Clialinida' aro especially almndant (16 species, 5 now). No essentially
new types occur ; but of two now genera, one {Toxochalina)
is formed in recognition of a character, hitherto overlooked, conncct-
in? this family with tho Dosmacidinida;. Seventeen Iteniorida; (5
new) occur, which are chietly remarkable for their close rosemhlanco
to European forms, all the genera and three species hcing_ already
known from Europe. The Desmacidinid;c have 19 species, and
include 9 new forms, and a species for Avhich I have established a
new genus, Gelliodcs, which appears to he an extreme development
of the well-known European Gellius {Desmacodes, Schmidt), also
two species for Avhich a genus {loti-ochota) is formed, in tardy
recognition of their great distinctness ; it is jirohahly related rather
to the deep-sea genera Chondrociadia and CladorrJiiza than to any
littoral genera, "except Monanchora, Carter, and is remarkable as
being a persistent littoral representative of what was probably one
of tiie earliest types of Desmacidines, viz. th at in v-hich the aneho-
rate spicule was'symmetrical. Such old types usually survive only in
the deep sea or fresh water : we have already seen th at the deep sea
produces examples of it, aud probably the Spongillida? with biro-
tnlate spicules are also modern representatives of this type, which
(or whose ancestors) have taken refuge iu fresh water. Remarkable
as are the outward forms assumed by the species of llhizocha-
lina here described, they will not surprise those who have studied
the paper in which Mr. Carter recently described (under the name
Pldceodictyon) a number of species belonging to this genus from
various parts of the world; perhaps, however, Torres Straits will
prove to he more prolific in this respect than any other locality.
The Ectvonidae are remarkably rich in new forms (10 species out
of 17). ' Clathria, which is small in growth and not very rich in
species even in the Mediterranean, here assumes a great development
in size and number of species. The distribution of the Axi-
neUidffi is as much bathybial as littoral, in accordance with which
fact we only have three species here. Of the 8 species of Suheritidge,
4 are new.
The suborder TetractineRida is, in conformity with the fondness
for greater depths and the relative scarcity of individuals which its
members commonly exhibit, represented by only 7 species, of which
four are new, and all belong to the Choristida? {SoUas).
The Calcarea are poorly represented (3 species), and afford nothing
of great interest from a taxonomic point of view.
I have given further details, Avhere necessary, of the more remarkable
systematic points under the different groups themselves, and a
classified list of the species is inserted in the account of the Geographical
Distribution.
Anatomy and Histology o f Soft Parts.— \Yant of time has prevented
me from thoroughly investigating these subjects at present,
interesting and important in the extreme as they are, and favourable
in many cases for the purpose as is the material contained in the
coUection. A few notes relating specially to the histology will
he found scattered throughout the Report (see especially Aplysina,
Dysidea, lotrochota, Ithaplddophlas, Acanthella). In tho systematic
descriptions ol tlm genera and sjæcies I have employed the old
oxprossion “ sarcodo” for tho soft tissues generally, as being intelligible,
comprelionsivc, and as having the advantage of involving no
S])ecial theory or view with regard to tho homologies of the parts
reiorrod to ; tlio greater part of tlie tissues included under tho term
are, liowever, tho “ mesoderm ” of E. E. Schulze, together with the
ciliated chambers and the walls of the canal-system which it
encloses.
Individual Variation.—A few remarks on this subject are suggested
by the study of this large collection. Eirst, variation in the
size of spicules is an almost invariable occurrence in different specimens
ot the same species, as it is in individual spicules in tho same
spccinacn ; in the one case, however, it rightly falls under the head of
variation, in the latter chiefly under th at of growth. In the descriptions
below will he found statements which show the range of this
form of variation within tho limits of a species to be frequently
wide, see especially Leucojfhloeas fenestratus, Echinodictyum (the
spiucd spicule), and Stelletta purpurea. The Ectyonidæ exhibit,
as a rule, surprisingly little variation of this kind, and little use is
to be made of characters based on size in distinguishing even species
in this group. Chalinidæ and Desmacidinidse are also very fairly
constant as a rule. Secondly, variation in the form of spicules is
less common. The Suberitidæ exhibit variation of the head of the
skeleton-spicnle from sub-acuate to spinulate {Suberites). Alodifi-
cations of the form of the ends of acerate spicules are certainly not
often to be noticed ; bnt this collection shows th a t in Pellina muricata
the ends of the acerate vary from being gradually sharply pointed
to being rounded off almost as thoroughly as in the usual “ cylind
ric a l;” and in Cladochalina nuda the ends may taper gardually
from about four diameters from end of spicule, or else from within
about 1 | diameters (var. ahruptispicula, mihi), producing a very
different appearance. Thirdly, as to variation in the external form
of the Sponge within the limits of the same species, striking examples
are afforded by the series oi lotrochota purpurea and Clathria
reinwardti (where a multi-personal origin appears to explain the most
remarkable case). The number o f vents present has been used as a
generic character in the Tetractinellida by Prof. Solías {Geodia,
Isops). In one of the species of Stelletta here described this seems
to he constant, in the other not ; in the species of Geodia described
below it is doubtful whether absence of vents (“ lipostomy,” Hdckel)
is constant.
“Person”-theory.—The individuality of those parts of a Sponge
which enclose a single cloacal cavity seems to be regarded as a fact
by Marshall, who speaks (Zeitschr. wiss. Zool. xxxv. p. 98 &c.) of
species of Dysideidæ as being “ monozoisch” or “ polyzoisch.” I t is
difficult to see how the different cloacal tubes which are formed
during adult life by folding-over of a flat wall, as appears to be the
case in the species named below, Nip/iowocAaZma Imllata and Dysidea
semicanalis, can be said to constitute individuals. I t seems possible
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