48 U.S. NATIONAL MUSEUM BULLETIN 272 



their width 11-14 n; the few amphistrongyla measure 110-120 n in 

 length and 12-13 m in width. 



Microscleres have not yet been recorded. 



Gemmoscleres of similar variability as found in megascleres; the 

 majority are short and stout, abruptly pointed and cylindrical amphi- 

 oxea, often assuming an amphistrongylous character, entirely smooth; 

 a large number of deformed scleres, ranging from spheres to irregularly 

 shaped bodies, also present; length range of larger amphioxea 68-88 ii, 

 width range 10-12 n] strongyla and styles of the gemmule armature 

 attain a length of 64 ju and a width of 10 ix. 



Gemmules apparently not yet observed in natural condition; those 

 treated with boiling hydrochloric acid (fide Weltner, 1913) are almost 

 spherical, range 500-800 n in diameter, and appear to lack a micropyle ; 

 they are surrounded by tangentially arranged layers of gemmoscleres. 



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

 near Banalia in Central Africa. 



Color in life. — Recorded as white. 



Discussion. — Stratospongilla schubotzi obviously is most closely 

 related to S. rousseletii, the only usable separating criterion being 

 the absolutely smooth surface of the gemmoscleres in the former. 

 However, additional collections may yet substantiate the assumption 

 of the present authors that Weltner's species merely represents a 

 malformed specimen of S. rousseletii, and that eventually it will have 

 to become a synonym of that species. The great irregularity of spicular 

 components in S. schubotzi appears to be a reliable indication of an 

 adverse environment and the lack of granules or spinules on its gem- 

 moscleres could well be an ecomorphic phenomenon. In spite of the 

 almost complete agreement of other criteria in both S. rousseletii and 

 S. schubotzi, it is thought advisable to retain their separate specific 

 status until additional evidence becomes available. 



Stratospongilla gilsoni (Topsent, 1912) 



Spongilla (Slratospongilla) gilsoni Topsent, 1912, p. 187. — Stephens, 1919, p. 99. — 



Gee, 1931e, p. 39; 1932c, p. 38. 

 Spongilla gilsoni Penney, 1960, p. 19. 



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



Description. — Sponge, according to Topsent (1912), forming flat 

 cushions on rocks of volcanic origin, present in the vicinity of rapids; 

 surface slightly lobose and irregular, oscula inconspicuous but numer- 

 ous. Skeleton apparently of somewhat loose construction. Consistency 

 comparatively soft. 



Megascleres feebly curved rather cylindrical amphioxea with 

 abruptly pointed tips, covered with short straight spines except at the 

 extremities; length range 135-230 /j,, width range 11-15 n. 



