28 PROCEEDINGS OF THE ACADEMY OF [1885. 



February IT. 

 Mr. Thomas Meehan, Vice-President, in the chair. 

 Twenty-five persons present. 



February 24. 

 Mr. Jacob Binder in the chair. 

 Twenty -one persons present. 



A New Fresh-water Sponge from Nova Scotia. — Mr. E. Potts 

 described a form recently identified by him as follows : — 



Hetekomkykma Pictouensis, n. sp. 



Sponge light green, even when dry, massive, encrusting ; 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 frequentlj' a single large spine or acute termination 

 is seen at one or both extremities. 



Dermal spicules absent or undiscovered. 



Birotulatesof 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 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 widen- 

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

 and fiiu'ly lacinulate at their margins ; occasionally bearing 

 spines. 



Measurements. — Skeleton spicules 0-0075 inch long, by - 00075 

 inch thick; length of long birotulates 0"0021 inch; of short biro- 

 tulates 00012 inch ; diameter of disc of latter 0*0009 inch. 



Habitat. — On submerged wood, etc. 



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

 B. S., of i'lctou, Nova Scotia, from several lakes upon the water- 

 shed of that region. 



