324 H. J, Clark on the animality of Sponges. 
There is still another new genus which I would like to men- 
tion here because it forms a collateral link with Codosiga in the 
affiliation of the Sponges with the Monadina. This genus I 
have called Salpingeca. It is, as it were, a single individual of 
Codosiga which does not possess a stem, but is seated in a calyx, 
from which it protrudes, or into which it retracts, at will. There 
are three well marked species, of which one is marine. 
I come now to the principal object of this communication. 
The sponge which formed the main basis of these investigations 
is the well known marine species Leucosolenia (Grantia) botry- 
oides Bowerbank. It is preéminently a branching form, and, on 
account of the slenderness and transparency of its tapering, 
hollow ramules, is‘a most desirable object for study. A branch- 
let—and in fact the whole colony—may be stated to be essen- 
tially a double tube. The outer tube consists of a glairy, gelat- 
inifurm stratum in which the spicules are im in a certain 
order, and is pierced by numerous ostioles, which are continued 
through the interior tube to its hollow center. The inner layer, 
or tube, is entirely made up of the individual members of the 
colony, the bodies of which are packed together closely, side by 
side like pavement stones, with their posterior ends slightly im- 
bedded in the glairy substance of the outer tube, and their an- 
terior ends projecting freely into the general cavity. To de- 
scribe the shape and organization of one of these individuals 
would be to repeat, almost word for word, what I have already 
said of the monad of Codosiga ; in short Leucosolenia bears some 
such sort of relationship to Codosiga that Salpingeca does; the 
latter being as it were a stemless Codosiga seated in a calyx, 
whilst Leucosolenia is comparable to a stratum of the monads 
of Codosiga imbe in a spiculiferous envelope. It is clear 
therefore that the organic difference between Leucosolenia and 
Jodosiga is scarcely enough to locate them in two different faml- 
lies; in fact I am inclined to consider them only as generically 
distinct, and hardly, if at all, more widely separated in this re- 
spect than are Salpingaca and Codosiga. : 
What are the diversities of other genera of the Spongie Ciliate 
