REVISION OF FRESHWATER SPONGES OF SPONGILLIDAE 45 



Gemmules ranging 420-500 a* iii diameter, subspherical, with 

 flattened base, usually firmly adhering to the support of the sponge; 

 pneumatic coat feebly and irregularly developed, without discernible 

 air spaces, usually forming a basal membrane by which the gemmule 

 is fastened; gemmoscleres forming a dense, tangentially arranged 

 mosaic layer over inner gemmular membrane; foramen provided with 

 a short and straight porus tube. 



Distribution. — Apparently ranging from Thailand via India to 

 Africa. 



Color in life. — Recorded as green to gray. 



Discussion. — The spicular components of S. indica are sufficiently 

 different from those of S. smnatrana, as here restored, to enable an 

 easy separation of these two species. The megascleres of this complex 

 are always distinct amphistrongyla, and the gemmules are as a rule 

 fixed in groups at the base of the sponge, although free gemmules are 

 occasionally also produced. The reasons for placing some of the 

 "varieties," previously considered races of S. sumatrana, into S. indica 

 have been given in the discussion of the foregoing species. 



Stratospongilla gravelyi (Annandale, 1912) 



Plate 3, figures 15-18 



Spongilla {Stratospongilla) gravelyi Annandale, 1912d, p. 384. 

 Spongilla sumatrana vai*. gravelyi Annandale, 1918a, p. 212; 1919a, p. 161. — 

 Stephens, 1919, p. 99.— Gee, 1931e, p. 39; 1932c, p. 42.— Penney, 1960, p. 30. 



Material.— Slides of syntype (N. Gist Gee). 



Description. — Sponge, according to Annandale (1912), forming 

 small and shallow cushions on solid supports; external surface smooth, 

 oscula minute, surrounded by shallow radiating channels beneath the 

 dermal membrane. Skeleton consisting of a regular network of single 

 spicules and slender, ill-defined spicule fibers, the vertical ones more 

 distinct than the transverse. Consistency of live sponge very hard but 

 easily broken. 



Megascleres almost straight, fusiform, and sharply pointed amphi- 

 oxea; their surface neither smooth, nor spiny, but covered with 

 minute irregular blunt projections; sometimes a ring of terminal short 

 spicules present around the tips of the scleres; length range 230-310 fi, 

 width range 11-17 /i. 



Microscleres not abundant, and chiefly restricted to dermal mem- 

 brane and vicinity of gemmules; they are sharply pointed and almost 

 straight amphioxea, covered with relatively long and very irregular 

 spines, inserted at right angles to the axis of the sclere; length range 

 42-56 fx, width range 3-4 n. 



