensis Thomson and Henderson, A. gregorii Gray,
A. normani Verrill, A. rigida Wright and Studer, A. robusta Thomson and Henderson, A.
simplex Verrill, A. spiculosa Verrill and the additional species about to be described.

i. Acanella sibogce new species. (Plate III, figs. 2, 2«; Plate V, fig. 4).

Stat. 85. o°36'.5S., H9°29'.5E. 724 meters. Fine grey mud.

Stat. 170. 3°37'.7S., i3i°26'.4E. 924 meters. Fine grey mud.

Stat. 178. 2° 40' S., I28°37'.5E. 835 meters. Blue mud.

Stat. 211. 5°4o'.3S., I2O°45'.5 E. 1158 meters. Coarse grey mud.

Stat. 241. 4°24<.3S., i29°49'.3E. 1570 meters. Dark sand with small stones.

Type specimen fragmentary, 7.3 cm. long, the proximal part missing. The largest fragment
consists of a central straight shaft from which spring four pairs or opposite branches. In two
cases there is a third branch origin between the bases of the opposite pairs, showing a tendency
toward the formation of verticels so common in this genus, the verticels being 1.4 cm. apart
and springing from the horny internodes, which are so narrow that they constitute mere bands.

15

The branchlets are curved, each consisting of a single calcareous internode varying from 1.3
to 1.8 cm. in length. The calyces are arranged in loose irregular spirals, the distance between
their bases being usually from 2 to 4 mm. They are more closely approximated on the distal
than on the proximal portions of the branchlets.

The individual calyces are columnar in some cases and obconical in others. A typical
calyx is 4 mm. in height, with an average diameter of 1.6 mm., the body being somewhat
expanded below. Another is much constricted below, and is 5. mm. in height and 1.7 mm. in
diameter at the middle. The columnar form, however, is by far the more common. The calyces
project at right angles from the branch, but bend somewhat upward, or distally. Their walls
are rilled with curved spindles arranged horizontally in the basal parts and obliquely in the
distal parts of the walls, those on the abaxial side being larger than those on the adaxial side
of the polyp, and extend from the abaxial mid-line upward and obliquely around the calyx
walls, somewhat resembling a reversed chevron. The adaxial side is filled with smaller spicules
disposed horizontally, in the main.

There is usually a crown of eight well-marked points around the margin, each point
consisting of the distal end of a single spicule. The tentacles bear numerous stout, bar-like
forms, without any very definite arrangement.

Spicules. These sometimes attain a length of nearly 3 mm., are much more uniform
in size than in the other species in the collection, and are much more regularly placed, when
in situ, except in case of the tentacular spicules.

Color. The colony, in alcohol, is ivory white, with light, almost white, polyps.

A direct comparison of the Siboga material of this species with a portion of the Challenger
type of A. rigida, used by Dr. VERSLUYS in his studies, shows that while the two agree well
in form of calyces and maximum size of spicules, they differ in comparative uniformity in size
of spicules in the calyx walls. The walls of A. rigida contain a few comparatively large spicules
on the abaxial side, interspersed with others much smaller. In A. sibogce the abaxial wall is
filled with a compact series of more slender spindles of comparatively uniform size, without a
noticeable admixture of large and small. A. sibogce differs from A. normani in the robustness
of the calyces and spicules, and from A. arbuscula in the same points as from A. normani.
Indeed, these two latter may be identical.

The present species differs from the next {A. weberi] in having much stouter calyces,
which are directed outward, and by its marginal crown of points.

2. Acanella weberi new species. (Plate III, figs, i, i#; Plate V, fig. 6).
Stat. 74. 5°3'-5S., H9°o'E. 450 meters. Globigerina ooze.

Colony arborescent, 18.5 cm. in height. Root consisting of three (originally four) calcareous
cylindrical projections pointing downward and outward, all incomplete. Main stem 2.2 cm. long,
breaking up into a whorl of branches at its distal end, there being 5 branches in the whorl, with

i6

a 6th slender one in the centre. These branches send off one or two pairs of usually opposite
branchlets, the first pair being from 8 to 10 mm. from the bases, the second pair being 9 to
10 mm. above the first. Above these pairs an occasional lateral branchlet is produced, especially
toward the distal ends of the branches. Some of the branchlets, however, are simple throughout
their length of as much as 1 2 cm. The branches arise from horny nodes. The calcareous inter-
nodes vary in length from the second, which is 3 mm. long, to a length of 14 mm. on the
terminal branchlets. The horny nodes vary from the basal one of 2 mm. to about .2 mm. on

the terminal twigs.

The diameter of the main stem near the base is 2.5 mm., decreasing to a thread-like
axis on distal branchlets. The calyces tend to a biserial arrangement on the branches, but are
much more thickly emplanted on distal parts. On the tip of one branch they are thickly
emplanted over the surface of an oval object which is probably a parasitic barnacle. The
branches are erect, forming a symmetrical and graceful colony.

The individual calyces are club-shaped, and inclined toward the distal end of the colony,
sometimes with the adaxial wall contiguous with the branch throughout.

Their adaxial side measures about 2 mm. in length, and their abaxial about 3 mm.
Diameter at margin i.i mm., at base about .8 mm. The calyx walls are filled with large and
small spindles, many of them spirally arranged and more or less bent or wavy. Some of them
attain a length of 2.1 mm., or even 3 mm., extending the whole length of the calyx from
base to summit. These larger spicules are usually placed on the abaxial wall of the calyx, and
sometimes they occur in two series forming a sort of rude inverted chevron on the abaxial wall.
There are a few similar but smaller spindles arranged vertically on the adaxial side. While the
points of the spindles often extend beyond the margin, they do not form a regular series of
eight marginal points such as is found in many other hides.

The tentacles are armed with numerous bar-like spicules irregularly placed, but most
often transversely disposed.

The coenenchyma is thin, and contains a few of the large spindles longitudinally disposed,
and more numerous small, bar-like forms.

Spicules. These have already been described. Their maximum length, 3 mm., agrees
with VERRILL'S description of A. normani \ but the manner of branching seems quite distinct.
The surfaces of the spicules are covered with fine conical points, evenly distributed.

Color. The colony is white, in alcohol, with the polyps a very light golden brown.
The horny nodes of the axis are dark golden brown.

This species is doubtless nearest -A. normani Verrill; but a direct comparison of the
Siboga material with a specimen identified by VERRILL as A. normani shows that A. weberi
differs from A. normani in the shape of the calyces, which are much longer and more slender
in A. normani; and in the spicules, which are much more slender and form a regular crown

r

of points in A. normani.

1 Bulletin of Museum of Comparative Zoology, XI, N« i, p. 17.

«7

3. Acanella sp. ?

Stat. 45. 7° 24/S., ii8°i5'.2E. 794 meters. Fine grey mud.

The specimen consists of a fragment comprising three calcareous internodes joined at
their bottom to a horny internode which supports the three. The longest of these internodes is
1.8 cm. long, and the others are nearly as long. Diameter 1.2 mm. The surface is longitudinally
grooved or fluted.

This specimen may possibly be Acanella chilensis T which has the branches arranged in
irregular whorls of two or three.

M o p s e i n ae. (See definition on page 4).
MopSCa Lamouroux.

Mopsea Lamouroux. Histoire des Polypiers coralligenes flexibles, 1816, p. 465.

Mopsea (in part) Ehrenberg. Corallenthiere des Rothen Meeres, 1834, p. 131.

Mopsea Gray. Proceedings Zoological Society of London, 1857, p. 283.

Mopsea Milne Edwards et Haime. Histoire naturelle des Coralliaires, Vol. I, 1857, p. 197.

Mopsea (in part) Dana. Synopsis of the Report on Zoophytes, Wilkes Expedition, 1859, p. 144.

Mopsea Studer. Monatsbericht der Konigl. Akademie der Wissenschaften zu Berlin, 1878, p. 665.

Mopsea Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 46.

Mopsea Wright and Studer. Challenger Reports, the Alcyonaria, 1889, pp. XLV, 40.

The original definition for this genus (LAMOUROUX 1816) is as follows:

"Polypier dendroide a rameaux pinnes: ecorce mince, adherente, couverte de mamelons
tres petits, elonges, recourbes du cote de la tige, epars ou subverticelles".

Subsequent writers modified this definition so as to admit certain species of Melithteidte ,
until STUDER (1887) defined it as follows:

"Colonie in einer Ebene verzweigt, Polypen klein, keulenformig, in dichten Spiralen
ringsum den Stamm angeordnet. Kelchschuppen klein, niedrig und stachlig".

WRIGHT and STUDER (1889) expanded this definition to considerable length on page 40,
but give a much shorter definition on page XLV which is practically the same as the one by
STUDER, quoted above.

"The colony is branched and expanded fan-like in one plane. The polyps are small,
club-like in form, and arranged in dense spirals around the stem. The calyx scales are small,
short and spiny".

The above definition is the one adopted in this work.

The type species of this genus is Mopsea encrinula (Lamarck). Other known species
are M. dichotoma (Linn.), and the two new species about to be described.

i. Mopsea flava new species. (Plate IV, figs, i, \a\ Plate V, fig. 5).

Staf. 117. i°o'.5 N., 122° 56' E. 80 meters. Sand and coral.
Colony strictly flabellate in form, 26 cm. in height, and 17 cm. broad. 3.6 cm. above

1 Challenger Report, the Alcyonaria, 1889, p. 31.

SIBOOA-EXPED1TIE XIII 0*.

i8

its base the main stem sends off two opposite branches each bearing branches which themselves
bear lateral twigs irregularly spaced. Branches of the 4th order are sometimes produced,
main stem, after giving off these branches, continues upward in a wavy course giving off a few
lateral branches and ultimate twigs to its distal end. These laterals are very unevenly spaced,
but average about 5 mm. apart. Diameter of main stem 5.5 mm., of the lateral twigs 2 mm.
The stem and main branches have even surfaces, there being no swellings nor constrictions at
the nodes. Proximally the horny nodes are longer than the calcareous internodes, the former
being 2.7 mm. long, and the latter 2 mm. Above the origins of the branches, however, the
internodes are the longer, being 5.5 mm. long, while the nodes are but 2.2 mm. long. Both
nodes and internodes are rather deeply grooved in the main stem, the grooves being numerous
and parallel. The -branches spring from the calcareous internodes. The polyps are small, and
are emplanted on all sides of the larger branches, but tend to be lateral on the smaller twigs.
Sometimes, however, they are on all sides, even to the tips of the ultimate branchlets.

The specimen is so completely covered with a parasitic sponge with small needle-like
spicules that the details of the individual calyces are hard to ascertain. The calyces are small,
and shaped like a truncated cone; or else are dome-shaped verrucae. A typical one measures
1.3 mm. in height and i.i mm. in diameter. The calyx walls are covered with a mosaic of
scale-like spicules with ctenate edges nicely fitted together and without regular arrangement in
either vertical or transverse rows. The polyp is completely retractile. There are a few very
small scales or calcareous granules on the dorsal surface of the tentacles.

Spicules. These are all small, oval or irregular scales, which are densely covered with
relatively large tubercles. Occasionally they are somewhat branched, but not extensively so, and
the branches are short. Occasionally, also, double heads are seen, and very rarely collar-button
forms such as are found in the muriceid genus Bebryce. Ccenenchyma covered with similar scales.

Color. The entire colony is a light straw yellow in color, probably brighter yellow in life.

2. Mopsea alba new species. (Plate IV, figs. 2, 2«; Plate VI, fig. 4).

Stat. 156. o° 29'.2 S., i3O°5'.3E. 469 meters. Coarse sand and broken shells.

Colony flabellate in form, attaining a height of 15 mm., and a spread of 20 mm. The
main stem arises from a disk-like base and contains one short, unbranched internode 1.2 mm.
in length. The other internodes bear branches, except the distal one which is very slender and
short. These internodes are 3.5 mm., 8 mm., and 2.9 mm. long, going from the 2nd to the
4th and last. The second internode bears two side branches and the third three. These main
branches are rudely alternate and curved .upward like candalabra. The lower one bears three
curved branchlets, and the third, one. All of the branches arise from calcareous internodes.

The axis is rather faintly grooved, and seems to be hollow; but the specimen was too
small to justify dissection to ascertain this point. The polyps are biserial, alternate, and rather
distant, being almost 2 mm. apart.

The individual calyces are club-shaped, directed outward basally, and curving upward, or
towards the branch termination, distally. A typical one measures 1.6 mm. in height and i mm.

19

across the margin. The calyx walls are covered with numerous small scales transversely disposed,
but in numerous rows both vertical and transverse. These scales are very short and broad with
their upper exposed edges finely ctenate and apparently overlapping the base of the next scale
above. The number of scales in a horizontal row is hard to determine owing to their small
size, but there seems to be as many as 20 or more in each row. The tentacles are covered
with similar rows of narrow scales fitting the dorsal surface and looking like continuations of
the rows on the calyx walls.

Spicules. These are narrow scales with curved and ctenate borders. On the basal
parts of the calyces and in the ccenenchyma of the stem and branches they become so narrow
as to assume the form of spindless with tuberculate or echinulate surfaces.

Color. The color is almost pure white, in alcohol.

Peltastisis new genus.
and

Colony unbranched; polyps uniserial and provided with true opercula consisting of eight
parts or flaps, each part consisting of a single triangular scale; calyces with spicules of the
primnoid type, being flattened scales with irregular branched or ctenate edges and with thorny
points on the surface.

The type of this genus is Peltastisis uniserialis Nutting. The only other known species,
also found in the Siboga collection, is described beyond.

These two species undoubtedly belong to the family Isidte, and can, without violence, be
admitted into the subfamily Mopseina. They are so different, however, from any previously known
members of this group that it becomes necessary to construct a new genus for their reception.

The genus Peltastisis bridges the narrow gulf between the Isidee and Primnoidcz in one
important particular in that it combines the jointed axis of the former and the characteristic
operculum of the latter, which it also resembles closely in its spiculation. Indeed, it is so
directly intermediate between the two families that it can only arbitrarily be placed in either.
The character of the axis is, however, of sufficient importance in the opinion of the writer to
determine the position of Peltastisis as a member of the family Isidez.

i. Peltastisis uniserialis new species. (Plate IV, figs. 3, 3#; Plate VI, fig. 3).

Stat. 145. o°54' S., I28°39'.9E. 827 meters. Hard. Pumice stone.
Stat. 159. o°59'.iS., I29°48'.8 E. 411 meters. Coarse sand.

Colony consisting of a very delicate unbranched stem growing from a calcareous, lobulated
flattened base and attaining a length of 6.2 cm. The basal i.i cm. of the stem is devoid of
polyps. The basal internode measures 2 mm., the second 2.9 mm., the third and succeeding
•ones about 3 mm. The horny nodes are very short, about .5 mm., and much narrower than the
calcareous ones. The polyps are uniserial and about 1.7 mm. apart, from summit to summit.

The individual calyces are club-shaped or conical, i mm. in height on their abaxial side,
inclined toward the branch so that the adaxial side is almost contiguous with it. The margin

20

is even, without evident crown of thorns or other conspicuous ornamentation. The calyx walls
are armed with regular imbricating series of oval scale-like plates with ctenate edges and surfaces
thickly emplanted with rounded points. There are about seven of these plates on each abaxial
row, and two or three on the adaxial rows. Towards the base of the calyx these plates are
narrowed and resemble transversely placed spindles. There is a strong operculum of the primnoid
type, composed of eight flaps, each flap consisting of a single scale-like spicule. These opercular
scales are covered with closely emplanted rounded points, and the entire operculum completely •
covers the infolded tentacles, there being no spaces between the individual segment or flaps.

Between each pair of adjacent polyps there is a swelling of the ccenenchyma of the
branch or stem, the swellings alternating regularly with the polyps and containing ova. The
cqenenchyma also contains a layer of rather heavy tuberculate spindles, arranged longitudinally.

Spicules. These are mainly of two types. Ist. the regular spicules of the coenenchyma.
These are spindles the surfaces of which are covered with rather sharp rounded point. 2nd. the
scale-like spicules of the calyx walls, which are covered with similar points which, on the edges,
give the appearance of a ctenate border. These two types of spicules intergrade on the basal
parts of the calyces. The triangular scales forming the opercular segments constitute another,
but much more infrequent type.

Color. The colony is almost white, in alcohol, the axis being pure white, and the
calyces light brown.

While but a fragment of this very curious form was secured at Station 145, a number
of specimens, apparently complete, were dredged from Station 159. The largest specimen was
8.5 cm. long. All are unbranched.

2. Peltastisis cornuta new species. (Plate IV, figs. 4, 40; Plate VI, figs, i, 2, 5).
Stat. 300. io°48'.6S., 123° 23'.! E. 918 meters. Fine grey mud.

The type consists of a small fragment, unbranched, 2.9 cm. long. The calcareous inter-
nodes vary from the proximal one which is 6.5 mm. long to the distal one which is 5.5 mm.
long, decreasing regularly from proximal to distal ends of the specimen. The horny nodes are
very short, less than .5 mm. They are more slender than the calcareous internodes, being
about .5 mm. in diameter, while the latter are about .7 mm. The calyces are uniserial, quite
regularly spaced, being about 2.5 mm. apart and three to each calcareous internode.

The individual calyces are short and thick, shaped like a short, curved club or horn,
the distal end being inclined towards the stem or branch, as is characteristic of many of this
family and of the Primnoida:. The calyx is about i mm. in height (measured directly with
dividers), and a little over i. mm. in diameter across the margin.

The abaxial side of the calyx wall is supported by a most remarkable stay or brace
consisting of a comparatively enormous spicule that is bent into a bow-shape so that its distal
part is applied longitudinally to the curved abaxial contour of the calyx and its proximal portion
is applied to the calcareous internode of the branch in such a manner as to curve downward
and partly around it. This stay is therefore unsymmetrically placed as regards the branch, its

21

proximal part passing around to the right of the midline of the polypiferous surface of the
branch. The stay has a smooth surface except at the ends, where it bears numerous nodules,
resembling that of the calcareous internodes, and showing ivory white against the darker color
of the polyp. It gradually narrows to a point at the proximal end, but is broadened into a
shape resembling a shoe-horn at the distal end, the concavity of the "shoe-horn" fitting the
curve of the calyx margin to which it is applied. The stay is applied to the entire anterior face
of the calyx, ending flush with the margin, and when it is removed it leaves a bare, impressed,
band-like space on the abaxial wall, reaching from the base of the calyx to the marginal row
of scales which, however, it does not invade. The stay is 1.5 mm. in length, measured with
dividers, but would be much longer if measured around the curves.

The calyx walls are covered with minutely ctenate scales greatly resembling those found
in several genera of Primnoidte, e.g. Plumarella or Caligorgia. These scales are arranged in
seven or eight vertical rows, except that there is but one scale (the marginal) to each of the
adxaxial rows, and there are about eight scales to each abaxial row. The margin is even,
without evident lobes, teeth or spines.

The operculum consists of eight segments, each segment consisting of a triangular scale-like
spicule neatly fitted to the dorsal surface of a tentacle and with its surface covered with fine
rounded nodules. At first view it looks as if each flap is made up of a fine mosaic of many
minute plates; but, when separated from the tentacle, it is seen to be a single large thin plate or
scale. The ccenenchyma of the branch is thin and contains a layer of longitudinally placed, thin,
scale-like spicules which are spindle-shaped in profile, but much flattened. They are ornamented
with small, very definite, rounded knobs or points thickly and rather evenly emplanted over the
surface. Intermingled with these are clear bar-like and needle-like forms.

About midway between adjacent polyps and on the polypiferous face of the stem or
branch are low rounded swellings which contain ova, as in the last species. This is a very
exceptional arrangement among the Gorgonacea.

The axis is quite smooth, hard and white. The specimen was so small that it seemed
inadvisable to dissect it to determine whether it is hollow or not. A small fragment of a twig
termination shows that the axis does not extend to the end of the branch or stem, although
this terminal part bears polyps and the strange bracket-like supports for the calyces apparently
as well developed as on the proximal parts.

Spicules. These have been already described, and are of several kinds. Ist. The small
ctenate scales of the calyx walls. 2nd. The flattened, scale-like spindles of the ccenenchyma.
3rd. The large, thin, triangular plates of the operculum. 4th. The occasional bar-like or rod-like
forms in the ccenenchyma, and 5th. The remarkable curved stays or supports on the abaxial
faces of the calyces.

Color. The fragment is almost white, with the calyces and ovigerous swellings a
medium brown.

DISTRIBUTION OF THE 1S1DM COLLECTED BY THE SIBOGA EXPEDITION.

List of Stations

at which Isidee were collected by the Siboga Expedition, and a
List of Species collected at each Station.

STATION 45. 7° 24 S., ii8°i5'.2E. 794 meters. Fine grey mud, with some radiolariae and diatomes.
Acanella sp.?

STATION 52. 9°3'.4S., ii9°56'.7E. 595 meters. Globigerina ooze. Ceratoisis pliilippinensis, Ceratoisis
paucispinosa.

STATION 71. Makassar and surroundings. Up to 32 meters. Mud, sand with mud, coral. I sis hippuris.

STATION 74. S°3'-5S., ii9°o'E. 450 meters (chart). Globigerina ooze. Acanella iveberi.
STATION 85. o°36'.5S., ii9°29'.5E. 724 meters. Fine grey mud. Acanella sibogcz.
STATION 87. o°32'S., U9°39'.8E. 655 meters. Fine, grey mud. Ceratoisis wrighti.
STATION 117. i°o'.5 N., 122° 56' S. 80 meters (chart). Sand and coral. Mopsea flava.

STATION 122. i°58'.5 N., I25°o'.s E. Near Menado, Celebes. 1264 — 1165 meters (chart). Stone. Cera-
toisis pliilippinensis, Ceratoisis spec.

STATION 133. Anchorage off Lirung, Salibabu Island. Up to 36 meters. Mud and hard sand. Isis
hippuris.

STATION 142. Anchorage off Laiwui, coast of Obi Major. 23 meters. Mud. Isis hippuris.

STATION 144. Anchorage North of Salomakie (Damar) Island. 45 meters. Coral bottom and Litho-
thamnion. Isis hippuris.

STATION 145. o°54'S., I28°39.9E. 827 meters. Hard. Pumice stone. Peltastisis uniserialis.

STATION 149. Fau anchorage and lagune, West coast of Gebe Island. 31 meters. Coral. Isis hippuris.

STATION 156. o°29'.2S., I30°5'.3E. 469 meters. Coarse sand and broken shells. Mopsea alba.

STATION 159. o°59'.i S., I29°48'.8E. 411 meters. Coarse sand. Peltastisis uniserialis.

STATION 170. 3°37'-7s-> i3l026'.4E. 924 meters. Fine grey mud. Acanella sibogce.

STATION 173. 3°27'S., i3i°o'.sE. 567 meters. Fine yellow grey mud. Ceratoisis philippensis.

STATION 178. 2°4o'S., 128° 37'.$ E. 835 meters. Blue mud. Acanella siboga, ? Ceratoisis philippinensis.

STATION 211. 504o'.7S., i2o°45'.sE. 1158 meters. Coarse grey mud. Acanella sibogce.

STATION 241. 4° 24.35., I29°49'.3E. 1570 meters. Dark sand, with small stones. Acanella siboga.

23
STATION 258. Tual anchorage, Kei Islands. 22 meters. Lithothamnion, sand and coral. Isis hippuris.

STATION 273. Anchorage off Pulu Jedan, East coast of Aru Islands. 13 meters. Sand and shells.
Isis reticulata.

STATION 279. Ruma-Kuda Bay, -Roma Island. 36 meters. Mud and sand. Isis hippuris.

STATION 300. io°48'.6S., 123° 23'.! E. 918 meters. Fine grey mud. Peltastisis cornuta.

STATION 301. io°38'S., I23°25'.2E. 22 meters. Mud, coral and Lithothamnion. Isis hippuris.

STATION 303. Haingsisi, Samau Islands. Up to 36 meters. Lithothamnion. Isis hippuris.

It appears from the above list that Isidce were collected at 26 stations during the
Siboga Expedition. By far the most widely spread of the species collected, so far as the territory
covered by the Siboga is concerned, is Isis hippuris, which was secured from 9 stations, over
one third of the total number. It is a somewhat remarkable fact that in only two cases (one of
which is uncertain) were more than a single species taken from one station; while no station
yielded more than two species of Isida. Contrasted with the 17 species of Muriceida from
Station 310, this seems a decidedly pour showing.

The genus Isis is the only one that can be regarded as comprising distinctly shallow
water forms, its range being from 22 to 45 meters. All of the other genera are truly inhabitants
of the deep water, the bathymetric distribution of the Siboga material being as follows:

Ceratoisis, 595 to 1264 meters; Acanella, 450 to 1570 meters; Mopsea, 80 to 469 meters;
Peltastisis, 827 to 918 meters.

Literature cited
in the Report on the Isidae of the Siboga collection.

BOURNE, G. C. A Treatise of Zoology, edited by E. RAY LANKESTER; Part II, The Anthozoa, Chapter VI,
The Anthozoa, London, 1900.

DANA, J. D. Synopsis of the Report on Zoophytes of the U. S. Exploring Expedition around the world,
Under C. WlLKES, U.S. N. Commander, in the years 1838—1842, New Haven, 1859.

ESPER, E. J. C. Die Pflanzenthiere in Abbildungen nach der Natur, mit Farben erleuchtet nebst Beschrei-
bungen, Niirnberg, 1/91.

ELLIS, J. and SOLANDER, D. The Natural History of many curious and uncommon Zoophytes, London, 1786.

GRAY, J. E. Synopsis of the Families and Genera of the Axiferous Zoophytes or Barked Corals. Pro-
ceedings of the Zoological Society of London, Part 25, London, 1857.

Catalogue of Lithophytes or Stony Corals in the collections of the British Museum, London, 1870.

HlCKSON, S. J. National Antarctic Expedition. Natural History, Vol. Ill, Ccelentera Alcyonaria, 1907.

KOLLIKER, A. Icones Histiologicse, oder Atlas der vergleichenden Gewebelehr, 2. Abth., i. Hf., Leipzig, 1865.

LAMARCK, J. B. P. A. DE. Histoire naturelle des Animaux sans vertebres, Vol. II, Paris, 1836.

LAMOUROUX, J. F. V. Histoire des Polypiers coralligenes flexibles, vulgairement nommes Zoophytes, Caen, 1 8 1 6.

LlNNE, C. Hortus Cliffortianus, 1737.

- Systema Naturae, roth Edition, 1758.

- Systema Naturae, I2th Edition, Tome i, Part 2, Holmae, 1767.

MILNE EDWARDS, H. et HAIME, J. Histoire naturelle des Coralliaires ou Polypes proprement dits, Tome

premier, Paris, 1857.
NUTTING, C. C. Descriptions of the Alcyonaria collected by the U. S. Bureau of Fisheries Steamer Albatross

in the vicinity of the Hawaiian Islands in 1902. Proceedings of the U. S. National Museum,

Vol. XXXIV, Washington, 1908.

PALLAS, P. S. Elenchus Zoophytorum, Hague, 1766.
STUDER, TH. Ubersicht der Anthozoa Alcyonaria, welche wahrend der Reise S. M. S. Gazelle um die Erde

gesammelt wurden. Monatsbericht der Koniglich Preussischen Akademie der Wissenschaften zu

Berlin, September und October 1878, Berlin, 1878.

- Versuch eines Systemes der Alcyonaria. Archiv fur Naturgeschichte, 53ster Jahrgang, Bd. I, Heft I, 1887.

- Alcyonaires provenant desCampagnes de l'Hirondelle(i886 — 1888). Resultats des Campagnes scientifiques

accomplies sur son yacht par Albert ler, Prince Souverain de Monaco, Fascicule XX, Monaco, 1901.
THOMSON, J. A. and HENDERSON, W. D. An account of the Alcyonarians collected by the Royal Indian
Marine Survey Ship Investigator in the Indian Ocean. Vol. I, The Alcyonarians of the Deep Sea,
Calcutta, 1906.

- and SIMPSON, J. J. An account of the Alcyonarians collected by the Royal Indian Marine Survey

Ship Investigator in the Indian Ocean'. Vol. II, The Alcyonaria of the Littoral Area, Calcutta, 1909.
VERRILL, A. E. Report on the Anthozoa, and on some additional Species dredged by the Blake in 1877 1879,

and by the U. S. Fish Commission Steamer Fish Hawk in 1880. Bulletin Museum Comparative

Zoology at Harvard College, Vol. XI, N° I, Cambridge, 1883.
WRIGHT, E. P. Notes on Deep Sea Dredging, Annals and Mag. of Nat. Hist., 4th Ser., Vol. 2, p. 423, 1868.

- On a New Genus of Gorgonidae from Portugal. Ann. and Mag. of Nat. Hist., 4th Sen, Vol. 3, p. 23, 1869.

- and STUDER, TH. Report on the Alcyonaria. Report on the Scientific Results of the Voyage of

H. M. S. Challenger, etc. Zoology, Vol. XXXI, London, 1889.

EXPLANATION OF PLATES

The photographs were made from nature by the author.
The spicules were drawn under the camera lucida by Mr. DAYTON STONER.

PLATE I.

Fig. i. /sis hippuris Linnaeus. Natural size. la, part of branch X 5. ib, cross section of axis x 5.
Fig. 2. /sis reticulata Nutting. Natural size. 2 a, part of branch X 5.

SIBOOA-EXPEDITIE XIII6-- C. C. NUTTING. ISIDAE.

(a

PLATE II.

Fig. i. Ceratoisis wrighti Nutting. Natural size. \a, part of stem )

SIBOGA-EXPEDITIE XIII*" C. C. NUTTING, !SiDAE.

PLATE III.

Fig. I. Acanella weberi Nutting. Natural size, la, part of branch X 5-
Fig. 2. Acanella sibogcz Nutting. Natural size. 2a, part of branch X 5.

SIDOOA-EXPEDITIE Xilf^- C. C. NUTTING, 1SIDAE.

Ill

PLATE IV.

Fig. I. Mopsea flava Nutting. Natural size. \a, part of branch X 5-

Fig. 2. Mopsea alba Nutting. Natural size. 2 a, branch X 5.

Fig. 3. Peltastisis uniserialis Nutting. Natural size. 3 a, part of stem X 5-

Fig. 4. Peltastisis cornuta Nutting. Natural size. 40, part o/ stem X 5.

SIBOGA-EXPEDITIF. X11I*2- C. C. NUTTING, IS1DAE.

IV

PLATE V.
/

Fig. i. Group of six spicules, a, b, c, d, e, f, of I sis hippuris Linn. X 120.

Fig. 2. Group of five spicules, a, b, c, d, e of I sis reticulata Nutting X 120.

Fig. 3. Group of three spicules, a, b, c, of Ceratoisis wrighti Nutting >< 64. (Approximately one half of

each spicule is shown).

Fig. 4. Group of three spicules, a, b, c, of Acanella sibogce Nutting X I2O.

Fig. 5. Group of four spicules, a, b, c, d, of Mopsea flava Nutting X 120.

Fig. 6. Group of three spicules, a, b, c, of Acanella weberi Nutting X 1 20.

Siboga-Expeditie Xlllb 2. Q. C. NUTTINO, Isidae.

c

) .. • . *

a

PLATE VI.

Fig. i. Group of eight spicules of Peltastisis cornuta Nutting, a, one of the opercular spicules; b, one of
the spindles of the ccenenchyma; g, a spicule intermediate between the calyx scales and the
spindles of the ccenenchyma; c, d, e, f, i, scales from the calyx walls. All x 120.

Fig. 2. One of the "bony stays" consisting of a single peculiar spicule of Peltastisis cornuta Nutting X 64.

Fig. 3. Group of five spicules from Peltastisis uniserialis Nutting X 120. e, one of the characteristic trian-
gular spicules of the operculum; a, b, c, spindles from the ccenenchyma; d, calyx scale.

Fig. 4. Group of six spicules, a, b, c, d, e, f, from Mopsea alba Nutting X 120.

Fig. 5. Calyx of Peltastisis cornuta Nutting X 64. op., opercular scale; s. curious "bony stay" which is
formed of a single very large spicule and supports the calyx in front.

Siboga-Expeditie Xll|t>2. C. C. NUTTING, Isidae

2

REESE

THE GORGONACEA OF THE SIBOGA EXPEDITION

VL THE GORGONELLID^:

REESE

Siboga-Expeditie

XIII b3

THE

GORGONACEA OF THE SIBOGA EXPEDITION

VI. THE GORGONELLID^:

BY

C. C NUTTING

Professor of Zoology, State University of Iowa

With 11 plates

(Aided by a grant from the ELIZABETH THOMPSON SCIENCE FUND)

. J. BRIJL.L

PUBLISHERS AND PRINTERS

LEYDES 1910

and the tentacle bases are beset with spicules. The spicules are almost always girdled forms,
i. e. with a median band which is bare of verrucse, and hence appear to have an impressed
girdle. This results in the formation of double heads, double clubs, double spindles, double
stars, etc. ; and these forms are quite characteristic of the Gorgonellidae, although not strictly

confined to this family.

Dichromatism is exhibited in a marked degree, a number of species of Juncella and
Scipearella being characterized by having two color phases, red and white, which do not
appear to be corellated with sex or age.

The systematic arrangement of this family offers great difficulties, as is apt to be the
case with forms which have been long known. The original descriptions are entirely inadequate,
and it is usually impracticable to decide just what forms the authors had before them. None
of them paid any attention to the feature that has later been found of prime importance in
generic definitions, e. g. the spicules, and confined themselves almost exclusively to general
habit, mode of branching, etc., features of almost no generic import whatever. Subsequent
writers have very generally neglected the discussion of the genera in any broad way.

MILNE EDWARDS and HAIME (1857) recognize1 the four genera Juncella, Ctenocella,
Gorgonella and Verrucella, which they separated by modes of branching and character of the
calyces. Kolliker (1865) was the first to thoroughly investigate the spicules of this family, and
he recognized the genera Gorgonella, Juncella and Verrucella; but included the genus Riisea
of DUCHASSAING and MICHELOTTI, which appears to belong to the family Chrysogorgidae. He
includes the genus Ctenocella in his genus Gorgonella.

GRAY (1870) divides the genus Juncella into the three genera Juncella, Ellisella and Vime-
nella and restores the genus Scirpearea. He established the genera Nicella, Reticella, Raynerella,
Phenella and Heliana. Two of these, Reticella and Raynerella, appear to belong to Gorgonella.
STUDER, (1878) discusses and further defines the genera Gorgonella, Juncella, Ellisella,
Ctenocella and Scirpearella; and in 1887 the same writer gives a careful discussion of the
genera of this family, defining according to modern methods the following genera : Nicella,
Scirpearea, Juncella, Ellisella, Verrucella, Gorgonella, Ctenocella, Phenelia and Heliana. The
last two of these genera he defines after GRAY without giving the spicule characters which are
absolutely necessary for modern definition. This treatment is the most satisfactory that has yet
been presented, and the generic definitions here given are very largely adopted without essential
modification by the present writer.

The last general treatment of the family Gorgonellidae as a whole is found in WRIGHT and
STUDER'S Challenger Report, Alcyonaria, 1889, p. 153, where the definitions of STUDER, as just
discussed, are practically adopted in their entirety. They add, however, one genus, Scirpearella
and throw doubt on the identity and validity of the old genus Scirpearea of CUVIER, quoting
the discussion of Scirpearea mirabilis by KOLLIKER J who shows that the name was originally
used for a pennatulid.

THOMSON and SIMPSON, in their excellent monograph of the Alcyonaria secured by the

1 Anat.-Syst. Beschr. der Alcyonarien, Die Pennaluliden, 1872, p. 26.

Investigator in the Indian Ocean, Part II, 1909, p. 265 et seq. merely name the family.
They distinctly recognize the great difficulty and perplexity attending the work of the systematist
in this family, saying (p. 267), in reference to their new species Nicella pustulosa :

"It is a matter of no small difficulty to distinguish between Nicella, Gorgonella and

Verrucella. Distinctions based on spicules alone are very unsatisfactory in this group because

the spiculation varies at different levels and transition forms are so numerous and varied that it

is sometimes almost impossible to distinguish between double spheres, double stars and double

clubs, each in turn passing gradually to double spindles".

Again, on page 269:

"The system of classification which at present obtains in regard to the Juncella group
of gorgonellids, including Juncella, Ellisella, Scirpearea and Scirpearella is far from satisfactory.
In fact it is a debatable question whether these should be ranked as separate genera. Many of
the species which have from time to time been described have unquestionably been established
on young colonies, and, in addition to this, the characters which are taken as diagnostic, e. g.
arrangement and retractility of verrucae, vary so much in individual specimens that little or no
importance can be attached to them".

These writers content themselves with a table, giving a comparison in numerous details
of the several specimens collected by the Investigator, without attempting to name them.

The present writer, although profoundly impressed with the extreme difficulty of the
problem, does not feel justified in turning his back on these perplexities. The amount of
material belonging to the Gorgonellidae secured by the Siboga Expedition is so considerable,
representing some 2 1 species, that an attempt will be made to straighten out as many of the
difficulties as may be. While entire success is not to be hoped for, some progress toward a
reasonably correct generic classification should be possible.

First, however, it is necessary to more clearly define the main types of spicules that
present, after all, the best basis of classification in this, as in other groups.

As already indicated, nearly all of the spicules which present characteristic features of
value for our purpose are "girdled spicules". The basic form from which nearly all of the
others are derived is the girdled spindle, showing at its middle a smooth impressed zone, free
from verrucae. This form differs from the typical spindle only in the fact that this zone is more
conspicuous in the girdled form. The typical spindle is terete in form and its surface is orna-
mented with more or less regular whorls of tubercles. Between the whorls are comparatively
bare zones, and such a zone is very constantly seen near the centre of the spicule. It is only
when such a zone is comparatively large and conspicuous that a "girdled spindle" is produced.
This basic form is modified in the following ways :
Ist. Symmetrical forms

a. The girdle divides two similar parts of the original spindle in such
a manner that each part bears verrucas and is terete in outline.

This produces the D o uble Spin die.

b. The girdle divides two similar parts each with its outer end some-
what turgid and armed with verrucas, resulting in the. . . . . Double Club.

c. The girdle divides two similar parts which are spherical in outline
and are ornamented with symmetrically disposed verrucae. Such an

arrangement results in the spicule which we will call the. . . . Double Head.

d. The girdle divides two similar parts which are spherical in outline

and ornamented with radiating points. These are Double Stars.

e. The spicule is rod-like in general form, with a girdle dividing two
parts which are gradually enlarged toward the outer ends, have
comparatively straight sides, rounded distal corners and are covered

with fine and densely aggregated verrucse. These will be called . Double Bars.
/. The spicule is rod-like, without the girdle Bars.

2nd. Unsymmetrical forms.

a. The girdle separates two unlike parts, one a club and the other a

star. Such forms may be called '. . .. . Club-Stars.

b. The girdle separates two unlike parts, one a club and the other

a head. Forms of this kind may be called Club-Heads.

c. The girdle separates two unlike parts, one a star and the other a

head. These will be called Star-Heads.

d. The girdle separates two unlike parts, one a club and the other a

spindle. This rather rare form may be called Club-Spindle.

e. The girdle separates two unlike parts, one a star and the other a

spindle. These may be designed as Star-Spindles.

Besides the above, which may be called girdled forms, there are often crosses produced
by a double head being longitudinally divided by an impressed vertical zone.

While it is true that a given species, or even a single specimen, may show several of
these forms and numerous intergradations, it is also true that certain forms predominate in a
given genus, and it is these dominant types of spicules, and not the others, that are available
for generic diagnosis ].

While the spicules are the most important features for generic distinctions, we may also
avail ourselves of any other character which seems to be possessed by a group of allied
species, e. g. mode of branching, shape of calyces, character of axis, etc., in attacking the
problem before us.

Artifical key to the genera of the GORGONELLID^;.

Main branches arising from a forking of the main stem. Colony flabellate,
widely diverging, the main branches bearing a series of simple branchlets
on upper side only. Branchlets vertical and parallel, and resembling the
teeth of a comb Ctenocella

1 See a discussion on this point, as well as a statement of the position of the author on the matter of the retention of established
generic names, in the Report on the Muriceidas of the Siboga Expedition, NUTTING, 1910, p. 5.

Colony simple, or, if branched, not bearing branchlets in the manner described
above. Spicules :

Club-stars and double stars Juncella

Lenticular, disk-shaped or fiddle-shaped Plumigorgia

Much larger, bar-shaped, sometimes lenticular; surface smooth Isidoides

Double bars or girdled bars Nicella

Spindles and clubs predominating Ellisella.

Double heads and girdled spindles largely predominating.

Colony flabellate, often reticulate; calyces low verrucae Gorgonella.

Colony flabellate or dichotomous, the heavily spiculated bases of tentacles

forming an 8-rayed pseudo-operculum, star-like when viewed from above Verrucella
Colony simple, forked or bushy ; calyces usually in spirals, prominent ;

spicules often cruciform, although not abundant Scirpearella

The genus Scirpearea is apparently invalid, as the name was used originally for a
pennutalid, according to LAMARCK *.

Later LAMARCK (Hist. Xat. Anim. sans vert.. II, 1836, p. 614) places this in his genus
Funiculina. This writer points out that this species has been erroneously confounded with
Pennatula mirabilis Linn. WRIGHT and STUDER (Challenger Report, Alcyonaria, 1889, p. 155)
say that the type specimen of Funiculina cylindrica Lamk. is a gorgonellid (and probably a
Juncella]. Studer, however, had previously figured a couple of spicules of Scirpearea mirabilis
Cuv. in the plate (Plate Y, 29) and Scirpearea mirabilis Pallas in the text, of his paper in the
Monatsbericht der Konigl. Akad. der Wissenschaften zu Berlin, 1878, p. 660.

It is impossible at this time to disentangle the real situation and to determine just
what CUVIER had before him which he named Scirpearea mirabilis. In view of this situation
it seems best to abandon the genus altogether.

The following genera are not represented in the collection made by the Siboga, neither
do they seem to have received adequate definition at any time. Without further discussion the
definitions of STUDER ~ are given in translation as follows :

"Phenilia Gray. Colony arborescent, with short, divergent, usually quadrate branches
which sometimes coalesce. Calyces low, in two or three irregular rows on both sides of the
branches. Ccenenchyma horny, with plain lateral grooves. Spicules?"

" He 'liana Gray. Colony tree-like, branching dichotomous? Twigs ascending and divergent.
Lower twigs occassionally anastomosing. Ccenenchyma hard, horny. Calyces exserted, subcylin-
drical short, sometimes bent, in two three or four alternating rows on the sides of the twigs,
and irregularly disposed on the branches. Axis hard, stony, gray-brown".

1 Scirpearea mirabilis Cuvier, (Regne Animal. I ed. IV, 1817, p. 85) Pennatula mirabilis Pallas.
1 Versuch eines Systemes der Alcyonaria, 1887, pp. 68, 69.

