REVISION OF FRESHWATER SPONGES OF SPONGILLIDAE 75 



sponges, which consequently were considered mere "varieties" of 

 S. lacustris or S. alba, often by the same author. This resulted in an 

 ever widening separation of S. cerebellata from the other "species" 

 described, and their true generic and specific relationship became 

 thus permanently obscured. Although Schroder (1933) correctly 

 relegated S. proliferens to a synonym of S. biseriata, he too failed to 

 realize that Annandale's three additional species, together with 

 Weltner's species, are morphometrically fully identical with S. 

 cerebellata Bowerbank. This latter species finally became so obscure 

 that it is not even mentioned in the latest and comprehensive 

 revision of Penney (1960). 



The results of the present studies, during which niunerous specimens 

 and slides of all recorded "species" of this complex were examined, 

 demonstrate beyond doubt that S. biseriata, S. reticulata, S. pro- 

 liferens, S. semispongilla, S. micron, and even S. sectospina are morpho- 

 metrically fully comparable vdth S. cerebellata, and that they must 

 be considered synonymous mth Bowerbank's species. While S. 

 reticulata and S. proliferens are fully mdistinguishable, and S. secto- 

 spin^ merely displays abnormal spines on its gemmoscleres often also 

 found in S. proliferens, S. biseriata, and S. semispongilla merely differ 

 in the apparent absence of "microscleres," as recorded in the remain- 

 ing species of Annandale and Rezvoj. Since these immature gemmo- 

 scleres are by no means a constant criterion, and all the remaining 

 features, i.e., megascleres, gemmoscleres, and characteristics of the 

 gemmules, are fully identical in all the sponges of this complex, the 

 separate status of all these "species" even on a subspecific level 

 appears unjustified. 



R. cerebellata differs from all other Eadiospongilla spp. in possessing 

 smooth megascleres and in the peculiar double arrangement of 

 gemmoscleres on its gemmules, which thus usually attain a rather 

 large diameter. The occasionally occurring single layer of gemmo- 

 scleres, such as described by Annandale (1909b) in S. semispongilla, 

 most certainly is the result of seasonal variations or refers to immature 

 gemmules of developing specimens. 



? Radiospongilla cinerea (Carter, 1849) 



Spongilla cinerea Carter, 1849, p. 82; ISSlb, p. 263.— Bowerbank, 1863, p. 468.— 

 Gray, 1867, p. 553.— Potts, 1887, p. 197.— Weltner, 1895, p. 114.— Annan- 

 dale, 1907c, p. 26; 1911b, p. 225; 1911c, p. 79; 1912c, p. 137; 1912d, p. 384; 

 1918a,p.211; 1919a, p. 158.— Gee, 1929d,p.297; 1931e,p. 35; 1932c, p. 36.— 

 Jewell, 1952, p. 448.— Penney, 1960, p. 15 (not Weber, 1890, p. 35). 



fSpongilla (Euspongilla) perviridis Annandale, 1919a, p. 159. — Gee, 1931e, p.46; 

 1932c, p. 41. 



fSpongilla perviridis Penney, 1960, p. 26. 



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



279^30—68 6 



/ 



