Pe NOES ON FRESHWATER SPONGES. 
By N. ANNANDALE, D.Sc., Superintendent, Indian Museum. 
XII.—DESCRIPTION OF A NEW SPECIES FROM CAPE COMORIN. 
The sponge described below was discovered by Mr. R. S. N. 
Pillay of the Trivandrum Museum in a tank near Cape Comorin, 
the southernmost point of the Indian Peninsula. I have examined 
several specimens. - 
Genus SPONGILLA. 
Subgenus Stratospongilla, Annandale. 
Spongilla ultima, sp. nov. 
Sponge hard and strong, forming a thin layer on solid objects, 
of a pale green colour (dry); the oscula small but rendered con- 
spicuous by the deep radiating furrows that surround them; 
external surface of the sponge rough but not spiny. 
Skeleton forming a compact but. somewhat irregular reticu- 
lation, in which the radiating fibres are not very much more 
distinct than the transverse ones; a considerable amount ot 
almost colourless spongin present. 
Spicules.—Skeleton spicules smooth, stout, amphioxous, as a 
rule straight or nearly straight, not infrequently inflated in the 
middle or otherwise irregular. No flesh spicules Gemmule 
spicules variable in size, belonging to practically every type and 
exhibiting practically every abnormality possible in the genus, the 
majority being more or less sausage-shaped and having a rough- 
ened surface, but others being cruciform, spherical, subspherical, 
rosette-like, needle-like, bifid or even trifid at one extremity. 
Gemmules adherent, spherical, large, each covered by two 
distinct layers of horizontal spicules; the outer layer intermixed 
with skeleton spicules and often containing relatively large sili- 
ceous spheres, a large proportion of the spicules being irregular in 
shape ; the spicules of the inner layer much more regular and as a 
rule sausage-shaped. ‘The outer layer is contained in a chitinous 
membrane, which spreads out over the base of the sponge. The 
foraminal tubules short and straight. 
This sponge is allied to S. bombayensts, from which it is dis- 
tinguished not only by the abnormal characters of its gemmule 
spicules and the absence of flesh spicules, but also by the form of 
its skeleton spicules and the structure of its skeleton. 