Synoptic view of the genera and species of GORGONELLID/E
collected by the Siboga Expedion.

New species are indicated by an asterisk (*).

Gorgonella.

G. orientalis , umbraculum , *delicatula ,
* rigid a.

Verrucella.
V. rubra, flaviflora (new name), *stellata.

C. pectinata.

Juncella.

Scirpearella.

S. rubra, gracilis, *regia, *hemispherica.

Nicella.

N. *coralloides, *carinata.

Ellisella.

E. *flava.

Plumigorgia (new genus).

P. *hydroides.

Isidoides (new genus).

/. *armata.

y. juncea, gemmacea, racemosa, *sanguinea.

The table shows that the Siboga Expedition secured 2 1 species of Gorgonellidae 1 1 of
which are new; and that these species were divided among 9 genera, 2 of which are new.

Systematic description of genera and species.
Genus Gorgonella Valenciennes (modified).

Gorgonella Valenciennes. Comptes-rendus, tome XLI, 1855, p. 14.

Gorgonella Milne Edwards et Haime. Histoire Naturelle des Coralliaires, Vol. I, 1857, p. 183.

Gorgonella Kdlliker. Icones Histiologicae, II, 1865, p. 139.

Gorgonella Studer. Monatsbericht der Konigl. Akademie der Wissenschaften zu Berlin, 1878,

p. 66 1.

Gorgonella Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 68.

Gorgonella Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. LXVI.

Gorgonella (Val. emended), Delage et Herouard. Traite de Zoologie concrete, II, 2, 1901, p. 428.

Gorgonella Hickson. Alcyonaria of the Maldives, 1905, p. 817.

The original discription of this genus is as follows:
"Le sclerobase ramifie en fines branches rameuses et tres-divisees".
MILNE EDWARDS and HAIME (1857) define the genus as follows:

"Colony much branched, ccenenchyma very thin; calyces included or but little exserted".
(Translation).

KOLLIKER (1865) appears to have been the first to make a critical study of the spicules
of this genus. His definition, freely translated, is as follows:

"Axis commonly without layers, radiately striated. Calyces when evident, low warts.
Spicules of the coenenchyma warty double spheres and double spindles. .07 to .1 mm. in length
Polyp spicules are spindles .13 mm. long.

STUDER (1878) accepts the genus as originally denned by VALENCIENNES, and in 1887
he formally defined the genus as follows :

"•Gorgonella Milne Edwards et Haime. Colonie mannigfach in einer Ebene verzweigt,
oft durch Anastomosen der Zweige ein Xetzwerk bildend. Kelche niedrig warzenformig an zwei
Seiten der Aste angeordnet. Achse lamellbs, radienstreifig. Im Coenenchym warzige Doppelkuo-eln
und Doppelspindeln".

WRIGHT and STUDER (1889) define the genus practically as just quoted. HICKSON (1905)
points out the difficulty in distinguishing between Gorgonella and Verrucella.

The definition adopted for the present work will be as follows :

Colony flabellate, often reticulate; calyces low dome-shaped, or low truncated cones;
calyces on two or three sides of the branches, usually the former except on ultimate branches ;
coenenchyma thin ; axis solidly calcareous, without horny lamellae ; spicules double heads, girdled
spindles and true spindles.

The type species of this genus is Gorgonella sarmentosa (Lamarck). Other known species
are Gorgonella bianci Koch, G. distans Studer, G. granulata Esper, G. miniacea W. and S.,
G. orientalis W. and S., G. stricta (Lamk.), G. sarmentosa (Lamk.), G. umbella (Esper),
G. umbraculuvi (Ellis and Solander), G. verriculate Milne Edw. and Haime, and the new
species of the Siboga collection.

The writer believes that Nicella reticulata and N. pustulosa of THOMSON and SIMPSON
(Alcyonarians of the Indian Ocean, Vol. 2, 1909, pp. 266, 267) should be included in the
Genus Gorgonella. Their spicules are typical of that genus rather than of Nicella.

i . Gorgonella orientalis Wright and Studer.

Gorgonella orientalis Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 161.

Stat. 274. 5°28'.2S., I34°53'.9E. 57 meters.

Stat. 305. Mid channel in Solor Strait off Kampong Menanga. 113 meters.

Stat. 306. 8°27'S., 1 22° 54'. 5 E. 247 meters.

Stat. 310. 8°3o'S., ii9°7'.5E. 73 meters.

Colony (fragmentary) flabellate and reticulate in form. The specimen described is the
terminal part of a branch of a colony that was probably much larger. Height 6.1 cm., diameter
5.6 cm. The central branch is connected by numerous anastomoses with two others, one on
each side. The diameter of the largest branch is 2.5 mm. This forks 4 mm. above its proximal
end and each of the resulting branches gives off several lateral branchlets that anastomose
freely with branchlets from other branches. Ultimate branchlets from 1.5 mm. to 9 mm. apart.
The calyses are distributed on three sides of the branches, are thickly emplanted, and have a
tendency to a lateral arrangement. There is no evident longitudinal furrow or ridge on the
branches.

The individual calyces are rather low, dome-shaped verrucse with evenly rounded summits
and with their walls often contiguous. Their distal ends show a faintly indicated rosette or
star-shaped pattern, not nearly so evident as in Verrucella. A typical calyx measures .9 mm.
in height and has a diameter of 1.8 mm. The walls are remarkably thick and tough, consisting

8

of a dense mass of spicules immersed in a tough matrix of connective tissue. The polyps are
completely retractile and the upper surfaces of the tentacles are encrusted with spicules, many
of which are transversely placed.

The axis is hard, calcareous and without corneous layers.

Spicules. These are double heads and girdled spindles whose surfaces are covered
with verrucse which are often in whorls and not so massed together as in Nicella. There are
also true symmetrical spindles with pointed ends and regular whorls of verrucae ; and many
intergradations between the double heads and girdled spindles, and between the latter and true
symmetrical spindles. A few crosses are also seen.

Color. The colony is yellowish brown in color, ocraceous in places, and also shows
areas of grayish brown. The polyps are colorless in alcohol.

General distribution. The type locality is the Hyalonema ground, off Japan.
345 fathoms.

This specimen is referred with some hesitation to this species. Taking into account the
changes in form of the calyces in different stages of contraction it agrees fairly well with the
original description.

2. Gorgonella umbraculum (Ellis and Solander).

Gorgonia umbraculum Ellis and Solander. Natural History of Zoophytes, 1787, p. 80.
Gorgonia umbraculum Lamouroux. Exposition Methodique, 1821, p. 34.
Rhipidigorgia umbraculum Valenciennes. Comptes rendus, Acad. Sci., Paris, 1855, p. 13.
Rhipidigorgia umbraculum Milne Edwards et Haime. Hist. nat. des Coralliaires, 1857, p. 178.
Umbracella umbraculum Gray. Proc. Zool. Society of London, 1857, p. 288.
Gorgonella umbraculum Verrill. Bull. Museum of Comp. Zool., 1864, p. 37.
Gorgonella umbraculum Studer. Alcyonarien aus der Sammlung des Naturhistorischen Museums
in Liibeck, 1894, p. 118.

Stat. 204. 4°2o'S., i22°58'E. 75 to 94 meters.

Colony strictly flabellate and reticulate, 15 cm. in height and with a spread of 8.2 cm.
Main stem 2.7 cm. long and 2.8 mm. in diameter. At its distal end it breaks up into three
branches, one of which forms nearly the whole of the specimen. This branch is fairly symme-
trical in itself. Considering it as a colony its main stem is 14 mm. long and 2.6 mm. in
diameter, round in section and devoid of calyces. It can be traced for 4.4 cm. before it breaks
up and is dissipated in the general network of the colony. It gives off alternate branches
which are short or feebly branched, except the upper one which curves upward and outward
nearly to the top of the colony, giving off numerous lateral twigs which go to form the
reticulate mass. The anastomoses are quite numerous. The ultimate branchlets are very short,
and about 3.6 mm. apart, and very slender, being about i mm. in diameter. One side of the
branched colony is devoid of calyces. The latter are in two alternating rows, but are not
strictly lateral being more on the side opposite the nude face, and, if that be regarded as
anterior, being antero-lateral in position.

The calyces are more like truncated cones than verrucae ; or, they may be likened to
domes with their tops removed. A typical one measures i.i mm. in height and 1.5 mm. in
diameter. The top is flattened, not rounded as in G. rigida, and there is a distinct series of
8 lobes around the margin. The dorsal surface of the tentacles bears a number of spicules,
principally girdled spindles.

The coenenchyma is thin, and the axis solidly calcareous.

Spicules. These are mostly double heads and girdled spindles, as in the last species.
A few small, regular tuberculate spindles and clubs are also seen. The tubercles, although
closely set, are usually plainly in whorls on the spindles. Sometimes the girdle is obliterated
by such a whorl.

Color. The colony is bright scarlet throughout.

General distribution. The type locality is Batavia ; East Indies in general.

3. Gorgonella delicahila new species. (Plate I, figs. 2, 20; Plate X, fig. i).
Stat. 257. In Duroa Straits, Kei Islands. To 52 meters.

Specimens fragmentary, the largest being a flabellate branch, incomplete at both ends,
5.4 cm. long. The main branch is curved in a very open "S", and gives off seven branchlets
from one side, four of which are compound ; and four branches from the other side, three of
which are compound. The branchlets give off ultimate twigs in an irregularly alternate manner.
The main branch is but 1.2 mm. in diameter, and the ultimate twigs about .5 mm. The latter
are usually regularly curved. The calyces are lateral and alternate in position.

The individual calyces are very low rounded verrucae, a typical one measuring .5 mm.
in height and i.i mm. in diameter at the base They are about i mm. apart, on the average,
and vary greatly in size. The ends of the twigs are swollen, and contain two opposite calyces
that are considerably larger than the others. In general, however, the calyces are much smaller
than in any other species of this genus in the collection. There are a few minute spicules on
the dorsal surfaces of the tentacles, but it is difficult to ascertain their arrangement.

The axis is very hard, calcareous, with very deep grooves or impressions of the water-
vascular canals. The coenenchyma is thin.

Spicules. These are much like those of Gorgonella rigida, consisting of very heavily
tuberculated girdled spindles, quite stout, oval in outline and with the girdle often obliterated
by the encroachment of the tubercles. The double heads are relatively much less abundant
than in other species of the genus in the collection, and regularly tuberculate spindles with
the tubercles in whorls seem to be lacking.

Color. The colony is bright coral red, distal parts of the calyces yellow and the polyps
(in alcohol) white.

This species is much more delicate than any other member of the genus that the writer
has seen.

SIIMlGA-EXPEUITIE XII: ft*. 2

1O

4. Gorgonella rigida new species. (Plate I, figs. 3, 3*; Plate X, fig. 2).

Stat. 50. Bay of Badjo, West coast of Flores. Up to 40 meters.

Stat. 204. 4° 20' S., 1 22° 5 8' E. 75—94 meters.

Stat. 260. s°36'.5S., i32°55'.2E. 90 meters.

Stat. 305. Mid channel in Solor Strait off Kampong Menanga. 113 meters.

Colony incomplete, the basal portion and two large branches being present, flabellate
in form. The root forms a lobular mass growing over a pebble. Main stem to first branch
14 mm. long and 1.9 mm. in diameter, round in section. The first branch is large, and grows
outward and then curves downward and outward again, and attains a length of 4.6 cm. It
gives off four stiff branchlets from its upper side, three of which give off branchings of the
3rd order. Above the first branch the main stem gives off three branches on one side and
two on the other. The lower of these latter is a large branch which gives off two branchlets
from its lower side (one of which is compound) and three from its upper side (one of which
is compound). There are no anastomoses and the branches are all stiff and rigid. One side or
face of the branches is devoid of calyces.

The calyces are alternate in position, but are not strictly lateral, being turned toward
the face of the colony. The distance between calyces is about 1.3 mm. on the average. The
axis is densely calcareous.

The individual calyces are low, dome-shaped verrucse, one measuring .7 mm. in height
and 1.3 mm. in diameter. When the polyp is retracted the calyx mouth is entirely obliterated, not
leaving the rosette pattern of lobes often seen in allied forms. The mouth is indicated, however,
by a spot of darker red color. The tentacles are heavily spiculated with tuberculate spindles.

Spicules. These are double heads, spindles and girdled spindles. All of these are
more densely covered with tubercles than is the case in G. orientalis, and the spindles are
stouter. Otherwise the spicules are much the same in the two species.

Color. The colony is a rather light scarlet, or coral red throughout. The calyx mouths
are darker red, verging on crimson.

The differences in habit of growth, size of calyces and in the spicules seem sufficient
to justify the separation of this form from G. orientalis and other members of the genus. It
is near G. distans, Studer, but differs in the disposition of the calyces, which are in three to
four rows in G. disians and in thickness of stem and branches.

Genus Verrucella Milne Edwards et Haime.

Verrucella (in part) Milne Edwards et Haime. Hist. Nat. des Coralliaires, I, 1857, p. 184.

Verrucella Duchassaing et Michelotti. Memoire sur les Coralliaires des Antilles, 1860, p 33.

Verrucella Kolliker. Icones Histiologies, II, 1865, p. 140.

Verrucella Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 68.

Verrucella Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. LXVI.

Verrucella Studer. Alcyonaires provenant des Campagnes de 1'Hirondelle, 1901, p. 54.

Verrucella Delage et Herouard. Traite des Zoologie concrete, II, 2, 1901, p. 429.

1 1

Verrucella Hickson. Alcyonaria of the Maldives, 1905, p. 817.
Verrucella Nutting. Descriptions of Hawaiian Alcyonaria, 1908, p. 597.

The original definition of this genus is as follows :

" Polypieroide tres rameux, sclerenchyme assez epais. Calyces a bords verruciformes tres-
saillants".

DUCHASSAING et MiCHELLOTTi (1860) accept the genus, but do not define it. KGLLIKER
(1865) restricts 'the genus by separating from it Juncella gemmacea (Verrucella gemmacea
Milne Edwards) and is the first to give careful attention to the spicules. A free translation of
his definitiod follows :

"Axis calcareous, without lamellae. Calyces very pronounced warts. The strongly calca-
reous bases of the tentacles forming an 8-rayed star within calyx opening. Spicules of the
ccenenchyma beset with rounded and conical verrucae ; double heads with transitions to double
and simple spindles (in two species with little thorny double stars). Polyp spicules flattened,
small warty spindles and double spindles . 1 2 to .20 mm. long, also found in the ccenenchyma,
besides many small simple spindles".

STUDER (1887) and WRIGHT and STUDER (1889) adopt the definition of KOLLIKER without
material change. I find no subsequent discussion of the genus which adds anything of impor-
tance as to generic characters. The definition adopted for the present work is simply a
condensation and modification of that given by KOLLIKER, as follows :

Gorgonellidae with calcareous, usually homogeneous axis ; colony variously branched but
never simple ; calyces verruciform, their distal portions rounded and including an 8-rayed star
formed by the heavily spiculated tentacle bases. Spicules mainly double heads and girdled
spindles intergrading with simple spindles.

The type species of this genus is hard to determine. The first species named by MILNE
EDWARDS and HAIME is Verrucella violacea ; but this species is correctly regarded by KOLLIKER
as not belonging to the genus or family, but to the family Gorgonidse. This being the case
it seems safer to the present writer to indicate as the type Verrucella guadeloupensis Duch. et
Mich., which conforms strictly to the definition of the genus and is the first species mentioned
by KOLLIKER who was the first to define the genus according to modern methods. Other
species are Verrucella bicolor Nutting, V. Candida Ridley, V. flexuosa (Lamarck), ? V.furcata
(Lamarck), V. grant/era Kolliker, V. giiernei Studer, V. rubra Thomson and Henderson and
the new species about to be described.

i. Verriicella rubra Thomson and Henderson.

Verrucella rubra Thomson and Henderson. Ceylon Pearl Oyster Report, The Alcyonaria,
1905, p. 314.

Stat. 310. 8° 30' S., U9°7'.5E. 73 meters.

Colony (incomplete) sparingly branched in a straggling manner, 19. 5 cm. high. Stem
and branches of about equal diameter (1.5 mm.) troughout. The stem forks about 2.4 cm.
from its proximal end. One of the resultant branches sends off a very short simple branchlet

12

2.8 cm. from its orgin. The remainder of this branch is simple and 9.2 cm. long. The other
main branch gives origin to two branchlets, one of which is forked near its end on its inner
side and is unbranched throughout its distal 11.6 cm. The stem and branches are round in
section and the calyces are entirely included, or so nearly so that the surface seems smooth
at first glance. There are, however, very slight swellings that indicate the positions of the
polyps. These are mainly lateral in position and tend to form two alternating rows (or one
zigzag row) on each side. The front and of the branches are largely devoid or polyps, although
they occasionally invade these surfaces.

The individual calyces are indicated by very low swellings and by their mouths, which
are 8-rayed in retraction, as is characteristic of the genus. These mouths are about 1.4 mm.
apart on the average. The polyps are so strongly retracted that their characters can hardly
be made out. The basal portions of the tentacles are thickly encrusted with warty spindles and
have no very definite arrangement. There is a tendency, however, to a longitudinal disposition.

A cross section of a branch shows a fairly thick ccenenchyma and an axis which appears
to be solidly calcareous without the concentric lamellae of alternating hard and soft layers
characteristic of several genera of Gorganellidae.

Spicules, The outer layer is composed mainly of small very characteristic double
heads. The inner ccenenchyma is filled with usually larger girdled spindles, terete spindles,
a few double crosses and an occasional very small club.

Color. The entire colony is of a dull pink color.

General distribution. Type locality is in the Gulf of Mannaar.

This specimen has a considerable superficial resemblance to certain slender plexaurids.
It is a true gorgonellid, however, but with entirely immersed calyces.

2. Verrucella flaviflora new name. (Plate I, figs, i, i a.) ;
Stat. 47. Bay of Bima, near South fort. 55 meters.

Colony subflabellate in form, 29 cm. in height. The main stem divides dichotomously
four times and attains a height of 12.5 cm. Above the basal forking it is round and 3 mm.
in diameter. 1.7 cm. above its base it divides into three branches in a curious manner, as if
the outer branch were stuck on to where the others fork. The further branching is dichoto-
mous in the main, but in one large branch it is unilateral, there being six upright and parallel
branchlets from one side. The terminal twigs are often quite long, one being about 15 cm.
in length. These twigs are flattened, this .appearance being exaggerated by the fact that the
calyces are bilaterally arranged. A slight elevated ridge or keel is evident on one side of
many of the branches, and sometimes this can be seen on both sides. The twio-s are

o

1.7 mm. X 2.2 mm. in cross section. The calyces are all lateral and usually in a single row
on each side. They are emplanted, however, alternately toward the front and back of the
colony, thus giving the appearance of two rows. They are rather regularly spaced, the distance
between them being usually under i mm.

13

The individual calyces are in the form of truncated cones, often somewhat inclined
toward the distal end of the branch, but perhaps quite as frequently directed straight outward.
A typical calyx measures 1.2 mm. in height and 1.7 mm. in diameter at its base. The walls
are often transversely corrugated near the base, as if by the strong contraction of the polyps.
The margin is divided into eight evident lobes, often giving an appearance characteristic of
the genus Yerrucella as originally defined. The tentacles are very thickly encrusted with densely
tuberculate spindles forming a mosaic of longitudinally disposed spicules.

A cross section of a branch shows a fairly thick ccenenchyma, large water-vascular
canals immersed in the ccenenchyma ; and an axis cylinder without horny layers, being com-
posed entirely of limestone and showing concentric markings.

Spicules. The most common form by far is the form that I have called the girdled
spindle, and that other writers often call a double spindle. Often the girdle is invaded by
the verrucse, and the result is a terete spindle encircled by close set whorls of verrucae.
Double heads are formed where the two ends of the spicule are rounded in outline. The form
which KOLLIKER calls the "double sphere" J is a double head which approaches the form of
the girdled spindle, as that term is used in this work. Ordinary spindles with regular whorls
of verrucse are sometimes seen, and when one end is more turgid than the other, a club
is formed.

Color. The colony is a deep scarlet ; the polyps tinged yellow by the heavy coat of
yellow spicules on the tentacles.

This species superficially resembles Platycaulus on account of the flattening of the
branches. It also resembles V. grant/era Koll., except in color and measurements of the
calyces, V. grant/era having calyces .8 mm. in height.

3. Verrucella stellata new species. (Plate II, figs, i, \a\ Plate X, fig. 3).
Stat. 310. 8°3O'S., II9°7'.5E. 73 meters.

Colony subflabellate in form, branching dichotomously, general habit very slender, loose
and straggling, 47 cm. in height. The main stem is 4 mm. in diameter, and forks 10.6 cm.
above its base. The main branch on one side has five forkings at distances of 3 cm., 3.8 cm.,
4.2 cm., 2.7 cm., and 2.8 cm. Or one might regard the main branch as sinuous, bearing five
branchlets on its upper surface, all of the branchlets being dichotomously branched from one
to four times. The branches are 3 mm. in diameter at their bases, and the ultimate twigs
1.5 mm. in diameter and sometimes attaining a length of 17 cm., the whole colony being
much more delicate and slender than either of the other species examined. The ccenenchyma is
thin. The calyces are very small scarcely evident verrucas disposed on all sides of the branches
except on proximal portions, where they are scattered or absent. There are none on the stem.
There are four rows of calyces, including all sides of the branch which the rows encircle in

f

1 Icones Histiologicae, II, p. 140, PI. XVIII, fig. 42.

14

a poorly marked spiral. There are no evident median bare spaces or grooves, and the calyces
are much more distant than in other species of this genus in the collection. They are more
sparsely scattered over the front and back than on the sides of the branches.

The individual calyces are low, dome-shaped verrucse with their openings directed out-
ward, not inward nor upward, as in Juncella. A typical one measures 1.5 mm. in diameter
at the base and about .7 mm. in height. The apertures are star-like owing to the lobed mar-
gins below which the tentacle bases form a star-shaped figure, the tentacles themselves being
infolded. The polyp bodies are short and stout, and their upper portions bear numerous small
spicules transversely disposed. The tentacle bases are encrusted with spicules so as to form a
sort of pseudo-operculum in retraction. A cross section of one of the larger branches shows a
denser structure of the axis than in Jzincella, but there is still a very distinct appearance of
lamination. The water-vascular canals are very regularly disposed around the axis and a short
distance outside of it. In a longitudinal section of a part of a branch round and regular
openings are seen in the walls of the primary canals, and these communicate with the body
cavities of the polyps.

Spicules. These are quite characteristic of the genus Verriicella. The most common
forms are small, densely tuberculate double heads, the heads being separated by a narrow
girdle. This girdle is often obliterated, forming oval densely tuberculate spindles. True tuber-
culate clubs are also found, as well as regular spindles. All possible gradations between the
heads, clubs and spindles are found.

Color. The colony is a lively coral red throughout.

Genus Ctenocella Valenciennes.

Ctenocella Valenciennes. Comptes rendus, XLI, 1855, p. 14.

Ctenocella Milne Edwards et Haime. Hist. Nat. des Coralliaires, 1857, P- 1&S-

Ctenocella Ridley. Zoological Collections of H. M. S. Alert, 1884, p. 348.

Ctenocella Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 68.

Ctenocella Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. LXVI.

The original description of the genus Ctenocella is as follows :

"Le sclerobase s'allongeant en baguettes droites et pectinees d'un seul cote de la tige
principale".

MILNE EDWARDS and HAIME (1857) define the genus as follows:

" Polypieroide s'allongeant en baguettes droites et pectinees d'un seul cote".

STUDER (1887) gives an adequate definition of the genus which is freely translated
as follows:

"Colony peculiarly pectinate, the twigs springing as unbranched upright switches from
the upper sides of the branches. Calyces not prominent, on two sides of the branchlets. An
evident median furrow is present (on the branches). The spicules are warty double clubs1,
those of the calyces being, according to RIDLEY, distinct from those of the coenenchyma, being

1 These spicules would be called "double heads" in the nomenclature adopted in the present work.

15

longer and with two or three whorls of tubercles. The middle whorl is in the centre of the
spicule, so that the middle zone, so characteristic of the spicules of the ccenenchyma, is
here absent".

This seems to have been the last formal definition of the genus, that of WRIGHT and
STUDER in the Challenger Report (1889) being merely a translation of it, and may well stand
as a characterization of the genus for our present purposes.

The type, and only known species is Ctenocella pectinata (Pallas).

i. Ctenocella pectinata (Pallas).

Gorgonia pectinata Pallas. Elenchus Zoophytorum, 1766, p. 179.

Gorgonia pectinata Ellis and Solander. Natural History of Zoophytes, 1786, p. 85.

Gorgonia pectinata Lamouroux. Histoire des Polypiers coralligenes flexibles, 1816, p. 416.

Ctenocella pectinata Valenciennes. Comptes rendus, XLI, 1855, p. 14.

Ctenocella pectinata Milne Edwards et Haime. Histoire Naturelle des Coralliaires, 1857, p. 185.

Ctenocella pectinata Gray. Catalogue Lithophytes in the Collections of the British Museum,

1870, p. 26.

Gorgonella pectinata Kolliker. Icones Histiologicae, II, 1865, p. 140.
Ctenocella pectinata Studer. Monatsbericht der Konigl. Akademie der Wissenschaften zu Berlin,

1878, p. 657.

Ctenocella pectinata Studer. Versuch eines Systemes der Alcyonarien, 1887, p. 68.
Ctenocella pectinata Saville Kent. Great Barrier Reef of Australia, 1893, p. 200.
Ctenocella pectinata Studer. Alcyonarien aus der Sammlung des Naturhistorischen Museums in

Liibeck, 1894, p. 119.

Stat. 273. Anchorage off Pulu Jedan, East coast of Aru Islands. 13 meters.
Stat. 299. io°52'.4S., 123° i'. i E. Cyrus Bay, Rotti Island. 34 meters.
*Dutch South New Guinea. Dr. J. W. R. KOCH leg. 1904.

Like many other well known and striking forms this species seems not to have received
detailed description.

Colony 21 cm. high and with a spread of 37.5 cm. The main stem is 2 cm. long and
with a diameter of 5 mm. The main branches into which the stem forks extend almost hori-
zontally outward proximally and then curve gradually upward in their distal portions. They
have a basal diameter of 4 mm. and the longest one is 22.5 cm. in length. The branchlets
are erect, strictly unilateral, parallel and usually simple. Occasionally, however, they are forked,
and the proximal one on each branch bears ultimate branchlets which are also erect and
parallel. The branchlets have an average diameter of about 2.3 mm., are closely set, regularly
spaced and average about 4 to 5mm. apart. The longest one is 14 cm. long. There are
33 branchlets on one branch and 34 on the other.

The median bare space is not well marked on the front and back of the branches, the
calyces being distributed on all sides but more sparsely on the front.

The idividual calyces are very low verrucse, often practically obsolete, and their openings
are often so tightly closed as to be invisible. When not closed they are seen to be not at
the summit of the verrucae but exentric and often lateral, opening toward the side of the
calyx, or inclined distally. The calyces are small, and so low that their dimensions can not

i6

well be ascertained on account of there being no line of demarcation between their walls and
the general surface of the ccenenchyma. Another specimen, from Station 299, has more pro-
minent verrucae, a typical one measuring 1.2 mm. in height and 1.5 mm. in diameter at base.
It is papilliform, inclined distally and has a terminal aperture. The polyps are very small and
have a few spicules on the their upper parts, included the tentacle bases.

Spicules. These are nearly all very compact double heads densely covered and with
a very narrow girdle. There are also many stout spindles approaching an oval form and without
any girdle. A few clubs are seen and an occassional small slender spindle probably from
the polyps.

Color. The specimen described is a dull, dark red. Others are a creamy white, the
species being apparently dichromatic.

General distribution. This species is widely distributed in the Indian Ocean and
the East Indian region in general, Chinese Seas, and Australian region.

The largest specimen of this species in the collection is from Station 273. It is one
meter in diameter and creamy white in color.

Genus Juncella Valenciennes.

Juncella (in part) Valenciennes. Comptes rendus a 1'Acad. Paris, XLI, p. 14.

Juncella Milne Edwards et Haime. Histoire Naturelle des Coralliaires, I, 1857, p. 186.

Juncella Kolliker. Icones Histiologicae, II, 1865, p. 140.

Juncella Studer. Monatsbericht der Konigl. Akademie der Wissenschaften zu Berlin, 1878, p. 655.

Juncella Versuch eines Systemes der Alcyonaria, 1887, p. 67.

Juncella Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. LXV.

Juncella Studer. Alcyonarien aus der Sammlung des Naturhistorischen Museums in Lubeck,

1894, p. 1 1 6.

Juncella Delage et Herouard. Traite de Zoologie concrete, II, 2, 1901, p. 429.
Juncella Hickson. The Alcyonaria of the Maldives, 1905, p. 818.
Juncella Thomson and Simpson. Alcyonaria of the Indian Ocean, II, 1909, p. 269.

It is very difficult if not quite impossible to distinguish surely between the genera
Scirpearea and Juncella of the earlier writers. The original definition of the genus Juncella
is as follows :

"A tiges droites en baguettes, couvertes de cellules polypiferes eparses sur la sclerobase".

MILNE EDWARDS and HAIME (1857) give practically the same definition, somewhat con-
densed. They include in the genus Juncella jimcea Val., J. vimen Val. (= Gorgonia Juncea
Ellis and Solander), J. hystrix Val., and J. elongata (Pallas).

KOLLIKER (1865) defines the genus- as indicated in the following translation:

"Axis with alternating layers of horny and calcareous material. Part of the surface -of
the stem also pure limestone. Calyces reasonably well developed. Spicules of the ccenenchyma
partly warty double heads and partly clubs and double stars .05 to . i mm. long. Polyp spicules
small spindles". This writer includes in the genus Juncella juncea (Esper) and J. gcmmacea
.(Valenciennes).

GRAY (Proceedings Zoological Society of London, 1859) divides the genus into several

I/

genera, i. e. Juncella, Ellisella, Vimenella and ? Helicella, a step in which he has not been
followed by later writers.

STCDER (1878) found that this perplexing group could be divided into two subordinate
groups on the basis of the spicules, one group having an outer layer of clubs and an inner
layer of double clubs, the other group being characterized by double clubs and spindles. By
using this feature and certain characters of the calyces he arrived at a definition of the genus
Juncella which may be translated as follows:

- Stem simple or dichotomously branched ; calyces moderately or strongly exserted,
club-shaped. Coenenchyma thick, with an outer layer of clubs beneath which is a layer of
double clubs". This author includes in the genus as thus defined Juncella juncea (Pallas), J.
flexilis Studer, J. gemmacea (Valenciennes) and (provisionally) J. vimen Val. and y. tevts Verrill.

Later (1887) the same writer uses practically the same definition, but adds that the
"Calyces are in two lateral rows", a character that does not hold, although repeated by WRIGHT
and STUDER (1889).

HICKSON (1905) discusses the genus at some length and points out clearly the great
difficulty in difining the genera of this family. He combines the genera Juncella and Ellisella
of previous writers in the one genus Juncella. He would thus include about ten species in
the genus. Four of these (Juncella elongata Val., Ellisella calamus Studer, E. maculata Studer,
and Jnncclla spiral is Hickson) the present writer would not admit in the genus, using the
very characters pointed out by HICKSON, i. e. the presence or absence of club-shaped spicules.

THOMSON and SIMPSON (1909) do not attempt to define the genus or to place the large
collection of Jnncella and its allies at their disposal in their proper genera or species. A
course which they explain as follows :

"At the same time we refrain from multiplying species without some sound basis of
classification. This we hope to supply in a future study".

The present writer, while naturally appalled by a task from which such able authorities
shrink, feels that it is possible to make at least some progress in defining this perplexing
group, and particularly that the genus Juncella itself is capable of being fairly well seperated
from allied genera such as Ellisella and Scirpearella. He therefore suggests the following
definition for the genus Juncella :

Colony simple or branched, never anastomosing and usually dichotomous when branched.
Calyces usually on all sides of the colony, (except in young specimens where they are lateral)
often leaving a bare space on two opposite sides of the branches, papillate or club-shaped, inclined
distally, capable of partial retraction along with the strongly retracted polyp. Spicules in an
outer layer of club-stars with club end beset with distally directed spines underneath which is
a thick coenenchyma with very numerous double heads and double stars. Axis cylinder with
concentric layers of horny and calcareous matter.

The type species of this genus is Juncella juncea (Pallas). Other known species are
J. barbadensis Wright and Studer, J. flagellum Johnston, J. flexilis Studer?, J. fragilis
Ridley, J. gemmacea Valenciennes, J. racemosa Wright and Studer, J. trilineata Thomson
and Herderson, and the new species described beyond.

SIROGA-EXPEDITIE XIII i3. 3

i8

A number of other forms have been ascribed to this genus, but they are so inadequately
discribed as to make it impracticable to locate them properly.

i. Juncella juncea (Pallas). (Plate III, figs, i — 4).

Gorgonia juncea Pallas. Elenchus Zoophytorum, 1766, p. 180.

Gorgonia juncea Lamarck. Hist. Nat. Anim. sans Vert., 1816, p. 325.

Gorgonia juncea Ellis and Solander. Natural History of Zoophytes, 1786, p. 81.

Gorgonia juncea Pallas. Characteristic der Thierpflanzen, 1/87, p. 226.

Gorgonia juncea Lamouroux. Hist. Polypes coral, flexibles, 1816, p. 419.

Gorgonia juncea Lamarck. Hist. Nat. Anim. sans Vert., 1836, p. 499.

Gorgonia juncea Valenciennes. Comptes rendus, XLI, 1855, p. 14.

Juncella juncea Milne Edwards et Haime. Histoire Naturelle des Coralliaires, I, 1857, p. 186.

Helicella juncea Gray. Proceedings Zool. Society London, 1857, p. 481.

Juncella juncea Verrill. Bulletin Museum Comparative Zoology, 1864, p. 37.

Juncella juncea Kolliker. Icones Histiologicas, II, 1865, p. 140.

Juncella juncea Gray. Catalogue Lithophytes Brit. Museum, 1870, p. 25.

Juncella juncea Studer. Monatsbericht der Konigl. Akad. der Wissenschaften zu Berlin,

1883, p. 253.

Juncella juncea Ridley. Annals and Magazine of Natural History, Series V, Vol. XI, 1883, p. 253.
Juncella juncea Wright and Studer. Challenger Reports, Alcyonaria, 1889, p. 158.
Juncella gemmacea Wright and Studer. Challenger Reports, Alcyonaria, 1889, p. 158.
Juncella juncea Studer. Alcyonarien aus der Sammlung des Naturhist. Museums in Liibeck,

1 894, p. 1 1 6.

Juncella juncea Hickson. Alcyonaria of the Maldives, 1905, p. 820.

Juncella juncea Thomson and Henderson. Ceylon Pearl Oyster Report, Alcyonaria, 1905, p. 314.
Juncella juncea Thomson and Crane. Alcyonarians from Okhamandal and Kittiawar, 1909, p. 133.

It is altogether likely that several described forms, where the description was based on
young colonies (as was probably the case with several included in the above synonymy), should
be included here.

Stat. 50. Bay of Badjo, West coast of Flores. Up to 40 meters.

Stat. 60. Haingsisi, Samau Island near Timor. 23 meters.

Stat. 66. Bank between Islands of Bahuluwang and Tambolungan, south of Saleyer. 8 to

10 meters.

Stat. 162. Between Loslos and Broken Islands, West coast of Salawatti. 18 meters.

Stat. 164. i°42'-5 S., I30°47'.5 E. Near New Guinea. 32 meters.

Stat. 240. Banda Anchorage. 9 to 45 meters.

Stat. 250. Anchorage off Kilsuin, West coast of Kur Island. 20—45 meters.

Stat. 258. Tual Anchorage, Kei Islands. 22 meters.

Stat. 273. Anchorage off Pulu Jedan, East coast of Aru Islands. 13 meters.

Stat. 282. 8°25'.2S., i27°i8'.4E. 27—54 meters.

Stat. 310. 8°3o'S., ii9°7'.sE. Flores Sea. 73 meters.

Stat. 315. Anchorage East of Sailus Besar, Paternoster Islands. Up to 36 meters.

Colony unbranched, 64 cm. long. Axis calcareous, rigid proximally and flexible distally,
with a round cross section. There is a median dorsal and ventral line which is free from
calyces, narrow but evident. The diameter of the colony is 6.6 mm., and of the axis 3 mm.
The calyces are thickly and evenly emplanted on all sides of the colony, except on the narrow
median lines. Their arrangement is hard to make out, but they tend toward oblique rows of

19

eight or nine to the row, extending from the dorsal to the ventral median line. The basal
portion of the colony is almost bare of calyces. locm. from the base there are about 6 calyces
to the row, although almost the greatest diameter of the colony is here attained.

The individual calyces are papillate projections directed distally, but with their adaxial
sides appressed to the stem and their mouths turned directly towards the stem, so that they
look like fleshy scales with flattened, semicircular free margins. They average about 2.2 mm.
long and .8 mm. in diameter. Their distal ends are often somewhat furrowed longitudinally,
but this is not constant. There are also often pronounced grooves which are vertical and
appear on the sides of the calyces. These are sometimes so pronounced as to give the margin
the appearance of being trilobed, the middle lobe being much the largest. The calyx opening
proper is entirely concealed in the preserved specimens by being turned directly toward the
stem, leaving merely a curved, slit-like opening between the outer calyx wall and the ccenen-
chyma of the stem. The inner or adaxial wall is very short and thin compared with the outer,
and is entirely covered by the latter. The polyps are very small, resembling those of Isis
hippuris. They are so strongly retracted and so difficult to separate from the mass of small
spicules of the fleshy calyx that is is exceedingly difficult to ascertain their characters. The
mass of retracted tentacles is bent at an angle with the basal part, the latter being at right
angles to the axis and the former inclined toward it. The polyp body has its walls thickly
strewn with small oval or lenticular spicules and clubs, the former being probably undeveloped
clubs, some of which extend to the dorsal surface of the tentacles.

A section across the stem shows :

1 . A layer of club-stars with their club ends directed towards, and forming the surface of
the colony.

2. A very thick ccenenchyma filled with similar clubs in the outer portions intergrading with
symmetrical double heads and double stars in the inner parts.

3. A series of small round openings of the primary water-vascular canals symmetrically disposed
a short distance outside of the axis.

4. The axis cylinder, composed of a series of concentric lamellae of calcareous matter alter-
nating with horny layers within which is a practically solid core of calcareous matter.

A longitudinal section shows that the polyps communicate with the water-vascular canals
by definite round openings rather regularly disposed in the walls of the canals.

Spicules. These are all very minute and symmetrical. Those of the superficial layer
of the coenenchyma are club-stars, showing a distal clavate end truly club-shaped, covered with
thorny points directed distally. Below this spiny portion is a perfectly smooth shank of much
less diameter. The proximal end of the spicule shows a number of radiating points forming a
many-rayed star, or a head with numerous pointed rays symmetrically disposed on all sides.
They intergrade with the double stars or double heads which pack the inner portions of the
coenenchyma. These are beautifully symmetrical, minute spicules with a many-rayed head at
each end and a median perfectly smooth girdle. The outer spicules are yellow, while the

2O

double heads are mostly colorless. Small oval or lenticular spicules are found on the polyp
bodies and smaller ones in the tentacles. These intergrade with the club-stars, many of which
are found in the polyp walls.

Color. The colony described is a coral red. The exterior of the axis is olive and
the interior is white. Spicules yellow and white. Other specimens are yellow.

General distribution. The type locality is the Indian Ocean. It has also been
reported, probably erroneously, from the West Indies. It seems to have a wide range in the
East Indies.

This species is typically dichromatic, red and yellow colonies of apparently the 'same age
and from the same station being found. Other specimens are nearly white, in alcohol. Still
others are salmon color, and some are deep crimson.

A specimen about 5 cm. long from station 164 is found with others much larger. It
has the calyces laterally disposed and resembles some of the so-called species described as
new by previous writers. This intergrades completely with typical specimens as described above,
and from the same station. There seems no doubt that a number of specific descriptions have
been based on young specimens.

2. Juncella gemmacea (Valenciennes). Plate IV, figs, i, i a.

Gorgonia gemmacea Valenciennes. Manuscript in coll. of Museum, Paris, (fide Wright and

Studer).

Juncella vimen Valenciennes. Comptes rendus, XLI, 1856, p. 14.

Verrucella gemmacea Milne Edwards et Haime. Histoire Naturelle des Coralliaires, I, 1857, p. 185.
Juncella gemmacea Kolliker. Icones Histiologicae, 1865, p. 140.
Ellisella gemmacea Gray. Catalogue Lithophytes British Museum, 1870, p. 26.
Juncella gemmacea Klunzinger. Corallenthiere des Rothen Meeres, I, 1877 — 79, p. 53.
Juncella gemmacea Studer. Monatsbericht der Konigl. Akad. der Wissenschaften zu Berlin,

1878, p. 659.

Juncella gemmacea Ridley. Collection H. M. S. Alert, Alcyonaria, 1884, p. 346.
Juncella gemmacea Wright and Studer, Challenger Reports, the Alcyonaria, 1889, p. 158.
Juncella gemmacea Thomson and Henderson. Ceylon Pearl Oyster Report, Alcyonaria,

^OS, p- 313-

Stat. 273. Anchorage off Pulu Jedan, East coast of Aru Islands. 13 meters.
Stat. 299. Lat. io°52'.4S., i23°i'.iE. 34 meters.

Colony subflabellate in form, attaining a height of 25.5 cm. The first forking occurs
4.5 cm. above the base. Each of the resulting branches forks about 3.5 cm. above its origin.
The whole colony is regularly dichotomous in its branching, branchings of the ioth order being
attained. The average distance between forkings is perhaps 2 cm., although there is considerable
variation in this respect. As in many other cases of dichotomous branching it is possible to
regard the branchlets as all springing from one side of a sinuous branch. This is true in some
but not all of the branches. The writer thinks it possible that Juncella racemosa Wright and
Studer (Challenger Report, p. 159) is this species, and that these authors have taken this view
of what I believe to be dichotomous branching.

The basal part of the stem is devoid of ccenenchyma, the axis being 3.2 mm. in

21

diameter. The largest branch is nearly round in section and 4.5 mm. in diameter. This diameter
is fairly well maintained throughout the median portions of the colony. In general there is a
tendency to a flattening of the branches, although this is due more to the median grooves,
which extend in the mid-anterior and mid-posterior surfaces of all of the branches, than to any
real flattening of the branches. The terminal twigs are from 2.8 cm. to 7 cm. in length. The
calyces are evenly and thickly distributed on all sides of the branches except along the narrow
but evident median lines, resembling in their distribution those of species of Eunicea^ for
instance-, being so closely packed as to be usually contiguous. In some places they show a
strong tendency to an arrangement in spirals or oblique rows. On twigs they are arranged in
oblique rows of three or four on each side.

