REVISION OF FRESHWATER SPONGES OF SPONGILLIDAE 119 



Anheteromeyenia pictovensis (Potts, 1885) 



Plate 10, figures 5-7 



Heteromeyenia pictovensis Potts, 18S5a, p. 28; 1886, p. 228. — MacKay, 1885, 



p. 233; 1886, p. 21; 1889, p. 87. 

 Heteromeyenia ryderi var. pictovensis Potts, 1887, p. 244. — Arndt, 192Sb, p. 164. — 



Gee, 1931e, p. 46; 1932c, p. 34. 

 Heteromeyenia ryderi forma pictovensis Stephens, 1920, p. 241. — Arndt, 1926, 



p. 344. 

 Heteromeyenia pictouensis Smith, 1921, p. 17. 

 Heteromeyenia ryderi pictovensis Smith, 1930, p. 184. 

 Anheteromeyenia ryderi var. pictovensis Schroder, 1927b, p. 108. 

 Heteromeyenia ryderi var. pictouensis Penney, 1960, p. 45. 



Material. — A small number of specimens from Canada (N. Gist 

 Gee) and the New England States (Penney). 



Description. — Sponge, according to previous descriptions, forming 

 massive crusts on solid objects; surface smooth to slightly irregular, 

 oscula conspicuous and numerous. Skeleton forming an irregular 

 network joined together by a considerable amount of spongin. Con- 

 sistency of live sponge recorded as comparatively firm, texture 

 compact. 



Megascleres cj^lindrical, comparatively short and robust amphi- 

 strongyla, sometimes amphioxea with rounded or abruptly pointed 

 tips, superficially resembling amphistrongyla ; they are covered with 

 strong spines throughout their length, which are straight and conical 

 in the central portion of the sclere, and gradually curving towards 

 its tips near the extremities; length range 165-210 //, width range 

 17-23 M. 



Microscleres absent. 



Gemmoscleres bu'otulates of similar differences in length and shape 

 as in A. ryderi, but with either smooth or only sparsely spined shafts; 

 length range of longer class 52-75 n, width of shaft 6-8 n; length 

 range of smaller class 30-40 ix, width range of shaft 3-4 /z, of rotule 

 25-28 M. 



Gemmules not very abundant in mature sponge, ranging in diameter 

 350-380 M, spherical; pneiunatic layer well developed and granular, 

 consisting of minute spherical air spaces; gemmoscleres embedded in 

 this layer strictly radially, their longer class conspicuously protruding 

 from the outer gemmular membrane; foramen more or less simple, 

 not forming a distinct porus tube, only slightly elevated. 



Distribution. — Apparently restricted to eastern Canada, ranging 

 south to about New York. 



Color in life. — Recorded as light green. 



Discussion. — Although the shape of the gemmular spicular com- 

 ponents demonstrates a close affinity to A. ryderi, the existing mor- 

 phological differences, particularly the entirely different structure of 



