CO 
38 Records of the Indian Museum. [Vou. VII, 
shaft, which is always more or less curved and invariably smooth. 
It bears at both ends a circle of relatively long and strongly 
recurved, slender spines, which are proportionately long enough, 
as well as sufficiently close together, to give the appearance of a 
regular rotule with back-turned margin. 
The skeleton spicules are normally short, stout, cylindrical, 
blunt and spiny. They are, however, subject to great individual 
variation and in some species (e.g., C. ultima) exhibit many 
abnormal forms. 
Gemmules.—The gemmules are sometimes of two kinds, fixed 
and free, The latter are either spherical or subcylindrical. In 
either case they have a close layer of spicules arranged like a 
mosaic on the external surface and are further enclosed in a dense 
case formed of chitinous substance in which true gemmule-spicules, 
more or less deformed, or modified megascleres and sometimes 
even birotulate flesh-spicules are firmly bound together. Some- 
times the wall of this outer case can be separated into definite 
layers. Its inner surface is separated from the gemmule by an 
empty space. Pneumatic substance is altogether absent or very 
poorly developed. The wall of the case is in continuity with the 
basal membrane of the sponge. 
The free gemmules are situated in the parenchyma, lying in 
interstices of the skeleton. They are invariably spherical. Each 
has a horizontal layer of spicules on its external surface and is 
surrounded, outside these spicules, by a pneumatic coat. Out- 
side the pneumatic coat there is, in some species, a cage of more 
or less deformed megascleres. The microscleres of the free gem- 
mules are as a rule longer and more slender than those of the 
fixed ones. hus the former differ from those of certain species 
of the subgenus Eunapius (e.g., Spongilla fragilis) in which a 
‘‘>avement-layer’’ of gemmules is sometimes formed, in that they 
have a different structure from the fixed gemmules. 
Both fixed and free gemmules sometimes occur in the same 
sponge, but probably only free ones are produced in some species. 
Remarks.—Even the more delicate forms of the genus can be 
distinguished, so far as my experience goes, from any other 
oriental Spongillidae (except certain Spongillae of the subgenera 
Eunapius and Stratospongilla) by their very hard consistency. In 
skeletal structure the species vary considerably ; but the skeleton, 
owing to the large number of megascleres, is always extremely 
massive. 
Although free microscleres of the type described are always 
present, their number is very variable even in sponges of the same 
species taken at different times and they are sometimes scattered 
so scantily in the parenchyma that it is difficult to find them.! 
The dermal membrane is apparently aspiculous. 
1 Great care is also necessary to prevent them floating away if spicule- 
preparations are made by allowing the spicules to settle in a liauid. 