The individual calyces are stout club-shaped, with their distal swollen portions abruptly
bent toward the branch and their apertures facing the latter. A typical one measures a trifle
over 2 mm. in height and 1.3 mm. in its greatest diameter. The adcauline wall is less than
i mm. in height. In lateral view a slight appearance of lobulation of the margins is seen.
The tentacles are armed with small club-shaped spicules.

A cross section of the axis shows much the same features as in J. juncea, except that
there is a less symmetrical and regular alternation of calcareous and horny rings, the appear-
ance being more like that of the outer portions of the axis of Plexaurella.

Spicules. These are mainly of two sorts, which however intergrade. Ist a double
headed spicule with one head like a many-rayed star and the other oval or almost equally
round, but with distally directed imbricating spines. These intergrade completely with typical
double stars, much less numerous than the double heads.

Color. The colony is a light tan, or yellowish brown.

General distribution. The type locality is the Red Sea. Also reported from Ceylon
and the Indian Ocean.

3. jfuncella racemosa Wright and Studer.

Juncella racemosa Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 159.
Juncella racemosa Thomson and Simpson. Alcyonaria of the Indian Ocean, II, 1909, p. 268.

Stat. 99. 6° 7'-5N., 120° 26' E. 16 — 23 meters.

Stat. 164. i°42'.5 S., 1 30° 47'. 5 E. 32 meters.

Stat. 258. Tual Anchorage, Kei Islands. 22 meters.

Stat. 260. 5°36'.5S., I32°55'.2E. 90 meters.

Stat. 310. 8° 30' S., H9°7i'.5E. 73 meters.

Colony subflabellate, straggling in habit, 38 cm. in height, branching dichotomously.
The first forking is 7 cm. above the base. The main stem is mostly decorticated and has a
diameter of 3,3 mm. The branches are dichotomous, or unilateral according to interpretation \

1 It seems to the writer that there is much confusion over this point. He would call the branching unilateral when the main
branch is straight (not undulating) and bears branchlets on one side only. When the main branch is regularly undulating and sends
forth branches from the knees of the undulations the branching is dichotomous.

As a good illustration of the former Ctenoctlla may be cited, while the present species is an excellent illustration of the latter.

22

branchings of the fifth order being sometimes attained. The distance between branches varies
from 5.5 cm. to 3.5 cm. thus averaging much more than in the preceding species. The ter-
minal twigs are much longer, reaching a length of 1 6 cm. The diameter of the branches
varies from 3 mm. to 2 mm. near tips of branches. The median grooves are evident on the
proximal parts of the colony, but are almost obliterated on the distal parts. The calyces are
emplanted on all sides of the branches, and are in oblique rows of 3 to 5, although the rows
are often obscured by younger calyces being intercalated between the older and larger ones.
In some places the calyces on one side of the branch are inclined upward, while those on the
other side are inclined downward ; but this is exceptional.

The individual calyces are club-shaped, prominent, with their distal ends enlarged and
inclined toward the branch. The aperture seems in general to be more strictly terminal than
in other species and less inclined to face the branch. This, however, may be largely due to
the stage of contraction of the polyp. A typical calyx measures 1.6 mm. in length and
1.2 mm. in diameter. There is a slight appearance of lobulation around the margin. The dorsal
surfaces of the tentacles are armed with small, often bar-like spindles transversely disposed.

A cross section of a branch shows that the ccenenchyma is rather thick and the axis
is composed of many concentric and interrupted rings of calcareous and horny material alter-
nately disposed. The water-vascular canals are symmetrically disposed arround the axis, but
some distance outside of it.

Spicules. These are of two kinds characteristic of the genus. The club-stars have
the club ends more slender, as a rule, than in the last species, and simple clubs are rather
common. Typical double stars are rare. Double crosses are also found, as well as an occasional
simple spindle.

Color. The colony is a bright coral red throughout. The polyps are white.
General distribution. Type locality off Japan, 345 fathoms. This species is also
found in the Indian Ocean.

The specimens referred to this species are identified with some doubt, but the one
described agrees fairly well with the original description, particularly as regards spiculation,
manner of growth and the calyces.

THOMSON and SIMPSON regard Juncella miniacea as a synonym for this species.

4. Jucella sanguinea new species (Plate V, figs, i, ia- Plate X, fig. 4).

Star. 258. Tual Anchorage, Kei Islands. 22 meters.
Stat. 299. io°52'.4S., i23°i'.iE. 34 meters.

Colony (incomplete) subflabellate in form and attaining a height of 37.5 cm. The speci-
men consists apparently of one of the main branches of a much larger colony. The branching
is partly dichotomous and partly irregular. The main stem, or branch, is 4 mm. in diameter
and its first forking is 3.5 cm. above its base. The resultant branches are quite irregular, the
smaller one giving off branchlets from the outer side only, while the larger one is dichotomously

23

branched. The distance between branchings is from 6.8 cm. to 9 mm. (on distal parts). The
polyps are regularly and thickly emplanted on all sides of the branches, there being but a
slight indication of median grooves on the anterior and posterior surfaces ; but more thickly
on the distal than on the proximal parts of the colony. They are arranged in somewhat
irregular diagonal rows of about four to each row, reaching from back to front of the colony.

The individual calyces are much as in the last species, being club-shaped with their
openings turned toward the branch and often pressed against it. A typical calyx measure
2.8 mm. in height and 1.3 mm. in greatest diameter. The adcauline wall is about 1.3 mm.
long, the calyx being less extensively appressed to the branch than in J. gemmacea. The
oral end shows a small central aperture surrounded by eight rather shallow lobes. I am unable
to detect any spicules on the tentacles.

A cross section of the axis near the base shows a distinct difference from other species
of the genus examined. There is no central core of homogenious consistency, but the whole
axis is made up of interwoven calcareous and horny material, very much as is represented by
KOLLIKER in his figure of the axis of J. gemmacea l.

Spicules. These are much as in the last species, being almost exclusively of two
types, the most common being double heads or rather club-stars according to the nomenclature
adopted in this work. The second form is a typical double star. I can find no. true spindles
except some very minute ones which I suppose to be young spicules.

Color. The colony is deep crimson throughout. The axis has an olive green cast and
the polyps are white.

This species is closely allied to J. gemmacea. It differs, however, in being more robust
in habit, in the size and shape of the calyces, in having no tentacular spicules, and in color.
This last character, however, would not, alone, be a sufficient one to justify us in regarding
it as distinct. It differs from J. racemosa in size of calyces and in the character of the spicules.

Note on the genus Scirpearea.

The writer has already (p. 5) given his reasons for regarding this genus untenable.
He is further of the opinion that the species heretofore included in Scirpearea could be acom-
modated in other genera. Some of these species could be placed in Juncella, and such
species as Scirpearea furcata Hickson 2 could go into the genus Scirpearella as defined by
WRIGHT and STUDER.

Genus Scirpearella Wright and Studer.

Scirpearella Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 154.
Scirpearella Delage et Herouard. Traite de Zoologie Concrete, Tome II, 2me Partie, 1901, p. 429.

1 Icones Histiologies, II, 1865, plate XIV. fig. 4.
- Alcyonaria of the Maldives, II, 1905, p. 822.

24

The original definition of this genus is as follows :

"Colony simple or very feebly branched. Axis calcareous, brittle, smooth or symmetrically
grooved on the surface. Polyps arranged in spirals or sometimes in rows on the stem ; tentacles
and upper portion of the polyps retractile within prominent verrucae. Ccenenchyma moderately
thick, with spiny spindles and double clubs forming a roughened outer layer".

The mode of branching does not seem to be a good generic character in this group,
and is not available for this genus. The spicules, according to the figures given by WRIGHT
and STUDER (Plate XXXIV, figs. 5, 6. 7 and 8) are seldom true double clubs. This is also
true of the species in the Siboga collection. The forms called "double clubs" by WRIGHT
and STUDER would be called double heads by the present writer who would define the genus
as follows :

Gorgonellidae which are variously branched, but in no known case reticulate. Calyces
arranged in spirals or oblique rows in adult colonies, but opposite in young colonies, low ver-
rucae or domes capable of retracting with the polyps. Spicules mostly double heads and girdled
spindles, but simple spindles and a few clubs are also found.

The type of this species is Scirpearella profitnda Wright and Studer. Other known
species are Scirpearella aurantiaca Thomson and Henderson, 5. divisa Thomson and Hen-
derson, S. gracilis Wright and Studer, 5. indica Hickson, S. monilifdrmis Weight and Studer,
S. rubra Wright and Studer, S. (Scirpearea) fzircata (Hickson) and the new species des-
cribed beyond.

i. Scirpearella rubra Wright and Studer (Plate VI, figs, i — 5).

Scirpearella rubra Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 157.

Stat. 60. Haingsisi, Samau Island near Timor. 23 meters.

Stat. 80. 2°25'S., 1 17° 43' E. 50—40 meters.

Stat. 91. Muaras Reef, inner side, East coast of Borneo. Up to 54 meters.

Stat. 133. Anchorage off Lirung, Salibabu Island. Up to 36 meters.

Stat. 164. i°42'.5S., I30°47'.5 E. 32 meters.

Stat. 204. 4°2o'S., i22°s8'E. From 75 to 94 meters.

Stat. 240. Banda Anchorage. 9 — 45 meters.

Stat. 258. Tual Anchorage, Kei Islands. 22 meters.

Stat. 260. s°36'.5S., i32°5s'.2E. 90 meters.

Stat. 305. Mid Channel in Solor Strait, off Kampong Menanga. 113 meters.

Stat. 310. 8°3o'S., ii9°7'.sE. 73 meters.

Colony an unbranched stem (incomplete) 125 cm. long. Diameter near proximal end
6 mm., near distal end 4 mm., near middle 7 mm. The calyces are arranged in more or less
regular spirals around all sides of the stem, there being usually from seven to ten calyces in
a spiral, a little more than 2 mm. apart on the average. Proximally they are much more
distant, distally somewhat more closely approximated. Near the distal end one side of the
colony shows a rather broad bare band, but this is not evident on most of the stem. On the
proximal part there is a tendency to show two such bands, frequently invaded however, on
opposite sides of the colony.

25

The individual calyces are in the shape of a reversed horn or curved cone, the sum-
mit being curved upward and the opening being directed upward, or upward and a little
outward. A typical calyx measures 2.7 mm. in height and 2.8 mm. in diameter at base. Near
the distal end it has a diameter of 1.4 mm. and the walls on the distal portion show faint
indications of eight streaks of reddish against the lighter distal parts of the wall. The walls
are crowded with vertically disposed spicules, most of which seem to be tuberculate spindles.
The dorsal surfaces of the tentacles bear transversely disposed spindles. There are also short
stout spindles in the lower portion of the mesenteries, usually vertically placed. Very large
ova were found attached to four of the mesenterial filaments.

A cross section of the stem shows a moderately thick coenenchyma. The axis cylinder
is much like that of Juncella, with a comparatively dense core showing but slight evidence,
of concentric lamellation, and an outer envelope composed of concentric layers of horny and
calcareous matter. The water-vascular canals are regularly disposed around the axis and their
walls are filled with stout double clubs.

Spicules. By far the most common form is the densely tuberculate double head. Occa-
sionally these take the form of very stout crosses through longitudinal division of the heads.
The next most common form is the regular spindle, found mainly in the polyps themselves.
Sometimes these have regular whorls of verrucae, but they are usually stout, with irregularly
disposed warts. Clubs are rarely seen.

Color. The colony is coral red, as are also the polyps. Other colonies are creamy white.

General distribution. Type locality. Hyalonema Ground, off Japan, 345 fathoms.

A large series of this species makes it possible to determine that the young specimens
may be of either color. In these the calyces are lateral and usually opposite.

These intergrade with typical colonies, sometimes from the same station. Several spe-
cimens are slightly branched.

2. Scirpearella gracilis Wright and Studer. (Plate VII, figs, i — 5).

Scirpearella gracilis Wright and Studer. Challenger Report, the Alcyonaria, 1889, p. 156.

Stat. 58. Bay of Nangamessi, Sumba. Up to 36 meters.

Stat. 166. 2°28'.5S., i3i°3'.3E. 118 meters.

Stat. 204. 4°2o'S., 1 22° 58' E. 75 — 90 meters.

rStat. 208. 5°39'S., I22°12'E. 1886 meters.

Stat. 260. 5°36'.5S., i32°55'.2E. 90 meters.

Stat. 274. 5°28'.2S., I34°53'-9E. 57 meters.

Stat. 289. 9° o'.3S., 1 26° 24'.$ E. 112 meter?.

Colony originally forked, but with one branch missing. 44.5 cm. in length. Main stem
to fork 4.4 cm. long, 3.5 mm. in diameter, and devoid of calyces. Main branch devoid of
calyces for 13.5 cm., 3.5 mm. in diameter near base and diminishing to 3 mm. near distal
end. There is a shallow but distinct groove running along one side of the colony, and that

SIBOGA-EXPEDIT1E XIII

26

side is less thickly emplanted with calyces than the other and there is a distinct tendency
toward a bare band on either side of the groove. The calyces are thus on three sides of the
stem, where they often tend to a spiral arrangement, there being usually four calyces in each
oblique row from the impressed line on one side around to the one on the other. On the
distal part of the colony there are two opposite grooves, each in the centre of a distinct band
devoid of calyces. Here there is a double row of calyces on each side. Another fragment in
the same bottle appears to be the distal end of the branch just described. It is 32 cm. long.
It is therefore probable that this colony was originally 76.5 cm. long, tapering to a very
fine, slender end.

The individual calyces are subconical or rather truncated cones, rather low and broad.
A typical one measures i mm. in height and 1.9 mm. in diameter at the base. The tenta-
cles bear spicules, mostly double spindles, thickly encrusted over their basal portions.

Spicules. These are almost exclusively double heads and girdled spindles (double
spindles?) They are all densely tuberculate. Heavy fusiform spicules are formed when the
depressed girdles are obliterated by the invasion of tubercles. The double heads and girdled
spindles intergrade in every possible degree. Regular spindles, such as are common in S. rubra,
are almost never seen. Small crosses formed of four tuberculate heads joined by a cross-
shaped smoother part, are rather common, the four heads being so close as to be often con-
tiguous. I find no clubs.

Color. The colony is light grayish brown throughout, with a tinge of olive.

General distribution. Type locality. Off New Hebrides. 130 fathoms.

A young specimen from station 289 is 22.5 cm. long, very slender, with a length
of 9 mm. without calyces, and 15 mm. with calyces. The calyces are lateral and regularly
alternate, averaging about 2.3 mm. apart. In form they are low cones with rounded summits
which are directed outward. The spicules are as in the specimen described above. Another
specimen from the same station has lateral calyces which appear much more prominent on
account of the partial expansion of the polyps. It also shows a faint median impressed line.
A specimen taken from station 208, depth 1886 meters agrees quite well with young speci-
mens from station 260 (90 meters) and 204 (94 meters).

It is altogether likely that some of -the so-called species of this genus that have been
described as specifically distinct and are listed on page 24 are based on young specimens
of this form.

3. Scirpearella regia new species. (Plate VIII, figs, i, ia- Plate X, fig. 5).
Stat. 172. Gisser; anchorage between this Island and Ceram-Laut. 18 meters.

Colony (dried) an enormous bushy mass profusely branched in a dichotomous manner,
1 34 cm. in height. The base is a rudely hemispherical mass embracing corallines, wormtubes
etc., 19 cm. in diameter and 8 cm. high. The stem is 2.1 cm. in diameter at its base, bears

27

a stub of a branch 4 cm. from its proximal end and bifurcates about 1 2 cm. from its base.
The main branches bifurcate 10.5 cm. above their origin and continue to divide dichotomously
until branchings of the 8th order are attained. The ultimate twigs are very long and slender,
sometimes 60 cm. long, with an average diameter of 3.5mm. The branches and twigs are all
erect and proximately parallel, and are very numerous, there being considerably over 100. The
coenenchyma is thin, and the main branches are without calyces and often denuded of ccenen-
chyma. The calyces are distributed on all sides of the smaller branches and twigs. There is
no evidence of a median groove in the dried specimen, and the calyces are so shrunken in
the type that they can not be studied in a satisfactory manner. At the distal ends of the
twigs the coenenchyma is so shrunken that a cross section is sometimes triangular and some-
times quadrangular.

A cross section of a small branch shows a rather thin coenenchyma, regularly disposed
primary water-vascular canals and axis with a hard amorphous core of limestone and an outer
relatively thick investment of concentric layers of partly calcareous and partly horny material.

S p i c u 1 e s. These are mostly densely tuberculated double heads with the girdle usually
quite well marked and seldom entirely obliterated. These intergrade with girdled spindles,
double crosses, etc. Regular Greek crosses are also seen, but the most common form, next
to the double head, is the double cross. Simple spindles and clubs are rarely seen.

Color. The dried colony is a rather light reddish brown or terra cotta. It was probably
bright red in life. The spicules are an orange yellow.

This is by far the largest gorgonellid in the collection, and must have been a truly
magnificent specimen when alive.

4. Scirpearclla hemisphcrica new species. (Plate V, figs. 2 and 2 a ; Plate X, fig. 6).
Stat. 60. Haingsisi,' Samau Island near Timor. 23 meters.

Colony unbranched, 18 cm. in height. The basal part of the stem is devoid of calyces
and is 2.2 cm. in diameter. 5 cm. from its base the colony seems to have been forked and
one of the braches broken off short. Above this point the stem is bare for 2.6 cm., and but
1.2 mm. in diameter across the polypiferous portion. The calyces are very irregularly but rather
closely scattered on all sides of the stem with a tendency toward a more compact arrangement
on the sides.

The individual calyces are regularly hemispherical or dome-shaped, varying greatly in
size. One of the larger ones is 1.7 mm. in height and 2.3mm. in diameter at its base. They
are so completely closed by the strong contraction of the polyps that the openings are seen
with difficulty, but appear to be somewhat inclined toward the distal end of the colony. The
distal end of the polyp body is filled with a mosaic of spicules in the form of double heads
and double spindles, and these run out over the basal portions of the tentacles in broad bands
which appear conspicuously on the tentacles after the polyp has been dissected away from the
calyx, the red spicules contrasting with the yellowish polyp.

28

Spicules. Practically all of the spicules are very densely tuberculated double heads
with the girdles very narrow and often obliterated so as to produce an oval form compactly
covered with very closely aggregated verruca. Spindles are very rarely seen, and these are
probably from the polyps.

Color. The colony is coral red, the part of the stem which bears no calyces is dull
pink. The axis is light yellowish and the polyps yellow.

This species appears to be clearly distinct from the others in the collection, and I am
unable to identify it with any of the described forms. The shape of the calyces, although often
not very reliable specific characters, seems to be quite characteristic in this case. The spicu-
lation of the polyps also furnishes a good character. It is probably nearest 5. gracilis ; but
that species seems constant is color, no red specimens having been found.

\

Genus Nicella Gray.

Nicella Gray. Catalogue Lithophytes in the British Museum, 1870, p. 40.

Nicella Studer. Versuch eines Systemes der Alcyonarien, 1887, p. 67.

Nicella Wright and Studer. Challenger Reports, the Alcyonaria, 2889, p. LXV.

STUDER (1887) gives the only satisfactory definition of this genus that I have been
able to find. The following is a translation :

"Stem upright, branched, with thin coenenchyma and exserted calyces which stand vertically
and have their ends truncated. Calyces lateral on stem and branches, leaving a median space
bare. The spicules form an outer layer of small double clubs and an inner layer of longer
cylindrical or spindle forms, thickly covered with verrucae".

WRIGHT and STUDER (1889) give practically the same definition as the one quoted above.

With the single change of the words "double clubs" to "double heads" the definition
as given by STUDER can stand as acceptible for our present purpose.

The type of this genus appears to be Nicella dichotoma (Gray) a. But two other species
of the genus seem to have been described, i. e. Nicella pustulosa and N. reticulata, both by
THOMSON and SIMPSON. It seems, however, from the descriptions and figures, that neither of
these species can be regarded as belonging to this genus as defined by STUDER.

i. Nicella coralloides new species. (Plate IX, figs. 2, 2«; Plate XI, fig. i).

Stat. 117. i°o'.5 N., i22°56' E. 80 meters.

Stat. 257. Duroa Strait, Kei Islands. Up to 52 meters.

Colony flabellate in form, 1 1 cm. in height and with a spread of 9.5 cm. The base is
wanting, and also one large branch. The main stem is 1.8 cm. long to where it forks, and
one of the resultant branches is broken off. Diameter of stem about 2 mm. The main branch

1 This species, according to WRIGHT and STUDER, was originally named Scirpcarca dichotoma Gray and afterward changed by the
original describer to Nicella mauritiana Gray. This proceeding would not be considered allowable under our present rules of nomenclature,
and therefore the species should, in my opinion, be Nicella dichotoma (Gray).

29

is curved in the shape of a sickle and sends off a number of secondary branches which again divide
in an irregularly alternate manner and often fork distally, the ultimate branchlets being short,
rarely exceeding 1.5 cm. in length. The distance between secondary branches averages about
5 mm. There is no evident keel or groove in the median line, although it is indicated in
places. The calyces are lateral and alternate in position, and are usually about 1.5 mm. apart.

The individual calyces are cylindrical in form and are projected nearly at a right ancrle
with the branch, although they tend to be distally inclined. A typical calyx measures 1.3 mm.
in height and i.i mm. in diameter. The basal end is usually somewhat broader than the
distal. The margin is surrounded by eight lobes which are continuous with the bases of the
tentacles. These lobes are not so distinct as in the next species.

The tentacles are very thickly encrusted with a mosaic of bar-like spicules, and similar
spicules are placed vertically in the body wall of the polyp.

A cross section of a branch shows a relatively thin coenenchyma and a regular series
of water-vascular canals which, in a large branch, is separated from the axis by a thin layer
of ccenenchyma. The axis is calcareous, without lamellae of horny material.

Spicules. As in the next species, these are of two kinds, an outer layer of small
double heads and an inner layer of much larger bar-like forms with rounded corners and a
densely and finely tuberculate surface. This species differs from the next, however, in having
the girdles almost always obliterated in these bar-like forms, although it is occasionally seen
in what are probably immature spicules.

The double heads sometimes become double stars, and the bar-like forms sometimes
intergrade with slender spindles.

Color. The colony is a bright coral red; the polyps are white, but may originally
have been yellow. The axis is greenish.

Other specimens from the type locality have verruciform calyces. This is probably due
to the fact that the calyces partake of the retraction of the polyps. Another specimen is very
large, broken, the largest fragment being 25 cm. long.

2. Nicella carinata new species. (Plate IX, figs, i, i a\ PI. XI, fig. 2).

Stat. 117. i°o'.5 N. 122° 56' E., 80 meters. (Type).

Stat. 154. o°7'.2 N., i3O°25'.5 E. 83 meters.

Stat. 213. Saleyer Anchorage and surroundings, including Pulu Pasi Tanette, near the North

point of Saleyer Island. Up to 36 meters.

Stat. 257. In Duroa Strait, Kei Islands. Up to 52 meters. (Type).

Stat. 260. 5°36'-5S., i32°55'.2E. 90 meters.

Stat. 305. Mid Channel in Solor Straits, off Kampong Menanga. 113 meters.

Colony very profusely branching, irregular in form, but tending to form a sub-flabellate
structure. The base is absent, and the main stem is branched about 7.5 cm. from its proximal
end. It is about 3.1 cm. in diameter, round in section and ascends in a feebly geniculate
manner giving off branches alternately to the right and left. These branches are sometimes

3°

fairly straight and at others tortuous, and give off branchlets which tend to an alternate
arrangement and rebranch until branchings of the 6lh order are sometimes attained. The front
and back of the branches are devoid of calyces and often show a median longitudinal ridge
or keel. The distance between branches varies greatly, but will average perhaps 8 mm. The
tips of the twigs bear a pair of nearly opposite calyces with a blunt point between them indi-
cating the end of the axis. Calyces regularly alternate.

The individual calyces are quite prominent for this group, cylindrical in form and regu-
larly alternate in position. They are directed outward, upward and slightly forward or toward
the front of the colony. A typical calyx measures 1.6 mm. in height and 1.3 mm. in diameter.
They are often slightly longer in the distal parts of the colony. The walls show a tendency
to form eight longitudinal ridges or corrugations on the distal parts. The margin is eight-
lobed and the bases of the infolded tentacles are very prominent, forming a radiate mass, the
intervals between the tentacles showing as a star-like figure. The tentacle bases are heavily
spiculated, mostly with double heads similar to those on the calyx walls and general ccenen-
chyma. They encrust the dorsal surface of the tentacles well to the distal end. The ccenen-
chyma is rather thin and the axis is calcareous without evident lamellae of chitinous matter.

S p i c u 1 e s. These are very characteristic and consist mainly of two forms ; i st an outer
layer of minute double heads, densely tuberculate ; 2nd an inner and thicker layer of spicules
which differs from any others that I have seen aside from this genus. They are much larger
than the double heads, and bar-like in outline. The bars are somewhat narrowed at the ends
and have their corners rounded, although the ends are fairly square. Their surface is very
finely and densely tuberculate, so that the actual surface of the spicule is almost completely
hidden except for the median girdle which is usually sharply cut but sometimes obscured or
completely obliterated. Almost all of the spicules are one or the other of these two forms.
Rarely minute crosses are seen and very rarely minute regular spindles.

Color. The colony in general is yellowish golden brown ; the polyps very dark brown
or chocolate, a most unusual color, which is quite conspicuous when the polyps are dissected
out. None were expanded in the specimen described.

This species is a typical Nicella according to the original definition by GRAY, and
demonstrates the validity of the genus.

In a specimen from Station 257 the calyces are more crowded and proportionally shorter,
and grayish in color, as if bleached. A small specimen from station 260 has the calyces much
more distant than in the type, and is grayish brown in color.

Genus Ellisella Gray (modified by Studer).

Ellisella Gray. Proceedings Zoological Society of London, 1857, P- 257-

Ellisella Gray. Catalogue Lithophytes British Museum, 1870, p. 25.

Ellisella Studer. Monatsbericht der Konigl. Akademie der Wissenschaft. zu Berlin, 1878,9.659.

Ellisella Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 68.

Ellisella Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. LXVI.

STUDER (1878) defines the genus as follows:

"Stamm einfach oder gabelastig, Warzen kaum vorspringend, in zwei Reihen seitlich am
Stamm angeordnet. In der Rinde nur dopple Keulen und Spindeln".

The same author (1887) gives a slightly extended definition, translated as follows:

"Colony simple, or with forked branches, thick ccenenchyma and scarcely developed
calyces which are arranged in two rows. Ccenenchyma contains double clubs and spindles".

This definition is practically repeated by WRIGHT and STUDER (1889) since which time
it has apparently received no further definition. STUDER'S last definition may therefore stand as
the one here adopted, with the understanding that the "Dopple Keulen" of that writer be
interpreted as "double heads" according to the system here used.

The type of this genus appears to be Ellisella elongata (Pallas). Other species are
Ellisella calamus Studer, E. maculata Studer, and the single species secured by the Siboga
Expedition.

i . Ellisella flava new species (Plate IX, fig. 4, 4 a ; Plate XI, fig. 3).
Stat. 117. i°o'-5 N., 122° 56' E. 80 meters.

Colony fragmentary, the largest piece being 6.5 cm. long, dichotomously branched twice,
the first forking being immediately above the proximal end of the specimen. One of the
resultant branches is simple and is 4.1 cm. long. The other branch forks 3.7 mm. above its
origin, the resulting branchlets being simple, the longer 2.6 mm. and the shorter 1.4 cm. long.
The branches are slender with a comparatively uniform diameter of .7 mm. There is a clearly
defined furrow along the front of the branches. The calyces are disposed on two opposite
sides of the branches, in some places being regularly opposite in position and in others being
irregular. The former, however, seems to be the normal arrangement.

The individual calyces are very low subconical verrucae appearing as mere swellings
along the sides of the branches. A typical calyx measures 1.1 mm. in its longer diameter (being
oval in section) and .6 mm. in height. The margin is feebly marked with eight lobes. The
calyx walls are filled with regular spindles which are vertically disposed on the distal parts
and point toward the margin. Similar spindles encircle the basal parts and are longitudinally
disposed in the ccenenchyma of the branches. The tentacle bases are thickly encrusted with
smaller spindles disposed longitudinally, as a rule. On the distal parts of the tentacles there
is a dorsal band of small transverse spindles.

The coenenchyma is comparatively thin and the axis is hard, white and calcareous.

Spicules. The spicules of this form do not have the general facies of the spicules of
the Gorgonellidae at all. The most common form by far is the tuberculate spindle, terete in
form and almost never with a distinct girdle. The tuberculation is usually quite dense, so as
to hide the actual surface of the spicule. There are also a few clubs, crosses, small irregularly
branched forms and, very rarely, double heads.

Color. The colony, in alcohol, is rather bright yellow.

32

Were it not for the calcareous axis, without joints, the writer would hardly suspect this
species of belonging to the Gorgonellidae. It seems to fit better in the genus Ellisella than
in any other, although the practical absence of double clubs is not in accord with the defini-
tion adopted for that genus.

Genus Plumigorgia new genus.

Colony bearing symmetrically disposed, delicate, pinnately arranged ultimate branchlets,
greatly resembling a plumularian hydroid. Calyces minute. Spicules very minute, oval lenticular
and disk-shaped forms embedded in a translucent horn-like ccenenchyma from which it is
difficult to separate the spicules.

i. Plumigorgia hydroides new species. (Plate IX, fig. 3, 3 a; Plate XI, fig. 4).

p

Stat. 96. Southeast side of Pearl Bank, Sulu Archipelago. 1 5 meters.
Stat. 123. North Bay, Biaru Island. 36 — 27 meters. (Type).

Colony straggling in form, branches truly pinnate, greatly resembling a plumularian
hydroid; total height 13. 7 cm. The colony arises from an irregularly calcareous mass. The main
stem is 2 mm. in diameter near its base and forks 2.8 mm. above its origin. The main branches
are stiff and tortuous, most of their branchlets being broken off, but their stubs show that they
were rather regularly alternate, at least on the distal parts of the colony. The ultimate branchlets
are regularly alternate offshoots from the secondary branches, and are gracefully curved exactly
as are the hydrocladia in a plumularian. The ultimate twigs are about 3.5 mm. apart and
attain a length of 13 mm. The axis in these branchlets is exceedingly attenuated, being at
the ends no larger than a hair, and is calcareous throughout. The calyces are all lateral, but
are otherwise irregularly disposed, being opposite, subopposite or alternate in different parts
of the same twig.

The individual calyces are very minute for alcyonarians, a typical one being less than
.5 mm. in height and about as wide as high. They vary in shape, some being dome-shaped
and others in the form of short cylinders. Their walls are full of minute disk-shaped or
biscuit-shaped spicules. These are embedded in the ccenenchyma in a peculiar manner, not
being contiguous, but distinctly spaced as if stuck in a horn-like translucent ccenenchyma, each
spicule being distinctly isolated from its fellows. This horn-like matrix is peculiar in that it
resists boiling in a potash solution and comes off from the axis like a transparent pellicle with
the spicules still firmly embedded. An end view of a calyx shows that the aperture is very
small, when the polyp is retracted, and the margin is surrounded by eight not very strongly
marked lobes. The tentacles have very long and slender pinnules and their dorsal surfaces
are packed with minute disk-like spicules which are even smaller than those in the calyx walls
and ccenenchyma.

Spicules. These are of two forms which are really but modifications of one. They
are all lenticular or disk-shaped. Often the oval is constricted in the middle and thus a biscuit

33

form is produced. Their surfaces are all covered with fine granules which are much smaller
than verrucae. None of them are girdled and the granules are so thick that the spicules are
not translucent.

Color. The whole colony is creamy white.

A number of specimens from Station 96 were preserved in formalin and the spicules
were exceedingly hard to demonstrate. A few, however, were found and proved to be of the
same peculiar forms as described above.

Genus Isidoides new genus.

Axis solidly calcareous; calyces club-shaped; spicules comparatively large bar-like forms
with the ends swollen and the surface comparatively smooth, without evident verrucce. The
operculum is composed of eight segments, each consisting of a plate formed of adherent longi-
tudinally disposed bars.

i. Isidoides armata new species. (Plate VIII, figs. 2, 2«; Plate XI, fig. 5).
Stat. 267. 5°54'S., I32°56'.7E. 984 meters.

The specimen is fragmentary, the largest fragment being straggling in form, 1 5 cm.
high and with the base lacking ; although it is partly retained in another, where it is solidly
calcareous. The main stem, or branch, forks 5 cm. from its base, one of the resulting bran-
ches being broken off 3 cm. from its base and the other forming practically the entire spe-
cimen. This latter is denuded to its first lateral branchlet 4.4 cm. from its origin, i.i cm.
above this branchlet another arises on the same side which forms the main part of the spe-
cimen and is about 8.6 cm. long. It bears one terminal simple twig on one side and two on
the other. The axis is solidly calcareous, round, 1.5 mm. thick at its base. The calyces are
almost all lateral in position on the main branches, but may be on all sides of the distal
parts of the twigs. They are irregular in distribution, averaging about 2 mm. apart.

The individual calyces vary greatly in size and shape according to age and stage of
contraction of the polyps. Ordinarily they are tubular when retracted and club-shaped when
expanded, but the distal ends are almost always enlarged, even in retraction. A typical calyx
with retracted polyp measures 1.8 mm. in height and 1.4 mm. in diameter near its distal end.
One with the polyp partly expanded is 4 mm. high and 1.5 mm. in diameter. The calyx
walls are packed with comparatively large, bar-like or lenticular spicules which are criss-cross
but show a tendency to be vertical when the polyp is expanded and horizontal, especially
near the margin, when the polyp is retracted. The tentacles are closely folded over the oral
disk and their dorsal surfaces are heavily armed with longitudinally disposed bar-like spicules
like those in the calyx walls. These completely cover the dorsal surface with an imbricating
series, the distal ends of some overlapping the basal ends of others, and are adherent to
each-other so that the whole pseudo-operculum is made up of eight segments, each covering
one tentacle with an adherent mass of overlapping bar-like spicules.

SIROGA-EXPEDITIE XIII b*. 5

34

Spicules. These are all of the bar-like form, the bars often being somewhat expanded
distally. Their ends are evenly rounded and their surfaces are quite smooth showing merely
a very fine, dense, granulated appearance under moderately high powers of the microscope.
Their profiles are smooth, not showing verrucae or points of any size. They resemble in form
certain spicules found in the Isidae, e. g. Bathygorgia profunda, but are smoother than any
others that the writer has seen.

Color. The colony is very light brown and the axis is the same.

This remarkable form shows a close resemblance to certain Isidae, and would be placed
in that family were the axis jointed. It also shows an approach to the Primnoidae in the cha-
racter of the operculum.

DISTRIBUTION OF THE GORGONELLIDyE COLLECTED BY THE SIBOGA EXPEDITION.

List of Stations

at which Gorgonellidae were secured, together with the depth and character
of the bottom ; and the species collected at each Station.

STATION 47. Bay of Bima, near South Fort. 55 meters. Mud, with patches of fine coral sand.
Verrucella flaviflora.

STATION 50. Bay of Badjo, West coast of Flores. Up to 40 meters. Mud, sand and shells, according
to locality. Gorgonella rigida, Juncella juncea.

STATION 53. Bay of Nangamessi, Sambu. Up to 36 meters. Coral sand, mud near shore. Scirpea-
rella gracilis.

STATION 60. Haingsisi, Samau Island near Timor. 23 meters. Juncella juncea, Scirpearella rubra,
Scirpearella hemispheric*.

STATION 66. Bank between Islands of Bahuluwang and Tambolungan, south of Saleyer. Dead
Coral, Halimeda, Lithothamnion. 8 to 10 meters. 'Juncella juncea.

STATION 80. 2°25'S., U7°43'E. Borneo bank. From 40 to 50 meters. Fine coral sand. Scirpea-
rella rubra.

STATION 91. Muaras Reef, inner side; East coast of Borneo. Up to 54 meters. Hard coral sand.
Scirpearella rubra.

STATION 96. Southeast side of Pearl Bank, Sulu Archipelago. 15 meters. Lithothamnion bottom.
Plumigorgia hydroides.

STATION 99. 6°/'.5 N., 120° 26' E. North Ubian, Sulu Archipelago. 16 — 23 meters. Lithothamnion.
Jnncella racemosa.

STATION 117. i°o'-5 N., 122° 56' S. Kwandang Bay entrance, Celebes. 80 meters. Sand and coral.
Nicella coralloides, Nicella carinata, Ellisella flava.

STATION 123. North Bay, Biaru Island. 36—27 meters. Stone and Lithothamnion bottom. Plumi-
gorgia hydroides.

STATION 133. Anchorage off Lirung, Salibabu Island. Up to 36 meters. Mud and hard sand.
Scirpearella rubra.

STATION 154. o°7'.2 N., 130° 25'. 5 E. 83 meters. Grey muddy sand, shells and Lithothamnion.
Nicella carinata.

STATION 162. Between Loslos and Broken Islands, West Coast of Salawatti. 18 meters. Coarse and
fine sand, with clay and shells. Juncella juncea.

STATION 164. i°42'.5 S., 130° 47'.$ E. near New Guinea. 32 meters. Sand and stone mixed with
mud. Juncella racemosa, J. juncea, Scirpearella rubra.

36
STATION 166. 2°28'.sS., I3I°3'.3E. near Misool. 118 meters. Hard coarse sand. Scirpearella gracilis.

STATION 172. Gisser, anchorage between this Island and Ceram-Laut. 18 meters. Coral and Litho-
thamnion bottom. Scirpearella regia.

STATION 204. 4°2o'S., 122° 58' E. Huron Strait. 75—94 meters. Sand with dead shells. Gorgonella
umbraculum, G. rigida, Scirpearella rubra, S. gracilis.

STATION 208. 5°39'S., I22°I2'E. Banda Sea. 1886 meters. Solid green mud. Scirpearella gracilis.

STATION 213. Saleyer Anchorage and surroundings, including Pulu Pasi Tanette, near the North
point of Saleyer Island. Up to 36 meters. Nicella carinata.

STATION 240. Banda Anchorage. 9 — 45 meters. Black sand. Coral. Juncella juncea, Scirpearella rubra.

STATION 250. Anchorage off Kilsuin, West coast of Kur Island. 20 — 45 meters. Juncella juncea.

STATION 257. In Duroa Strait, Kei Islands. Up to 52 meters. Lithothamnion, sand and coral.
Gorgonella delicatula, Nicella coralloides, N. carinata.

STATION 258. Tual Anchorage, Kei Islands. 22 meters. Lithothamnion, sand and coral. Juncella juncea,
y. racemosa, J. sanguinea, Scirpearella rubra.

STATION 260. 5°36'.5S., I32°55'.2E. Near Kei Islands. 90 meters. Sand, coral and shells. Gorgo-
nella rigida, Juncella racemosa, Scirpearella rubra, S. gracilis, Nicella carinata.

STATION 267. 5°54'S., I32°56'.7E. Gray mud with brown upper layer. 984 meters. Isidoides armata.

STATION 273. Anchorage off Pulu Jedan, East coast of Aru Islands, (Pearl Banks). 13 meters. Sand
and shells. Ctenocella pectinata, Juncella juncea, J. gemmacea.

STATION 274. 5°28'.2S., I34°53'.9E. near Aru Islands. 57 meters. Sand and shells, stones. Gorgonella
orientalis, Scirpearella gracilis.

STATION 282. 8°2S'.2S., i27°i8'.4E. Anchorage between Nusa Besi and the N. E. point of Timor.
27 — 54 meters. Sand, coral and Lithothamnion. Juncella juncea.

STATION 289. 9°o'.3 S., I26°24'.5E. South coast of Timor. 112 meters. Mud, sand and shells.
Scirpearella gracilis.

STATION 299. io°52'.4S., 123° I'.i E. Buka or Cyrus Bay, South coast of Rotti Island. 34 meters.
Mud, coral and Lithothamnion. Ctenocella pectinata, Juncella gemmacea, J. sanguinea, Scirpearella gracilis.

STATION 305. Mid Channel in Solor Strait, off Kampong Menanga. 113 meters. Stony. Gorgonella
orientalis, G. rigida, Scirpearella rubra, Nicella coralloides, Nicella carinata.

STATION 306. 8°27'S., I22°54'.5E. near Floras. 247 meters. Sandy mud. Gorgonella orientalis.

STATION 310. 8°3o'S., II9°7'.5E. Flores Sea. 73 meters. Sand, dead coral. Gorgonella orientalis,
Verrucella rubra, V. stellata, Juncella juncea, J. racemosa, Scirpearella rubra.

STATION 315. Anchorage East end of Sailus Besar, Paternoster Islands. Up to 36 meters. Coral
and Lithothamnion. Juncella juncea.

It appears from this list that Gorgonellidae were secured at 35 stations out of about
147 stations where the bottom was sucessfully explored with the dredge or trawl.

Station 310 seems to have yielded the greatest number of Gorgonellidae, six species
having been secured, the next best yield being Station 260 and Station 305 where five species
were secured, while stations 204, 258 and 299 yielded four species each.

The most abundant species of Gorgonellidae in the collection is Jimcella juncea, which
was secured at 12 stations, the next in abundance being Scirpearella rubra which was dredged
from ii stations; Scirpearella gracilis coming 3rd, being found at 8 stations. But one species
of Gorgonellidae was secured from each of 21 stations in the foregoing list.

37

Table showing the geographic and bathymetric distribution
of the Gorgonellidae collected by the Siboga Expedition.

BATHYMETRIC.

GEOGRAPHIC, ASIDE FROM DUTCH
EAST INDIES.

i to
50
meters

50 to

100

meters

100 to
200

meters

Over

200

meters

Gorgonella onentalis ....

*

•
*
*

*

•
•
12

*
•
*
•
*
*
*

*

*

*
*

*
*
*

H

*
*

*
*

*

•

6

*

•
*

3

Off Japan.
East Indies in general (Studer).

Gulf of Manaar.
Red Sea.

Indian Ocean, New Guinea, China Sea, Australian
Indian Ocean. [waters.
Red Sea.
Japan.

Off Hyalonema Ground, Japan.
Off New Hebrides.

Gorgonella umbraculum ....
Gorgonella detlicatula

Gorgonella rigtda

Verrucella rubra

Verrucella flaviftora

Verrucella stellata

Ctenocella pectinata

jfuncella juncea

Juncella getnmacea

jfuncella racemosa

Juncella sanguined

Scirpearella rubra

Scirpearella Tacilts . . .

Scirpfarella regia

Scirpearella hemispherica . . .
\icella coralloides

Nicella carinata

Rllisella J?ai>a

Plumigorgia hydroides

Isidoides artnata

Totals ....

