Miscellaneous. 425 



straight one, as it is represented above. It is quite probable that 

 the line began to break with the appearance of the starfish. — Johns 

 Hopkins University Circulars, March 1885, p. 67. 



A new Freshwater Sponge from Nova Scotia. 



Mr. E. Potts described a form recently identified by him as 

 follows : — 



Heteromeyenia pictouensis, n. sp. 



Sponge light green, even when dry, massive, incrusting ; texture 

 very compact ; spicules non-fasciculated, persistent ; surface mostly 

 smooth. 



Gemmules very scarce, spherical, crust thick. 



Skeleton-spicules cylindrical, short, robust, rounded or abruptly 

 terminated ; entirely spined, spines conical at the centre of the 

 spicule, elsewhere generally curving forward, or towards each 

 extremity. Rounded terminations of spicules covered with short 

 spines, though frequently a single large spine or acute termination 

 is seen at one or both extremities. 



Dermal spicules absent or undiscovered. 



Birotulates of the longer class surrounding the gemmules, rather 

 numerous, one half longer than the others ; shafts conspicuously 

 fusiform or largest at the centre, where are frequently found one or 

 more long spines. Their rotules consist of from three to six irregu- 

 larly placed rays, recurved at the extremities. 



Birotulates of the shorter class abundant and compactly placed 

 around the gemmule ; shafts mostly smooth, though sometimes 

 bearing a single spine , irregularly cylindrical, but rapidly widening 

 to support the rotules, which are large, umbonate, nearly flat, 

 and finely lacinulate at their margins ; occasionally bearing spines. 



Measurements. Skeleton-spicules 0*0075 inch long by 0-00075 

 inch thick ; length of long birotulates 0-0021 inch, of short birotu- 

 lates 0-0012 inch ; diameter of disk of latter 0-0009 inch. 



Habitat. On submerged wood &c. 



Locality. Collected only by or for Mr. A. H. McKay, B.A., B.S., 

 of Pictou, Nova Scotia, from several lakes upon the watershed of 

 that region. 



This beautiful and interesting sponge was first discovered by 

 Mr. McKay during the summer of 1884. At that time its novelty, 

 as indicated by its unusually robust entirely spined skeleton-spicules, 

 was easily recognized ; but the absence of gemmules at that season 

 piecluded the determination of its generic relations, and it has con- 

 tinued unnamed. During the last week of December, however, a 

 further search was rewarded by the finding of other " specimens 

 upon sticks pulled up through a break made in the ice," and amongst 

 these a few, and but a few, gemmulaj have now been discovered. 



These suffice to place it clearly within the genus Heteromeyenia, 

 near //. Ryderii, while the peculiarities of its birotulates distinguish 

 it from that or any other species. 



