100 U.S. NATIONAL MUSEUM BULLETIN 2 72 



two classes of birotulates are present in all Heterorotvla species (cf. 

 Heteromeyenia, Anheteromeyenia, Dosilia, and Corvomeyenia) the length 

 differences between the longest and shortest gemmoscleres are most 

 conspicuous. 



Lendenfeld (1887) described the megascleres of this species as 

 being entirely smooth. A wide range of specimens examined (Racek, 

 MS.), however, revealed that the surface of megascleres of H. nigra 

 is frequently covered with minute spines, which can be seen only 

 under very high power. Lendenfeld's specific name, referring to a 

 black color in life, is quite insignificant, since most of the specimens 

 of H. nigra examined were of flesh color or of somewhat darker 

 brownish shades. The presence of mud particles within any live sponge 

 often changes the original color of specimens from swampy regions 

 into darker hues, irrespective of species or genera. 



Heterorotula multidentata (Weltner, 1895) 



Plate 8, figures 3, 7, 10, 11, 13 



Tubella multidentata Weltner, 1895, p. 142. 



Ephydatia multidentata Weltner, 1900, p. 519. — Gee, 1931d, p. 51; 1931e, p. 44; 



1935, p. 264. 

 Meyenia multidentata Penney, 1960, p. 53. 



Ephydatia lendenfeldi Traxler, 1896b, p. 97. — Gee, 1931d, p. 28. 

 Spongilla lacustris var. sphaerica Lendenfeld, 1887, p. 90. — Weltner, 1895, p. 



119.— Gee, 1931d, p. 28. 



Material. — Slides of syntype (AusM, MG, and N. Gist Gee); 

 numerous specimens from eastern and northern Australia (Racek). 



Description. — Young sponge forming shallow encrustations of 

 varying dimensions ; mature sponge rather massive and often spherical ; 

 surface distinctly lobose, with high and rounded ridges of irregular 

 shape separated from each other by deep clefts; oscula inconspicuous, 

 dermal membrane well developed and slightly separated from the 

 underlying symplasm. Skeleton consisting of rather thick vertical 

 spicule fibers, coated together by only little amounts of spongin, and 

 of ill-defined transverse fibers. Consistency of live sponge moderately 

 soft and very fragile. 



Megascleres feebly curved and slender amphioxea, distinctly fusi- 

 form, ranging from entirely smooth to distinctly microspined; spines 

 small and inconspicuous, never present on tips of scleres; length 

 range 280-320 n, width range 10-18 ju. 



Microscleres absent. Some slender amphioxea of 120-140 n length 

 occasionally present in symplasm, covered with fine granulations 

 throughout, their tips bearing several rows of small and sharp spines; 

 their identity has not yet been resolved. 



Gemmoscleres birotulates with a moderately slender, finely granu- 

 lated shaft which often bears stout but blunt conical teeth, and 