This table shows clearly that the Gorgonellidse are essentially shallow water forms, all
but one of the twenty one species in the Siboga collection having been secured from waters
less than 100 meters in depth. While six species in the above list are known to be from
more than 100 meters, but three of these Scirpearella gracilis, Gorgonella orientalis and Isidoides
artnata, were taken from over 200 meters by the Siboga Expedition. The records show that
about So hauls of the dredge or tawl were taken in over 200 meters, and these should have
yielded more than three species of Gorgonellidae, if that family is at all common at such depths.

The deepest water from which a gorgonellid was taken was at Station 208 where
Scirpearella gracilis was dredged. This species also has a very remarkable bathymetric range,
being found from 34 to 1886 meters. Isidoides armata was taken from a depth of 984 meters.

The geographical distribution indicated by the table is, as would be expected from the
bathvmetric table, much more restricted than would have been the case with more characteristic

*

deep water forms. All of the species represented by the Siboga collection are restricted to the
Indo-Pacific region. A few species of the family Gorgonellidae are, however, found outside of
this region, at least five species Verrucella gnadalupensis, V.ramosa, V. granulif era, Juncella
extans and J. hystrix having been reported from the Atlantic.

It remains true, however, that the apparent centre of distribution for this family is in
the Oriental region and that its occurence elsewhere is exeptional.

Literature cited
in the Report on the Gorgonellidae of the Siboga collection.

DELAGE et HEROUARD. Traite de Zoologie concrete; Tome II, 2me Partie, les Coelenteres, Paris, 1901.

DUCHASSAING et MlCHELOTTI. Memoire sur les Coralliaires des Antilles ; Memorie della Reale Accademia
delle Scienze di Torino, Serie 2, Vol. XIX, 1860.

ELLIS and SOLANDER. The Natural History of many curious and uncommon Zoophytes collected from
various parts of the Globe by the late JOHN ELLIS, systematically arranged and described by
the late DANIEL SOLANDER; London, 1786.

ESPER, E. J. Die Pflanzenthiere in Abbildung nach der Natur, mit Farben erleuchtet nebst Beschreibung;
Niirnberg, 1791.

GRAY, J. E. Synopsis of the Families and Genera of the Axiferous Zoophytes or Barked Corals; Pro-
ceedings of the Zoological Society of London, Part 25, London, 1857.

- Catalogue of Lithophytes or Stony Corals in the collections of the British Museum, London, 1870.
HlCKSON, SYDNEY J. The Alcyonaria of the Maldives, Part III, the Families Muriceidas, Gorgonellidae,

Melitodiae and the Genera Pennatula, Eunephthys; Fauna and Geography of the Maldive and
Laccadive Archipelagoes, Vol. II, part IV, 1905.

KoLLIKER, A. Icones Histiologicse oder Atlas der vergleichenden Gewebelehre; 2te Abtheilung, der feinere
Bau der hoheren Thiere; istes Heft, die Bindsubstanz der Ccelenteraten ; Leipzig, 1865.

- Anatomisch-systematische Beschreibung der Alcyonarien, iste Abth., die Pennetuliden; Frankfurt, 1872.
KLUNZINGER, C. B. Die Corallenthiere des Rothen Meeres, I. die Alcyonarien und Malacodermen, 1877.
LAMOUROUX, J. F. V. Exposition Methodique des Genres de 1'ordre des Polypiers, Paris, 1821.

- Histoire des Polypiers coralligenes flexibles, vulgairement nommes Zoophytes; Caen, 1816.
LAMARCK, M. DE. Histoire naturelle des Animaux sans vertebres, Tome 2; Paris, 1836.

MlLNE EDWARDS et HAIME. Histoire naturelle des Coralliaires, ou Polypes proprement dits, Tome pre-
mier, I; Paris, 1857.

NUTTING, C. C. Descriptions of the Alcyonaria collected by the Bureau of Fisheries Steamer Albatross
in the Vicinity of the Hawaiian Islands in 1902. Proceedings of the U. S. National Museum,
Vol. XXXIV, 1908.

PALLAS, P. S. Elenchus Zoophytorum, Hagae, 1766.

- Characteristik der Thierpflanzen; Nurnberg, 1787.

RlDLEY, S. O. The Coral-fauna of Ceylon, with descriptions of new Species. Annals and Magazine of
Natural History, Series 5, Vol. XI, London, 1883.

- Report on the Zoological Collections made by H. M. S. Alert, London, 1884.

STUDER, TH. Ubersicht der Anthozoa Alcyonaria, welche wahrend der Reise S. M. S. "Gazelle" urn die
Erde gesammelt wurden; Monatsbericht der Koniglich Preussischen Akademie der Wissenschaften
zu Berlin; Berlin, 1879.

- Versuch eines Systemes der Alcyonaria; Archiv fur Naturgeschichte; 53ster Jahrgang, Bd. i, Heft I, 1887.

39

STUDER, TH. Alcyonarien aus der Sammlung des Naturhistorischen Museums in Liibeck; Separatabdruck

aus den Mitteilungen der Geographischen Gesellschaft und des Naturhistorischen Museums in

Lubeck, II Ser., Heft 7 und 8; Lubeck, 1894.
Alcyonaires provenant des Campagnes du Yacht 1'Hirondelle (1886 — 1888). Resultats des Campagnes

scientifiques accomplies sur son Yacht par Albert ler, Prince Souverain de Monaco, Fascicule XX;

Monaco, 1901.
THOMSON and CRANE. Report on a Collection of Alcyonariens from Okhamandal and Kittiawar ;

London, 1909.
THOMSON and HENDERSON. Report to the Government of Ceylon on the Pearl Oyster Fisheries in the

Gulf of Manaar. By W. A. HERDMAN, Supplementary Reports, N°. XX, the Alcyonaria;

London, 1905.
THOMSON and SIMPSON. Report on the Alcyonaria collected in the Indian Ocean by the Royal Indian

Marine Survey Ship " Investigator"; Part II, the Alcyonarians of the Littoral Area; Calcutta, 1909.
VALENCIENNES, M. Extrait d'une monographic de la famille des Gorgonidies de la Classe des Polypes;

Comptes rendus hebdomadaires des Seances de 1'Academie des Sciences, XLI, Paris, 1855.
VERRILL, A. E. List of the Polyps and Corals sent by the Museum of Zoology to other Institutions in

Exchange, with Annotations; Bulletin of the Museum of Comparative Zoology, Vol. I, N°. 3,

Cambridge, 1864.
WRIGHT and STUDER. Report on the Alcyonaria collected by H. M. S. Challenger during the years

! 873—76. The Voyage of H. M. S. Challenger, Zoology, Vol. XXXI, London, 1889.

EXPLANATION OF PLATES

The photographs were made from nature by the author
The spicules were drawn under the camera lucida by Mr. DAYTON STONER.

PLATE I.

Fig. i. Verrucella flaviflora (new name), Natural size, i a, part of branch x 5-
Fig. 2. Gorgonella delicatula n. sp. Natural size 2 a, part of branch X 5-

Fig. 3. Gorgonella rigida n. sp. Natural size. 301, part of branch X 5-

SIBOOA-EXPEDITIE XIII b'. C. C. NUTTING, GORGONELL1DAE.

PLATE II.

Fig. I. Verrucdla stellata n. sp. Natural size. I a, part of tip of branch X 5-

S1BOQA-EXPEDITIE. XIII b*. C. C. NUTTING, GORGONELLIDAE.

PLATE III.

Fig. I. Juncella juncea (Pallas). Part of large red specimen, natural size.

Fig. 2. Juncella juncea. Part of another colony, red, with calyces more prominent. Natural size. 2 a, part

of same specimen X 5.

Fig- 3- Juncella juncea. Part of a white colony, showing median impressed line. Natural size.
Fig. 4. Juncella juncea. Part of another white colony, much smaller. Natural size.

SIBOOA-EXPEDITIE XIII b». C. C. NUTTING, GORGON ELLI DAE.

Ill

PLATE IV.

Fig. I. Juncella gemmacea (Val.). Natural size, i a, part of branch X 5.

SIBOGA-FXPEDITIE XIII b". C. C. NUTTING, GORGONELLIDAF.

IV

PLATE V.

Fig. i. Juncella sanguinea n. sp. Natural size. i a, part of branch X 5.

Fig. 2. Scirpearella hemispherica n. sp. Natural size. 2 a, part of branch X 5.

SIBOOA-RXPEDITIE XIII b3. C. C. NUTTING, GOROONELL1DAE.

PLATE VI.

Fig. i. Scirpearella rubra W. and S. Large red colony. Natural size, i a, part of colony X 5-

Fig. 2. Scirpearella rubra. Smaller red specimen. Natural size.

Fig. 3. Scirpearella rubra. More slender, white form. Natural size.

Fig. 4. Scirpearella rubra. Small red specimen. Natural size.

Fig. 5. Scirpearella rubra. Young colony, white, with opposite calyces. Natural size.

S18OOA-EXPEDITIE XIII b3. C. C. NUTTING, GOROONELLIDAE.

VI

PLATE VII.

Fig. i. Scirpearella gracilis W. and S. Fairly large colony, with calyces on all sides. Natural size.

i a, part of colony X 5-
Figs. 2, 3 and 4. Smaller colonies of the same species, with alternate calyces. Natural size. 30, part of

colony X 5.
Fig. 5. A very young colony, same species, with very regular lateral and alternate calyces.

S1BOOA-EXPEDITIE XHF b'. C. C. NUTTING, GORGONELLIDAF.

VII

•* *

*• e

'

PLATE VIII.

Fig. i. Scirpearella regia n. sp., with meter rod at right to show actual size, i a, part of branch X 5-
Fig. 2. Isidoides armata n. sp. Natural size. 2 a, part of branch X 5-

SIBOOA-EXPEDITIE XIII b*. C. C. NUTTING, GORGONELLIDAF.

VIII

v . V « %• •

. t :,-. - • ; •. .-
.- :

k . .
. -. .

PLATE IX.

Fig. i. Nicella carinata n. sp. Natural size. i a, part of branch X 5-

Fig. 2. Nicella coralloides n. sp. Natural size. 2 a, part of branch X 5-

Fig. 3. Plumigorgia hydroides n. sp. Natural size. 30, part of colony X 5-

Fig. 4. Ellise lla flava n. sp. Natural size. 4 a, part of branch X 5-

SIBOOA-EXPEDITIE XIII b3. C. C. NUTTING, GORGON ELL1 DAE.

IX

;v

PLATE X.

Fig. I. Gorgonella delicatula n. sp. Group of four spicules, a, b, c and d. X 330.

Fig. 2. Gorgonella rigida n. sp. Group of four spicules, a, b, c and d. X 330.

Fig. 3. Verrucella stellata n. sp. Group of five spicules, a, b, c, d and e. X 330.

Fig. 4. Juncella sanguinea n. sp. Group of four spicules, a, b, c and d. X 330.

Fig. 5. Scirpearella regia n. sp. Group of four spicules, a, b, c and d. X 330.

Fig. 6. Scirpearella hemispherica n. sp. Group of three spicules, a, b and c. X 330.

Siboga-Expeditie XIII b3 C. C. NUTTINQ, Gorgonellidae.

Dayton Stoner del.

PLATE XL

Fig. i. Nicella coralloides n. sp. Group of five spicules, a, b, c, d and c. X 330.

Fig. 2. Nicella carinata n. sp. Group of three spicules, a, b and c. X 330.

Fig. 3. Ellisella flav a n. sp. Group of three spicules, a, b and c. X 330.

Fig. 4. Plumigorgia hydroides n. sp. Group of four spicules, a, b, c and d. X 330.

Fig. 5. Isidoides armata n. sp. Group of five spicules, a, b, c, d and e. X no.

Siboga-Expeditie XIII b3 C. C. NUTTING, Gorgonellidae.

XI

i

--

1
1

•

Dayton Stonsr del.

THE GORGONACEA OF THE SIBOGA EXPEDITION

VII. THE GORGONID/E

Siboga-Expeditie

XIII b*

THE

GORGONACEA OF THE SIBOGA EXPEDITION

VII. THE GORGONID^:

BY

C C NUTTING

Professor of Zoology, State University of Iowa

With 3 plates

(Aided by a grant from the ELIZABETH THOMPSON SCIENCE FUND)

LATE E. J.

PUBLISHERS AND PRINTERS

LEYDEN —

REESE

THE GORGONACEA OF THE SIBOGA EXPEDITION

VII. THE GORGONID^E

BY

.C. C. NUTTING,

Professor of Zoology, State University of Iowa.

With 3 plates.

(Aided by a grant from the ELIZABETH THOMPSON SCIENCE FUND.)

Family GORGONID^E Verrill.

Gorgonacees (in part) Milne Edwards et Haime. Histoire naturelle des Coralliaires, I,

1857, p. 144.

Gorgonia Kolliker. Icones Histiologies, II, 1865, p. 135.
Gorgonidce Verrill. Transactions Connecticut Academy of Arts and Sciences, I, 2, 1867 — 71,

p. 384.
Gorgonacees (in part) Duchassaing de Fontbressin. Revue des Zoophytes et des Spongiaires

des Antilles, 1870.

Gorgonida Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 61.
Gorgonidce (in part) Ridley. Alcyonaria of the Mergui Archipelago, 1888, p. 233,
Gorgonida Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 146.
Gorgonince Delage et Herouard. Traite de Zoologie Concrete, II, 2, 1901, p. 420.
Gorgonida: Hickson. Alcyonaria of the Cape of Good Hope, II, 1904, p. 227.
Gorgonida Nutting. Alcyonaria of the Californian Coast, 1909, p. 722.

Although VERRILL (1867 — 71) appears to have been the first one to use the name
Gorgonidae in its restricted sense as a family designation, he does not appear to have defined
it, although he discusses several of its genera at considerable length.

SIBOGA-EXPEDITIE XII! 6*. '

KOLLIKER (1865) uses the word Gorgonidae as a family designation, but as thus used
it embraced the whole of what is now known as the Gorgonacea. This writer employs the
name "Gorgonacea" for a section of his subfamily "Gorgoninae", thus practically reversing the
relative rank of the names as we now know them. In his genus "Gorgonia" he includes
practically all of the species then known that would now go into the family Gorgonidae. The
first formal and adequate definition of the family was given by STUDER in 1887 in his classic
work "Versuch eines Systemes der Alcyonaria" which is probably the most helpful single con-
tribution to our knowledge of the general systematic treatment of the Alcyonaria. His definition
will be adopted for our present purpose, and may be translated as follows :

"Colony upright, branched, usually flabellate, with horny (rarely calcareous) axis. Polyps
bilaterally or biradially placed on stem and branches, corresponding to a biradiate arrangement
of the canal system. The upper part of the polyp is retractile either into an exserted calyx
or within the ccenenchyma which presents a smooth surface. The spicules are small, preponder-
atingly spindles which are not arranged in two layers".

The region explored by the Siboga Expedition is one in which the family Gorgonidae
is very poorly represented, and the collection contains so few species (five in all) that it does
not offer a basis for a systematic discussion. The writer will therefore content himself with
adopting, in the main, the excellent generic definitions of STUDER, and will discuss only the
four genera represented in the collection.

The paucity of representation of this family in this and other extensive collections in
the East Indies is remarkable when contrasted with the great number of Gorgonidae in the
West Indies and on the Pacific Coast of tropical America, and indicates very plainly that the
centre of distribution of the Gorgonidae is in the warmer waters of the Western Hemisphere.

Synoptic view of the genera and species of GORGONID/E
collected by the Siboga Expedition.

New species are indicated by an asterisk (*).

Lophogorgia.

Lophogorgia *pinnata.

Leptogorgia.

Leptogorgia *formosa.

Stenogorgia.

Stenogorgia miniata, S. *stiideri.

Platycaulus.

Platyca^t:lus *sibogce.

The only previously known species in this list, Stenogorgia miniata (Valenciennes) has
hitherto been known only from the Atlantic Ocean, where it has been taken in the West
Indies and Azores.

Systematic description of genera and species.
Genus LophogOfgia Milne Edwards et Haime.

Lophogorgia Milne Edwards and Haime. Histoire naturelle des Coralliaires, I, 1857, p. 167.

Gorgonia (in part) Kolliker. Icones Histiologicae, II, 2, 1865, p. 139.

Leptogorgia (in part) Verrill. Transactions Connecticut Academy of Arts and Sciences, I, 2,

1867—71, p. 387.
Leptogorgia Duchassaing de Fontbressin. Revue des Zoophytes et des Spongiaires des Antilles,

1870, p. 17.

Lophogorgia Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 63.
Lophogorgia Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 150.
Lophogorgia Delage et Herouard. Traite de Zoologie Concrete, II, 2, 1901, p. 420.

The original definition of this genus is as follows:

" Polypieroide etale en forme de panache ou d'eventail, a une ou a plusieurs branches
maitresses et a tige aplatie".

KOLLIKER (1865) placed practically all of the genera of Gorgonidae, including Lophogorgia,
in the genus Gorgonia.

No further definition of the genus appears until STUDER, (1887) gave the definition of
which the following is a translation :

"Colony upright, flabellate, with flattened stem and branches and cylindrical twigs.
Polyps without calyces, immersed in the ccenenchyma and scattered on all sides of the ultimate
branchlets. The larger water-vascular canals are on the flattened sides of the branches, but are
peripheral on the round twigs. Spicules small double spindles".

WRIGHT and STUDER, (1889) give a definition which is practically identical with the one
just quoted, and which is adopted in the present work.

The type of the genus Lophogorgia is Lophogorgia palma (Pallas). Other described
species are Lophogorgia alba *, L. crista Mobius, L. irregularis Thomson and Henderson,
L. liitkeni Wright and Studer, L. rubrotincta T. and H. and the single new species in the
Siboga Collection ~.

i. Lophogorgia pinnata new species. (Plate I, figs, i, \a\ Plate III, fig. i).
Stat. 273. Anchorage off Pulu Jedan, East coast of Aru Islands. 13 meters.

Colony flabellate in form, branching pinnate, not anastomosing, height 31 cm., spread
about 1 2 cm. The stem and larger branches are flattened and marked on their flat surfaces
with impressed grooves which are often tortuous and irregular in number and extent. Stem
with a cross section of 4.5 mm. X 3-6 mm. 4 cm. from its base it divides into two large and
subequal branches. One of these is quite tortuous in its proximal part, giving off irregularly
alternate and lateral branchlets which are usually simple, slender and curved outward. The
distal part of this branch is comparatively straight and gives off usually simple irregularly

1 This species is merely mentioned by DUCHASSAING DE FONTBRESSIN (1870) who does not give the authority.

* L. flammta (Ellis and Solander) is regarded by MILNE EDWARDS and HAIME as a synonym of L. palma (Pallas).

alternate branches some of which bear branchlets of the third order. The other main branch
is straighter than the first, gives off branchlets from one side only of its proximal part and is
pinnately branched distally. One of the proximal branchlets bears a regularly spaced row of
slender unilateral branchlets resembling those of Ctenocella. The ultimate branchlets are all
long, slender, round and usually erect. They reach a length of 17 cm. and are about 1.5 mm.
in diameter. The calyces are entirely included, being indicated by mere tumidities on the surfaces
of the branches and by their openings. They are lacking on the main stem and proximal parts
of the larger branches and are mostly lateral on the smaller branches, but sometimes on all
sides of the twig terminations.

The individual calyces are so entirely included that they do not admit of description or
measurement. Their mouths are indicated by oval openings such as are found in many Plexaurids,
and often approach the form of linear slits about 5 mm. in length. Their margins form a
slightly elevated rim with scarcely any evidence of lobes. The polyps are deeply retracted
within the ccenenchyma, where they take the form of flattened discs with an oval outline and
with their tentacles armed with longitudinally disposed spindles.

A cross section of the stem shows a thin ccenenchyma and large water-vascular canals
on all sides of the flattened horny axis.

Spicules. These are nearly all double spindles or girdled spindles, more slender than
usual and often curved. They are surrounded by symmetrical whorls of verrucse, the two whorls
which bound the girdle being more conspicuous than the others, which diminish gradually in
size towards the ends of the spindle. The spicules of this species are remarkably uniform in
character, differing mainly in size, due probably to relative age.

Color. Colony white, axis black proximally, lightening distally.

Genus Leptogorgia Milne Edwards (emended by Verrill).

Leptogorgia (in part) Milne Edwards et Haime. Histoire naturelle des Coralliaires, I, 1857, p. 163.

Gorgonia (in part) Kolliker. Icones Histiologicae, II, 1865, p. 139.

Leptogorgia Verrill. Transactions Connecticut Academy of Arts and Science, I, 2, 1867 — 71,

P- 387-

Leptogorgia Verrill. American Journal of Arts and Science, XL VII, 1869, p. 419.
Leptogorgia Studer. Monatsbericht der Konigl. Akad. der Wissenschaften zu Berlin, 1878, p. 654.
Leptogorgia Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 151.
Gorgonia (in part) Hickson. Alcyonaria and Hydrocorallinse of the Cape of Good Hope,

1900, p. 8 1.

Leptogorgia Delage et Herouard. Traite des Zoologie concrete, II, 2, 1901, p. 420.
Leptogorgia Nutting. Alcyonaria of the California!! Coast, 1909, p. 722.

The original definition of this genus is as follows :

"Les especes a axe non calcifere, dont le ccenenchyme est pelliculaire c'est-a-dire tres-
mince, et d'un tissu serre et dont les calyces n'ont pas les bords saillants. Elle se distingue
done des Gorgones proprement dites, par 1'absence de verrues caliciferes et s'eloigne des
Plexaures par la disposition du coenenchyme, qui, chez ces derniers, est remarquablement epars
et d'une texture subereuse".

5

VERRILL (1869 — 71) defines the genus as follows:

"Spicula of the ccenenchyma mostly small double-spindles of two forms, longer and
shorter. Branches usually slender, subdividing in various ways; often reticulate, pinnate or
bipinnate. Cells usually prominent, sometimes flat, mostly in lateral rows or bands".

STUDER (1887) gives a definition which is acceptable for our purpose, and of which the
following is a translation :

"Colony variously branched, more or less flabellate, often reticulate. Calyces small or
included, usually disposed laterally with naked ccenenchyma between. On the bare surfaces the
water-vascular canals are indicated by furrows. Spicules minute double spindles of longer and
shorter forms.

The type of this genus is Leptogorgia viminalis (Esper). A large number of species
have been assigned to this genus, especially by VERRILL, and most of the species in the following
list are given on his authority, the present writer having been unable to examine the types or
to identify the species by the usually very brief descriptions.

Leptogorgia adamsii Verrill, L. alba Verrill, L. agassizii Verrill, L. arbuscula (Philippi),
L. arenata (Val.), L. aurantiaca (Val.), L. australiensis Ridley, L. boryana (Val.), L. californica
Verrill, L. carolinensis Verrill, L. caryi Verrill, L. cauliculus (Val.), L. cuspidata Verrill, L.
divergens Studer, L. diffusa Verrill, L. flora Verrill, L. floridiana Verrill, L. flavida. Verrill,
L. flexilis Verrill, L. labiata Verrill, L. media Verrill, L. mineacea (Esper), L. mineata Verrill,
L. nobilis Verrill, L. peruana Verrill, L. pinnata (Lamk.), L. porissima Edwards and Haime,
L. pulchra Verrill, L. pumila Verrill, L. purpuracea (Pallas), L. purpurea (Pallas), L. ramulus
(Val.), L. rigida Verrill, L. rosea (Lamk.), L. rutila Verrill, L. tennis Verrill, L. setacea Verrill,
L. sangninolcnta (Pallas), L. sarmentosa (Esper), L. sanguinea (Val.), L. stenobrachis Verrill,
L. feres Verrill, L. torresia Thomson and Herderson, L. webbiana (Val.), L. virgea (Val.),
L. virgnlata (Lamk.), and the species described beyond.

Many of the above named species have been so inadequate^- described that identification
is practically impossible. In view of this fact the writer thinks it better to describe the single
species in the Siboga Collection as new, although he is fully aware that it may be one of the
species in the above list.

i. Leptogorgia formosa new species (Plate I, figs. 2, 2#; Plate III, fig. 2).
Slat. 33. Bay of Pidjot, Lombok. 22 meters and less.

Colony (dried) strictly flabellate, not reticulate although there are a very few anastomoses.
Stem and branches round. The main stem extends almost straight to the distal end of the
colony. Height n.8 cm., spread 7.3 cm.; diameter of main stem 2.4 mm. About i cm. above
its disk-shaped base of attachment the main stem gives off two very strong opposite branches.
Above this it gives off irregularly lateral branches at short intervals throughout its length.
These in turn give off numerous lateral branchlets most of which are simple, but some of which
rebranch until branchings of the fourth order are attained. The whole forms a densely branched
typically flabellate structure which appears at first sight to be reticulate, but is not really so.

The distance between branches varies from 2.5 mm. to 11.5 mm. but 3 mm. is a common
distance. The calyces are mainly lateral in position, but may be on all sides of the branches.
In the dried specimen they are hardly evident, appearing to be entirely included in the
ccenenchyma. They were probably low warty verrucae in the fresh specimen.

The individual calyces can not be successfully studied in the specimen described. In many
cases their mouths are so completely closed that there is no trace of an opening, and their
diameter can not be measured on account of their walls fading insensibly into the general
ccenenchyma of the branch. In some cases the openings- appear as oval pores. The characters
of the polyps can not be ascertained from the type.

The axis is horny, but shows traces of impregnation by lime salts, particularly in the
basal parts. There are no grooves on the stem or branches.

Spicules. These are small spindles, double spindles, girdled spindles and a few double
heads. All are regularly tuberculated, the tubercles being usually in definite whorls.

Color. The dried specimen is a dark, bright pink, tending to a carmine. The spicules
are mostly carmine.

Genus Stenogorgia Yen-ill.

Stenogorgia Verrill. Bulletin Museum Comparative Zoology, XI, i, 1883, p. 29.
Stenogorgia Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 64.
Stenogorgia Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. LXII.
Stenogorgia Delage et Herouarcl. Traite de Zoologie Concrete, II, 2, 1901, p. 420.
Stenogorgia Nutting. Alcyonaria of the California!! Coast, 1909, p. 722.

The original description of the genus Stenogorgia is as follows :

"Axis horny, branched. Ccenenchyma thin, consisting chiefly of small, warty fusiform
spicula, with a few smaller, short, irregular, rough, granule-like spicula next the outer surface, but
not forming any regular layer. Calyces scattered or two rowed, more or less prominent, eight-rayed
at summit, and filled with spicula like those of the ccenenchyma. Tentacles filled with fusiform
spicula and usually incurved, commonly not retracted within the calyces, but capable of it".

STUDER (1887) and subsequent writers adopt this definition without material modification.

The type species of this genus is Stenogorgia casta Verrill. Other known species are
Stenogorgia ceylonensis Thomson and Henderson, S. kofoidi Nutting, S. miniata (Valenciennes),
S. rosea Grieg and the new species collected by the Siboga Expedition.

i. Stenogorgia miniata (Valenciennes).

Gorgonia miniata Valenciennes. Comptes rendus, XLI, 1855, P- I2-

Gorgonia miniata Milne Edwards et Haime. Histoire Naturelle des Coralliaires, I, 1857, p. 160.

Gorgonia miniata Pourtales. Contributions to the Fauna of the Gulf Stream at Great depths,

1868, p. 1 60.
Stenogorgia miniata Studer. Alcyonaires provenant des Campagnes de 1'Hirondelle, 1901, p. 51.

Stat. 80. 2° 25' S., 1 17° 43' E. From 50 to 40 meters.
Stat. 117. i° o'-SN., 122° 56' E. 80 meters.
Stat. 310. 8° 30' S., 119° 7'-5 E. 73 meters.

Colony (incomplete) flabellate and not reticulate in form, 4.6 cm. high and with a
spread of 4.7 cm. The main stem is round in section and 1.5 mm. in diameter. The branches
are all lateral, there being 7 on one side and 4 on the other. 5 of the branches are compound,
giving off irregularly disposed lateral branchlets, branchings of the third order being sometimes
attained. There is no regularity whatever in the distance between branches. The calyces are
mainly lateral in position, but may be on all sides of the terminal twigs, and are very unevenly
spaced, being from less than i mm. to 2 mm. apart.

The individual calyces are dome-shaped verrucae with the summits divided into 8 not
very strongly marked lobes. A typical one measures. 6 mm. in height and i mm. in diameter
near the base. The upper part of the calyx wall is filled with spicules arranged en chevron
and rising in 8 low points around the margin. The polyps are completely retractile and show
a well-marked but slender collaret composed usually of a single row of transverse spindles.
The tentacles have comparatively large spindles arranged en chevron on their proximal
parts and longitudinally placed on the distal parts.

The general ccenenchyma is covered with rather large tuberculate spindles which are
usually longitudinal but may lie in any direction. The axis is wholly corneous and the water-
vascular canals are not conspicuous.

Spicules. These are nearly all regularly and densely tuberculated terete spindles,
usually straight but sometimes curved. They never show a distinct girdle. Most of them are
less than .5 mm. long, but an occasional one is found which is relatively large, reaching a
length of i mm. Minute crosses and irregularly branched forms are occasionally seen.

Color. The colony is a rather dark scarlet, and the spicules are yellowish red or orange.

General distribution. The type was secured in the Antilles. It has also been
reported by STUDER from the Azores, depth 454 meters.

The Siboga specimens agree well with the description and figures given by STUDER.
This form reminds one of certain species of the muriceid genus Muricella, but the spicules
are much smaller than is usual in that genus.

2. Stenogorgia studeri new species. (Plate II, figs i, \a\ Plate III, fig. 193).
Stat. 310. 8° 30' S., II9°7'.5E. 73 meters.

Colony flabellate and not reticulate, rigid in habit. The main stem and larger branches
are distinctly flattened and grooved on their flat surfaces. Colony 1 1 cm. in height. The main
stem is 2.5 mm. by 2 mm. in section. 4.4 mm. from its base the stem forks, but one of the
resultant branches is broken off at its origin. The other main branch bears a number of laterally
disposed branchlets which are irregularly spaced and themselves bear lateral branchlets which
occasionally bear twigs of the fourth order of branching. The stem and main branches are
distinctly furrowed on one of the flattened sides and indistinctly so on the other. Almost all
of the calyces are lateral in position and tend to be alternate on the distal parts of the twigs.

The individual calyces are warty of dome-shaped verrucse, a typical one measuring

8

8 mm. in height and 1.3 mm. in diameter at the base. They are closely approximated on the
distal parts of the colony and more distant, although still rather closely emplanted on the
proximal parts. The margin is surrounded by 8 lobes which form an 8-rayed figure when
viewed from above. The calyx walls are filled with densely tuberculate spindles which are
usually horizontal on basal parts and tend to be vertical on distal parts, especially in the mar-
ginal lobes. In the ccenenchyma the spicules are longitudinal as a rule. The polyps are com-
pletely retractile, and in retraction lie well below the infolded lobes of the calyx margin. The
collaret is very weak, scarcely evident. The tentacles are covered on their dorsal surfaces by
small tuberculate spindles which are longitudinal on the distal parts and tend to an en chevron
arrangement on the proximal parts.

The ccenenchyma is moderately thin. A cross section of the stem shows inconspicuous
water-vascular canals and a corneous axis which is slightly flattened.

Spicules. Stout, densely tuberculate spindles of moderate size, with the tubercles not
arranged in distinct whorls, are the characteristic form of this species. Those in the tentacles
are smaller and more slender. Rarely a clubshaped form is seen.

Color. The colony, in alcohol, is a light brown with a faint reddish cast in places.

Genus PlatycauluS Wright and Studer.
Platycaulus Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 148.

The original definition of this genus is as follows :

"Colony branched, the branches in one plane, anastomosing. The axis is horny, flattened,
with a calcareous centre and calcareous particles interspersed amid the horny layers: the nutrient
canals surrounding the central axis almost as in Plexaura. Polyps prominent, on the sides of
the stem and branches, retractile within verrucse. Ccenenchyma moderate, like shagreen. Spicules
straight and curved spiny spindles and stellate forms".

The type, and hitherto the only known species of the genus Platycaulus is Platycaulus
danielsseni Wright and Studer.

i. Platycaulus sibogte new species. (Plate II, figs. 2, 2a\ Plate III, fig. 4).
Stat. 213. Saleyer Anchorage and surroundings. Up to 36 meters.

Colony flabellate, not reticulate, although there are a few anastomoses, loose and flabby
in texture, 35 cm. high. Several upright stems spring from a single encrusting base. The largest
of these has its main stem and many of the branches and twigs flattened. The stem forks
2 cm. from its base into two unequal branches the largest of which is 6.5 mm. X 5 mm. in
section. After giving off several small lateral branches it again forks, 1 1 cm. from its base,
and the resultant branchlets again give off irregularly disposed lateral branchlets at intervals
of about i cm. Branches of the 6th order are sometimes attained. In a few cases the branches
anastomose, but not often. The ultimate twigs are flattened, being about 2 mm. by i mm. in
section, short, and generaly pinnate in arrangement. The calyces are usually lateral in position,

but are not infrequently disposed on three sides of the smaller branches. Quite a number of
the medium sized branches are round in section.

A cross section of a branch shows a rather thin coenenchyma and a comparatively thick
axis cylinder with a central white core. The water-vascular canals are not prominent.

The individual calyces are low verrucse the margins of which are 8-lobed and do not
seem capable of closing over the retracted polyps. A typical calyx measures i mm. to the top
of the infolded mass of tentacles and is i mm. broad at its base. The calyx walls are filled
with transversely placed slender crimson spindles which tend to an en chevron arrangement
near the margin. The polyp has a well-marked collaret of similar spindles beset with sharp
thorny points, and the tentacle bases bear similar crimson spindles arranged longitudinally on
their dorsal surfaces. On the proximal parts of the tentacles these spindles tend to an en
chevron arrangement. These spicules show in conspicuous relief against the pallid substance
of the tentacles.

Spicules. These are mainly slender spindles with their surfaces often comparatively
smooth and often, especially in the case of the spindles, beset with sharp thorny points. Many
of these slender spindles are curved and some of them are relatively very large, attaining a
length of 1.5 mm. These large spicules are generally on the surface of the coenenchyma, where
they are longitudinally disposed. I do not find any stellate forms such as are described as
occurring in Platycaulus danielsseni.

Color. The colony is a very dark rich wine-color or dark crimson. The polyps (in
alcohol) are white with crimson spicules, but they may have been yellow in life.

This species bears a superficial resemblance to Gorgonia radula Mobius J, but the
spicules are entirely different.

1 Neue Gorgoniden des Naturhistorischen Museums zu Hamburg, Jena, 1861, p. 9, pi. HI-

SIBOGA-EXPED1TIE XIII i4.

DISTRIBUTION OF THE GORGONID^ COLLECTED BY THE SIBOGA EXPEDITION.

List of Stations

at which Gorgonidse were collected by the Siboga Expedition and
the Species collected at each Station.

STATION 33. Bay of Pidjot, Lombok. 22 meters, and less. Mud, coral and coral sand. Leptogorgia
formosa.

STATION 80. 2°25'S., H7°43'E. Borneo bank. From 50 to 40 meters. Fine coral sand. Stenogorgia
miniata.

STATION 117. i°o'.S N., 122° 56' E. Kwandang Bay entrance, Celebes. 80 meters (chart). Sand and
coral. Stenogorgia miniata.

STATION 213. Saleyer Anchorage. Up to 36 meters. Mud and mud with sand. Platycaulus sibogtz.

STATION 273. Anchorage off Pulu Jedan, East coast of the Aru Islands, (Pearl Banks). 13 meters.
Sand and shells. Lophogorgia pinnata.

STATION 310. 8°30'S., H9°7'.5E. Flores Sea. 73 meters. Sand with a few pieces of dead coral.
Stenogorgia miniata, Stenogorgia studeri.

The data given above show that all of the Gorgonidse collected by the Siboga were
taken from comparatively shallow water, the deepest haul being from Station 117 where the
depth, indicated by the chart, was 80 meters.

But one species in the above list is known to occur outside of the region visited by the
Siboga, and that is Stenogorgia miniata which was previously recorded from the West Indies,
and also from the Azores from a depth of 454 meters. This is the same species which was secured
from the greatest depth yielding a member of the family Gorgonidae secured by the Siboga.

Literature cited
in the Report on the Gorgonidae of the Siboga collection.

DELAGE et HEROUARD. Traite de Zoologie Concrete; Tome II, 2me Partie, les Coelenteres, Paris, 1901.
DUCHASSAIXG DE FONTBRESSIN, P. Revue des Zoophytes et des Spongiaires des Antilles, Paris, 1870.
HlCKSON, S. J. Alcyonaria and Hydrocorallinae of the Cape of Good Hope, Cape Town, 1901.

- Alcyonaria of the Cape of Good Hope, Part II, Cape Town, 1904.

KOLLIKER, A. Icones Histiologies oder Atlas der vergleichenden Gewebelehre; 2te Abtheilung, der feinere
Bau der hoheren Thiere; istes Heft, die Bindsubstanz der Ccelenteraten ; Leipzig, 1865.

MlLNE EDWARDS et HAIME. Histoire naturelle des Coralliaires, ou Polypes proprement dits, I, 1857.

NUTTING, C. C. Alcyonaria of the Californian Coast. Proceedings of the U. S. National Museum, XXXV,
pp. 68 1 — 727, Washington, 1909.

POURTALES, L. F. DE. Contributions to the Fauna of the Gulf Stream at Great Depths, 2d Series. Bulletin
of the Museum of Comparative Zoology, Vol. I, N° 7, Cambridge, 1868.

RlDLEV, S. O. Alcyonaria of the Mergui Archipelago, 1888.

STUDER, TH. Ubersicht der Anthozoa Alcyonaria, welche wahrend der Reise S. M. S. "Gazelle" um die
Erde gesammelt wurden; Monatsbericht der Koniglich Preussischen Akademie der Wissenschaften
zu Berlin, September und October 1878; Berlin, 1878.

- Versuch eines Systemes der Alcyonaria; Archiv fur Naturgeschichte; 5 ister Jahrgang, Bd. I, Heft I, 1887.

- Alcyonaires provenant des Campagnes du Yacht 1'Hirondelle (1886 — 1888). Resultats des Campagnes

scientifiques accomplies sur son Yacht par Albert ler, Prince Souverain de Monaco, Fascicule XX;
Monaco, 1901.

VALENCIENNES, M. Extrait d'une Monographic de la famille des Gorgonidees de la classe des Polypes;
Comptes rendus hebdomadaires des Seances de 1'Academie des Sciences, XLI, Paris, 1855, p. 7.

VERRILL, A. E. Review of the Corals and Polyps of the West Coast of America. Transactions of the
Connecticut Academy of Arts and Sciences, Vol. I, Part. 2, New Haven, 1867.

- Critical Remarks on Alcyonoid Polyps, N° 3. The American Journal of Sciences and Arts, XLVII,

New Haven, 1869.

- Report on the Anthozoa, and on some additional Species dredged by the Blake in 1877 — 1879,

and by U. S. Fish Commission Steamer Fish Hawk in 1 880 — 1882. Bulletin of the Museum of
Comparative Zoology at Harvard College, Vol. XI, N° I, Cambridge, 1883.

WRIGHT, E. P. and STUDER, TH. Report on the Alcyonaria collected by H. M. S. Challenger during the
years 1873—76. The Voyage of H. M. S. Challenger, Zoology, Vol. XXXI, London, 1889.

EXPLANATION OF PLATES

The photographs were made from nature by the author
The spicules were drawn under the camera lucida by Mr. DAYTON STOXER.

PLATE I.

Fig. i. Lopliogorgia pinnata n. sp. Natural size, la, part of branch x 5-
Fig. 2. Leptogorgia formosa n. sp. Natural size. 2 a, part of branch X 5-

SIBOOA-EXPED1TIE X11I b'. C. C. NUTTING, GOROONIDAE.

PLATE II.

Fig. i. Stenogorgia studeri n. sp. Natural size. i a, part of branch >
Fig. 2. Platycaulus sibogce n. sp. Natural size. 2 a, part of branch X 5.

SIBOGA-EXPEDITIE XIII b<. C. C. NUTTING, GORGONIDAE.

II

PLATE III.

Fig. i. Lophogorgia pinnata n. sp. Group of 2 spicules, a and b X 350.

Fig. 2. Leptogorgia fonnosa n. sp. Group of 4 spicules, rt, ^, r and d y 250.

Fig. 3. Stenogorgia studcri n. sp. Group of 5 spicules, a, b, c, d and r X 120.

Fig. 4. Platycaulus siboga n. sp. Group of 4 spicules, a, b, c and d X 120.

Siboga-Expedltie Xlllb*. C. C. NUTTINO, Gongonidae.

III.

Dayton Stoner del.

ERRATUM

Monographic 40: LOMAX, Die Pantopoden der Siboga-Expedition, 1908, S. 66.

Die neue Pallenopsis-A.rt (P. plumipes) hat leider irrtiimlich denselben Namen erhalten
wie die bereits friiher von MEINERT (Den Danske Ingolf-Expedition, V. 3, 1899, Pycnogonida, p. 51)
aus dem Xord-Atlantik beschriebene Tiefsee-Species.

Demnach muss die von der Siboga-Expedition aus der Kwandang-Bai in Nord-Celebes
gedredschte Art einen andern Namen bekommen, und ich schlage jetzt vor sie

Pallenopsis Sibogae nom. nov.
zu nennen.

Amsterdam, Mai 1911. J. C. C. LOMAN.

THE GORGONACEA OF THE SIBOGA EXPEDITION

VIII. THE SCLERAXOXIA

Siboga-Expeditie

XIII b5

THE

GORGONACEA OF THE SIBOGA EXPEDITION

VIII. THE SCLERAXONIA

BY

C C. NUTTING

Professor of Zoology, State University of Iowa

With 12 plates

(Aided by a grant from the ELIZABETH THOMPSON SCIENCE FUND)

LATE E. J. BRILL.

PUBLISHERS AND PRINTERS

LEYDEN

THE GORGONACEA OF THE SIBOGA EXPEDITION

VIII. THE SCLERAXONIA

BY

C. C. NUTTING,

Professor of Zoology, State University of Iowa.

With 12 plates.

(Aided by a grant from the ELIZABETH THOMPSON SCIENCE FUND.)

Section SCLERAXOXIA Studer.
(= PSEUDAXONIA von Koch.)

Scleraxonia Studer. Versuch eines Systemes der Alcyonaria, 1888, p. 24.

The definition of this section of the Gorgonacea, as given by STUDER, is indicated in
the following translation :

"Fixed, upright branched colonies in which the short polyp cavities are immersed in a
canal-bearing ccenenchyma which contains numerous embedded spicules. The branches consist
of a cortical substance containing the polyps and a medullary- substance which contains spicules
of different forms from those of the ccenenchyma, densely aggregated and either connected by
a horny substance or bound together by a limestone substance into a stony axis in which the
individual spicules are plainly evident".

