REVISION OF FRESHWATER SPONGES OF SPONGILLIDAE 145 



spongin. Consistency of live sponge stony hard, dry sponge resembling 

 coral growths, 



Megascleres apparently of only one class, i.e., stout, distinctly 

 curved, and entirely smooth amphistrongyla ; a great number of mega- 

 scleres of smaller dimensions often typically amphioxous, probably 

 representing immature scleres; length range typically 270-310 /z, width 

 range 45-50 m- 



Microscleres absent, 



Gemmoscleres have not yet been reliably recorded, since gemmules 

 of this species apparently are still unknown. 



Distribution. — Known only from the Uruguay R,. (type locality) 

 and the Amazon E,. 



Color in life. — Apparently gray to light brown. 



Discussion. — In view of the paucity of specimens collected and the 

 absence of gemmules in the material available for this study, additional 

 criteria cannot be demonstrated. From the account of this and related 

 species of Urugumja by Cordero (1925) and the key to species of this 

 genus given by that author, it appears that gemmule-b earing speci- 

 mens of U. corallioides have not yet been found. This fact impairs our 

 present knowledge of this sponge, and future extensive studies by 

 workers in South America would appear imperative before any reliable 

 conclusions as to its intrageneric relationship can be made. 



Uruguaya macandrewi Hinde, 1888 



Plate 13, figures 3, 4 



Uruguaya macandrewi Hinde, 1888, p. 4. — Weltner, 1895, p. 114. — Gee, 1931e, 



p. 42; 1932c, p. 44.— Cordero, 1925, p. 117 (key). 

 Uruguaya macandrewsi Penney, 1960, p, 60. 



Material. — SHdeof type (BM). 



Description. — Sponge, according to Hinde (1888), forming anasto- 

 mosing branches, arising from a flat base; surface smooth and even; 

 oscula conspicuous, distributed rather irregularly over the surface of 

 the branches. Skeleton apparently of similar construction as that of 

 the foregoing species. Consistency rigid and very hard. 



Megascleres used for the skeleton of only one class, i.e., moderately 

 stout, distinctly curved amphistrongyla, entirely covered with ex- 

 tremely minute granulations; length range 250-320 n, width range 

 30-40 Ml smaller megascleres found only in the vicinity of gemmules. 



Microscleres absent. 



Gemmoscleres minute birotulates with a stout, smooth, and short 

 shaft, and terminally with equal rotules of strongly recurved circular 

 margins; length of shaft 13-14 n; its thickness about 5-6 /x; diameter of 

 rotules 16-17 ju. 



