Knowledge of the Spongida. 103 
not repeat any part of this here; but among the late Dr. 
Bowerbank’s sponges I found some more specimens, from the 
S.W. coast of Australia and Ceylon (Trincomalee) respectively, 
which require notice. 
Thus, among those from the $.W. coast of Australia is one 
which, on account of its black colour, nodulated form, and 
doughy consistence (now hard from dryness), closely resem- 
bles the type specimens of A. aérophoba from the Adriatic Sea, 
sent to the British Museum by Prof. Oscar Schmidt; but the 
“fibre” is different, inasmuch as it is not cylindrical although 
branched, but scanty and made up of several small incom- 
pletely developed fibrils longitudinally fasciculated in an 
irregularly fluted form (Pl. IX. fig. 1,); so that, in the 
transverse section, it presents a crenulated outline, agate-like, 
in which the horny laminze do not entirely surround the axial 
substance of the different fibrils indicated (fig. 1,7), thus con- 
stituting a confused composite structure of ill-developed and 
ill-formed horny material contrasting strongly with the simple, 
single, perfectly cylindrical fibre of other species (fig. 11). 
Besides this, it ditfers from A. aérophoba in the presence of 
dark black-purple pigmental cells (figs. 1,f, and 3, a), which 
are so abundant throughout the specimen as greatly to obscure 
the scantily developed fibre. What the colour when fresh 
might have been [cannot say ; for A. aérophoba also, although 
nearly black in the dried state, is, according to Schmidt’s dia- 
gnosis, ‘‘ greenish yellow’ when fresh. That the Australian 
is the same as that which I have noticed under the name of 
“ Aplysina purpurea” in my first report on the Manaar speci- 
mens (‘ Annals,’ 1880, vol. vi. p. 86), I have no doubt; but 
having had a very poor supply of the latter for description, 
this, of course, is correspondingly imperfect. Now, however, 
I find that not only some of the Australian specimens, but 
that from Trincomalee, to which I have alluded (‘ Annals,’ 
ibid.), are all of the same species, and among them furnish 
sufficient for the following amended description. 
Aplysina purpurea. (PI. IX. figs. 1, a—c, and 2, a-c.) 
Form of specimen pyramidal, somewhat compressed, cactus- 
like externally, light (Pl. 1X. fig. 1, Ceylon), or nodular, 
compact, and heavy (fig. 2, Australia). Colour black-purple. 
Surface, in the Ceylon specimen, even minutely reticulated in 
relief (fig. 1, c, and 2, 6) in the dried state, interrupted irregu- 
larly by large puckered monticular or cactiform elevations 
(fig. 1, 0) more or less obtuse on the summit, where, in a grana- 
lar form, still darkened by the pigmental cells of the dermis 
and on a level with the latter, may be seen the termination 