This definition, although correct, may be considerably shortened without losing its
effectiveness. Leaving out unessentials, the following will serve our purpose :

Gorgonacea with an axis in which the individual spicules can be recognized and in
which they are connected into a more or less compact mass either by a horny substance or
calcareous matter.

SIBOGA-EXPEDITIE XIII b*. I

Although there is some intergradation between the Briareidse on the one hand and the
Gorgonellidae, a holaxonian family, on the other; and although there is evident relationship
between the Isidse, another holaxonian family, and the Melitodidse, this Section is of practical
use in a treatment of the Gorgonacea and serves to segregate that great order into two groups
which are fairly natural.

Family BRIAREID/E Gray.

Briaracees (in part) Milne Edwards et Haime. Histoire Naturelle des Coralliaires, 1857, p. 188.
Briareidce Gray. Annals and Magazine of Natural History, Vol. IV, 1859, p. 443.
Briareidce Verrill. Memoirs Boston Society of Natural History, I, 1863, p. 10.
Paragorgiacece Kolliker. Beitrage zur Kenntniss der Polypen, 1870, p. n.
Briaridce Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 26.
Briareidce Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. XXXI.
Briareidce Bourne. A treatise on Zoology, part II, Chapter VI, 1900, p. 25.
Briareidce Nutting. Alcyonaria of the Hawaiian Islands, 1908, p. 569.

MILNE EDWARDS and HAIME (1857) defined the "Briaracees" as follows:

"Polypieroide dont 1'axe est occupe par un tissu subereux ou spiculifere, ou par une
cavite vide".

In accordance with this definition these writers included in the family the genera Briareuni,
Solanderia, Paragorgia and Coelogorgia, the last of which, Ccelogorgia is not now regarded as
belonging in the Scleraxonia.

GRAY (1859) defines the family Briareidce as follows:

"Coral arborescent, fleshy, supported by a central axis formed of numerous intertwined
fusiform spicules". This writer includes but one genus, Briareum, in the family.

VERRILL (1867 — 71) includes the genera Briareum, Paragorgia, Titanidiiim and, tenta-
tively, his genus Callipoditim which is not now regarded as belonging to the Gorgonacea at all.

KOLLIKER (1870) practically adopts the definition of MILNE EDWARDS and HAIME, but
leaves off the last part "ou par une cavite vide", thus excluding Ccelogorgia. He divides the
family into two sections, "Sympodidae" with an encrusting coenenchyme and "Paragorgiacese"
in which the branched colony exhibits a differentiated cortical and nuclear portion or axis. This
second section is practically identical with the Briaracece as at present accepted.

STUDER (1887) offers a definition which has stood without essential modification until the
present time, and a translation of which appeared in the Challenger Report, the Alcyonaria,
1889, as follows:

"Scleraxonia in which the coenenchyma consists of a polyp-bearing cortex and a medullary
substance of closely packed spicules; these are either developed on the surfaces of an upright
shrubby colony, or the latter is relegated to the interior of a cylindrical stem over which is
spread the former. In the latter case a more or less well-defined axis is formed which may be
penetrated by nutritive canals, or may be quite without them".

The Briareidce thus fall into two sub-divisions Briareinse and Spongioderminse.

All of the material of this family collected by the Siboga Expedition belongs to the
subfamily Briareinse. Icilogorgia, which has been placed by STUDER in the Spongioderminae, has
well-marked water-vascular canals in the axis and must therefore be included in the Briareinae.

A definition which will sharply differentiate the family Briareidae from Sclerogorgidae,
and at the same time give the necessary diagnostic features, is offered as follows:

Scleraxonia in which the spicules of the axis cylinder are either beset with distinct thorny
points or wart-like verrucae and are not possessed of horny sheaths by which they are agglutinated
together either directly or by cross connections. Branches consisting of a cortex containing the
calyces and an axis consisting of spicules closely packed in a matrix of connective tissue.

The amount of material collected by the Siboga Expedition and belonging to this family
is hardly sufficient to justify a general discussion of the generic groups. The writer will therefore
confine himself to a discussion of the genera represented.

Synoptic view of the genera and species of BRIAREHXE
collected by the Siboga Expedition.

New species are indicated by an asterisk (*).

Solenocaulon.

Solenocaulon sterroklonium, S. grayi,
S. *querciformis, S. *jedanensis.

Titanidium.
Titanidium *friabilis.

Semperina.
Semperina rubra, S. *brunnea.

Suberia.

Suberia kollikeri, S. *excavata,
S. *macrocalyx.

Paragorgia.
Paragorgia splendens.

Iciligorgia.

Iciligorgia orientalis.

Systematic description of genera and species.
Genus Solenocaulon Gray.

Solenocaulon Gray. Annals and Magazine of Natural History, Series 3, Vol. X, 1862, p. 147.

Solenocaulon Genth. Zeitschrift f. wissenschaft. Zoologie, Bd. 17, 1867, p. 428.

Solenocaulon Studer. Monatsbericht der Konigl. Akademie der Wissenschaften zu Berlin, 1878,

p. 668.

Solenocaulon Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. XXXI.
Solenocaulon Brundin. Alcyonarien aus der Sammlung des Zool. Museums in Upsala, 1896, p. 12.
Solenocaulon Germanos. Gorgonaceen von Ternate, 1897, p. 145.
Solenocaulon Delage et Herouarcl. Traite de Zoologie Concrete, II, 2, 1901, p. 412.
Solenocaulon Hickson. Alcyonaria of the Maldives, part I, 1903, p. 493.
Solenocaulon Thomson and Simpson. Alcyonaria of the Indian Ocean, II, 1909, p. 153.

GRAY (1862) gives a somewhat lengthy generic description accompanied by a good figure
of the type species. His description is as follows:

"The coral coriaceous, tubular, circular, and simple below, compressed, subquadrangular,
tortuous, and more or less branched above, the branches being similar in size and form to the
main stem. The main stem and branches furnished with more or less elongate, subsolid, slender
branches, which are placed on the edge of the large holes in the main stem and branches
which communicate with the main tube. These branchlets, (and sometimes the branches at the
base of them) are furnished with large cells for the polyps, which are placed in one (more
frequently in two) series on each side of the branchlets. The polyp cells are rather large,
circular, nearly superficial, and furnished with a cup divided into eight conical connivent lobes,
each lobe being formed of some transverse spicules at the base and some obliquely-placed
spicules diverging from each lateral edge toward the top above".

STUDER (1878) simply quotes the definition given above and, in 1887, gives a lengthy
description which is translated in the Challenger Report (1889). This may be condensed
as follows :

Colony with a flattened stem bearing polyps on its margins and one face. Coenenchyma
of two layers, cortical and medullary. Cortex with spicules varying from spindles to club-shaped ;
thick and polypiferous on one side of the axis, thin and barren on the other. The medullary
portion has a very thin cortical layer and bears no polyps. Medullary mass consisting of closely
approximated rod-like spicules united by horny material. Stem and branches inrolled on the
side which does not bear polyps. It thus happens that in the stem and larger branches the
margins will often touch so as to form a hollow tube, while the smaller twigs only exhibit a
channeled stem.

GERMANOS (1897) discusses this genus at considerable length and divides it, very strangely,
into two sub-genera on the basis of the presence or absence of a stem. The present writer
agrees with HICKSON, and THOMSON and SIMPSON in regarding this division as unwarrented,
especially as he (GERMANOS) includes Solenocaulon tortuosum in his subgenus Malacosolenocaulon,
which is characterized as without a stem, when the figure given by GRAY in connection
with his original description of that species shows an undoubted stem. GERMANOS added three
new species to the genus, i. e. Solenocaulon sterroklonium, S. diplocalyx and S. akalyx.

HICKSON (1903) made a somewhat extended study of numerous specimens of this genus
and concluded that Solenocaulon tortuosum Gray, S. grayi Studer, ^. tubulosa Genth, and Le^t-
coella cervicornis (Gray) all belong to the same species, S. tortnosum, and supports his thesis
by what seems a somewhat labored argument regarding the action of parasitic or symbiotic
crustaceans on the growth of these forms. -He then adds a new species, S. ramosa, which seems
to be established on much the same sort of characters as are the species which he discards.

THOMSON and SIMPSON (1909) recognized two valid species, S. sterroklonium and S.
tortuosum among the specimens collected by the "Investigator" in the Indian Ocean. These
writers also point out the inconsistency of HICKSON in establishing his species S. ramosa "when
the only diagnostic feature seems to be the tunnel-like expansions".

The present writer feels that there is little gained by substituting such terms as sub-

species, varieties or "facies" for specific names, and is further of the opinion that it is impracticable
to regard as "good species", in the Metazoa, those forms only which do not intergrade. The
ccelenterata especially seem to be in such a plastic condition that extreme variation is common,
and absolutely exclusive definition of species impracticable. In view of such conditions it seems
best to regard a genus as simply a group of species more closely allied to each other than
to other groups, and a species as a group of individuals more nearly allied to each other than
to other similar groups, even if some degree of intergradation is shown.

The type species of this genus is Solenocaulon tortuosum Gray. Other species that have
been described * are Solenocaulon cervicornis (Gray), S. akalyx Germanos, S. diplocalyx Germanos,
5. grayi Studer, S. sterroklonium Germanos, ? S. simplex 2 Brundin, 6". tubulosum Genth and
the new species described in the following pages.

i . Solenocaulon sterroklonium Germanos.

Solenocaulcn sterroklonium Germanos. Gorgonaceen von Ternate, 1897, p. 151.
Solenocaulon tortuosum (in part) Hickson. Alcyonaria of the Maldives, 1903, p. 495.
Solenocaulon tortuosum Thomson and Simpson. Alcyonaria of the Indian Ocean, II, 1909, p. 157.

Stat. 49*. 8°23'-5S., II9°4'.6E. 69 meters. Coral and shells.

Stat. 80. 2°25'S., ii7°43'E. From 50 to 40 meters. Fine coral sand.

Stat. 154. 4°7'.2N., I3O°25'.5E. 83 meters. Grey muddy sand, shells, Lithothamnion.

Stat. 240. Banda Anchorage. 9 to 45 meters. Black sand, coral.

Stat. 273. Anchorage off Pulu Jedan, East coast of Aru Islands. 13 meters. Sand and shells.

Stat. 274. 5°28'.2S., I34°53'.9E. 57 meters. Sand and shells. Stones.

Stat. 282. 8°2s'.2S., i27°i8'.4E. 27 — 54 meters. Sand, coral and Lithothamnion.

Stat. 285. 8° 39'. i S., I27°4'.4E. 34 meters. On the limit between mud and coral.

Stat. 318. 6° 36'. 58., II4°55'.5E. 88 meters. Fine yellowish grey mud.

Stat. 319. 6° i6'-5 S., U4°37'E. 82 meters. Fine yellowish grey mud.

Stat. 320. 6°5'S., ii4°7'E. 82 meters. Fine grey mud.

Colony plumiform, 40.5 cm. in height and with a spread of 3.7 cm. The stem is about
14 cm. long, flattened proximally and distally and round on other portions, basal expansion
i.i cm. X 3 mm. in cross section, distal expansion semicircular in section, the flat face being
anterior and about 7 mm. in diameter, and the round portion of stem 6 mm. in diameter. The
upper part of the stalk appears to have born leaves which have dropped oft". The branched
part of the stem, corresponding to the rachis of pennatulids, bears a number of broad, usually
opposite, greatly expanded leaves which bend around toward the front where they meet and
coalesce, forming about 8 bands or girdles enclosing a tunnel-like passage along the front of
the stem. These passages are inhabited by a macrouran crustacean, and vary from 9 to i 7 mm.
in width, measuring at their narrowest part in front. The branches give forth from their edges
flattened branchlets which are narrow distally and become round in section, often measuring
about i mm. in diameter. The distal part of the rachis is much flattened and ends in a frilled

1 The present writer does not feel that he is in a position to decide on the validity of species of this genus which he has not
had an opportunity to study.

2 In the case of Solenocaulon simplex the writer has entertained a serious doubt as to the validity of the species because there
is nothing either in the description or figure to separate it from other yonng species of the genus. See BRUXDIS, Alcyonarien aus der
Sammlung des zoologischen Museums in Upsala, 1896. p. 9.

lobate expansion. The calyces are pretty evenly and regularly distributed along the edges of
the leaves and their various expansions and processes, but there are also a few scattered ones
on the anterior surfaces of the girdles.

The individual calyces are in the form of short cylinders when the polyp is expanded
and, rounded domes when it is retracted. A typical one measures about 1.6 mm. high and
1.8 mm. broad. The calyx walls are filled with small spindles which are horizontally disposed
basally and vertically disposed distally. The margin is ornamented with 8 angular points formed
by the converging ends of spindles. The polyps are many of them well expanded, white in
color, their walls with 8 series of horizontal spicules which are curved to fit the contour of
the walls. Below the tentacle bases these spindles are arranged en chevron and rise in 8
points corresponding to those of the calyx margin ; each point being composed of the distal
ends of several spindles. The dorsal surface of each tentacle bears a symmetrical closely set
double row of spindles arranged en chevron, but with their points directed toward the bases
of the tentacles. There are 10 to 12 pairs of pinnules to each tentacle. A fully expanded
polyp, (in alcohol) measures 5 mm. in spread, across the tentacles.

There is a well-marked axis composed of a densely aggregated, felted mass of very
slender needle-like or rod-like spindles with their surfaces ornamented with scattered thorny
points. Mixed with these is a much less numerous form which is entirely different, being much
larger, very stout, sometimes oval spindles with remarkably coarse and irregular verrucse.

Spicules. These have been described. Those of the axis are remarkably slender, rod-
like, comparatively smooth, but with scattered thorny points; and a few strikingly dissimilar oval
or irregular spindles with coarse verrucse. These two types are also found in the ccenenchyma
of the branches; but here the larger spicules are slender, comparatively regular spindles with
ordinary verrucae. The ccenenchyma contains many of the irregular oval spindles found sparingly
in the axis. There are also slender spindles in the calyces.

Color. The leaves are bright scarlet, the polyps white, the stem and rachis rather
dull pink and the flattened basal part of stem very light pinkish or livid.

General distribution. Type locality. Ternate, also reported from the Maldives and
the Indian Ocean.

This species is quite variable in color. Some of the specimens are white with pink
calyces, and others are creamy white with brownish or salmon colored calyces. One young
specimen from Station 319 is much like the colored figure of the original described by GERMANOS.

2. Solenocaulon grayi Studer.

Solenocaulon grayi Studer. Monatsbericht der Konigl. Akademie der Wissenschaft. zu Berlin,

1878, p. 671.

Solenocaulon thomsoni (in part) Hickson. Alcyonaria of the Maldives, part I, 1903, p. 497.
? Solenocaulon tortitosum (in part) Thomson and Simpson. Alcyonaria of the Indian Ocean, II,

1909, p. 1 60.

Stat. 47. Bay of Bima, near South Fort. 55 meters. Mud with patches of fine coral sand.

Stat. 51. Madura Bay and other localities in the southern part of Molo Strait. 691091 meters.

Fine grey sand, coarse sand with shells and stones.
Stat. 114. o°58'.5N., i22°55'E. 75 meters. Hard sand, very fine.
Stat. 117. i°o'-5 N., 122° 56' E. 80 meters. Sand and coral.
Stat. 162. Between Loslos and Broken Islands, West coast of Salawatti. 18 meters. Coarse

and fine sand with clay and shells.

Colony complete with the exception of the basal end of the stem, 44.5 cm. high. The
stem is unbrached for 16 cm. of its length and its basal portion has been worn or cut away
on one side so as to give it an appearance of being flattened although it is otherwise nearly
round, i cm. in diameter, with a channel or groove on one side and a number or longitudinal
irregular corrugations on its surface. The stem forks 1 6 cm. from its base into two rather unequal
branches. One of these is gutter-shaped throughout, being convex on its dorsal and concave on
its ventral aspect, with the exception of one "girdle" 1.5 cm. broad. The other, and larger,
branch is solid and round in section for 6.5 cm. from the base, beyond which it is alternately
guttered and partly girdled, the girdles in places being so extensive as to form long tunnels
or arcades, in one case 4.1 cm. long. Both of the main branches give off numerous lateral
branchlets which are greatly expanded basally and curve forward and then inward to meet and
coalesce, thus forming the girdles or arcades. The branches bear many simple and a few
compound branchlets alternately disposed. All of the ultimate branchlets are much flattened
and more or less guttered, the guttering sometimes disappearing on the distal ends near which
the twigs have a cross section of about 3.5 mm. X i-7 mm.

The calyces are practically all lateral in position, being usually in fairly regular rows
along the edges of the branches and branchlets. There are also a few groups of scattered
calyces on the front surfaces of the girdles and arcades.

The individual calyces are very low conical verrucae, a typical one measuring 1.2 mm.
in height and 2 mm. in diameter at the base, and are from 2 to 3 mm. apart from centre
to centre. Their walls are filled with vertically disposed spindles which tend to form 8 low
marginal points which are much more evident than in Solenocaulon sterroklonium. The polyps
are retractile, but in the specimen described stand as much as 2 mm. above the calyx margin.
The basal part of the polyp body is armed with transverse spicules which higher up are en
chevron and still higher lie in vertical bands, 8 of which surround the margin and encroach
upon the tentacle bases. The distal parts of the tentacles are covered with a complete armature
consisting of two series of delicate spicules with serrated edges, the series meeting on the
mid-dorsal surfaces of the tentacles and extending obliquely forward, outward and downward,
ending in a line \\ith the bases of the pinnules. The polyp spicules are lighter and more jagged
than those of 5. sterroklonium^ and the polyp seems more slender and delicate.

A cross section of a stem shows an outer layer of comparatively heavy and disk-like,
sometimes almost globular, spicules covered with coarse verrucse. The water-vascular canals are
around the periphery of the axis and appear in section as regular oval openings. The axis is
a felted mass of slender rod-like and needle-like spindles whose surfaces bear short thorny spines
which are more prominent and numerous than in S. sterroklonium. The ccenenchyma of the
branches is filled with rather slender spindles which intergrade on the one hand with rod-like

forms beset with thorny points, and on the other with typical spindles with ordinary verrucae
in regular whorls. A few true clubs are also seen, and an occasional branched spindle. Many
of the slender spindles are bent in an arc, and some are doubly curved.

Color. The colony is a light tan brown, the polyps differing but little from the

coenenchyma.

General distribution. Type locality. Northwest Coast of Australia, 50 fathoms.

This species is also reported from the Indian Ocean.

The writer finds himself unable to agree with the opinion expressed by HICKSON, and
THOMSON and SIMPSON that this species is identical with Solenocaulon tortuosum. The absence
of the Y-shaped spicules regarded by THOMSON as characteristic of S. tortuosum seems a good
specific character. The basal part of the stem in the type specimen was missing, hence the
oval spicules were not described by GRAY.

3. Solenocaulon q^lerciform^s new species. (Plate I, fig. i, ia; Plate XI, fig. i).

Stat. 142. Anchorage off Laiwui, coast of Obi Major. 23 meters. Mud. (Young specimen).
Stat. 284. 8°43'. i S., i27°i6'.7E. 828 meters. Grey mud. (Type specimen).

Colony dendritic in form, but somewhat flabellate, 23.5 cm. in length. A stem 14 cm.
long, found in the same bottle, appears to belong to the same specimen. If so, the colony was
37.5 cm. in length. The stem and all branches except the ends of the twigs are strongly
flattened, the larger branches being coarsely and deeply furrowed lengthwise, but in a slightly
spiral manner, these furrows being numerous and conspicuous. The stem measures 9.5 mm.
X 7 mm. in section. The first branch is short and flat and soon coalesces with a larger one
above it. A large branch is given off a little above the first and on the opposite side. This
is much flattened, distorted and furrowed, and gives off numerous, usually lateral branchlets
which are laterally expanded at their origins and are turtuous, like the branches of an oak
tree, and sometimes give off branchings of the third order. The main stem gives off two
other large branches which are greatly expanded laterally and also at the bases of the
branchlets, and bear a series of unequal grooves and furrows at the front and back. The
largest of these main branches is 9 mm. X 6 mm. in section near its base. After giving off
these main branches the stem pursues an undulating course, giving off irregular lateral branches
and breaking up at its distal end into a tuft of branchlets which re-divide until branchings of
the 5th order are attained, the whole forming a clump of aggregated branchlets. The ultimate
twigs are usually quite round in section, having a diameter of about 1.3 mm. The calyces
are confined mostly to the smaller branches and twigs where they are usually lateral in position
and rather distant, being about 3 mm. apart on the average.

The individual calyces are conical in form and vary greatly in size. A typical one
measures 1.5 mm. in height and about the same in diameter. They are often slightly inclined
toward the distal ends of the twigs. Their walls "are filled with vertically disposed spindles.
The polyps seem to be but partially retractile and most of them rest with their very heavy

collarets on the calyx margin. The collaret is composed of 8 to 10 rows of transverse spindles,
the upper two or three rows curved, so that they form an en chevron arrangement on the
tentacle bases. Still higher up on the basal part of the tentacles the spicules are arranged in
longitudinal groups, one to each tentacle, each group forming a jagged point. Above these
points the tentacles curve inward and their dorsal surfaces are armed with a double row of
slender spindles, each row extending from near the mid-dorsal surface of a tentacle to near
the pinnule bases.

A cross section of a stem shows a comparatively thin coenenchyma with an ill-defined
circlet of water-vascular canals around the periphery of the axis. The axis is composed of very
slender rod-like or needle-like spindles with distant thorny points immersed in a horny matrix,
and is penetrated with conspicuous water-vascular canals of irregular size.

Spicules. Those of the coenenchyma of the stem are small, rounded, disk-like, or
compact irregular forms with prominent and irregularly disposed verrucse. Those in the axis are
very slender rod-like forms which are smooth on the greater part of their surface, bearing
distant thorny points and longitudinally disposed, forming a felted mass immersed in a horny
matrix. The spicules of the ccenenchyma of the branches and of the calyx walls are mainly
spindles of various forms, usually with irregularly disposed verrucae. All intergradations between
the forms described above are seen.

Color. The colony is light yellowish brown or tan color.

This species differs from all the others described in this genus in having all of the
branches solid and without tunnels or belts inhabited by symbiotic crustaceans.

A label in the jar in which this specimen was found bears the word ^Spongioderma'}
In all essential characters, however, it seems to be a Solenocaulon. The axis is penetrated by
conspicuous water-vascular canals, and this character would prevent its being placed in the
* Spongioderminte" of WRIGHT and STUDER.

Some fragments from station 142 are referred with doubt to this species. They are
evidently from a young specimen. The stem and basal parts of branches are grooved and show
a tendency to flattening. The calyces are rather distant and prominent. The polyps agree with
the type in spiculation.

4. Solenocaulon jedanensis new species. (Plate II, figs, i, i«; Plate XI, fig. 2).

Stat. 164. i°42'.5 S., i3O°47'.5 E. 32 meters. Sand, small stones and shells.
Stat. 273. Anchorage off Pulu Jedan, East Coast of Aru Islands. 13 meters. Sand and shells.
(Type locality).

Colony (base lacking) pinnate in general form, 16.5 cm. in height and with a spread
of 4.8 cm. The main stem is oval in section, measuring 1 1 X 8 mm. 4.6 cm. above its proximal
end it becomes tubular and gives off short tubular branches ending in small flattened, some-
times round, twigs. The tubular part of the main stem is compressed; but 9.4 cm. from its
base it looses its tubular character and becomes alternately deeply channeled and belted,
there being three belts about i cm. broad and three deeply channeled portions. The branches

SIBOGA-EXPED1TIE XIII b*.- 2

10

tend to be lateral and alternate in position. They each have a short broad tubular basal part
and each of these tubular parts bears a long projection from its distal end. These projections
are sometimes lobular, sometimes narrow and flattened, and sometimes round in section. They
are exceedingly irregular in disposition and are usually simple, but may bear short irregular
branchlets. The calyces are born almost exclusively on these processes and are always lateral
in position,, where they are in one broken row, or two rows, on each side of twigs.

The individual calyces are almost entirely included, appearing as very low swellings
with hardly appreciable height and a diameter of about 2 mm. Their apertures are surrounded
by eight not very pronounced lobes filled with longitudinally disposed tuberculate spindles. The
polyps are entirely retractile and in this specimen are withdrawn well below the margins, which
close over them. They have their walls armed with curved transverse spindles below and spindles
arranged en chevron towards the upper part and on the tentacle bases. Above this the
tentacles are armed with longitudinal spindles, and their distal parts are bent abruptly inward
and bear two rows of small spindles arranged en chevron and reaching to the bases of
the pinnules.

A cross section of the stem shows the ccenenchyma filled with discs and rounded, heavily
tuberculate spindles. The water-vascular canals are large and conspicuous, a number of them
traversing the axis. The latter consists of a felted mass of slender rods and needles longitudinally
disposed and bearing thorny points.

S p i c u 1 e s. These have alreadly been partly described. Besides the slender forms in the
axis there are oval and round, heavily warted spicules in the general ccenenchyma and the
outer layer of calyx walls ; and heavy, coarse tuberculate clubs and spindles of the inner wall
of the calyces. Curved, moderately heavy spindles are abundant in the polyps, and much more
slender and smaller ones in the tentacles. There are no Y-shaped forms.

Color. The colony is a rather light brown. Other specimens are darker brown.

This species seems distinct from the others, particularly in the spiculation of the calyx
walls. It bears considerable resemblance to Solenocaulon tortuosum, but lacks the peculiar
Y-shaped spicules which THOMSON and SIMPSON regard as characteristic of this species \ Some
of the specimens bear symbiotic brachyuran crabs, instead of the Macroura found in
other species.

Genus Semperina Kolliker.

Semperina Kolliker. Beitrage zur Kenntniss der Polypen, 1870, p. 9.
Semperina Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 28.
Semperina Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. XXXII.

In the original description of the genus Semperina Kolliker gives a detailed account of
the species, Semperina rubra in which specific and generic characters are in no wise differentiated.
A diagnosis can, however, be gathered from his analysis of the genera of his " Paragorgiacese"
(pp. [ i and 1 2) as follows :

1 Aleyonarians of the Indian Ocean, II, 1909, p. 155.

1 1

Colony branched, the stem and branches having well differentiated cortical and nuclear
portions, the latter forming an axis which is penetrated by large water-vascular canals. Polyps
only partially retractile. Stem cylindrical.

STUDER (1887) considers this genus to be closely related to Solenocaulon and defines it
as shown in the following translation :

"But here the stem has a more cylindrical form and the nuclear mass withdraws more
to the axis of the colony although it is always excentric and the polyps, as in the previous
genus, are situated mainly on one side of the stem and branches".

This definition is repeated by WRIGHT and STUDER in their Challenger Report (1888)
and is adopted for the present work.

The type and, up to the present time, the only known species of the genus is Semperina
rubra Kolliker. One new species is added in the present work.

i . Semperina rubra Kolliker.

Semperina rubra Kolliker. Beitrage zur Kenntniss der Polypen, 1870, p. 9.

Stat. 258. Tual Anchorage, Kei Islands. 22 meters. Lithothamnion, sand and coral.

Colony incomplete, straggling in habit, 13.5 cm. in height. The main stem is hollowed,
probably by some parasite or pathological condition, and probably flattened naturally, 2.3 cm.
long to first forking and i cm. in greatest diameter. One of the main branches is simple,
irregularly flattened, (a cross section near its base being 7 mm. X 4 mm.) and somewhat
spirally twisted. The other main branch bears a number of very irregular mostly lateral
branchlets projecting in an erratic manner from the main branch. One of the apparent branchlets
is really a branchlet from a missing part of the colony which has anastomosed with the part
secured. All of the branchlets are simple, most of them round in section and clavate at the
ends. The calyces are distributed on three sides of the branches, with a marked tendency to
aggregate in groups or clumps on one face of the branch or on the ends of the branchlets.

The individual calyces are almost entirely included in ihe ccenenchyma and appear as
very low verrucae about 2 mm. in diameter and with scarcely appreciable height. The polyps
seem to be non-retractile, at least all are expanded in the specimen studied. They are very
heavily spiculated, there being an unusually broad and heavy collaret of encrusting spindles
which assume an en chevron arrangement just below the tentacle bases. The proximal part
of the tentacles are covered with longitudinal spindles in several rows, and the distal parts
are completely covered dorsally with spindles arranged in two series placed en chevron and
reaching to the bases of the pinnules.

A cross section of a branch shows a rather thin ccenenchyma in which is embedded a
regular circlet of water-vascular canals around the periphery of the axis. The axis is flattened
and penetrated by a number of conspicuous water-vascular canals.

Spicules. These are exceedingly varied in form, but most of them are modifications
of the simple spindle. The spindle forms range from excessively slender rods with smooth

12

surfaces or very distant thorn-like projections to proportionally very heavy and coarse spindles
with surfaces covered with coarse, irregularly warty tubercles. There are also many oval spicules,
such as are common in this family, true clubs and a few irregularly branched forms.

Rarely, girdled spindles and irregular crosses are seen, such as are figured by KOLLIKER,
the original describer of the species.

Color. The colony is a dark, rather deep red; the polyps yellowish and the spicules

red and white.

General distribution. Type locality, "Bohol", KOLLIKER.

Another specimen from the same station is pale in color and some of the polyps are
completely retracted.

2. Semperina brimnea new species. (Plate II, figs. 2, 20. ; Plate XI, fig. 3).

Stat. 273. Anchorage off Pulu Jedan. 13 meters. Sand and shells.

Stat. 164. i°42'.5 S., 1 30° 47'. 5 E. 32 meters. Sand, small stones and shells.

The colony is branched, rudely flabellate in form, 20.5 cm. in height and with a
spread of about 8 cm. The base is lacking. The main stem is approximately round in section,
4.8 cm. long to first branch, and 8 mm. in diameter. After giving off three stubs of branches
it sends off a compound branch with four branchlets. 1.5 cm. above this it forks into two
approximately equal branches each of which again branches dichotomously, one quite regularly
so, until branchings of the 4th order are attained. All of the branches are round in section
and more or less clavate at the ends. The main branches are about 5 mm. in diameter, the
secondary branches about 4 mm., and the distal twigs 3 mm. At some of the furcations on
the distal parts of the colony there is a membrane-like expansion or web of the coenenchyma
which fills in the angle sometimes as much as 8 mm. above the actual angle of the fork. The
calyces are on three sides of the stem and branches, leaving the fourth side comparatively bare.
On the other three sides the calyces are thickly and regularly implanted about 1.3 mm. apart.

The individual calyces are low dome-shaped verrucae which vary greatly in height with
the degree of expansion of the polyps. A typical one measures 2 mm. in diameter, and the
upper parts of the walls are strongly 8-lobed and covered with coarsely tuberculate spindles
and short oval forms. The polyps are completely retractile and very strongly spiculated. The
collaret is composed of about 6 rows of encircling spindles which assume an en chevron
arrangement on the tectacle bases. The distal part of each tentacle bears a strong band of
longitudinal spindles which seem to encrust it to its tip.

Spicules. These are of the usual type for the genus. The axis bears relatively few
long slender rod-like forms with distant spiny points, and relatively numerous strongly tuber-
culate spindles in which the tubercles are fairly distant on the slender forms and much crowded
and irregular on the stouter forms. These intergrade with stout oval spindles covered with a
compact mass of tubercles. The spicules 'of the ccenenchyma do not differ appreciably from
those of the axis.

A cross section of the stem shows a not very well defined axis, a relatively thin
ccenenchyma, a series of water-vascular canals around the axis, and few if any large canals
penetrating the axis itself ....

Color. The colony is a dark umber brown, lighter on the side devoid of polyps. A
much larger specimen than the one described, from Station 273, is yellowish in color from a
sponge which covers it, and the axis is penetrated by conspicuous water-vascular canals.
A number of large dried specimens were also secured from the same station.

Genus Suberia Studer.

Suberia Studer. Monatsbericht der Konigl. Akademie der Wissenschaften zu Berlin, 1878, p. 666.

Suberia Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 28.

Suberia Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. XXXII.

Suberia Delage et Herouard. Traite de Zoologie Concrete, II, 2, 1901, p. 413.

The original definition of this genus, as given by STUDER, may be translated as follows :
"Stem simple or branched, upright. Axis formed of not coalesced rod-like spicules
immersed in a horny substance and without water-vascular canals. Ccenenchyma thick, containing
thorny spindle-shaped spicules, Calyces large, standing at right angles from the stem, with an
eight-rayed margin. Polyps with fine spindle-shaped spicules from the base to the tentacles.
A circlet of longitudinal canals around the axis".

The same writer (1887) modified somewhat this definition as follows:
"In Suberia the nuclear mass is well defined and constitutes the axis of the cylindrical
stems, which are slightly branched and bear polyps on all sides. Calyces aggregated, particularly
on the club-shaped ends of the stems. The upper part of the polyp is retractile within a distinct

•

calyx. A canal system of relatively large water- vascular canals penetrates the axis".

WRIGHT and STUDER (1889) give a translation of the original definition of STUDER; but
STUDER'S later definition, just quoted, seems preferable.

Suberia kollikeri Studer is the type of this genus. Other known species are Suberia
clavata Studer, S. gent hi Wright and Studer and the new species in the Siboga collection.

i. Suberia kollikeri Studer.

Suberia kollikeri Studer. Monatsbericht der Konigl. Akad. der Wissenschaften zu Berlin, 1878,
p. 667.

Stat. 297. io°39'S., i23°4o'E. 520 meters. Soft grey mud with brown upper layer.

Colony incomplete, consisting of a central stem and five laterally disposed branches.
Length 20.3 cm. The main stem is round, varying from 6 mm. to 3.5 cm. in diameter, the
latter measurement being taken near the middle of the colony. There are several knob-like
swellings on the stem that may indicate new branch origins. There are three branches on one
side and two on the other, all being simple except one which is forked. They vary from 1.5 cm.
to 7.3 cm. in length and are about 3 mm. in diameter, except at the clavate ends which are
7.3 mm. across. These enlarged ends remind one of the genus Paragorgia. The calyces are

irregularly distributed on all sides of the colony, being somewhat more numerous on the sides
of the stem and branches and most closely aggregated on the club-like branch terminations.
They vary from 3.3 mm. to 7 mm. from summit to summit.

The individual calyces are low but evident verrucae varying greatly in size. A typical
one measures 1.3 mm. in height and 3.5 mm. in diameter. There are eight sharply defined
marginal lobes which close over the retracted polyps, the slit-like spaces between the lobes
forming an eight-rayed star. The walls of the calyces, like the general ccenenchyma, are filled
with oval, densely tuberculate spicules. The polyps are completely retractile and the dorsal
surfaces of the tentacles are completely encrusted with oval, very tuberculate spicules.

A transverse section of a branch shows a comparatively thin ccenenchyma in which is
a very regular series of many water-vascular canals. The axis is spongy in texture and filled
with a felted mass of rather long, slender, rod-like or needle-like spindles with their surfaces
ornamented with rather distant thorny points. The axis is penetrated with numerous canals
of various sizes.

Spicules. The spicules are of two main types. Ist the rod-like thorny spindles of the
axis. These are not so delicate as in Solenoca^^lon, and the thorns are comparatively larger.
Many are spindle-shaped rather than rod-like. The second type is a minute, oval, sometimes
round spicule with very prominent verrucse which are usually arranged in symmetrical whorls
and also cap the ends. Commonly there are two such whorls and two caps. Nearly all of the
spicules are one or the other of these two types, or easily recognizable modifications of them.

Color. The specimen is creamy white throughout.

General distribution. Type locality. North of Three Kings Islands, North of New
Zealand, 90 fathoms.

2. ? Suberia excavata new species. (Plate III, figs. 2, 20, ; Plate XI, fig. 4).
Stat. 142. Anchorage off Laiwui, coast of Obi Major. 23 meters. Mud.

Specimens in a very fragmentary condition. The one described is a part of a branch
3.9 cm. long and with a diameter of 8 mm. approximately round in section. The surface is
almost covered with papilliform calyces resembling those of Eunicea.

The individual calyces are club-shaped, pointed obliquely upward and outward, averaging
about 3.5 mm. long and 1.8 mm. in diameter near the distal end. They are adnate to the
branch throughout their length and their margins terminate is 8 not very conspicuous lobes
which are tightly closed over the retracted polyps. The calyx walls are filled with regular
spindles disposed longitudinally. The polyps are entirely retractile and appear to be devoid
of spicules.

A cross section of a branch shows a rather thin ccenenchyma and an axis cylinder
composed of purple and deep violet spicules embedded in a horny matrix. The axis is hollow
throughout the length of all of the fragments, having a tunnel apparently made by a small
bivalve mollusk, one of which was found in situ. The tunnel is not round, but flat, to fit the
mollusk, and the greater part of the axis has been absorbed or in some manner removed,

15

leaving but a thin wall of the substance of the axis which thus has a flattened section which
may be due to the mollusk and not a natural character.

The water-vascular canals are mostly arranged around the axis, but some of them
penetrate the latter.

Spicules. Those of the axis are deep purple in color and are large strong spindles
with narrow very regular whorls of blunt spines and warts. There are also triradiate forms,
Y-shaped spicules and irregularly branched forms, all larger than is common in this genus.
The spicules of the ccenenchyma are colorless and of much the same shape as those in the axis,
spindles with numerous whorls of verrucae being by far the most common forms, although the
others are not lacking.

Color. The colony is very light yellowish brown, the axis deep purple and the polyps,
or at least the tentacles, yellow.

This is the first instance in which the writer has seen a mollusk apparently living a
symbiotic life in the interior of the axis cylinder of a gorgonian.

3. Siiberia macrocalyx new species. (Plate III, figs. 3, 30:; Plate XI, fig. 5).
Stat. 122. i°58'.5N., I25°9'.5 E. 1264 — 1165 meters. Stone.

Specimen incomplete, consisting of an erect stem with short scattered branches. Length
13.5 cm. The stem and branches are round, the former 3 mm. in diameter. The first branch
arises 2.6 cm. from the basal end of the stem and is simple. There are six other short simple
branches irregularly disposed on all sides of the stem. Three of these, and the stem termination,
end in definite swellings bearing each a clump of calyces. The calyces are irregularly distributed
on three sides of the proximal parts of the stem and branches and on all sides of the distal
parts of the colony. They are about 3 mm. apart on the proximal parts of the specimen and
more closely approximated on the terminal twigs, where they form definite clumps or clusters
with the individual calyces averaging about 1.5 mm. apart.

The individual calyces are long, tubular and project at right angles from the branches.
A typical one measures 1.8 mm. in height and 2 mm. in diameter. The calyx walls are filled
with long thorny spindles arranged en chevron, especially on the upper parts where they rise
into eight angular points around the margin. The polyps are retractile, but usually rest (in the
type) with their collarets just above the calyx margins. The collaret is very strong, consisting
of several closely set rows of transverse spindles arranged en chevron over the tentacle bases,
where they project in definite points. Beyond this the tentacles have their dorsal surfaces
armed with longitudinally placed spindles.

A cross section of the stem shows a rather thin ccenenchyma filled with slender longi-
tudinal , spindles, a not very well defined series of water- vascular canals around the axis and
an axis composed of a felted mass of slender thorny spindles and penetrated by conspicuous
water-vascular canals.

Spicules. These are all slender spindles differing mainly in the number of thorn-like

i6

points scattered over their surfaces. Some are almost smooth while others have the points
thickly implanted over their surfaces. The spicules of the axis do not differ materially from
those of the calyces and general ccenenchyma.

Color. The colony is very light yellowish brown, the polyps not differing in color
from the stem and branches.

This specimen came from a greater depth than is often recorded for members of this family.

Genus Paragorgia Milne Edwards and Haime.

Paragorgia Milne Edwards et Haime. Histoire Naturelle des Coralliaires, I, 1857, p. 190.
Paragorgia Kolliker. Icones Histiologies, II, 1865, p. 141.
Paragorgia Kolliker. Beitrage zur Kenntniss der Polypen, 1870, p. 12.
Paragorgia Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 28.
Paragorgia Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. XXXIII.
Paragorgia Delage et Herouard. Traite de Zoologie Concrete, II, 2, 1901, p. 413.

The original description of this genus by MILNE EDWARDS is as follows :

"Polypieroide arborescent, composed of a thin layer of cortical sclerenchyma in the
thickness of which is limited the body cavities of the polyps, and a tubular (fistuleux) very
large axis in the form of a spongy tissue very rich in calcareous spicules. Polyps united in
groups on the extremities of the branches or upon the lateral tubercles, quite distant and
irregularly disposed".

KOLLIKER (1865) confines himself to a definition of the spicules, and (in 1870) gives a
sort of key to the genera of his "Briaracea" of which he makes a section " Paragorgiaceae"
characterized by a branched colony in which the branches show a distinct cortical and nuclear
part (axis). The genus Paragorgia is characterized by the presence of large water-vascular
canals in the axis, entirely retractile polyps and wart-like calyces irregularly distributed.

STUDER (1887) gives a definition which can be adopted for our present purpose and is
translated as follows:

"Colony upright, branched, branches cylindrical, with irregularly disposed warty calyces
within which the polyps are retractile. The slightly differentiated axis contains large water-
vascular canals. Besides the polyps there are, in P. nodosa Kor. and Dan., siphonozooids
without tentacles".

The type species of this genus is Paragorgia arborea. Other species are Paragorgia
nodosa Koren and Danielsen, P. splendens Thomson and Henderson and the new species secured
by the Siboga Expedition.

i. Paragorgia splendens Thomson and Henderson. (Plate III, figs. 4, 4^).

Paragorgia splendens Thomson and Henderson. Alcyonarians of the Indian Ocean, Part I,
1906, p. 20.

Stat. 95. 5°43'.5 N., 119° 40' E. 522 meters. Stony bottom.

Two fragmentary specimens secured. The largest measures 2.3 cm. in height and has a
spread equal to the height. The main stem, or branch in 3 mm. in diameter and bifurcates

'7

4.5 mm. from its proximal end. One of the resultant branches gives off a single branchlet,
and the other two, besides several nodules with groups of calyces as is characteristic of the
genus. These nodules, as well as the single calyces, are all on three sides of the stem and
branches, and are more closely crowded that in other species of the genus. The diameter of
a terminal branch is 1.3 mm., while its swollen end is 5 mm.

The individual calyces are well marked, proportionally more prominent than in allied
species and very unequally distributed. A typical calyx measures 1.3 mm. in height and 2 mm.
in diameter. The margin is closed over the retracted polyp and bears eight rather feebly-
marked lobes. The calyx walls as well as the general ccenenchyma are covered with a super-
ficial layer of small oval spicules. The polyps are completely retractile. There is a narrow but
distinct band of red spindles on the dorsal surface of each tentacle, the bands becoming
narrower and disappearing distally.

Zooids do not appear to be present in this species.

