REVISION OF FRESHWATER SPONGES OF SPONGILLIDAE 57 



spiculis Annandale (1913b) as fully comparable with the typical form 

 of C. bohmii, an opinion which cannot be shared by the present 

 authors. Although the shape and average measurements of the 

 megascleres seem similar in the two species just mentioned and also 

 in C. micramphidiscoides, the microscleres of C. bohmii cannot be 

 confused with those of any other species of the genus. Until additional 

 collections and data become available it is better to consider these 

 three sponges closely related but separate species. 



Corvospongilla micramphidiscoides Weltner, 1913 



Corvospongilla micramphidiscoides Weltner, 1913, p. 477. — Annandale, 1914, 

 p. 240.— Stephens, 1919, p. 95.— Gee, 1931e, p. 43; 1932c, p. 27.— Arndt, 

 1936, p. 10.- Penney, 1900, p. 37. 



Material. — Slides of type material (N. Gist Gee no. 54994). 



DescRiPTioN. — Sponge, according to original description, forming 

 shallow encrustations on shells of Aetheria elliptica; surface of live 

 sponge not yet recorded. Skeleton consisting of slender, spicule fibers, 

 formed by 2-4 scleres, somewhat loosely defined and iiTegularly 

 reticulate. Consistency of live sponge not recorded. 



Megascleres slightly curved and cylindrical amphistrongyla, 

 sparsely covered with minute spines, and of greatly varying dimen- 

 sions; length range 115-150 n, width range 18-20 /x; occasionally 

 slightly spiny amphioxea of somewhat smaller dimensions also 

 present. 



Microscleres of two distinct series: (1) slightly curved to almost 

 straight, sharply pointed amphioxea, covered with long perpendicular 

 spines that are longest in the center of the scleres; length range 

 52-70 iJL, width range 7-8 ju; and (2) microbirotulates Avith a slightly 

 curved, smooth shaft and terminally vdih a smaller number of strongly 

 recurved hooks; average length 19-21 /z, diameter of rotide 10-12 ju. 



Gemmoscleres rarely straight, usually strongly curved and stout 

 amphistrongyla, finely granidated, and of greatly varying dimen- 

 sions; length range 32-55 n, width range 8-12 ix. 



Gemmides separate, not forming aggregations, chiefly fastened to 

 the support but occasionally also free in inner S3anpl;ism of sponge; 

 they are spherical to subspherical, ranging 250-450 n in diameter, 

 apparently lack a pneumatic coat as weU as a micropyle (fide Weltner, 

 1913) ; gemmoscleres arranged in 2-5 concentric layers, the lowest one 

 in contact Avith the inner gemmular membrane. 



Distribution. — Kuoami only from the Congo R. system, Africa. 



Color in life. — Not recorded; dry sponge gray. 



Discussion. — The affinities of this species to other closely allied 

 forms have already been commented on in the discussions of C. 

 bohmii and C. scabrispiculis, respectively. Annandale (1913b), after 



