REVISION OF FRESHWATER SPONGES OF SPONGILLIDAE 49 



Microscleres appareiitly absent. 



Gemmoscleres short and wide amphistrongyla, ranging in appear- 

 ance from subspherical or ovoid bodies to almost straight rods, 

 covered with fine spines or granules; length range 8-21 n, width 

 range 8-11 n. 



Gemmules abundant in the lower part of the sponge, subspherical 

 to ovoid, ranging in diameter 110-180 n; pneumatic layer ill-developed, 

 and without discernible air spaces; gemmoscleres embedded in this 

 layer tangentially, or sUghtly in-egularly, usually present in two 

 tiers; foramen not distinctly tubular, but elevated in the form of a 

 broad cone. 



Distribution. — Found only in the type locality, the Waidina R. 

 on Viti Levu, Fiji Islands. 



Color in life. — Recorded as dark green. 



Discussion. — The reexamination of type material of this species 

 has not revealed any additional criteria for discussion. However, 

 S. gilsoni differs from most of its congeners by its rather fragile and 

 comparatively soft consistency, its abundant and nonadherent gem- 

 mules, and its gemmular micropyles that are not produced into a 

 typical tubule but merely represent a conical elevation. In most other 

 features, S. gilsoni seems most closely related to the African congeners 

 S. rousseletti and S. schubotzi from which, however, it is readily sep- 

 arable. The retention of the separate specific status of S. gilsoni is 

 therefore fully justified. 



A future study of additional material of aU Stratospongilla spp. may 

 yet demonstrate the possibility, or necessity, of a generic or sub- 

 generic separation of the group of species possessing free microscleres 

 from those apparently lacking these spicular components. At the 

 present such a separation appears ill-documented and therefore 

 unwarranted, and additional data are highly desirable. 



Stratospongilla dementis (Annandale, 1909) 



Plate 3, figures 19, 20 



Spongilla dementis Annandale, 1909h, p. 631; 1911c, p. 53; 1918a, p. 201. — Ste- 

 phens, 1919, p. 99.— Gee, 1926c, p. 110; 1927b, p. 58; 1927a, p. 1; 1918, p. 

 225; 1930e, p. 27; 1931c, p. 69; 1931e, p. 36; 1932f, p. 507; 1932c, p. 37.— 

 Arndt, 1936, p. 14.— Penney, 1960, p. 15. 



Spongilla yunnanensis Annandale, 1910d, p. 197; 1911c, p. 53. — Gee, 1931e, p. 52. 



Material. — Piece of syntype of S. dementis, donated by Annandale 

 to the AusM, Reg. no. Z 860; also slide of type (USNM). 



Description. — Sponge, according to Annandale (1909), forming 

 small cushions on solid supports; external surface usually smooth, 

 oscula large, nmuerous, and elevated. Skeleton consisting of a rather 

 regular network of spicule fibers of moderate thickness. Consistency 