A section across a branch shows a poorly differentiated axis composed of rather slender
tuberculate spindles and penetrated by water-vascular canals. There is a rather regular series
of these canals surrounding the axis. The coenenchyma is filled with stouter spindles inter-
grading with the oval densely tuberculate forms which constitute the superficial layer. There
are also a few small crosses, stars, etc.

Spicules. These have already been described and consist almost exclusively of tuber-
culate spindles and densely tuberculate oval forms, with all degree of intergradation between them.
Color. The colony is a bright coral red throughout.

Genus Iciligorgia Duchassaing de Fontbressin.

Iciligorgia Duchassaing de Fontbressin. Revue des Zoophytes et des Spongiaires des Antilles,

1870, p. 12.

Iciligorgia Ridley. Zoological Collections of H. M. S. Alert, 1884, p. 351.
Iciligorgia Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 29.
Iciligorgia Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. XXXIV.
Iciligorgia Delage et Herouard. Traite de Zoologie Concrete, II, 2, 1901, p. 413.

The original definition for this genus is as follows :

"Axis mollis, spongiosus, spiculis farctus: cortex tenuis, spiculis aciniformibus formatus;
calycibus mammseformibus, obtusis, in utroque latere ramorum uniseriatis".

RIDLEY (1884) defines the genus as follows:

"Central spicular axis dense, imperforate. Longitudinal canals forming a circumaxial zone.
Erect, branched : stem and branches antero-laterally compressed, with knife-like lateral edges.
Zooids wholly retractile, arranged in single series along each edge of the branches ; no
external verrucae".

STUDER (1887) defines the genus as seen in the following translation:

"Here the colony is in the form of an upright branched stem. Stem and branches
compressed. Polyps borne in irregular rows on the thin borders of the branches, entirely retractile".

S1BOGA-EXPEDITIE XHI^5. -?

i8

WRIGHT and STUDER (1889) give a somewhat more detailed description of the genus
as follows :

"The colony is upright and branched; the stem and branches are compressed, irregular
in section; the completely retractile polyps occur in a row within a groove along the sharp
edge of the branches. The medullary mass forms an axis of spicules. It is close, but -brittle
in texture, not penetrated by, but surrounded by, longitudinal canals".

The only modification of this definition that the present writer would suggest is the
omission of the last phrase. While it is true that the axis in many of the smaller branches is
notpenetrated by the canals, it is also true that the large stem of the Siboga specimen about
to be described is penetrated by perfectly evident, indeed conspicuous, water-vascular canals.

The type species of this genus is Iciligorgia schrammi Duchassaing. The only other
known species is Iciligorgia orientalis Ridley.

i. Iciligorgia orientalis Ridley. (Plate IV, figs, i, ia).

Iciligorgia orientalis Ridley. Zoological Collections of H. M. S. "Alert", 1884, p. 351.

Stat. 273. Anchorage off Pulu Jedan, East coast of Aru Islands. 13 meters. Sand and shells.
Stat. 315. Anchorage east of Sailus Besar, Paternoster Islands. Up to 36 meters. Coral and
Lithothamnion.

Colony incomplete, flabellate, profusely branched, 31 cm. in height and about 25 cm.
in spread. Base missing. The main stem is irregular in section proximally, flattened higher up
where it has a section of 8 X 12 mm. It gives off a branch 4.8 cm. from its proximal end.
Almost immediately above this it forks into two main portions each of which again forks.
Beyond this the branching is irregular, but there is a distinct tendency toward a unilateral
arrangement of the ultimate twigs, and branchings of the 4th and 5th orders are attained. The
ultimate twigs are long and slender, sometimes being as much as 1 7 cm. long. All of the
branches and branchlets are more or less flattened, one of the main branches having a cross
section of 1 1 X 7 cm. and an ultimate twig a section or 3.5 mm. X 2 mm-

The branches have a lateral sharply compressed edge or border, very strongly marked
proximally and becoming practically obliterated on the distal parts. In the narrow edges of
these ridges or borders there is a sharply impressed groove, like a knife cut, running along
the sharp edges of all of the branches and twigs, although it is often practically obliterated
by the closing of the adjacent coenenchyma over the groove. In this groove the polyps are set
in a single row on each side of the branches.

There are no calyces, except a few irregularly and sparsely scattered over isolated
localities on what appears to be the back of the colony. These are low rounded verrucae,
sometimes round, sometimes oval, and showing indications of eight lobes around the margins.
They can hardly be considered as normal. The polyps are completely retractile. There are a
few curved spindles on the basal parts of the tentacles which show a tendency toward an en
chevron arrangement.

A cross section of the stem shows a thin coenenchyma filled mainly with oval coarsely

'9

tuberculate spicules. There is a regular series of water-vascular canals immediately arround the
axis and many others which conspicuously penetrate the axis. The axis is composed of a felted
mass of slender rod-like or needle-like spicules, or spicules with distinct thorny points, or
spindles with conspicuous irregular verrucae.

A cross section of a twig shows a relatively thick coenenchyma in which the polyps
are embedded. Here the water- vascular canals do not seem to penetrate the axis.

Spicules. The ccenenchyma is filled with oval and coarsely tuberculate spicules the
tubercles being so closely packed as to give a distinct resemblance to a morula, there being no
appearance of definite whorls. The axis contains spicules of various forms, the rod-like or needle-
like spindles with thorny points predominating. There are also true spindles with coarse irregular
verrucae, and oval forms like those in the ccenenchyma. There are all sorts of intergrading
forms as well as an occasional cross, club or irregularly branched form.

Color. The colony is creamy white throughout. Other specimens, however, are tan-colored.

Other specimens from Station 273 are much larger than the one described. One of these
is quite symmetrical, 41 cm. in height and with all of the terminal branchlets growing from
the upper sides of branches. The color of this specimen is more decidedly a brownish yellow
than any other of this species in the collection. Still another specimen shows a larger number
of verruciform calyces on the flattened side of the colony. In places the lateral grooves in which
the calyces are found, form a series of short definite slits, rather than a continuous groove.

It seems evident from a study of these specimens that Iciligorgia can not go into the
sub-family Spongioderminae ; because the axis is conspicuously traversed by large water-vascular
canals, while that sub-family is characterized by an axis which is not penetrated by these canals.

Genus Titanidium Agassiz.

Titanidium (Agassiz Manuscript) Verrill. Revision of the Polypi of the Eastern Coast of the

United States. Memoirs Boston Society of Nat. Hist. I, 1863, p. 10.
Briareinn Kolliker. Icones Histiologicae, II, 2, 1865, p. 141.
Titanidium Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 29.
Titanidium Kolliker. Beitrage zur Kenntnjss der Polypen, 1870, p. 8.
Titanidium Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. XXXIII.

The original definition of this genus is as follows :

"Corallum irregularly dichotomous or simple; ccenenchyma rather thick, suberous, very
spiculose, traversed by well-developed longitudinal ducts arranged in a single series around the
axis. Cells disposed on all sides of the branches, not prominent. Axis perfectly distinct from
the ccenenchyma, compact, but soft, cork-like, composed of closely united calcareous spicula".

KOLLIKER (1870) gives the following, which is a adopted in the present work:

"Axis moderately well defined, cortex of a single layer of hard sarcosome with minute
canals. Polyps as in Plexaztra, contained in pits in the cortex. Spicules 3 — 4 — 6 and 8-rayed
with warty ends"

This author also gives the only good figure that I have seen of Titanidium suberosum
(Ellis and Solander) the type and, up to the present time, the sole species of this genus.

2O

i. Titanidium friabilis new species. (Plate III, figs, i, iff; Plate XI, fig. 6).
Stat. 304. Lamakera, Solor Island. 16 meters. Coral and sand.

Specimen dried and exceedingly brittle, as if made of soft chalk, 31 cm. in height.

Two large stems are coalesced shortly above their bases and are closely adherent for
8.3 cm. These and all of the branches are round in section, the larger stem being 1.5 cm. in
diameter. One of these stems is broken off before branching and the other forms the remainder
of the specimen. The stem curves strongly, becoming almost horizontal for .5 cm., after which
it suddenly breaks up into a dense tuft of branches and branchlets which form a dense clump
or cluster of numerous ultimate twigs. The stem also gives off a single straight branch where
it separates from the other stem. This branch forks and one of the resultant branchlets subdivides
several times and adds to the clump forming the distal end of the colony. Branchings of the
5th order are sometimes attained. The ultimate branchlets are not noticeably turgid at their
ends and are usually about 4 mm. in diameter. The polyps are distributed on all sides of the
branches much as in Plexaura, and the calyces are entirely included.

The individual calyces are indicated externally by their apertures alone. These are oval
or slit-like according to the state of contraction of the polyps, and the slits are cut at various
angles to the axis of the branch and are more abundant on the terminal than on the proximal
parts of the colony. On the twigs they average a little more than i mm. apart and in places
show a tendency to a linear arrangement. The character of the polyps can not be ascertained
from the type, which is a dried specimen.

The axis is not well defined and is more friable than any other of this family that I
have seen. The ccenenchyma is rather thin and the water-vascular canals form an irregular
circlet around the axis.

Spicules. The spicules of the ccenenchyma are very densely tuberculate and short,
sometimes oval, spindles, the tubercles usually entirely concealing the actual surface. While
such forms as KOLLIKER figures a for Titanidium suberosum can be found, they are not nearly
so abundant as these densely and coarsely tuberculate spindles. In the axis there are a few
slender forms with thorny verrucae, approaching the characteristic spicules of the axis of Soleno-
caulon; but these are greatly outnumbered by the coarsely tuberculate spindles described above.
Occasionally more slender spindles are seen, which may be younger spicules.

Color. The colony (dried) is creamy white. When immersed in alcohol it assumes a
decidedly yellow color.

1 Icones Histiologies, II, 2, plate XIX, figs. 19,' 20 and 22.

DISTRIBUTION OF THE BRIAREID^ COLLECTED BY THE SIBOGA EXPEDITION

List of Stations

at which Briareidae were collected by the Siboga Expedition
and a List of Species collected at each Station.

STATION 47. Bay of Bima, near South Fort. 55 meters. Mud, with patches of fine coral sand.
Solenocaulon grayi.

STATION 49. 8°2o'.5S., ii9°4'.5E. 69 meters. Coral and shells. Solenocaulon sterroklonium.

STATION 51. Madura Bay and other localities in the southern part of Molo strait. From 69 to 91
meters. Fine grey sand; coarse sand with shells and stones. Solenocaulon grayi.

STATION 80. 2°25'S., ii7°43'E. From 50 to 40 meters. Fine coral sand. Solenocaulon sterroklonium.
STATION 95. S°4^-5 N., H9°4O'E. 522 meters. Stony bottom. Paragorgia splendens.
STATION 114. o°58'.5N., 122° 55' E. 75 meters. Hard sand, very fine. Solenocaulon grayi.
STATION 117. i°o'-5 N., 122° 56' E. 80 meters Sand and coral. Solenocaulon grayi.
STATION 122. i°58'.5N., I25°o'.5 E. 1264 — 1165 meters. Stone. Suberia macrocalyx.

STATION 142. Anchorage off Laiwui, coast of Obi Major. 23 meters. Mud. Solenocaulon querciformis,
Suberia excavata.

STATION 154. o°7'.2 N., 130° 25'.$ E. 83 meters. Grey muddy sand, shells and Lithothamnion.
Solenocaulon sterroklonium.

STATION 162. Between Loslos and Broken Islands, West coast of Salawatti. 18 meters. Coarse and
fine sand with clay and shells. Solenocaulon grayi.

STATION 164. i°42'.5 S., 130° 47'. 5 £.32 meters. Sand, small stones and shells. Semper ina brunnea,
S. jedanensis.

STATION 240. Banda Anchorage. 9 to 45 meters. Black sand. Coral. Lithothamnion bank in 18 — 36
meters. Solenocaulon sterroklonium.

STATION 258. Tual Anchorage, Kei Islands. 22 meters. Lithothamnion, sand and coral. Semperina rubra.

STATION 273. Anchorage off Pulu Jedan, East coast of Aru Islands. 13 meters. Sand and shells.
Solenocaulon sterroklonium, S. jedanensis, Semperina brunnea, Iciligorgia orientalis.

STATION 274. 5°28'.2S., i34°53'.9E. 57 meters. Sand and shells, stones. Solenocaulon sterroklonium.
STATION 282. 8°25'.2S., i27°i8.4E. Sand, coral and Lithothamnion. Solenocaulon sterroklonium.
STATION 284. 8°43'.i S., i27°i6'.7E. 828 meters. Grey mud. Solenocaulon querciformis.

22

STATION 285. 8°39'.iS., I27°4'.4E. 34 meters. On the limit between mud and coral. Solenocaulon
sterroklonium .

STATION 297. io°39'S., I23°40'E. 520 meters. Soft grey mud with brown upper layer. Suberia
kollikeri.

STATION 304. Lamakera, Solor Island. 16 meters. Coral and sand. Titanidium friabilis.

STATION 315. Anchorage East of Sailus Besar, Paternoster Islands. Up to 36 meters. Coral and
Lithothamnion. Iciligorgia orientalis.

STATION 318. 6°36'.5S., H4°55'.5E. 88 meters. Fine yellow grey mud. Solenocaulon sterroklonium.
STATION 319. 6°i6'.5S., ii4°37'E. 82 meters. Fine yellowish grey mud. Solenocaulon sterroklonium.
STATION 320. 6°5'S., H4°7'E. 82 meters. Fine grey mud. Solenocaulon sterroklonium.

This table shows that Briaridae were secured at 25 of the Stations explored by the
Siboga Expedition. Of the twelve species secured, seven were new. By far the most common
species was Solenocaulon sterroklonium which was found at eleven Stations, ranging in depth
from about 13 meters to 369 meters. The greatest depth at which a member of this family was
secured was 1165 to 1264 meters where Suberia macrocalyx was dredged. Other comparatively
deep-living species are Solenocaulon querciformis, from 828 meters; Paragorgia splendens, from
522 meters and Suberia kollikeri, from 520 meters.

All of the species are confined, so far as known, to the Indo-Pacific region. The
distribution of the five species previously named being as follows :

Solenocaulon sterroklonium, Ternate, Indian Ocean.

Solenocaulon grayi, Northwest coast of Australia and Indian Ocean.

Semperina rubra, Bohol, Philippine Islands.

Suberia kollikeri, North of New Zealand.

Iciligorgia orientalis, Indian Ocean.

Family SCLEROGORGID^ Kolliker.

Sclcrogorgiacece (Subfamily) Kolliker. Icones Histiologicae, II, 2, 1865, p. 142.
Suberogorgidce Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 29.
Sclerogorgiadce Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. XXXIV.
Sclerogorgidce Bourne. A treatise on Zoology, Part II, Chapter VI, 1900, p. 25.
Sclerogorgidtz Nutting. Hawaiian Alcyonaria, 1908, p. 569.

The original definition of this family is a follows :

"Gorgoniden mit ungegliederter Axe, die aus Hornsubstanz und verschmolzenen Kalk-
korpern besteht. Ccenenchyma wie bei Gorgonia".

STUDER (1887) amplifies this definition as the following translation shows:

"A plainly separable axis and horny substance which surrounds the thickly aggregated
spicules. The axis is surrounded by water-vascular canals which communicate with the branched
network of ccenenchymal canals which connect the polyps. The polyps show a warty exserted
calyx into which the upper, tentacle-bearing part (of the polyp) can retract".

WRIGHT and STCDER (1889) give practically the same definition as the above.

The present writer would modify this definition so as to further emphasize the peculiar
characters of the axis, as follows :

Scleraxonia with a well defined axis formed by an agglutinated mass of calcareous
spicules which have surfaces devoid of verrucae or of thorny points and are embodied in horny
sheaths which often form a mesh or network by cross connection and adhesions.

This is a very well-defined family with only about a dozen known species. It is represented
in the Siboga collection by two genera and eight species, three of which are new.

Synoptic view of the genera and species of SCLEROGORGID.E
collected by the Siboga Expedition.

New species are indicated by an asterisk (*).

Suberogorgia. Korceides.

.V. verriculata (Esper), S. ornata Thomson
and Simpson, 5. kollikeri Studer, 5. rubra
Thomson and Henderson, S. *appressa,
S. *tliomsoni, S. *pulchra.

K. koreni Wright and Studer.

24

Systematic description of genera and species.
Genus Suberogorgia Gray.

Suberogorgia Gray. Proceedings Zoological Society of London, 1857, P- J59-
Sclerogorgia Kolliker. Icones Histiologies, II, 2, 1865, p. 42.
Suberogorgia Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 30.
Suberogorgia Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. XXV.
Suberogorgia Delage et Herouard. Traite de Zoologie Concrete, II, 2, 1901, p. 413.

The original definition is not at present accessible to the writer, the above citation being
from WRIGHT and STUDER (1889).

KOLLIKER (1865) defines his genus Sclerogorgia as follows:

" Kalkkorper des Ccenenchymes zahlreiche warzige gelbe oder farblose Spindeln o, 10—
0,16 mm. lang, daneben auch einfachere Formen, die bei Scl. verrictilata auch als Doppel-
radchen mit zackigen Randern erscheinen. Kalkkorper der Polypen kleine warzige Spindeln in
gewohnlicher Anordnung".

STUDER (1887) claims that the name Suberogorgia has the priority for this genus, and
defines it as shown in the following translation :

"Upright, branched, sometimes reticulate colonies with slightly exserted calyces which
are situated mainly on the two sides of the slightly flattened stem and branches. The coenen-
chyma is thick and shows longitudinal furrows on the bare surfaces. The spicules are warty
spindles and double wheels".

WRIGHT and STUDER (1889) give practically the same definition, which will also serve
the purpose of the present work.

The type of this genus is Suberogorgia suberosa (Esper). Other species are S. kollikeri
Studer, S. ornata Thomson and Simpson, 5". patiila (Ellis and Solander), S. rubra Thomson and
Hend., S. s^lberosa (Pallas), 5. verriculata (Esper) and the new species in the Siboga collection.

i. Suberogorgia verricidata (Esper).

? Gorgonia reticulata E. and S. (Name only) Nat. Hist, of Zoophytes, 1786, p. 198.
Gorgonia verriculata Esper. Die Pflanzenthiere, II, 1794, p. 124.

Gorgonia verriculata Lamarck. Hist. Nat. Anim. sans Vert., 2me ed., 2, 1836, p. 489.
Gorgonella verriculata Valenciennes. Comptes rendus, XLI, 1855.
Rhipidigorgia verriculata Milne Edwards et Haime. Histoire Naturelle des Coralliaires, I,

1857, p. 176.

Sclerogorgia verriculata Kolliker. Icones Histiologicse, II, 2, 1865, p. 142.
Rhipidella verticillata Gray. Annals and Magazine of Natural History, Ser. 4, Vol. V, 1870, p. 407.
Suberogorgia verriculata Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 167.
Suberogorgia verriculata Thomson and Henderson. Alcyonaria of the Indian Ocean, II, 1909,

p. 164.

Stat. 299. io°52'.4S., 123° 1. 1 E. 34 meters. Mud, coral and Lithothamnion.
Stat. 307. Ipih Bay, South coast of Flores. 27 meters. Volcanic sand.

Colony strictly flabellate and reticulate, base lacking. The height of the specimen is
26.5 cm. and the spread is about 19 cm. The main stem keeps its identity throughout, has

25

a rudely geniculate course, is round in section and has a diameter near base of 7.5 cm.
From this main stem arise a few larger branches roughly alternating, and many smaller twigs.
These anastomose very extensively, forming a close network the meshes of which vary greatly
in size. The smaller twigs, forming the mesh, are round in section and have a rather uniform
diameter of about 1.5 mm. The network extends clear to the periphery of the colony and the
tips of the free twigs are not appreciably enlarged at the ends. The calyces are small and
are distributed on all sides of the branches, but appear to be absent from the main stem and
proximal parts of the larger branches. They are quite evenly distributed, averaging about I mm.
from mouth to mouth.

The individual calyces are very low dome-shaped verrucae, a typical one measuring
about .7 mm. in diameter and showing eight distinct marginal lobes. The calyx walls are
filled with minute round or oval spicules. When the polyp is entirely retracted the calyx is
completely included. The polyps are minute, disk-shaped when retracted, and have their infolded
tentacles armed with a dorsal series of longitudinally disposed spindles.

A cross section of a branch shows a moderate ccenenchyma and an axis composed of
agglutinated spindles with smooth surfaces and a horny investment which coalesces freely with
others. The axis is not penetrated by water-vascular canals, these being confined to a circlet
in the ccenenchyma.

Spicules. As in other species of this genus these are of two sharply distinguished
forms. Ist the long, often bent spindles with smooth surfaces and horny investment which
coalesces to form the axis; and, 2nd, spindles varying from nearly round or oval forms to the
typical terete spindle, and having their surfaces ornamented by regular verrucae in well defined
whorls. A few double wheels are also seen.

Color. The entire colony is a dull grayish brown.

General distribution. The type locality is not known; but was given, apparently
at a guess, by ESPER as the West Indies, which is extremely improbable. It is reported from
the Northwest coast of Australia by STUDER, and the Challenger secured it from the Hyalonema
grounds, off Japan, 345 fathoms. A very large specimen from Station 307 measures 77.5 cm.
in height and 52 cm. in diameter. The color of this specimen, which is dried, is earthy brown.

2. Suberogorgia ornata Thomson and Simpson.

Snberogorgia ornata Thomson and Simpson. Alcyonarians of the Indian Ocean. II, 1909, p. 164.

Stat. 8 1. Pulu Sebangkatan, Borneo Bank. 34 meters. Coral bottom and Lithothamnion.
Stat. 220. Anchorage off Pasir Pandjang, west coast of Binongka. 278 meters. Coral sand.
Stat. 257. Duroa Strait, Kei Islands. Up to 52 meters. Coral.

Colony flabellate and reticulate, n cm. in height and about 6.5 cm. in diameter. The
stem and branches are not appreciably flattened and are without evident median grooves. The
main stem grows from an encrusting base and is 2 mm. in diameter and 7.5 mm. long to
the first branch. This branch extends outward and then upward, bears a number of lateral
branches, one of which is compound, and is connected with the rest of the colony through

SIBOGA-EXPEDITIE XIII *s. 4

26

several anastomoses. Almost immediately above the first branch the main stem is rather abruptly
bent to one side and gives off numerous lateral branches which are irregularly spaced and
often compound and anastomose through their branchlets with other branches, forming a loose
and irregular network of very delicate texture. Many of the branchlets are not more than
.5 mm. in diameter, while the larger branches are scarcely i mm. thick. The calyces are
irregularly but rather thickly distributed on all sides of the terminal twigs, and on three sides
of the others. They average a little more than i mm. apart from summit to summit.

The individual calyces are small but prominent for the genus, being in the shape of a
dome averaging about .8 mm. in height and 1.5 mm. in diameter at base. The margin is
surrounded by eight lobes and the walls are provided with eight rather indefinite longitudinal
ribs which are also seen in the general ccenenchyma as rude longitudinal corrugations resembling
the bark of a tree. There is a superficial layer of small oval spicules and minute double heads
in the calyx walls, beneath which are larger regular spindles. The polyps are completely
retracted and much flattened or disk-shaped in retraction. They are provided with a rather
weak collaret with the spindles arranged en chevron on tentacle bases. There are rather
narrow longitudinal bands of spindles on the dorsal surfaces of the tentacles.

The axis is the typical one as described for the genus.

Spicules. These differ materially from other forms in this genus. There is a superficial
incomplete layer of quite small double heads or dumb-bell-shaped forms under which is a much
thicker layer of comparatively large spindles, often curved, with thick-set verrucse arranged in
regular whorls.

Color. The colony is a very light grayish brown.

General distribution. Type locality. Andaman Islands, Indian Ocean; also from the
Laccadives. Although much more delicate that the type described by THOMSON and HENDERSON,
this form agrees well with that species. The describers speak of spicules which they call
"double clubs", but their measurements show that they are double heads, as the term is used
in the present work. "Stellate forms" would appear when double heads were viewed end on.

3. Suberogorgia kollikeri Wright and Studer.

Suberogorgia kollikeri Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 167.
Suberogorgia kollikeri (var. ceylonensis] Thomson. Ceylon Pearl Oyster Report. Appendix to

Alcyonaria, 1905, p. 171.
Suberogorgia kollikeri (var. ceylonensis} Thomson and Simpson. The Alcyonaria of the Indian

Ocean, II, 1909, p. 164.

Stat. 164. i°42'.5 S., I30°47'.5'E. 32 meters. Sand, small stones and shells.

Stat. 273. Anchorage off Pulu Jedan, East 'coast of Aru Islands. 13 meters. Sand and shells.

Stat. 274. 5°28'.2S., i34°53'.9E. 57 meters. Sand and shells. Stones.

Stat. 305. Mid Channel in Solor Straits, off Kampong Menanga. 113 meters. Stony.

Stat. 310. 8°3o'S., H9°7'-5 E- 73 meters. Sand with few pieces of dead coral.

Colony roughly flabellate in form, not reticulate, 14.5 cm. in height. 'The base is
attached to a small dead coral. The main stem gives off a stub of a branch 1.6 cm. from its

proximal end, and a large compound outward and downward projecting branch 1.7 cm. above
the stub. The stem is somewhat flattened, with a cross section of 3.5 mm. X 1.8 mm. The
large branch bears unsymmetrically disposed branchlets, all from its upper side. Two of these
branchlets are close together, nearly parallel, each with a single terminal twig and both consi-
derably flattened. One of them has a cross section of 3.2 mm. X 1.8 mm. The part of the
stem above the main branch already described bears two compound and four simple branches
on its outer side. The stem and branches bear median grooves on front and back, and the
twigs are flattened usually nearly to their tips. The calyces are mainly lateral in position, but
there are a few on the front and back of the colony.

The individual calyces are prominent for this genus, dome-shaped, a typical one measuring
1.5 mm. in height and 2 mm. in diameter at the base. The walls are covered with short
oval spicules and there is but a faint indication of marginal lobes. The polyps are completely
retractile and show a feeble collaret and a few delicate longitudinally disposed spindles on the
dorsal surface of the infolded tentacles.

A cross section of a branch reveals the structure common to the genus, except that the
water-vascular canals may be more conspicuous than in other species in the Siboga collection.

Spicules. The ccenenchyma contains numerous spindles varying from almost round to
terete in form. The tubercles are very large and closely crowded, but still are in regular whorls.
In some cases girdled spindles are seen. The spicules of the axis are irregular, distorted forms
with a heavy envelope and agglutinated into a sort of mesh. They bear no points or verrucae.

Color. The colony is orange red, or red brown in color.

General distribution. Type locality. Hyalonema Grounds, off Japan, 345 fathoms.
It has also been reported (as variety ceylonensis) from the Ceylon Seas and from the Andamans
in the Indian Ocean.

4. Snberogorgia rubra Thomson and Henderson.

Suberogorgia rubra Thomson and Henderson. Ceylon Pearl Oyster Report. Appendix to the
Alcyonaria, 1905, p. 172.

Stat. 133. Anchorage off Lirung, Salibabu Island. Up to 36 meters. Mud and hard sand.

Stat. 260. 5°36'.5S., I32°55'.2E. 90 meters. Sand, coral and shells.

Stat. 301. io°38'S., i23°25'.2E. 22 meters. Mud, coral and Lithothamnion.

Colony flabellate, so profusely and finely branched as to give a false appearance of
reticulation although anastomoses are few. Specimen 30.5 cm. high and with a spread of about
21 cm. The stem and branches are round in section and show but slight indications of the
median grooves so common in this genus. The main stem is 4.5 mm. in diameter and tortuous
in its course. 2.2 cm. from its base it sends off a large branch which is tortuous and gives
off a number of lateral branchlets, 5 of which are compound. 3.7 cm. above this branch the
main stem divides into two subequal parts, each of which bears numerous lateral branchlets
some of which subdivide until brachings of the 6th order are reached. There is a tendency
toward a lateral arrangement of branchlets.

28

The terminal twigs are curved, slender, round in section and average about 1.5 mm.
in diameter and about 9 mm. apart. The calyces are sparsely distributed on the main stem
and branches and rather regularly distributed on all sides of the branchlets and twigs, although
there is a strong tendency to a lateral arrangement on distal twigs.

The individual calyces are conical or dome-shaped, a typical one measuring i mm. in
height and 1.3 mm. in diameter. The walls are filled with oval, densely tuberculate spicules
and the margin bears eight rather definitely marked lobes. The polyps are completely retractile
and the tentacles are heavily armed with spindles which are arranged en chevron on the
basal parts and in broad longitudinal bands on distal parts.

Spicules. The superficial spicules of the coenenchyma are oval, very densely tuber-
culate forms, the real surfaces being concealed by the crowding of the tubercles. Under these
are typical terete spindles with crowded verrucae, usually not in very definite whorls. True girdled
spindles seem to be wanting. The spicules of the axis are of the form typical of this genus.

Color. The colony is deep red or crimson throughout, and the polyps are yellow.

General distribution. Type locality. Ceylon Sea.

This handsome species is quite different in habit from any other of the genus in the
collection.

5. Suberogorgia appressa new species. (Plate V, figs, i, \a\ Plate XI, fig. 7).

Stat. 71. Makassar and surroundings. Up to 32 meters. Mud, sand with mud, coral.

Stat. 273. Anchorage off Pulu Jedan, East coast of Aru Islands. 13 meters. Sand and shells.

Colony flabellate, not reticulate. The stem and basal parts of main branches laterally
compressed, other branches flattened. There are sharply defined grooves or furrows on anterior
and posterior faces of all branches. The specimen is 46 cm. high and has a spread of about
50 cm. The main stem forks 4.2 cm. above its base and is very strongly laterally compressed,
having a cross section of 2.3 cm. X 1.2 cm. The two main branches are directed outward and
then curve upward and their basal parts are very strongly laterally compressed, further out
they become round and their distal portions are flattened. They are irregularly enlarged in
places, the enlargements being due to symbiotic barnacles. The main branches give off a few
short branchlets from their lower sides and a number of branchlets, both simple and compound,
from their upper sides; and these give off lateral branchlets until branchings of the 6th order
are attained. The distance between branches, as well as their arrangement, is very irregular.
The calyces are distributed in irregular patches on the surface of the main stem and branches,
but are nearly all lateral on the distal parts of the colony.

The individual calyces are quite low verrucae on proximal parts (although more prominent
on the enlargements due to barnacles), but are entirely included on the distal parts, where
they fade so insensibly into the general ccenenchyma that their size can not be determined.
Their openings are surrounded by eight lobes which are separated by sharp, slit-like radiating
incisions, quite different from other species that I have seen. The polyps are completely

29

retracted, and, when retracted, are disk-shaped. The entire dorsal surface of the infolded
tentacles is covered with a complete armor of flattened longitudinal spindles or bar-like forms,
there being numerous longitudinal series on each tentacle.

A cross section of a branch shows a relatively thin ccenenchyma filled with oval, closely
tuberculated spicules. The water-vascular canals are inconspicuous and not so regular as in
many species. They do not penetrate the axis. The axis is quite hard and well differentiated,
composed of an agglutinated mass of spicules with horny sheaths and smooth surfaces and
connected by various bridges and adhesions into a sort of mesh or network.

Spicules. These are almost entirely of two kinds; Ist regular, very short, usually oval
spindles with close-set whorls of tubercles, there usually being four such whorls besides the
distal caps ; 2nd the irregular smooth spicules of the axis described above. Besides these there
are the long flattened scale-like spindles of the tentacles.

Color. The colony is dark red, and the polyps white.

A very large specimen from Station 71 appears to belong to this species. It is 107 cm.
in height and very profusely branched, the branching often being dichotomous and sometimes
unilateral. The species agrees well in detail with the type, from Station 273, although the
spiculation of the polyps can not be very well determined, the specimen being dried. The
colony is covered with a white substance as if it had been overgrown with mould, but when
fragments are placed in water they show an orange red color.

6. Suberogorgia thomsoni new species. (Plate VI, figs. "2, 2#; Plate XI, fig. 8).

Stat. 154. o°7'.2N., I3O°25'.5 E. 83 meters. Gray muddy sand, shells and Lithothamnion.

(Type).
Stat. 204. 4°2o'S., 122° 58' E. 75 — 94 meters. Sand with dead shells.

Colony flabellate, not reticulate, 8.5 cm. high and with a spread of about 5.5 cm.
The stem and branches are round in section, although the latter appear flattened on account
of the lateral arrangement of the polyps. Stem 1.9 mm. in diameter and 1.8 cm. long to first
branch. The first branch is large, forming about half of the colony, and bears four lateral
branches, three of which are compound. The remainder of the main stem bears seven lateral
branchlets, two of which are compound. The branches tend to an alternate arrangement with
very unequal spaces between them. The ultimate twigs are about i mm. in diameter. There
are slight indications of median grooves on the main stem and larger branches, but they are
quite indistinct and finally lost on distal parts of the colony. The calyces are regularly lateral
and alternate in position.

The individual calyces are subconical in shape, a typical one measuring 1.2 mm. in
height and 1.9 mm. in diameter at the base. The calyx walls are filled with comparatively
heavy spindles, most of which are placed vertically. These differ materially from the oval forms
which are found in the calyx walls of other species of this genus.

The polyps are completely retractile. The collaret is delicate, consisting of but one
or two rows of slender encircling spindles, above which other spindles are arranged en chevron

30

over the tentacle bases. The rest of the dorsal surfaces of the tentacles bear a number "of
slender longitudinally disposed spindles.

A cross section of a branch shows practically the same structure described in connection
with other species of this genus.

S p i c u 1 e s. The spicules of the ccenenchyma are much more typical spindles, especially
in length, than those of other species described. The oval spicules so characteristic of other
species are here almost completely lacking, and the spindles are proportionally much more
slender. They are covered with conspicuous verrucse which are not ordinarily in regularly
disposed whorls. The spicules of the axis are smooth and are joined by cross connections into
a sort of mesh.

Color. The colony is a light reddish brown in color.

A number of fragments from Station 204 apparently belong to this species. Some are
more delicate than the type, but there are no other important differences.

7. Snberogorgia pulchra new species. (Plate VI, figs, i, \a\ Plate XI, fig. 9).

Stat. 315. Anchorage East of Sailus Besar, Paternoster Islands. Up to 36 meters. Coral and
Lithothamnion.

Several fragments, perhaps of the same specimen, were secured. The largest was
flabellate, but straggling in habit, 23.5 cm. in height. The main stem and branches are some-
what flattened, the former having a cross section of 6 mm. X 4 mm. 1.3 cm. above its
proximal end it gives off a simple undivided branchlet 14.8 cm. long, and 1.3 cm. higher it
bifurcates. Each of the resultant branchlets gives off a single branchlet on one side and several
usually simple ones, on the other. The ultimate branches are slender, slightly flattened and
about 3 mm. in greater diameter. All of the stem and branches are traversed by distinct
median grooves on one side, and most of them on two opposite sides. The calyces are all
lateral in position, in two or three interrupted rows on each side of the branch.

The individual calyces are almost completely included, leaving little indication of their
presence except in the very fine 8-rayed slits surrounding the calyx mouth. These slits are like
sharp cuts radiating from the centre. The polyps are completely retractile, very small, and the
dorsal surfaces of the retracted tentacles show a heavy armature of longitudinally placed red
spindles showing conspicuously against the yellow substance of the tentacles.

A cross section of the stem shows the characteristic features of this o-enus.

o

Spicules. These are of much the same character as in Suderogorgia appressa. The
ccenenchyma is packed with oval or disk-shaped forms which have their surfaces thickly crowded
with coarse verrucae, which, however, are not arranged in regular whorls, but are emplanted
irregularly but closely over the entire surface. The spicules of the axis form an agglutinated
mass of tortuous bodies which unite in a sort of network or mesh.

Color. The entire colony is a yellowish red or terracotta, with the mouths of the
calyces showing yellowish. The opercular spindles are crimson.

Genus Koroeides Studer.

Kor 'aides Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 30.

Kor aides Wright and Studer. Challenger Reports, the Alcyonaria, 1889, pp. XXXV, 168.

Korceides Nutting. Hawaiian Alcyonaria, 1908, p. 569.

The original definition, which has not been materially altered by subsequent writers so
far as I have seen, it as follows: (Taken from WRIGHT and STUDER, 1889).

"The upright colony branches in one plane; the polyps form wart-like verrucse, which
are given off mainly from the sides of the somewhat flattened branches, leaving an interspace
free. The spicules of the coenenchyma are large broad spindles and polygonal, often triangular
discs. These latter are closely approximated to one another, and form a pavement-like outer
layer in the coenenchyma. The calyces are thickly covered with polygonial scales, and the
tentacles also contain broad smooth spicules. The whole habit, and even the character of the
spicules, recall the genus Acis.

The axis is colorless and consists of closely intercalated calcareous spindles inclosed in a
horny fibrous substance, which remains and preserves the form of the axis after decalcification".

The type of the genus Korosides is K. koreni W. and S. Two other species have been
described, K. gracilis \Yhitelegge and K. pallida Hiles, both of which THOMSON and STIMPSON *
regard as synonyms of K. koreni.

i. Korceides koreni Wright and Studer. (Plate VI, figs.

,

Kor aides koreni Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 169.
Koroeides koreni Thomson and Simpson. Alcyonarians of the Indian Ocean, II, 1909, p. 167.

Stat. 117. i°o'.5 N. 122° 56' E., 80 meters. Sand and coral.

Colony incomplete, very fragile, strictly flabellate, with flattened branches, 7.5 cm. high
and with a spread of 14.5 cm. The main stem is round proximally, 3 mm in diameter and
8 mm. high to first branch. At that point it sends off two opposite long tortuous branches
which are round proximally and flattened distally. Their proximal branchlets are broken off,
with one exception; but they fork distally into compound branchlets which are slightly flattened.
The main stem is broken off 3.4 cm. above its base and is distinctly flattened above the first
pair of branches, having a section of 3.3 X 2 mm. It gives off two short stubs and one
compound branch on one side and one compound branch on the other. The compound branches
are flattened, tortuous, and give off rudely alternate branchlets, two of which are compound
and anastomose with branches below. The terminal twigs are really round, but appear to be
flattened on account of the lateral disposition of the calyces, which are very uneven in distribution.

The individual calyces are quite variable in size and shape. When the polyp is fully
retracted the calyx is almost entirely included. The usual form of the calyx, however, is a
very short tube consisting of a fence of upright spicules with their points projecting in a series

1 Alcyonarians of the Indian Ocean, II, 1909, p. 168.

32

around the margin. A typical calyx measures 1.5 mm. in height and about the same in
diameter. In some calyx walls the large vertical spindles tend to an en chevron arrange-
ment, in some they are vertical and in still others they are mainly horizontal. The polyps are
completely retractile. The collaret is feeble and the tentacle bases bear rather strong spindles
arranged en chevron, and above these each tentacle is armed with strong curved longi-
tudinal spindles.

A cross section of a branch shows a moderately thick coenenchyma filled with very
large, warty horizontal spindles. The axis is more dense and well defined than in other genera
of the Sclerogorgidae. The spicules are definite in form, usually terete, but with a smooth
surface like that of an icicle. They are not bound to each other by cross connections, but seem
to adhere by their contiguous sides.

Spicules. The ccenenchyma and calyces are filled with very heavy spindles which
have their whole surface packed with verrucae which are not in definite whorls. Some of these
spindles measure as much as 2.5 mm. in length and 1.5 mm. in diameter. They are almost
exactly like those found in the genus Muricella or Acts. The spicules of the axis have already
been described. They are much smaller than those of the coenenchyma.

Color. The colony is a brilliant scarlet, but this color is obscured and given a pinkish
cast by a whitish growth of sponge which covers it like a film. The axis is .light yellow ; the
polyps are whitish, probably yellow in life, and the spicules are crimson and yellow.

General distribution. Type locality. Hyalonema Ground, off the coast of Japan,
345 fathoms. It has also been reported from the Laccadive Islands.

If THOMSON and SIMPSON are right in combining the forms described as Korceides gracilis
and K. pallida with K. koreni, the range of this species is much greater, embracing Funifuti
(WHITELEGGE), Ceylon and the Andamans (THOMSON and HENDERSON), New Britain (HILES) and
the Hawaiian Islands (NUTTING).

DISTRIBUTION OF THE SCLEROGORGID^ COLLECTED BY THE SIBOGA EXPEDITION

List of Stations

at which Sclerogorgidae were collected by the Siboga Expedition
and a List of Species collected at each Station.

STATION 71. Makassar and surroundings. Up to 32 meters. Mud, sand with mud, coral. Subero-
gorgia appressa.

STATION 81. Pulu Sebangkatan, Borneo Bank. 34 meters. Coral bottom and Lithothamnion. Subero-
gorgia ornata.

STATION 117. i°o'.5 N., 122° 56' E. 80 meters. Sand and coral. Koroeides koreni.

STATION 133. Anchorage off Lirung, Salibabu Island. Up to 36 meters. Mud and hard sand.
Suberogorgia rubra.

STATION 154. o°7'.2N., I3O°25'.5E. 83 meters. Grey muddy sand, shells and Lithothamnion.
Suberogorgia thomsoni.

STATION 164. i°42'-5 S., I30°47'.5 E. 32 meters. Sand, small stones and shells. Suberogorgia kollikeri.
STATION 204. 4°2o'S., 122° 58 E. From 75 — 94 meters. Sand with dead shells. Siiberogorgia thomsoni.

STATION 220. Anchorage off Pasir Pandjang, West coast of Binongka. 278 meters. Coral sand.
Suberogorgia ornata.

STATION 257. In Duroa Strait, Kei Islands. Up to 52 meters. Coral. Suberogorgia verriculata.
STATION 260. 5°36'.5S., I32°55'.2E. 90 meters. Sand, coral and shells. Suberogorgia rubra.

STATION 273. Anchorage off Pulu Jedan, East coast of Aru Islands. (Pearl Banks). 13 meters. Sand
and shells. Suberogorgia kollikeri, S. appressa.

STATION 274. 5°28'.2S., I34°53'-9E. 57 meters. Sand and shell. Stones. Suberogorgia kollikeri.

STATION 299. io°52'.4S., i23°i'.iE. 34 meters. Mud, coral and Lithothamnion. Suberogorgia ver-
riculata.

STATION 301. io°38'S., I23°25'.2E. 22 meters. Mud, coral and Lithothamnion. Suberogorgia rubra.

STATION 305. Mid Channel in Solor Strait, off Kampong Menanga. 113 meters. Stony. Subero-
gorgia kollikeri.

STATION 307. Ipih Bay, South coast of Flores. 27 meters. Volcanic sand. Suberogorgia verriculata.

STATION 310. 8°3O'S., ii9°7'.5E. 73 meters. Sand with a few pieces of dead coral. Suberogorgia
kollikeri.

STATION 315. Anchorage off Sailus Besar, Paternoster Islands. Up to 36 meters. Coral and Litho-
thamnion. Suberogorgia pulchra.

