REPORT ON THE TETRA CTINELLID A. 
31 
Colour. — Ochreous-white, or cream-coloured. 
Habitat. — Station 163b, Port Jackson, Sydney, June 3, 1874; depth, 35 fathoms; 
bottom, hard ground ; bottom temperature, 63°. (Type specimen.) 
Var. a. Samboangan, Philippine Islands. • 
Var. Station 186, between Cape York and the Arrou Islands, September 8, 1874 ; 
lat. 10° 30' S., long. 142° 18' E.; depth, 8 fathoms ; bottom, coral mud. 
Remarks. — Bowerbank’s description of Tethea simillima, Bowerbank, loc. cit., is a 
medley of the characters of two specimens belonging to different species, and indeed 
different genera ; one, as can be readily seen from his illustrations, a cortical sponge like 
Craniella (figs. 7, 8, loc. cit.), and the other (fig. 6, ih.) non-corticate and apparently 
resembling Tetilla. Now a species has no claim to recognition unless it is described so 
that it can be distinguished, and instead of spending time on a discussion as to which of 
these two species the term simillima should be applied, I thought it safer when drawing 
up my Preliminary Eeport to suppress the name altogether ; though I had but little 
doubt as to the identity of the corticate sponge with Craniella howerhankii. Since then 
I have had an opportunity of examining one of the two types on which Bowerbank 
founded his species, and the other is not to be found ; it happens that the still existing 
type which is preserved in the collection of the Eoyal College of Surgeons is specifically 
identical with the sponge under description, and to save confusion I now return to 
Bowerbank’s name. Bowerbank does not give measurements of the spicules of this 
sponge, but as he states the magnification of his drawings it is possible to get approximate 
dimensions from these; thus I find the large oxeate spicule measures 3'15 by 0’031 mm., 
and is therefore much the same size as that in our specimens. 
Craniella simillima closely resembles Craniella carteri] from which it is distinguished 
by the absence of pigment-glands in the outer layer of the cortex. 
Three specimens of this sponge were obtained, one from Port Jackson, Sydney, 
20 mm. high by 23 and 16 mm. in diameter ; one from Samboangan, Philippine Islands, 
29 mm. high by 27 mm. in diameter, and the third from Torres Strait, 20 mm. high by 
15 mm. in diameter. In general appearance the specimens from Samboangan and Port 
Jackson are most similar, the Torres Strait specimen differs in the character of the 
conules, which are more slender and more numerous than in the other specimens, 
the projecting spicules of the conules also extend further from the surface than in those 
specimens. 
Similar differences exist between the other two specimens, that from Port Jackson 
being distinguished from that of Samboangan by coarser and more rigid conules. 
Differences occur also in the size of the spicules of all three specimens, but 
these are not sufficiently great for specific distinction. The measurements are as 
follows : — 
