64 U.S. NATIONAL MUSEUM BULLETIN 272 



been deposited, and certainly does not exist today, the true identity 

 of Haswell's species most likely will never be established. 



The generic position of S. cinerea Carter (1849), doubtfully referred 

 in this paper to Radiospongilla, has yet to be demonstrated. The 

 extent of the taxonomic difficulties involving this species has been 

 discussed in dealing with Stratospongilla gravelyi (p. 46). 



Radiospongilla sceptroides (Haswell, 1882) 



Plate 5, figures 4-G, 11, 12 



Spongilla sceptroides Haswell, 1882, p. 209. — Lendenfeld, 1887, p. 89. — Potts, 

 1887, p. 197.— Whitelegge, 1889, p. 306.— Weltner, 1895, p. 114; 1910, 

 p. 137.— Traxler, lS96b, p. 97.— Gee, 1931e, p. 48 (part); 1931d, p. 25; 

 1932e, p. 41.— Penney, 1960, p. 25. (Not Annandale 1909h, p. 627.) 



fSpongilla philippinensis Annandale, 1909h, p. 627; 1911c, p. 53; 1918a, p. 211. — 

 Gee, 1931e, p. 46; 1931c, p. 62; 1932e, p. 526; 1932f, p. 507.— Penney, 1960, 

 p. 26. 



Spongilla niuUispinifera Gee, 1933d, p. 456. — Penney, 1960, p. 25. 



Spongilla rotoitiensis Schroder, 1935, p. 98. — Penney, 1960, p. 27. 



Ephydatia crateriformis Gee, 1935, p. 263. 



Material. — Numerous specimens of R. sceptroides from eastern 

 Australia (collection AAE, and AusM) ; fragments and slides of type 

 of S. multispinifera (N. Gist Gee) ; slide material of S. sceptroides 

 Annandale, 1909h (USNM); slide material of S. rotoitiensis (N. Gist 

 Gee). 



Description. — Sponge forming flat encrustations on submerged 

 timber or aquatic plants, mature specimens often of considerable 

 spread; surface ranging from smooth to distinctly papillose, sometimes 

 producing long and thin finger-like projections; oscula numerous, in 

 specimens from lotic habitats often surrounded by a system of ra- 

 diating furrows; dermal membrane well developed. Skeleton consisting 

 of a rather regular arrangement of slender horizontal, and irregular 

 transverse fibers, both joined together by a comparatively small 

 amount of spongin. Consistency of live sponge rather firm and elastic. 



Megascleres slender and fusiform, slightly curved amphioxea with 

 sharply pointed tips, covered with minute and inconspicuous spines 

 except in the vicinity of their extremities; in acid environment these 

 spines often more numerous and readily visible, their tips occasionally 

 subdivided or otherwise malformed; length range 240-310 p., width 

 range 8-11 p.. 



Microscleres absent, though immature gemmoscleres occasionally 

 present in inner symplasm. 



Gemmoscleres moderately long and slender amphistrongyla, armed 

 with numerous acute spines that form distinct aggregations in the 

 vicinity of the extremities of the scleres, which represent scepter-like 

 distal arrangements of recurved teeth; in acid environment gem- 