SIFOGA-EXPEDITIE XIII*5. 5

34

The table shows that species of this family were secured at 18 stations, and that one
species was secured at each station, with the exception of Station 273 where two species were
found. This station must have been exceedingly rich in alcyonarian life, although but two of
the Sclerogorgidse were secured here.

This family seems to be largely confined to shallow water, as but a single species was
secured from a depth greater than 100 meters. The species referred to was Suberogorgia
kollikeri, secured at Station 305 at a depth of 1 1 3 meters.

Two of the species in the Siboga collection, however, were secured by the Challenger
off Japan at a depth of 345 fathoms. These are Suberogorgia verriculata and 6". kollikeri.

If THOMSON and SIMPSON * are correct in regarding Korceides gracilis and K. pallida as
synonyms of K. koreni, this species has a wider range than any other of the family Sclero-
gorgidae in the collection, extending from the Indian Ocean to Japan and the Hawaiian Islands.

1 Alcyonaria of the Indian Ocean, II, 1909, p. 167.

Family MELITODID^ Wright and Studer.

0

Melitea (in part) Lamouroux. Histoire des Polypiers coralligenes flexibles, 1816, p. 458.
Isidince (in part) Milne Edwards et Haime. Histoire Naturelle des Coralliaires, I, 1857, p. 192.
Melithaacea (in part) Kolliker. Icones Histiologies, II, 1865, p. 142.
Melithaadce -+- Mopsellada + Trinellidee -f- Elliselladce (in part) Gray. Catalogue of Lithophytes

in the British Museum, 1870, p. 24.
Trenellidcz Ridley. Contributions to the knowledge of Alcyonaria, Annals and Magazine of

Natural History, Series V, Vol. X, 1882, p. 130.

Melithceidce Ridley. Zoological Collections H. M. S. Alert, 1884, p. 356.
Melithczidce Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 30.
Melithaidce Ridley. Alcyonaria of the Mergui Archipelago, Journal Linnaean Society, 1888,

XXI, p. 244.

Melitodida Wright and Studer. Challenger Reports, the Alcyonaria, 1889, pp. XXXV, 170.
Melitodida Bourne. A treatise on Zoology, II, Chap. VI, 1900, p. 25.
Melitodida Kukenthal. Die Gorgonidenfamilie der Melitodidae Verrill. Zoologischer Anzeiger,

Bd. XXXIII, N° 78, 1908, p. 189.

On account of their striking superficial resemblance in the jointed axis to certain Isidae,
the species of the Melitodidae and Isidae were placed together by a number of the earlier
writers, much to the confusion of the systematic arrangement of these forms. LAMOUROUX (1816)
recognized the difference between the axes of this heterogeneous group of "Isidees" and formed
the genus Melitea to accommodate species with spongy and inflated internodes, and included
in it Melitea ochracea, M. de risso (= /sis coccinea Gmelin), M. retifera and M. textiformis.

MILNE EDWARDS and HAIME (1857) combine the genera Isis* Mopsea and Melith&a in
their subfamily Isidinae.

KOLLJKER (1865) included the genera Melith&a and Mopsea in his subfamily Melithaeaceae.

RIDLEY (1884) discusses the family " Melithaeidae" at considerable length and shows that
the three families Melithaeidae, Mopsellidae and Ellisellidae of GRAY can not be regarded as
distinct, and includes them all in one family Melithaeidae in which he includes the following
genera : Melitodes, Clathraria, Wrightella, Mopsella, Acabaria, Trinella and Parisis, and adds
a new genus Psilacabaria.

STUDER (1887) included in "Melithaeidae" the same genera as are included by RIDLEY,
but combines the genera Parisis of VERRILL and Trinella of GRAY.

WRIGHT and STUDER (1889) substitute the name Melitodidae for Melithaeidae of RIDLEY
because the basis name for the old family was Melitaea, which had previously been used for
a genus of insects; while VERRILL (1863) proposed the generic name Melitodes as practically a
substitute for Melitaea of earlier writers. This suggested the name Melitodidae as a family
designation proposed by. WRIGHT and STUDER, who include the same genera that are named
by STUDER. Their definition of the family is as follows :

36

"Scleraxonia with a well-marked axis, which is jointed, i. e., consisting of alternating
portions of a hard calcareous and a soft horny (substance. The hard joints (internodes) consist
of fused calcareous spicules, with but a trace of horny substance : the soft joints (nodes) are
formed of loose calcareous spicules in a mesh of horny substance".

KUKENTHAL (1908) gives a more extended definition, which may be translated as follows:

"Scleraxonia with an evident axis sometimes traversed by endodermal canals and consisting
of soft (nodes) and hard (internodes) joints. The hard joints consist of complety fused calcareous
spicules, and the soft joints consist of rod-like smooth spicules immersed in a horny material.
The branching is dichotomous, usually from the nodes, and the colony is usually flabellate. The
polyps are borne in calyces arranged either in the lateral borders or one side of the branches.
The polyp spicules are spindles or clubs, the cortex spicules are in part "Blattkeulen".

This definition is acceptable for the purpose of the present work.

This same writer (KUKENTHAL, 1908) furnishes an excellent key to the genera of the
family Melitodidae. This is so well devised that the following translation is offered, the new
genus Birotulata being added :
i . Polyps with exserted calyces.

A. Branchings from the nodes, only the terminal twigs sometimes from

the internodes.

1 . Cortex spicules spindles or thorny clubs.

a. Nodes and internodes traversed by water-vascular canals.

Polyps ordinarily placed on one side of the branches . . . Melitodes Verrill.

b. Water-vascular canals not in the internodes.

Polyps distant and biserially placed Acabaria Gray.

2. Cortex spicules foliaceous clubs Mopsella Gray.

3. The foliaceous clubs are nodular in form Wrightella Gray.

4. Cortex spicules double wheels . . Birotulata Nutting.

B. Branchings from the internodes only Parisis Verrill.

2. Polyps with inserted calyces (Clathraria) Gray.

Synoptic view of the genera and species of MELITODHX-E
collected by the Siboga Expedition.

New genus and species are indicated by an asterisk (*).

Melitodes.

M. ochracea, M. flabellum, M. variabilis,
M. esperi M. *squamata, M. *modesta.

Acabaria.

A. philippinensis, A. temiis, A. *formosa,
A. *kicksoni, A. *triangulata.

Mopseida.
M. clavigeri, M. *studeri, M. *spongiosa.

Wrightella.
W. coccinea, W. tongcensis.

Parisis.
P. fruticosa, P. minor.

^Birotulata.

B. *minor.

37

This table shows that the collection contained six genera, one of which is new and
nineteen species, eight of which are new. The genus Melitodes has the largest representation,
with six species, half of which are new ; and Acabaria comes nexth with five species, two of
which are new.

Systematic description of genera and species.
Genus MelitodeS Verrill.

Isis (in part) Linnaeus. Systema Naturae, I2th edition, 1767, p. 1287.

/sis (in part) Ellis and Solander. Natural History of Zoophytes, 1786, p. 104.

Isis (in part) Pallas. Elenchus Zoophytorum, 1766, p. 230.

Isis (in part) Esper. Die Pflanzenthiere, 1791, Vol. I, p. 29.

Melitea Lamarck. Memoires Museum nat. hist., I, 1815, p. 410.

Militea Lamouroux. Hist. Polyp, flex., 1816, p. 458.

Melitea Lamarck. Hist. nat. Anim. sans Vert., 2, 1836, p. 470.

Melitluza Milne Edwards et Haime. Hist. Nat. des Coralliaires, I, 1857, p. 199.

Melitodes Verrill. Bull. Museum of Comp. Zool., 1864, p. 38.

Melitella Gray. Proc. Zool. Society of London, 1859, p. 485.

Melitlicza (in part) Kolliker. Icones Histiologicae, II, 2, p. 142.

Melitodes Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 31.

Melitodes (in part) Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 171.

Melitodes Bourne. A treatise on Zoology, Part II, Chap. VI, 1900, p. 25.

Melitodes Delage et Herouard. Traite de Zoology Concrete, 1901, p. 414.

Melitodes Kiikenthal. Die Gorgonidenfamilie der Melitodidae, 1908, p. 190.

PALLAS (1766) and other of the earlier writers included the species then known of this
genus in the genus Isis.

LAMARCK (1815) separated the genus Melithaea from Isis, as then known, by a definition
which may be translated as follows :

"Colony fixed, tree-like, composed of a jointed axis and persistent cortical layer. Central
axis rooted, branched, formed of stony joints substriated, with spongy and inflated internodes.
The cortical layer contains the polyps when fresh, and small cellules when dried".

LAMARCK (1815) and MILNE EDWARDS and HAIME (1857) give practically the same
definition as the above.

VERRILL, (1865) shows that the name Melithaea is preoccupied, and proposes the present
name, Melitodidse, for the family, and STUDER (1887) adopts the name Melitodes for the type
genus of the family, in which he has been followed by subsequent writers. STUDER'S definition
for the genus may be translated as follows :

" Melitodes has all joints traversed by longitudinal canals. The spicules of the ccenen-
chyma are large warty spindles on the one hand and kneed ('knotige') spindles on the other".

KUKENTHAL (1908) gives a satisfactory definition which will be adopted here. A somewhat
condensed translation is as follows :

"Colony almost always flabellate, branching, dichotomous, with branches from the
nodes. Axis penetrated by water-vascular canals. Coenenchyma variable in thickness and filled

with straight spindles, half-sided, thorny and kneed spindles, thorny clubs and irregular forms,
but without foliaceous clubs. Polyps project from one side of the somewhat flattened branches
and on their borders, and are retractile within exserted clayces".

The type of this genus is Melitodes ochracea (Pallas). The following list of species is taken
largely from KUKENTHAL'S paper above referred to: M. africana Kiikth., M. albitincta Ridley,
M. arborea Kiikth., Melitodes densa Kukth., M. flabelhim Thomson, M. flabellifera Kiikth.,
M. fragilis Wright and Studer. M. Icevis Wrigt and Studer, M. nodosa Wright and Studer,
M. ornata Thomson and Simpson, M. pulchella Thomson and Simpson, M, rugosa Wright
and Studer, M. mbeola Wright and Studer, M. stormii Studer, M. simiata Wright and Studer,
M. sulplmrea Studer, M. variabilis Hickson and the new species described in this report.

i. Melitodes ochracea (Linnaeus).

Isis ochracea Linnaeus. Systema Naturae, io'h edition, 1758, p. 799.
I sis ocracea Pallas. Elenchus Zoophytorum, 1766, p. 230.

Isis ochracea Ellis and Solander. Natural History of Zoophytes, 1786, p. 105.
Isis ochracea Esper. Pflanzenthiere, I, 1791, p. 38.
Melitea ochracea Lamouroux. Histoire Polyps flexibles, 1816, p. 462.

Melitcea ochracea Lamarck. Histoire Naturelle des Animaux sans Vertebres, II, 1836, p. 472.
Melithcea ochraea Kolliker. Icones Histiologicae, 2, 1865, p. 142.

Melitodes ochracea Wright and Studer, Challenger Reports, the Alcyonaria, 1889, p. 292.
Melitodes ochracea Studer. Alcyonarien aus der Sammlung des Naturhistorischen Museums in
Liibeck, 1894, p. 109.

Stat. 71. Makassar and surroundings. Up to 32 meters. Mud. Sand with mud. Coral. (Numerous

specimens).

Stat. 85. o°36'.5 S., 1 19° 29'. 5 E. 724 meters. Fine grey mud.
Stat. 234. Nalahia Bay, Nusa Laut Island. 46 meters. Stony.

A number of large dried specimens, very much broken up, must be referred to this
species. One of these must have been a magnificent spectacle when alive, as the incomplete
specimen measures over one meter in height and 5.9 cm. in diameter at base. The main stem
and branches are strongly compressed laterally, but the smaller branches are ronnd. The nodes
are indicated externally by annular swellings, but they are almost obliterated internally in the
larger branches. In a branch 8 mm. in diameter, for instance, the nodes can scarcely be seen,
being indicated in a longitudinal section by an indistinct narrow band less than i mm. broad,
while the adjacent internode is 20 mm. long. The polyps are thickly distributed on three
sides of the branches, leaving a broad posterior face bare. The branching is usually dichoto
mous, but sometimes lateral. The calyces are included, and the characters of the polyps can
not be made out in the dried specimens. The axis is penetrated by numerous canals.

Spicules. The spicules are mostly small oval spindles with proportionally large densely
crowded verrucae. The hard internodes are made up of an agglutinated mass of rod-like
spicules which adhere together so strongly that they do not boil apart in caustic potash. The
ccenenchyma contains a number of warty clubs, and there are also warty spindles, probably
from the polyps.

39

Color. The entire colony is a dark brick red. Axis darker. In other specimens the
general surface of the smaller branches is yellow, with scarlet verruciform calyces, the back
and sides being bright yellow.

General distribution. The Indian Ocean, which is the type locality.

2. Melitodes flabelhim Thomson and Mackinnon.

Melitodes flabellum Thomson and Mackinnon. Alcyonaria of the Percy Sladen Trust Expedition,
Part II, 1910, p. 198.

Stat. 164. i°42'-5 S., I3o°47'.5 E. 32 meters. Sand, small stones and shells.

Stat. 261. Elat, West coast of Great Kei Island. 27 meters. Mud.

Stat. 273. Anchorage off Pulu Jedan, East coast of Aru Islands. 13 meters. Sand and shells.

Stat. 305. Mid Channel in Solor Strait, off Kampong Menanga. 113 meters. Stony.

Stat. 310. 8°3o'S., ii9°7'.5 E. 73 meters. Sand, with few pieces of dead coral.

Colony strictly flabellate and reticulate, 19.5 cm. long and with a spread of 12.5 cm.
The main stem is nearly round, the horny joints (internodes) being 5 mm. in diameter and
the calcareous nodes 3.5 mm. in diameter. The internodes are about 5 mm. long, and the
nodes 3 to 4 mm. The branches are borne on the internodes and are typically alternate and
lateral in position. From its basal 6.5 cm. the stem gives off occasional irregular branchlets
which do not form a part of the flabellate structure. Above this point the stem soon dissipates
itself in a reticulate mass of branches and branchlets, the branching being, in general, dicho-
tomous. In the fan the internodes are usually about 9 mm. in length and i mm. in diameter;
while the nodes are triangular, as a rule, the triangle being about 2 mm. long and nearly
equilateral. Most of the branchlets terminate in U-shaped bifurcations on the margins of the
fan. Nearly all of the calyces are lateral in position, forming a close-set row on each side of
the branches and twigs. In places the row is quite even, but in others it is decidedly zigzag.

The individual calyces are quite small, rather low, dome-shaped verrucae, averaging
less than .5 mm. in height and slightly over i mm. in diameter, the gradually sloping wall of
one meeting that of its neighbor so as to give a scalloped appearance to the margins of the
branches, when viewed from above. Their apertures are almost completely closed, in the
specimen described, and their walls are filled with heavily tuberculated spindles and spiny clubs
which form an indistinct circlet of prominences around the margins.

The polyps are minute, but show a well defined collaret composed of one or two rows
of bent spindles and a pseudo-operculum of similar spindles arranged en chevron basally
and disposed longitudinally on distal parts of tentacles ; the whole forming a symmetrical
rosette when viewed from above.

Spicules. Those of the axis are small, smooth, bar-like forms aggregated together
into a felted mass which is less dense in the horny and more dense in the calcareous nodes.
They do not boil apart in caustic potash. The spicules of the coenenchyma are exceedingly
varied in form, but are all modifications of the tuberculate spindle on the one hand and of
the spiny club on the other. The spindles are densely tuberculate and usually short and stout,

40

but sometimes slender and curved. The clubs are all of the spiny type, none of the Blatt-
keulen being present. The spindles immensely preponderate over the clubs in number.

Color. The colony of the specimen described is a light grayish brown and the spicules
are colorless. Another specimen from the same station is dull red.

General distribution. Type locality. Providence, Indian Ocean, 6 fathoms.

A specimen from station 305 is a flabellate, matted mass as if several fans lying in
parallel planes had been united by horizontal connections, very much resembling the illustration
given by THOMPSON and SIMPSON (Alcyonarians of the Indian Ocean, 88, 1909, p. 170) of
Melitodes variabilis. But one internode of the stem remains, and this is 3 mm. broad and nearly
4 mm. long and the accompanying internode is longitudinally furrowed, 2.3 mm. in diameter
and 4 mm. long. The stem forks at the node and the resultant branches bear numerous
branchlets, or bifurcate repeatedly; some of the branchlets being inclined forward and some
backward, each being compressed and flabellate thus forming a colony composed of several
palmate structures in parallel planes which are held together by branches passing from one to
the other and anastomosing. The resulting network is quite irregular. The main branches are
laterally compressed. In details and spiculation, however, this specimen agrees with the one
described above.

3. ? Melitodes variabilis Hickson.

Melitodes variabilis Hickson. The Alcyonaria of the Maldives, III, Vol. II, 1905, p. 809.
Melitodes variabilis Thomson and Simpson. Alcyonarians of the Indian Ocean, II, 1909, p. 169.
Melitodea variabilis Thomson and Mackinnon. Alcyonaria of the Percy Sladen Trust Expedition,
Part II, 1900, p. 198.

Stat. 60. Haingsisi, Samau Island, Timor. 23 meters. Lithothamnion in 3 meters and less. Reef.
Stat. 274. 5°28'.2S., I34°53'.9E. 57 meters. Sand and shells. Stones.

The specimens secured by the Siboga Expedition are fragmentary. They show the red

nodes and white internodes of this species. The larger specimen from Station 60 consists of

the base of attachment and a few stumpy and divergent branches.

In the specimen from station 274 the calyces are yellow.

General distribution. "Throughout the Maldives" (HICKSON). Indian Ocean.

4. Melitodes esperi Wright and Studer.

Melitodes esperi Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 179.

Stat. 33. Bay of Pidjot, Lombok. 22 meters and less. Mud, coral and coral sand.

Stat. 50. Bay of Badjo, West coast of Flores. Up to 40 meters. Mud, sand and shells.

Stat. 60. Haingsisi, Samau Island, Timor. 23 meters. Lithothamnion.

Stat. 80. 2°25'S., 1 17° 43' E. 50 — 40 meters. Fine coral sand.

Stat. 144. Anchorage north of Salomakiee (Damar) Island. 45 meters. Coral bottom and

Lithothamnion.

Stat. 164. i°42'-5 S., I30°47'.5 E. 32 meters. Sand, small stones and shells.
Stat. 257. In Duroa Strait, Kei Islands. Up to 52 meters. Coral.

Stat. 273. Anchorage off Pulu Jedan, East coast of Aru Islands. 13 meters. Sand and shells.
Stat. 315. Anchorage east of Sailus Besar, Paternoster Islands. Up to 36 meters. Coral and
Lithothamnion.

-

Colony strictly flabellate and reticulate, the distal part only being present and consisting
of four large branches connected by numerous anastomoses. Height 16.5 cm. Spread 10 cm.
The main branches are laterally compressed, a cross section of a typical one being 2 X 3-i cm.
The nodes are 6 to 14 mm. long, the longer ones being in the distal parts of the colony, and
the internodes are 2 to 5 mm. long, the longer ones being in the basal parts of the colony.
The branching is usually dichotomous, and the anastomoses are through short lateral connections.
The smaller branchlets also are laterally compressed, a typical one being i.i X 1.9 mm. in
section. The calyces are thickly distributed over three sides of the branches, leaving the back
of the colony bare, as a rule, although there are calyces on this side of some of the twigs.

The calyces are almost entirely included in the specimen described. This is probably
due, however, to the state of retraction of the polyps, for in other specimens, where the polyps
are expanded, the calyces appear to be tubular with spicules arranged en chevron around
the upper parts. The upper parts of the calyces are yellow, in sharp contrast to the rich
crimson of the general coenenchyma. Their walls are filled with short densely tuberculate spindles,
sometimes oval or disc-shaped, which appear like imbricating scales, the upper edge of one
overlapping the lower edge of another. The margin is surrounded by eight lobes.

The polyps are completely retractile and are furnished with a strong collaret above
which are eight points formed usually by two spicules at the base of each tentacle, each pair
having its distal ends approximated and its proximal ends divaricated. Above these points the
dorsal surface of each tentacle is covered with an incrustation of densely tuberculate yellow
spicules which are usually longitudinally disposed.

Spicules. Those found in the ccenenchyma are variously formed tuberculate spindles
and spiny clubs. The spindles are often oval or disk-shaped with the tubercles sometimes
arranged in definite whorls and sometimes very heavy and without definite arrangement. A few
curved spindles are also seen. Some of the clubs are tuberculate and others spiny.

Color. The colony is deep crimson with the polyps and calyx margins bright yellow.

General distribution. Type locality. Torres Strait.

A specimen from Station 144 agrees quite closely in coloration with RIDLEY'S figure of
Psilacabaria gracillima *.

5. Melitodes squamata, new species. (Plate VII, figs, i, la, Plate XII, fig. i).
Stat. 299. io°52.4S., 123° T. i E. 34 meters. Mud, coral and Lithothamnion.

Colony flabellate, but not reticulate, although it appears to be so. 27.5 cm. in height
and about 10 cm. in width. The stem and branches are approximately round in section. The
first large branch is 2.6 cm. above the base of the stem. The horny nodes are much swollen,

1 Zoological Collections H. M. S. Alert, 1884, pi. XXXVI, fig. E1.

SIBOGA-EXPEDITIE XIII b 5.

42

8 mm. in diameter and 6 mm. long. The calcareous nodes are 6 mm. in diameter and about

4 mm. long. All of the branches are borne on the horny nodes which vary in length from

5 mm. on proximal branches to 12.5 mm. on distal branchlets. The first are annular and the
latter triangular in outline. The calcareous nodes vary from 4.1 mm. to 12.5 in length, the
latter being the distal ones. The main branches are lateral and alternate in position, but the
distal branchings are regularly dichotomous, the forkings being U-shaped. The ultimate twigs
are very slender, being but i mm. in diameter. The polyps are distributed on all sides of the
smaller branches and branchlets, and on three sides of the more proximal branches and parts
of branches. They are usually lateral on the main stem and branches.

The individual calyces are minute, almost entirely included even when the polyps are
partly expanded, and about i mm. in diameter. They are rendered conspicuous by their color
which is a brilliant crimson while the general ccenenchyma is a yellowish red or deep orange.
Their walls are filled with crimson spicules which look like small imbricating disks when in
situ. The polyps are quite heavily spiculated. There is a strong collaret often of crimson, some-
times of light yellow spicules, above which is a pair of spicules forming a point above each
tentacle base by the approximation of their distal ends. These spicules are also often crimson
in color. Above these points other strong spindles lie along the distal parts of the dorsal
surfaces of the tentacles.

The ccenenchyma of the branches appears to be filled with rounded or disk-like imbri-
cating scales.

Spicules. Those of the ccenenchyma are disk-like tuberculate forms intergrading with
ordinary spindles with tubercles arranged in regular whorls. Tuberculate clubs are also seen
in moderate numbers, but I find no spiny clubs or Blattkeulen. The spicules of the axis are
smooth bars and needle-like forms, resembling fragments of spun glass when viewed through
the microscope. Bent tuberculate spindles are found in the polyps.

Color. The colony is orange red, in general coloration, but the distal parts lighten to
almost white, as if they had been partly dried or bleached. The calyces are crimson and the
polyps yellow or pallid.

6. Melitodes modesta, new species. (Plate VII, figs. 2, 20; Plate XII, fig. 2).

Stat. 164. i°42'.5 S., I30°47'.5 E. 32 meters. Sand, small stones and shells.

Stat. 273. Anchorage off Pulu Jedan, East coast of the Aru Islands. 13 meters. Sand and

shells. (Type).
Stat. 274. 5°28'.2S., 134°53'.9E. 57 meters. Sand and shells. Stones.

Colony strictly flabellate and moderately reticulate, 13 cm. high and with a spread of
7.5 cm. The main stem grows from an expanded base which seems originally to have supported
two such stems. The remaining stem shows that a large branch has been broken off imme-
diately above the base, and above this the stem gives off alternate branches, one from each
node. The second free node is about 4 mm. long and the same in diameter, while the internode
below it is about 3 mm. in diameter and length; but the nodes and internocles blend so as to
make it difficult to ascertain their limits. As in other species of this genus the nodes decrease

43

and the internodes increase in length as we go from proximal to distal parts of the colony
where the nodes are but a little more that i mm. and the internodes are sometimes 9 mm.
long. The branchings are mainly dichotomous and the forkings are U-shaped. Many of the
smaller branches are frequently girdled by a small parasitic form which looks like checkered
belts or bands tightly compressing the ccenenchyma. The calyces are mainly lateral and anterior
in position, and are so low as to be barely visible.

The individual calyces are very low rounded domes, more evident on the distal twigs
then elsewhere. They are very small, averaging scarcely more than i mm. in diameter. Their
walls are filled with spiny spindles and thorny clubs, the edges of which give a serrated
appearance. The polyps are very small and so completely retracted that their characters are
hard to make out. They have a strong collaret above which are spindles arranged en
chevron over the tentacle bases and longitudinally on the dorsal surfaces of the tentacles.
In certain stages of retraction these latter spicules form a series of points beyond which the
tentacles suddenly bend downward.

Spicules. These are mainly rather large spiny spindles, with the individual spines often
spinulate. There are also one-sided spindles, spiny clubs and numerous other forms, all of which
are but modifications of the spiny spindle characteristic of this genus.

Color. The colony is lemon yellow and the axis is dark pink.

Other specimens are more robust than the type described, and the calyces are distributed on
all sides of the distal branches. These specimens are light orange brown, instead of yellow, in color.

^HkHfl^te

Genus Acabaria Gray.

Acabaria 4- Anicella Gray, Annals and Magazine of Natural History, 4* Series, Vol. 2, 1868,

p. 444.

Acabaria Ridley. Zoological Collections H. M. S. Alert, 1884, p. 360.
Acabaria Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 31.
Acabaria Wright and Studer. Challenger Report, the Alcyonaria, 1889, p. XXXVI.
Acabaria Delage et Herouard. Traite de Zoologie Concrete, II, 2, 1901, p. 414.
Acabaria Kiikenthal. Die Gorgonidenfamilie der Melitodidae, Zoolog. Anz. Bd. XXXIII, 1908,

p. 194.

The original definition of this family is as follows:

"The coral very slender, branched dichotomous, expanded in a plane; branches and
branchlets very slender, compressed, with short swollen joints, more pronounced on the older
stems. Bark thin, hard, smooth. Cells short, broad, subcylindrical, truncated, in a single series
on each edge of the branches and branchlets, rather close together. Axis calcareous, solid, red,
longitudinally grooved ; internodes short, swollen spongy".

The same author proposes the genus Anicella, based on an Australian species with
internodes (nodes, as the term is now used) red, swollen. This can hardly be regarded as a
generic character, and the species should be included in Acabaria.

RIDLEY (1884) practically adopts the above definition, but establishes a new genus
Psilacadaria, which KUKENTHAL (1908) would include in Acabaria.

44

STUDER (1889) gives a very brief characterization of this genus.

" Acabaria Gr. Wie Mopsella, aber die Spicula der Rinde sind nur Spindeln".

KUKENTHAL (1908) gives a satisfactory definition, as indicated in the following translation :

"Branching flabellate, dichotomous, branches originating at the nodes. Branches very
slender, slightly or not at all flattened. Internodes not pierced by water-vascular canals. Polyps
retractile within large calyces, biserially arranged and usually widely spaced. Spicules never
foliaceous clubs".

The type species of this genus is Acabaria divaricata Gray. Other described species
are Acabaria australis Gray, A. biserialis Kukth., A. corymbosa Kiikth., A. erythracea (Ehrenb.),
A. frondosa (Brundin), A. gracillima (Ridley), A. habereri Kiikth., A. japonica Verrill,
A. philippinensis (Wright and Studer), A. serrata Ridley, A. tennis Kiikth., A. und^llata
Kiikth., A. valdivice Kiikth., and the new species described in the present work.

i. Acabaria philippinensis (Wright and Studer).

Melitodes philippinensis Wright and Studer. Challenger Reports, the Alcyonana, 1889, p. 176.
Melitodes philippinensis Thomson and Simpson. Alcyonarians of the Indian Ocean, II, 1909,
p. 172.

Stat. 310. 8° 30' S., Ii9°7'.5 E. 73 meters. Sand, with a few pieces of dead coral.

Specimens flabellate, the largest being a fragment 6.2 cm. long and about 4 cm. in
spread. Stem and branches round. Main stem 2.1 mm. in diameter and 1.5 cm. long to first
branch. The first complete node is 4 mm. long and 3 mm. in diameter, and a distal one is
1.2 mm. long. The proximal internode is i cm. long and 2 mm. in diameter, while a distal
internode is 1.4 cm. long and 8 mm. in diameter. The branching is irregularly dichotomous
and the furcations are Y-shaped rather than U-shaped. The calyces are mostly lateral leaving
a broad bare space on the back of the colony and a narrow one, sometimes invaded by
calyces, on the front. There is often a tendency to form a zigzag row on the side of the branch.

The individual calyces are dome-shaped verrucse, often hemispherical when the polyps
are completely retracted. They are somewhat closely approximated on the sides of the branches
and are rendered conspicuons by their dark red color in contrast with the dull yellow of the
coenenchyma. A typical calyx measures .7 mm. in height and 1.3 mm. in diameter at the
base. Their walls are filled with coarse tuberculate spindles which sometimes tend to an en
chevron arrangement around the margin and otherwise are horizontal or irregularly disposed.
A few of the more superficial spicules are yellow, but the rest are red, the predominating
color in the calyces. The polyps are retractile and have a strong collaret composed of about
three horizontal rows of red tuberculate spindles, above this other spindles are arranged en
chevron over each tentacle base, forming a series of 8 points above the collaret. The
remainder of the dorsal surface of the tentacles bears longitudinal yellow spindles.

Spicules. These are mostly rather stout terete spindles, sometimes assuming an oval
outline, and with definite whorls of promiment tubercles on the more slender spindles and

45

with irregularly placed tubercles on the stouter ones. There are also a number of clubs, most
of which are tuberculate rather than thorny. Many of the spindles are curved.

Color. The colony is red and yellow. The ccenenchyma is a dull yellow, owing to the
red axis showing through the yellow layer of spicules. The calyces are dark dull red with a
few superficial yellow spicules. The polyps are red and yellow.

General distribution. The type locality of this species is Samboangan Reefs. It
has also been reported from the Indian Ocean by THOMSON and SIMPSON.

2. Acabaria tenuis Kiikenthal.

Acabaria tenuis Kiikenthal. Die Gorgonidenfamilie der Melitodidae, Zoolog. Anz. Bd. XXXIII,
1908, p. 195.

Stat. 117. i°o'.5 N., 122° 56' E. 80 meters. Sand and coral.

Stat. 144. Anchorage north of Salomakiee (Damar) Island. 45 meters. Coral bottom and
Lithothamnion.

A number of fragments were secured. The largest is flabellate and not reticulate,
exceedingly delicate and fragile. Height 5.8cm., spread 2.1 cm. The main stem forks 7.1 mm.
from its proximal end, one of the resultant branches being missing. The stem is only 18 mm.
in diameter. The branching is in general dichotomous. The distal branches are less than
.5 mm. in diameter between the calyces. The basal node of the stem is 2 mm. long, while
the internode below it is 5 mm. long. Some of the distal internodes are 8 mm. long. The
branching is dichotomous, as a rule, and the furcations are Y-shaped rather than U-shaped.
The calyces are lateral in position and vary greatly in size as well as in spacing. They average
about 1.5 mm. apart.

The individual calyces are tubular in form and more prominent than is usual in this
family. A typical one measures .9 mm. in height and i mm. in diameter at the base. The
calyx walls are filled with spindles which are irregularly horizontal on the basal parts and
arranged en chevron on the distal parts, arising in 8 blunt points around the margin. The
polyps are retractile, but are often seen with their collarets resting just above the calyx margin.
The polyps are armed with yellow spicules. There is a collaret of relatively heavy spindles in
two or three rows, those of the upper row forming low points, each point consisting of the
approximated distal ends of two spicules on the tentacle base. Above these points a few other
spindles form a rude en chevron arrangement which is succeeded by vertically placed
spindles on distal parts of tentacles.

The ccenenchyma is thin and contains spindles and spiny clubs usually disposed
longitudinally.

Spicules. In this species there is a relatively large number of slender curved spindles,
most of which bear regular whorls of verrucse. Others bear irregularly distributed thorny points.
Clubs with thorny points are also found, but are much less numerous than the spindles. Besides
these there are a number of irregular forms, as in all species of this family ; but none are
sufficiently numerous to be regarded as characteristic of the species.

46

Color. The colony is a bright scarlet and the polyps are white with chrome yellow
spindles. The spicules are red and yellow.

General distribution. The type locality is Sagami Bay, Japan; 600 meters. It has
also been reported from Okinose Bank, Japan; 80 — 260 meters.

The specimen from Station 114 is very delicate, with reddish polyps. It is referred with
some doubt to this species.

3. Acabaria formosa new species. (Plate VII, figs. 3, 3^; Plate XII, fig. 3).

Stat. 240. Banda Anchorage. 9 to 45 meters. Black sand and coral. Lithothamnion bank in
1 8 — 36 meters.

The specimens consist of a number of fragments which are exceedingly fragile and
brittle. One of the larger fragments consists of a branch 8 cm. long. The denuded axis of
the main stem of the branch is 1.9 cm. long and is round, having a diameter of 1.2 mm.
It bifurcates at the first node which is triangular in form, 2.8 mm. long and almost equilateral.
Each of the branches bifurcates twice, but one resultant branchlet is missing, and the branches
are separated by a comparatively wide angle. The furcation is angular and not U-shaped as
in so many species of this genus. The internodes of the branches are fairly even, averaging
about 1.4 mm. long and 1.5 mm. in diameter between the calyces. The calyces are all lateral
and usually alternate, those on one side often showing a tendency to bend alternately to the
front and back, like the teeth of a saw.

The individual calyces are very large and conspicuous and their golden yellow color is
remarkably vivid. They are in the form of symmetrical truncated cones, a typical one measuring
1.7 mm. high and 2.1 mm. broad at the base. Their walls are straight and do not curve to
the general level of the coenenchyma, as is usually the case, but are sharply differentiated
from their very bases. The distance between adjacent calyces varies, but 1.5 mm. seems fairly-
typical. The margin bears 8 regular scallops or lobes, the polyps are retractile, but usually
rest with their collarets just above the calyx margins. They are heavily spiculated, with a
well-marked collaret composed of strong bent spindles in two or three encircling rows. Above
the collaret the spindles are arranged en chevron over the tentacle bases, forming 8 strong
points, each point being composed of a bundle of spindles. Beyond these points the dorsal
surfaces of the tentacles are armed with longitudinal spindles.

Spicules. These are thorny spindles and clubs. The spindles are usually more slender
than in most Melitodidse and often curved. They are relatively quite numerous. There are also
small spindles with two whorls of verrucas in addition to the terminal knobs. The characteristic
clubs show a proximal comparatively smooth acicular part and a clavate distal portion armed
with numerous spiny points. The spicules of the axis are deep crimson.

Color. The colony in general, including the polyps, is a very vivid chrome yellow and
the axis is bright crimson. The ccenenchyma is thin and allows the color of the axis to show
through as a bright pink. This is one of the most brilliantly colored species that I have seen.

47

Acabaria formosa is allied to A. biserialis Kiikenthal, but is stouter, and the calyces
are much larger.

4. Acabaria hicksoni new species. (Plate VIII, figs. 3, 30 ; Plate XII, fig. 4).

Stat. 60. Haingsisi, Samau Island near Timor. Reef. 23 meters. Lithothamnion in 3 meters
and less.

Specimens consisting of a number of fragments. The largest is sub-flabellate in form
and very erratic and straggling in its manner of growth. The proximal part is gone, and its
form is such that it is difficult to tell which is the main stem or branch. The specimen is
6.6 cm. in length and about 3.5 cm. in spread. The largest branch is 1.5 mm. in diameter
between the calyces. The nodes are not sharply distinguished from the internodes, and are
not so distinctly triangular in shape as is often the case. They vary from 2.5 mm. (proximal)
to 1.2 mm. (distal) in length. The internodes vary from 4 mm. (proximal) to 13 mm. (distal)
in length. The branching is such that the greater part of the specimen is in two parallel planes.
The branching is dichotomous, as a rule, but there are a number of ultimate lateral branchlets.
The furcations are Y-shaped rather than U-shaped. The calyces are mainly lateral in position,
where they are rather close set and tend to an alternate position.

The individual calyces are in the form of low domes when the polyps are completely
retracted, and short tubes when they are expanded. A typical one measures i mm. in height
and 1.2 mm. in diameter. The spiculation of the calyx walls shows a basal arrangement of
horizontal spicules, but an en chevron arrangement toward the margins. The polyps, in
partial retraction, form a strongly marked 8-rayed figure or rosette when viewed from above.
There is a well-marked collaret of reddish spicules, above which is an en chevron arrangement
of spindles on the tentacle bases which blends in color from red to yellow. The remainder of
the dorsal surfaces of the tentacles are provided with longitudinal yellow spindles, and an
oblique series of spindles is on each side of the tentacle extending from the dorsal surface to
the pinnule bases, forming an armature that is unusual in this family.

Spicules. These are much as in Acabaria tenuis Kiikenthal. The spindles seem to
be a little heavier on the average, but I fail to find any specific differences, so far as the form
of the spicules is concerned.

Color. The colony is a dark red and the polyps are red and yellow.

This species differs from Acabaria tenuis in being of a more robust habit, in irregularity
of branching, in larger calyces and thicker branches and in the spiculation of the polyps.

5. Acabaria triangulata new species. (Plate VIII, figs. 2, 2a : Plate XII, fig. 5).

Stat. 260. 5°36'.5S., I32°55'.2E. 90 meters. Sand, coral and shells.

Stat. 274. 5°28'.2S., I34°53'.9E. 57 meters. Sand and shells, stones. (Type locality).

The colony is sub-flabellate in form, 6.3 cm. high and 1.5 cm. broad. The stem and
branches are round in section. The main stem is 1.5 cm. long to the first branch and 1.9 cm.
in diameter. The second node is 3.8 mm. long and 3 mm. broad, and a distal node is i mm.

48

long. The second internode is 6 mm. long, and a distal one 8 mm. long. The main stem
bifurcates i 5 cm. from its base into two irregular branches which are erect and nearly parallel,
giving off alternate branchlets, one from each node. The largest branch is sinuous. The distance
between branches varies, as do the length of the internodes. The calyces are lateral in position,
not so crowded as in many species, and leave proportionally broader naked areas on the back
and front of the branches.

The individual calyces are quite small dome-shaped verrucae which show as dark red
swellings in contrast with the lighter red of the ccenenchyma. An average calyx measures .5 mm.
in height by .7 mm. in diameter, thus being smaller than any other species of this genus in
the collection. The calyx walls are filled with Stachelkeulen the spiny points of which give a
bristling appearance. The polyps are very small, retractile and, on account of their red color
being the same as that of the calyces, hard to study. The spiculation, however, seems to be
the same as in allied species, consisting of a collaret of transverse spicules above which 8 points
are formed by two or more spindles on each tentacle base meeting at an angle, and a distal
series of longitudinal spindles on the dorsal surfaces of the tentacles.

Spicules. These are quite different from those of other species of the genus the most
characteristic ones being triangular in outline with their surfaces covered with large warty
tubercles. These triangles are large, and are modifications of the spiny club type, many of them
showing short thorny or foliaceaous projections from their club end. Both Blattkeulen and
Stachelkeulen are found, the latter predominating. Ordinary spindles are rather rare. When
present they are usually short, curved and ornamented with whorls of verrucae.

Color. The colony is a dark, rather dull, coral red and the calyces and polyp spindles
a dark crimson red.

Genus Mopsella Gray.

Mopsella Gray. Proceedings Zoological Society of London, 1857, p. 248.
Mopsella Ridley. Zoological Collections H. M. S. Alert, 1884, p. 258.
Mopsella Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 31.
Mopsella Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. XXXVI.
Mopsella Kukenthal. Die Gorgonidenfamilie der Melitodidse, Zoolog. Anz. Bd. XXXIII, 1908,
p. 198.

The original definition of this genus is not at present accessible to the writer. RIDLEY
(1884) emphasizes the necessity of depending largely on spicule characters in defining genera
of this family.

STUDER (1887) gives as the character of the genus the penetration of the internodes by
the water-vascular canals and the presence of spindles and foliaceous clubs among the spicules.

KUKENTHAL (1908) gives the first satisfactory definition of the genus, which may be
translated as follows :

"Colonies usually flabellate. The branching is dichotomous and from the nodes. Axis
usually penetrated by water-vascular canals. Cortical spindles foliaceous clubs. Polyps in low
calyces on the sides and one surface of the usually not flattened branches".

49

This definition is a satisfactory one for our present purpose, and will be adopted.

The type species of this genus is Mopsella textiformis (Lamarck). Other described
species are Mopsella amboynesis Kiikth., M. clavigera Ridley, M. dichotoma (Pallas), M. coccinea
(Ellis and Solander), M. khmzingeri Kiikth., M. sanguinea Kiikth., M. zimmeri Kiikth. -, and
the new species described beyond.

1. Mopsella clavigera Ridley.

Mopsella clavigera Ridley. Zoological Collections H. M. S. Alert, 1884, p. 360.

Stat. 53. Bay of Nangamessi, Sumba. Up to 36 meters. Coral sand. Near the shore, mud.

A fragmentary specimen from this station shows the strongly compressed axis and
main stem, and peculiar spicules figured by RIDLEY, 1. c. Plate XXXVIII, fig. a, a', a'", for
M. clavigera. The specimen is dry and nearly all of the branches are missing. The internodes
are pinkish and the nodes crimson. The calyces and polyps can not be satisfactorily studied.

Spicules. The spicules are exceedingly various in form, but those figured by RIDLEY
are quite characteristic. There are numerous clubs with comparatively smooth surfaces, and
others flattened and longitudinally grooved, forming figures like two or three extended fingers
flattened and closely pressed together. Many also are like irregular potatoes in form, with
rounded swellings unlike other verrucse, and sometimes thorny points. Regular tuberculate
spindles with the verrucee in symmetrical whorls are also found.

Color. The colony is dull red and the axis has pink internodes and crimson nodes.

General distribution. The type locality of this species is in the Indian Ocean.

2. Mopsella studeri new species. (Plate IX, figs. 410-, Plate XII, fig. 6).

Stat. 71. Makassar and surroundings. Up to 32 meters. Mud, sand with mud, coral.

Stat. 273. Anchorage off Pulu Jedan, East coast of Aru Islands (Pearl Banks). 13 meters.

(Type locality).
Stat. 274. 5°28'.2S., I34°53'-9E. 57 meters. Sand and shells. Stones.

