REVISION OF FRESHWATER SPONGES OF SPONGILLIDAE 35 



crust on various supports; sui-face hispid due to projection of vertical 

 spicule fibers through dermal membrane. Skeleton consisting of large 

 irregular meshes at the base, and of strong vertical fibers in the upper 

 portion; spongin moderately abundant. Consistency of dry sponge 

 moderately firm but brittle. 



Megascleres very slender and sHghtly curved amphioxea, entirely 

 smooth, ranging from fusiform to cyUndrical in outline; length range 

 200-260 M, width range 4-9 ju- 



Microscleres absent. 



Gemmoscleres irregular in outhne, usually slightly curved am- 

 phioxea with lanceolate or rounded tips, covered with microspines that 

 often are more numerous at the tips of the scleres; length range 1 10-145 

 n, width range 1.5-4 ju. 



Gemmules somewhat flattened, subspherical, numerous and freely 

 scattered in groups of two or three throughout the upper portions of 

 the sponge, or forming a continuous layer on the support, held in posi- 

 tion by the skeletal mesh work; diameter 400-470 n; pneumatic layer 

 consisting of a thick layer of large polygonal air spaces showing a 

 columnar effect; gemmoscleres, few in number, embedded in this layer 

 in an irregular manner but usually tangentially; foramen producing a 

 moderately long, curved, and blackish tube. 



Distribution. — Known only from the type locality in the 

 Phihppines. 



Color in life. — Almost colorless when free of sediment. 



Discussion. — The relationship of E. tinei to other species of this 

 genus has yet to be resolved. It shares certain characteristics with 

 some species of the E. fragilis group, but in others appears to link up 

 with the group represented by E. nitens. Until additional material will 

 be available and comparative studies made, it is best to retain its 

 separate specific status, which at present seems well documented. 



Eunapius nitens (Carter, 1381) 



Plate 2, figures 17, IS 



Spongilla nilens Carter, 1881a, p. 89.— Hilgeiidorf, 1883, p. 87.— Potts, 1887, 

 p. 158.— Weltner, 1895, p. 114; 1913, p. 475.— Amiandale, 1914a, p. 245.— 

 Cunnington, 1920, p. 507.— Gee, 1931e, p. 45; 1932c, p. 41.— Topsent, 1932a, 

 p. 570.— Arudt, 1933c, p. 302; 1936, p. 9.— Burton, 1938, p. 458.— Jewell, 

 1952, p. 448. 



Spongilla nilens var. Gee, 1932c, p. 41. 



Material. — Fraction of sponge and two slides, from the Ugalla 

 R., Africa, obtained by N. Gist Gee. 



Description. — Sponge, according to previous descriptions, in- 

 variably massive and nodulose, surface from irregular to smooth. 

 Skeleton consisting of a regular network of radiating and transverse 