Colony flabellate and reticulate, 25.3 cm. high and with a spread of 11.5 cm. Two
main stems are coherent at base, forming a common stock 1.5 cm. X i cm. in diameter.
These separate about 2 cm. from the base, but are reunited by a single anastomosis of the
branches. Stem and branches laterally compressed, the larger stem having a cross section of
9 mm. X 7 mm. In the lower part of the main stem the nodes blend with the internodes so
as to make it difficult to ascertain their limits on superficial examination, but the nodes are
evidently much longer than the internodes. On the branches and twigs this relation is reversed,
the internodes being much the longer. Some of the distal nodes are but 2 mm. long, while
adjacent internodes are 1 1 mm. long. The branching is dichotomous in general, but sometimes
lateral and alternate. The furcations are usually U-shaped. Some of the main branches are
much compressed, one having a section of 3.8 mm. X 2 mm. The ultimate twigs are nearly
round and average about i mm. in diameter, the calyces are very thickly emplanted on three
sides of the stem and main branches and on all sides of the smaller branches and twigs.

SIBOGA-FXPEDITIE XIII* s. 7

50

The individual calyces are quite small dome-shaped verrucae when the polyps are
completely retracted, and short tubes when they are completely expanded. They are so closely
crowded on the surfaces of the branches as to be contiguous at their bases. A typical one
measures .9 mm. in diameter at the base. The height varies in accordance with the state of
expansion of the polyps, but seldom exceeds i mm. The calyx walls are armed with very
jagged spindles and Blattkeulen and, in certain stages of contraction of the polyps, the margin
is distinctly 8-lobed. The polyps have a rather slender collaret, above which the spindles form
eight points. Beyond these points there are a few longitudinal spindles, lying along the dorsal
surfaces of the tentacles. Minute spindles also extend from the dorsal surfaces diagonally to
the pinnule bases.

S p i c u 1 e s. The most characteristic forms are remarkable Blattkeulen which consist of
a tuberculate base from which project a number of parallel flattened finger-like points. Or they
may be likened to a plate which has been shattered by several vertical fissures. There is
complete intergradation between these Blattkeulen and typical Stachelkeulen, so that it is hard
to differentiate them. Besides these curious forms there are regular spindles often curved, from
the polyps, and clubs, besides a great variety of nondescript forms.

Color. The colony is a rather dull yellowish brown. The spicules are colorless.

3. Mopsella spongiosa new species. (Plate VIII, figs, i, i«, Plate XII, fig. 7).

Stat. 273. Anchorage off Pulu Jedan, East coast of Aru Islands (Pearl Banks). 13 meters.
Sand and shells.

Colony strictly flabellate and reticulate, spongy in texture and not so delicately branched
as in the other species, although the meshes are fine. Height of colony 21.5 cm. Spread 20 cm.
The main stem is irregular in section, but not appreciably flattened, and is 14 mm. in diameter.
About 1 8 mm. from its base it breaks up into numerous branches which redivide to make the
mesh. In the main stem the nodes and internodes are hardly distinguishable. In one of the
main branches the proximal node is 7.5 mm. long and 5 mm. in diameter, while the proximal
internode is 2.3 mm. long and 3 mm. in diameter. The nodes are much swollen and longer
than the internodes throughout the basal parts of the colony. A node near the edge of the
fan is 4 mm. long, while the internode just below it is 1 1 mm. long and 1.6 mm. in diameter.
Most of the branches are somewhat flattened, but the distal twigs are round. The meshes are
small, usually oblong, and the anastomoses are usually, but not always, at the nodes. The
calyces are emplanted very thickly on these sides of the main branches and on all sides of
the distal ones.

Spicules. The most typical form of spicule in this species is the foliaceous club, with
an irregular densely tuberculate basal part and a distal portion consisting of several flattened
expansions usually extending parallel to each other and often in the same plane. Frequently
these take the form of coarsely tuberculate spindles from one side of which the foliaceous
expansions arise, making "unilateral" spindles. These Blattkeulen are exceedingly varied in

form. There are also many spindles, some with irregular verrucae, and others with verrucae in
regular whorls. Bent spindles are found in the polyps.

Color. The colony is a very dull grayish brown, like that of many sponges. The axis
is dull crimson and the polyps are colored like the ccenenchyma.

Genus Wrightella Gray.

Wrightella Gray. Catalogue of the Lithophytes in the British Museum, 1870, p. 31.

Wrightella Ridley. Zoological collections of H. M. S. Alert, 1884, p. 580.

Wrightella Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 32.

Wrightella Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. XXXVI.

Wrightella Kiikenthal. Die Gorgonidenfamilie der Melitodidae, Zoolog. Anz. Bd. XXXIII,

1908, p. 200.
Wrightella Thomson and Mackinnon. Alcyonarians collected on the Percy Sladen Trust

Expedition, Part II, 1910, p. 199.

The earliest definition of this genus at present at hand is that of STUDER (1887) which
is as follows :

"Comprimirte Aste und Zweige, die vorragenden Polypenkelche vonviegend an den
Seiten. In der Rinde Blattkeulen. Keine Nahrkanale in der Axe".

WRIGHT and STUDER (1889) simply give a translation of the above definition.

KUKENTHAL (1908) defines the genus as indicated in the following translation:

"Colonies flabellate. Branches flattened and arising from the nodes. No water-vascular
canals in the axis. In the outer cortex there are small spherical spicules which are derived
from foliaceous clubs. The polyps are lateral or on one surface".

THOMSON and MACKINNON (1910) say that Wrightella is characterized by distinctive
spicules : " short clubs with very broad flanges. The heads of these clubs form a compact
pavement in the ccenenchyma, producing an almost roe-like appearance, as in species of Bebryce".

The type species of this genus is Wrightella coccinea Gray. Other species are Wrightella
variabilis Thomson and Henderson, W. tongaensis Kiikth. and the new species in the Siboga
collection.

i. Wrightella coccinea Gray.

: Isis cocinnea Ellis and Solander. Natural History of Zoophytes, 1786, p. 107.
? Isis coccinea Esper. Pflanzenthiere, I, 1781, p. 280.

Melit<ea de Risso Lamouroux. Histoire Polypiers coralligenes flexibles, 1816, p. 463.

Melitaa coccinea Lamarck. Histoire Naturelle des Animaux sans Vertebres, 2nd Edit., Vol. II,
1836, p. 473.

Wrightella coccinea Gray. Catalogue of the Lithophytes in the British Museum, 1870, p. 32.

Wrightella coccinnea Ridley. Zoological collections of H. M. S. "Alert", 1884, p. 581.

Wrightella coccinea Hickson. Alcyonaria of the Cape of Good Hope, II, 1904, p. 219.

Wrightella coccinea Thomson and Mackinnon. Alcyonarians collected on the Percy Sladen
Trust Expedition, Part II, 1910, p. 2OO.

Stat. 117. i°o'.5 N., 122° 56' E. 80 meters. Sand and coral.
Colony (incomplete) flabellate and reticulate, 12.5 cm. long. Main stem, to first branch,

52

3 cm. long. Second horny node 4.5 mm. broad and 4 mm. long. Calcareous internodes 2.1 mm.
broad and 4.5 mm. long. The nodes grow proportionally shorter and the internodes longer
until on the distal parts of the colony the former are but 2 mm. long and the latter reach a
length of 1 6 mm. The stem forks at the 5th node. The branches are somewhat compressed
laterally. The branching is partly dichotomous and partly alternate, all branches springing from
the horny joints and anastomosing through the joining of the ultimate twigs. The calyces are
on three sides of the colony, except on the distal twigs where they are on all sides. These
latter are quite slender, being but little over i mm. in diameter.

The individual calyces are low domes when the polyps are retracted and truncated
cones when they are partly expanded. They are rather regularly spaced, more so on the sides
than on the front of the colony. A typical calyx measures .6 mm. in height and i.i mm. in
diameter. The calyx walls, as well as the general ccenenchyma, are packed with foliaceous
clubs or Blattkeulen which appear when in situ and viewed under a low magnification as
rounded bodies or nodules, because they are thus seen "end on", in the calyx walls, the
foliaceous ends being directed upward and outward. The polyps are heavily spiculated, with a
strong collaret of bent tuberculate spicules. Above these each tentacle base is provided with
two spicules whose ends meet at a wide angle forming an upward directed point. The dorsal
surfaces of the tentacles are covered with longitudinal tuberculate spindles.

Spicules. The surface of the ccenenchyma is packed with vertically placed typical
Blattkeulen with their foliaceous ends directed outward. These spicules are very characteristic
of the genus Wrightella, consisting of a basal, irregular, often much branched and tuberculate
portion, and a distal part composed of foliaceous expansions gathered together into a globular
"head" resembling the bud of a tulip or rose and forming what appears to be a rounded
nodule when the spicules are viewed in situ under low magnification. Other Blattkeulen are
seen with wide foliaceous expansions which are flattened and longitudinally shattered or split.
These are often seen in the distal parts of the calyx walls. Curved, tuberculate spindles are
found in the polyps and tentacles.

Color. The colony is almost a brick red, or light scarlet. The polyps are yellow and
the axis deep crimson.

General distribution. The type locality seems to be the coast of Mauritius (£LLIS
and SOLANDER). It has also been reported from the Seychelles, 4 — 12 fathoms (GRAY); from
the Indian Ocean, Farquaar Atoll, Prashu, Seychelles (THOMSON and MACKINNON), and from
the Cape of Good Hope (RIDLEY).

2. ? Wrightella tongaensis Kukenthal.

Wrightella tongaensis Kukenthal. Die Gorgonidenfamilie der Melitodidas, Zoolog. Anz. Bd.
XXXIII, 1908, p. 200.

Stat. 240. Banda Anchorage. 9 to 45 meters. Black sand, coral.

Stat. 258. Tual Anchorage, Kei Islands. 22 meters. Lithothamnion, sand and coral.

Stat. 282. 8°25'.2S.( !27°i8'.4E. 27 to 54 meters. Sand, coral and Lithothamnion.

Colony subflabellate, not truly reticulate, although there are occasional anastomoses,

53

very profusely branched, forming a flattened clump. Height 11.2 cm., spread 12 cm. The basal
part is lacking, the proximal node of the stem is 9 mm. in diameter and the only remaining
internode is flattened and has a cross section of 8 mm. X 5 rnm. and a length of 6 mm.
This internode, however, appears to be really two coalesced internodes which have branched
from the preceding node and adhere throughout their length. As is usual the nodes decrease
in length while the internodes increase from the proximal to the distal parts of the colony
until the nodes are but 2 mm. in length while the internodes are sometimes as much as 18 mm.
long. The branching is irregularly dichotomous and the branches are round in section, the
distal twigs being but i mm. in diameter. The calyces are thickly emplanted on three sides of
the stem and branches, leaving the posterior face of the colony conspicuously bare.

The individual calyces are dome-shaped verrucae when the polyps are completely
retracted and truncated cones when they are expanded. They are rendered very conspicuous
by the fact that the upper parts of their walls are rich carmine while the lower parts of the
walls and general ccenenchyma of the branches are orange yellow. A typical calyx is .8 mm.
high and 1.3 mm. in diameter. The polyps are heavily spiculated with a collaret composed of
three or four rows of strong tuberculate spindles above which a pair on each tentacle base
form a point by the meeting of their distal ends. Above these points each tentacle bears a
triangular area of spicules, some of which are Stachelplatten with jagged projections. All of
these spicules are brilliant red, in sharp contrast with the white of the tentacles themselves.

Spicules. These are exceedingly various, the most characteristic being Blattkeulen,
small in size, with their folia compressed into a knob or ball resembling a closed bud. These
are superficial on the calyces and general ccenenchyma. Besides these there are a number of
ordinary spindles, clubs, bent spindles and variously branched forms, with occasional unilateral
spindles and Stachelplatten.

Color. The colony is a brilliant orange with the marginal areas of the calyces, polyp
spicules and axis bright crimson. The polyps are white. This is one of the most strikingly
colored forms that I have seen among the Melitodidae.

General distribution. The type locality of this species is Tonga Islands (KUKEXTHAL).

f

Genus Parisis Verrill.

Parisis Verrill. Bulletin Museum of Comparative Zoology, 1864, p. 67.

Parisis (in part) Gray. Catalogue of the Lithophytes in the British Museum, 1870, p. 13.

Parisis Ridley. Annals and Magazine of Natural History, 5*h series, Vol. X, 1882, p. 130.

Parisis Studer. Versuch eines Systemes der Alcyonaria, 1887, p. 32.

Parisis Wright and Studer. Challenger Report, the Alcyonaria, 1889, p. 181.

Parisis Delage et Herouard. Traite de Zoologie Concrete, II, 2, 1901, p. 414.

Parisis Kiikenthal. Die Gorgonidenfamilie der Melitodidae, Zoolog. Anz. Bd. XXXIII, 1908, p. 190.-

The original definition for this genus is not at hand.

RIDLEY (1882) says that Parisis differs from Trinella Gray in having spicular verrucae.

STUDER (1887) defines the genus as shown in the following translation:

" Branches differ from all other Melitodidae in springing from the calcareous y ints. The

54

exserted calyces are borne on the outer periphery of the thinner branches. The spicules resemble
those of his, being thick, irregular, often with a median constriction and beset with verrucse".

This writer says that Trinella swinhoei Gray is really the axis of a Parisis overgrown
by a sponge and bearing Polythoa which GRAY mistook for the polyps of his Trinella.

The type of this genus is Parisis fruticosa Verrill. The only other known species is
P. minor Wright and Studer.

WRIGHT and STUDER regard Parisis mauritiensis Ridley as a synonym for P. fruticosa^
and THOMSON and SIMPSON conclude that P. indica Thomson and Henderson should also be
relagated to the same well-known form.

i . Parisis fruticosa Verrill.

Parisis fruticosa Verrill. Bulletin Museum of Comparative Zoology, I, 1865, p. 23.
? Trinella swinhoei Gray. Catalogue of Lithophytes in the British Museum, 1870, p. 12.
Parisis mauritiensis Ridley. Annals and Magazine of Natural History, 5 A series, Vol. X,

1882, p. 131.

Parisis fruticosa Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 182.
Parisis indica Thomson and Henderson. Alcyonarians of the Indian Ocean, I, 1906, p. 23.
Parisis fruticosa Thomson and Simpson. Alcyonaria of the Indian Ocean, II, 1909, p. 176.

Stat. 204. 4°2o'S., 122° 58' E. From 75 to 94 meters. Sand with dead shells.
Stat. 260. 5° 36'. 58., I32°55'.2E. 90 meters. Sand, coral and shells.
Stat. 274. 5°28'.2S., I34°53'.9E. 57 meters. Sand and shells. Stones.

Colony subflabellate in form, 46.5 cm. in height, with a spread of about 15 cm., and
extensively encrusted with a sponge. The base of attachment is lacking. The stem and all
branches are round, the former being 7 mm. in diameter and 5.5 cm. long to first branch.
The calcareous and horny segments are equal in diameter and not externally evident, except
in the stem and larger branches. The nodes vary from 4 mm. (proximal) to less than i mm.
(distal) in length. The calcareous internodes are more constant in the sense that their extreme
variation is less, but do not increase as regularly from proximal to distal parts of the colony
as in many species of this family. They vary from 2 to 6 mm. in length. The main stem
gives off a number of small irregular lateral branches, four of which are compound, from its
proximal 10 cm., and the stem bends outward and then upward. It then forks into two unequal
parts and each of these gives off numerous lateral branchlets both simple and compound, some
of which rebranch until branchings of the 6th order are attained. The ultimate twigs are about
1.3 mm. in diameter, measured between the calyces. These latter are rather thickly distributed
on all sides of the distal branchlets, but usually they are on but three sides of the branches
and on some they are strictly lateral. .

The individual calyces are dome-shaped, but tilted so that their summits are inclined
toward the distal ends of the branches. A typical one measures 1.4 mm. high and 1.2 mm.
in diameter near its base. The calyx walls are filled with a neatly fitted mosaic of polygonal
spicules whose edges form close joints and do not seem to overlap. The polyps are very minute,
and their attachment to the inside of the calyx, when strongly contracted, is so firm that
satisfactoly investigation is very difficult. They are either devoid of spicules or very feebly spiculated.

55

Spicules. These are heavy plate-like forms of various shapes, but usually polygonal.
Their surfaces are covered with heavy rounded verrucae so thickly compacted as to be often
contiguous. Some of the smaller ones are radiate, stellate or cruciform. The larger ones some-
times attain a length of .6 mm.

Color. The specimen is a dull purplish or purplish brown, due largely to the presence of
the sponge. The nodes are dark brown and the internodes ivory white. The spicules are colorless.

A few fragmentary specimens from station 310 are free from the sponge growth. They
are partly creamy white and partly pinkish In one fragment the axis is a deep rose color,
and the polyps seem to be of the same color.

General distribution. The type locality for this species is Soolo Sea. It has also
been reported from Mauritius, Banda Sea, Australia, Formosa and the Indian Ocean.

2 . ? Parisis minor Wright and Studer.

Parisis minor Wright and Studer. Challenger Reports, the Alcyonaria, 1889, p. 1884.
Stat. 139. o°ii'S., I27°25'E. 397 meters. Mud, stone and coral.

A single specimen, representing the terminal part of a colony is referred with doubt to
this species. The fragment is 3.7 cm. long, and was broken off from the colony just below a
node which is incomplete and bears on its distal end a bifurcated internode. One of the resultant
branches bears a lateral branchlet on its proximal internode and bifurcates r.5 mm. from its
proximal end, or at the end of the first internode. One of the resultant branchlets is a mere
stub. The other is 2.5 cm. long and has adhering to it a piece of a branchlet from a missing
branch. The other main branch bifurcates twice, the furcations being Y-shaped rather than
U-shaped. Its distal internode is longest, measuring 17 mm. The calyces are nearly all lateral,
but a few are on the anterior face of the colony.

The individual calyces are in the form of truncated cones, a typical one measuring
.8 mm. in height and 1.5 mm. in diameter at the base. The calyx walls are filled with coarse,
heavily tuberculate spindles which are exceedingly irregular in arrangement. Sometimes they
are disposed horizontally and at other times those around the margin are vertical, forming a
rude series of irregular jagged points. The polyps are very heavily spiculated, with a relatively
narrow collaret above which a group of heavy spindles are placed almost vertically at each
tentacle base, forming a series of eight points. The polyps are retracted to their collarets and
the infolded tentacles form a conical mass which completes the cone-shape of the calyx.

Spicules. These are heavy spindles with short branched verrucae not in whorls. They
are not so large as in P . fruticosa and their branching is much more evident. A number of
more slender thorny spindles are found in the polyps. Although not so regular in form as
represented by WRIGHT and STUDER'S figures, they agree with them fairly well in essential features.

Color. The specimen described is grayish white in color.

General distribution. The type locality for this species is Hyalonema grounds,
Japan 345 fath.

56

Genus Birotulata new genus.

Colony flabellate. Both nodes and internodes traversed by water-vascular canals. The
branches are all borne on the nodes. Characteristic spicules double wheels.

Type species, Birotulata splendens Nutting.

•

i. Birotulata splendens new species. (Plate X, figs, i, ia, 2; Plate XII, fig. 8).
Stat. 258. Tual Anchorage, Kei Islands. 22 meters. Lithothamnion, sand and coral.

The type was originally a very large colony, but has been broken into many fragments.
The specimen was flabellate in form and not reticulate and probably originally measured as
much as i meter in height. The trunk and main branches are laterally compressed, the former
being 2.8 cm. X i-9 cm. in section, and the latter as much as 2.8 cm. X 2.2 cm. in section.
The main stem bifurcates 7 cm. from its proximal end into two very unequal branches. The
larger of these, after giving off four branchlets, the stubs of which remain, bifurcates into two
branchlets which are approximately round in section, the larger one having a diameter of 2 cm.
Some of the more distal branchlets are round and others slightly compressed laterally. The
branching is in part dichotomous and in part lateral, the former prevailing in the distal parts
of the colony, the ultimate branchlets being 1.5 mm. in diameter. The furcations are usually
U-shaped rather than Y-shaped. The calyces are on the sides and front of the colony, leaving
a bare posterior space, sharply distinguished by its bright chrome yellow color, as if the colony
were crudely painted scarlet on front and sides and yellow behind.

The individual calyces are closely set and have each a broad border of scarlet which
gives the red color to the branches. They are almost entirely included and very small, not
being over .5 mm. in diameter on the average. Their walls, like the general ccenenchyma, are
filled with small smooth double-wheels. The polyps are retractile, and bear a collaret which is
rather strong and composed of two or three rows of transverse red spindles. Above these a
few spindles are arranged en chevron on each tentacle base, and beyond this the spindles
are longitudinal. The nodes are not indicated superficially on the main stem and larger branches,
and are nowhere so conspicuous as in Melitodes ochracea. The internodes, as well as the nodes,
are penetrated by numerous water-vascular canals.

Spicules. The most conspicuous and numerous forms are the double-wheels charac-
teristic of the genus. These are on the surface and also constitute the chief element in the
ccenenchyma. They look much like two buns pressed together, sometimes unsymmetrically. Some
of them have a small nodule at each end in addition to the two wheels. There are also densely
tuberculate short stout spindles, and ordinary spindles, mostly from the polyps, and numerous
irregular forms which are usually minute. The spicules of the axis are smooth bar-like and
needle-like forms.

Color. The colony is scarlet and chrome yellow, the posterior face of the distal parts
of the colony being sharply differentiated, as if painted with vivid yellow. The yellow shows

57

also on the other sides between the scarlet borders of the calyces. The polyp spicules are
scarlet. The axis is a bright yellow, a characteristic which differentiates this species from Meli-
todes ochracea. The stem and main branches are dark red. Another colony has the distal
internodes creamy white and the nodes yellow.

This species bears a very close superficial resemblance to Melitodes ochracea.

T.HOMSON and MACKINNON 1 have called attention to two other cases of very close
approximation of species belonging to separate genera, i. e., Wrightella coccinea and Melitodes
coccinea (Esper) -, also Wrightella variabilis Thomson and Henderson and Melitodes variabilis
Hickson. The present case is quite similar to those noted by these writers.

There is very close resemblance between Birotulata splendens and Melitodes ochracea,
but the spiculation is so different as to justify a generic distinction between the two.

1 Alcyonarians collected by the Percy Sladen Trust Expedition. Part II, 1910, p. 200.

SIBOGA-EXPEDIT1E

DISTRIBUTION OF THE MELITODID^ COLLECTED BY THE SIBOGA EXPEDITION

List of Stations

at which Melitodidae were collected by the Siboga Expedition
and a List of Species collected at each Station.

STATION 33. Bay of Pidjot, Lombok. 22 meters, and less. Mud, coral and coral sand. Melitodes esperi.
STATION 50. Bay of Badjo, West coast of Flores. Up to 40 meters. Mud, sand and shells. Melitodes esperi.

STATION 53. Bay of Nangamessi, Sumbu. Up to 36 meters. Coral sand, mud near shore. Mopsella
clavigera.

STATION 60. Haingsisi, Samau Island near Timor. 23 meters. Lithothamnion in 3 meters and less.
Reef. Melitodes variabilis, M. esperi, Acabaria hicksoni.

STATION 71. Makassar and surroundings. Up to 32 meters. Mud, sand with mud, coral. Melitodes
ochracea, Mopsella studeri.

STATION 80. 2°25'S., H7°43'E. 50 to 40 meters. Fine coral sand. Melitodes esperi.

STATION 85. O°36'.5S., II9°29'.5E. 724 meters. Fine grey mud. Melitodes ochracea.

STATION 117. i°o'.5 N., 122° 56' E. 80 meters. Sand and coral. Acabaria tenuis, Wrightella coccinea.

STATION 139. o°n'S., 127° 25' E. 397 meters. Mud, stones and coral. Parisis minor.

STATION 144. Anchorage north of Salomakiee (Damar) Island. Coral bottom and Lithothamnion.
Melitodes esperi, Acabaria tenuis.

STATION 164. i°42;.5 E. I3O°47'.5 E. 32 meters. Sand, small stones and shells. Melitodes flabellum,
M. esperi, M. modesta.

STATION 204. 4°2o'S., 122° 58' E. 75 to 94 meters. Sand with dead shells. Parisis fruticosa.
STATION 234. Nalahia Bay, Nusa-Laut Island. 46 meters. Stony. Melitodes ochracea.

STATION 240. Banda Anchorage. 9 to 45 meters. Black sand, coral. Lithothamnion. Acabaria formosa,
Wrightella tongaensis.

STATION 244. 4° 25'.7 S., I30°3'.7E. 2991 meters. Fine bluish green mud. Mopsella studeri.
STATION 257. In Duroa Strait, Kei Islands. Up to 52 meters. Coral. Melitodes esperi.

STATION 258. Tual Anchorage, Kei Islands. 22 meters. Lithothamnion, sand and coral. Wrightella
tongaensis, Birotulata splendens.

STATION 260. 5° 36'. 5S., I32°55'.2E. 90 meters. Sand, coral and shells. Acabaria triangulata, Parisis
fruticosa.

STATION 261. Elat, West coast of Great Kei Islands. 27 meters. Mud. Melitodes flabellum.

STATION 273. Anchorage off Pulu Jedan, East coast of Aru Islands. 13 meters. Sand and shells.
Melitodes flabellum, M. esperi, M. modesta, Mopsella studeri, M. spongiosa.

STATION 274. 5°28'.2S., I34°53'.9E. 57 meters. Sand and shells, stones. Melitodes variabilis, M.
modesta, Acabaria triangulata, Mopsella studeri, Parisis fruticosa.

59

STATION 282. 8°2S'.2S., i27°i8'.4E. 27 to 54 meters. Sand, coral and Lithothamnion. Wrightella
tongaensis.

STATION 299. io°52'.4S., I23°i'.i E. 34 meters. Mud, coral and Lithothamnion. Melitodes flabellum,
J/. squamata.

STATION 305. Mid channel in Solor Strait, Off Kampong Menanga. 113 meters. Stony. Melitodes
flabellum.

STATION 310. 8°3o'S., 119° 7. 5 E. 73 meters. Sand with few pieces of dead coral. Melitodes flabellum,
Acabaria philippinensis, Parisis fruticosa.

STATION 315. Anchorage East of Sailus Besar, Paternoster Islands. Up to 36 meters. Coral and
Lithothamnion. Melitodes esperi.

The above list shows that Melitodidae were collected at 26 stations, or at about i3°/oofthe
stations at which successful hauls were made during the Siboga Expedition. The most abundant
genus of Melitodidse in the region covered by the expedition is the type genus Melitodes, which
was collected at 17 stations out of the 26. Melitodes esperi seems to be the most abundant species
of Melitodidae in the collection, having been collected at 9 stations; and M. flabellum is the next.

Table showing the bathymetric and geographic distribution
of the Scleraxonia of the Siboga Expedition.

BATHYMETRIC.

i to

50

meters

50 to
100

meters

I oo to
200

200 to
500

meters i meters

Over

500

meters

GEOGRAPHIC, ASIDE FROM DUTCH
EAST INDIES.

BRIAREID.-E.

Solenocaulon sterroklonium. . . * * .

Solenocaulon grayi * *

Solenocaulon querciformis ... *

Solenocaulon jedanensis *

Titanidium friabilis *

Semperina rubra *

Semperina brunnea *

Suberia k'ollikeri . *

Suberia excavata *

Suberia macrocalyx

Paragorgia splendens

Iciligorgia orientalis *

SCLEROGORGID.E.

Suberogorgia I'erriculata. ... *

Suberogorgia ornata *

Suberogorgia k'ollikeri * *

Suberogorgia rubra * *

Suberogorgia appressa *

Suberogorgia thomsoni . *

Suberogorgia pulchra *

Korceides koreni .... . *

Indian Ocean.
Australia, Indian Ocean.

Bohol, Philippine Islands.
North of New Zealand.

Indian Ocean.

Northwest coast of Australia, Japan.

Indian Ocean.

Japan, Ceylon, Indian Ocean.

Ceylon.

Japan, Indian Ocean.

6o

BATHYMETRIC.

i to

50

meters

50 to

100

meters

loo to
200

meters

200 to

500
meters

Over

500

meters

GEOGRAPHIC, ASIDE FROM DUTCH
EAST INDIES.

MELITODID.E.

Melitodes ochracea *

Melitodes flabellum * *

Melitodes variabilis *

Melitodes esperi * *

Melitodes squamata *

Melitodes modest a * *

Acabaria philippinensis . *

Acabaria tennis * *

Acabaria formosa *

Acabaria hicksoni ' »

Acabaria triangttlata

Mopsella clavigera *

Mopsella studeri * *

Mopsella spongiosa *

Wrightella coccinea . *

Wrightella tongaensis * *

Parisis fruticosa . *

Parisis minor

Birotidata splendens *

Indian Ocean.

Indian Ocean.

Indian Ocean.

Indian Ocean.

Indian Ocean.
Japan.

Indian Ocean.

Indian Ocean (Mauritius), Cape of Good Hope.
Tonga Islands. (South Pacific).
Sooloo Sea, Indian Ocean, Australia.
Hyalonema Grounds (Japan).

This table clearly indicates that the Scleraxonia are essentially Indo-Pacific in distribution,
but five species being found so far north as Japan, four extending south to Australia and one
to the Tonga Islands. Wrightella coccinea strays as far from the type locality as the Cape of
Good Hope. Fourteen of the twenty one hitherto described species are found in the Indian
Ocean, which seems the centre of distribution for the group, and not a single species is surely
known to occur in the Atlantic Ocean.

In bathymetric distribution this suborder is mainly from shallow water, thirty six of the
thirty nine species in the collection being found at less depths than 100 meters, and but ten
species reaching a depth of over 500 meters. It is a remarkable fact that eight of the ten
species referred to are also found at depths of less than 100 fathoms. The paucity of forms
found between 100 and 500 meters is doubtless mainly accidental, as it is reasonable to suppose
that the eight species found at less than 100 meters and over 500 meters really occur at
intermediate depths.

The deepest dredging at which a species of this suborder was secured in 2264 — 1165
meters, where Suberia macrocalyx was taken. Next to this comes Solenocaulon querciformis
from a depth of 828 meters. But the identification of this specimen is somewhat doubtful.

Literature cited
in the Report on the Scleraxonia of the Siboga Expedition.

BOURNE, G. C. A treatise on Zoology. Part II, Chapter VI, 1900.

BRUNDIN, J. A. Z. Alcyonarien aus der Sammlung des zoologisches Museums in Upsala. Bihang til k.
Svenska Vet. Akad. Handlingar, Bd. 22, Heft IV, N° 3, Stockholm, 1896.

DELAGE et HEROUARD. Traite de Zoologie Concrete. Tome II, 2>ne Partie, les Ccelenteres, Paris, 1901.
DUCHASSAING DE FoxTBRESSlN, P. Revue des Zoophytes et des Spongiaires des Antilles. Paris, 1870.

ESPER, E. J. C. Die Pflanzenthiere in Abbildungen nach der Natur, mit Farben erleuchtet nebst Beschrei-
bungen. Niirnberg, 1794.

GEXTHE, C. Uber Solenogorgia tubulosa (eine neue Gattung der Gorgoniden). Zeitschrift f. wiss. Zoologie,

Bd. XVII, 1867.

GERMANOS, N. K. Gorgonaceen von Ternate. Abhandl. Senck. Nat. Ges., Bd. XXIII, Heft I, 1897.
GRAY, J. E. Descriptions of some new Genera of Lithophytes or Stony Zoophytes. Proc. Zool. Soc.

London, 1859.

- On the arrangement of Zoophytes with pinnated tentacles. Annals and Magazine of Natural History.

Vol. V, 1859.

- Descriptions of two new Genera of Zoophytes (Solenocaulon and Belonella] discovered on the North

coast of Australia by Mr. RAYNOR. Annals and Magazine of Natural History, Series 3, Vol. X, 1862.

- Notes on some new Genera and Species of Alcyonoid Corals in the British Museum. Annals and

Magazine of Natural History, Series 4, Vol. V, 1870.

- Catalogue of Lithophytes or Stony Corals in the collections of the British Museum. London, 1870.

HlCKSON, S. J. The Alcyonaria of the Maldives, Part III, The Families Muriceidae, Gorgonellidae, Melito-
didae and the Genera Pennatula, Fnnephthys. Fauna and Geography of the Maldive and Laccadive
Archipelagoes, Vol. II, Part IV, 1905.

KOLLIKER, A. Icones Histiologicae oder Atlas der vergleichenden Gewebelehr; 2'e Abtheilung, der feinere
Bau der hoheren Thiere; istes Heft, die Bindesubstanz der Coelenteraten. Leipzig, 1865.

- Beitrage zur Kenntniss der Polypen, 1870.

KUKENTHAL. W. Die Gorgonidenfamilie der Melitodid^e Verrill. Zoologischer Anzeiger, Bd. XXXIII,
Nr. 78, 1908.

LAMARCK, J. B. P. A. DE. Histoire naturelle des Animaux sans vertebres, Vol. II, Paris, 1836.
LAMOUROUX, J. F. V. Histoire des Polypiers coralligenes flexibles, Caen, 1816.
LlNN,£U3, CAROLUS. Systema Naturae, 10* Edition, 1758.

- Systema Naturae, 12* Edition, 1767.

MiLXE-EDWARDS, H. et HAIME, J. Histoire naturelle des Coralliaires ou Polypes proprement dits, Tome
premier, Paris. 1857.

62

NUTTING, C. C. Alcyonaria of the Californian Coast. Proceedings of the U. S. Nationaal Museum, XXXV,
Washington, 1909.

- Descriptions of the Alcyonaria collected by the U. S. Bureau of Fisheries Steamer "Albatross" in

the Vicinity of the Hawaiian Islands in 1902. Proceedings of the U. S. National Museum, Vol.

XXXIV, 1909.

PALLAS, A. S. Elenchus Zoophytorum, 1866.
RIDLEY, S. O. Report on the Zoological Collections made in the Indian Ocean during the Voyage of

H. M. S. "Alert", 1881—2. London, 1884.
Contribution to the knowledge of the Alcyonaria, Part II, including new Species from Mauritius.

Annals and Magazine of Natural History, 5th Series, Vol. X, 1882.

- Alcyonaria of the Mergui Archipelago, 1888.

STUDER, TH. Ubersicht der Anthozoa Alcyonaria, welche wahrend der Reise S. M. S. "Gazelie" um die
Erde gesammelt wurden. Monatsbericht der Koniglich Preussischen Akademie der Wissenschaften
zu Berlin. Berlin, 1879.

Versuch eines Systemes der Alcyonaria. Archiv fur Naturgeschichte, 53ster Jahrgang, Bd. I, Heft i, 1887.

- Alcyonarien aus der Sammlung des Naturhistorischen "Museums in Liibeck; Separatabdruck aus den

Mitteilungen der Geographischen Gesellschaft und des Naturhistorischen Museums in Liibeck,
II Ser., Heft 7 und 8. Liibeck, 1894.

THOMSON, J. A. Appendix to the Report on the Alcyonaria. Report to the Government of Ceylon on

the Pearl Oyster Fisheries in the Gulf of Manaar. London, 1905.
and MACKINNON, D. A. Alcyonaria collected by the Percy Sladen Trust Expedition by Mr. STANLEY

GARDINER. Part II, The Stolonifera, Alcyonacea, Pseudaxonia and Stelechotokea. Transactions of

the Linnaean Society of London, Vol. XIII, part 2. London, 1902.
and HENDERSON, W. D. Report on the Pearl Fisheries of the Gulf of Manaar. Supplementary

Reports, the Alcyonaria. 1905.

- and - - An account of the Alcyonaria collected by the Royal Indian Marine Survey Ship "Inves-

tigator" in the Indian Ocean. Part I, The Alcyonarians of the Deep Sea. Calcutta, 1906.

and SIMPSON, J. J. Report on the Alcyonaria collected in the Indian Ocean by the Royal Indian

Marine Survey Ship "Investigator". Part II, The Alcyonarians of the Littoral Area. Calcutta, 1909.

VALENCIENNES, M. Extrait d'une monographic de la famille des Gorgonidees de la classe des Polypes.
Comptes rendus hebdomadaires des Seances de 1'Academie des Sciences, XII. Paris, 1855.

VERRILL, A. E. Memoirs of the Boston Society of Natural History, I, 1863.

- Review of the Corals and Polyps of the West Coast of America ; Transactions of the Conn. Academy

of Arts and Sciences, I, 2, 1867 — 71.

WRIGHT, E. P. and STUDER, TH. Report on the Alcyonaria collected by H. M. S. "Challenger" during
the years 1873—76. The Voyage of H. M. S. Challenger, Zoology, Vol. XXXI. London, 1889.

EXPLANATION OF PLATES

The photographs were made from nature by the author.
The spicules were drawn under the camera lucida by Mr. DAYTON STOXER.

PLATE I.

Fig. i. Solenocaulon querciformis n. sp. Natural size, i a, part of twig X 5-

SiBOOA FXPED1TIE XIII b . C. C. NUTTING, SCLERAXONIA.

\a

PLATE II.

Fig. I. Solenocaulon jedanensis n. sp. Natural size, i a, part of twig X 5-
Fig. 2. Seinperina brunnea n. sp. Natural size. 2 a, part of twig X 5.

SIBOGA-KXPEDITIE XIII b . C. C. NUTTING, SCLERAXONIA.

II

( :r^

PLATE III.

Fig. i. Titanidium friabilis n. sp. Natural size. \a, part of twig >< 5-

Fig. 2. Suberia excavata n. sp. Natural size. 2a, part of branch x 5-

Fig. 3. Suberia macrocalyx n. sp. Natural size. 3 a, part of branch X 5-

Fig. 4. Paragorgia splendens n. sp. Natural size. 40, part of branch X 5.

SIBOOA-EXPEDITIE XIII b . C. C. NUTTING, SCLERAXONIA.

•-

III

la

PLATE IV.

Fig. i. Iciligorgia orientalis Ridley. Natural size, la, part of twig X 5.

SIBOOA-EXPED1TIE XIII b'. C. C. NUTTING, SCLERAXON1A.

IV

PLATE V.

Fig. i. Suberogorgia appressa n. sp. Natural size, la, tip of branch X 5-

S1BOOA-EXPEDITIE Xlll b5. C. C. NUTTING, SCLERAXONIA.

PLATE VI.

Fig. I. Suberogorgia pulchra n. sp. Natural size. \a, part of branch )

Fig. 2. Suberogorgia thomsoni n. sp. Natural size. 2 a, tip of twig >

Fig. 3. Korceides koreni Wright and Studer. Natural size. 3^, tip of branch x 5

5-

SIHOQA -EXPEDIT1E XIII b . C. C NUTTING, SCLEKAXONIA.

VI

PLATE VII.

Fig. I. Melitodes squamata n. sp. Natural size.
Fig. 2. Melitcdes tnodesta n. sp. Natural size.
Fig. 3. Acabaria formosa n. sp. Natural size.

1 a, part of branch X 5-

2 a, part of twig X 5.
3«, part of branch X 5-

SIBOOA-EXPEDITIE XIII b5. C. C. NUTTING, SCLERAXONIA.

VII

PLATE VIII.

Fig. I. Mopsella spongiosa n. sp. Natural size. i«, tip of branch X 5.
Fig. 2. Acabaria triangulata n. sp. Natural size. 2 a, tip of branch X 5.
Fig. 3. Acabaria hicksoni n. sp. Natural size. 30, tip of branch X 5-

SIBOQA-EXPED1TIE XIII b'. C. C. NUTTING, SCLERAXONIA.

VIII

PLATE IX.

Fig. I. Mopsella studeri n. sp. Natural size. \a, part of branch X 5.

SIBOOA-EXPEDITiE XiH b . C. C. NUTTING, SCLERAXONIA.

IX

•'

• - • -

. . . .

PLATE X.

Fig. I. Birotulata splendens n. sp. Natural size. \a, part of branch < 5.
Fig. 2. Birotulata splendens n. sp. Another branch, natural size.

SIBOQA-EXPED1TIE XIII b>. C. C. NUTTING, SCLERAXONIA.

PLATE XI.

Fig. I. Solenocaulon querciformis n. sp. a, b and c, spicules from the ccenenchyma; d and e, spicules from

the axis, a >; 100; the others x 88.
Fig. 2. Solenotattlon jedanensis n. sp. a, spicule from the axis; b and c, forms from the inner walls of

calyces; d, from the coenenchyma. All X 120.
Fig. 3. Semperina brunnea n. sp. a and b, spicules from the axis; the others from the coenenchyma.

All X 120.
Fig. 4. Suberia excavata n. sp. a, spicule from the axis; b, a Y-shaped form from the ccenenchyma.

Both x 1 20.

Fig. 5. Suberia macrocalyx n. sp. a, b and c, spicules from the ccenenchyma; y 88.
Fig. 6. Titanidium friabilis n. sp. a and c, spicules from the ccenenchyma; d, an intermediate form; b, a

spicule from the axis. All X 120.

Fig. 7. Suberogorgia appressa n. sp. a and b, spicules from the ccenenchyma, c, an axis spicule. All x 250.
Fig. 8. Suberogorgia thomsoni n. sp. e, an axis spicule; a, b, c and d, forms found in the ccenenchyma.
Fig. 9. Suberogorgia pulchra n. sp. a and g, fragments of the spicular mesh of the axis; b, c, e and /,

oval forms from the ccenenchyma; d, rod-shaped form.

Siboga-Expeditie Xlllb5. C. C. NOTTINQ, Scleraxonia.

a

?B b

D. Stoner del.

PLATE XII.

Fig. I. Melitodes squamata n. sp. a, bent tuberculate spindle from polyp; b, c, d and e, spicules from the
ccenenchyma. All X 250.

Fig. 2. Melitodes modesta n. sp. a and b, spindles from the coenenchyma; c, one-sided spicule from ccenen-
chyma. All X 250.

Fig. 3. Acabaria formosa n. sp. a, b, c and f, bent spindles; d, spiny club; e, short, stout form. All X 250.

Fig. 4. Acabaria hicksoni n. sp. «, b and c, heavy bent spindles; d and e, irregular forms, a and e x I2O;
the rest X 250.

Fig. 5. Acabaria triangulata n. sp. a, triangular form; b, irregular spindle; c, club-shaped form. All X 120.

Fig. 6. Mopsella studeri n. sp. a, b and c, characteristic Blattkeulen with foliaceous projections; d, bent,
irregular spindle. All x 250.

Fig. 7. Mopsella spongiosa n. sp. a, bent spindle; b and f, foliaceous clubs; c, irregular spindle; d, charac-
teristic Blattkeule. All X 250.

Fig. 8. Birotulata splendens n. sp. a, bent spindle from polyp; b, a combination form; d and e, short
spindles; c, f, g, characteristic double wheels. All X 250.

Siboga-Expeditie Xlllb5. C. C. NUTTING, Scleraxonia.

'd

8

D. Stoner del.

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