20 



The Ottawa Naturalist. 



[April 





MUSCULIUM. 



partumeium, Say. 

 securis. Prime, 

 rosaceum, Prime, 

 truncatum, Linsley. 

 transversum, Say. 

 parvum, Sterki. 

 ryckholti, Norm, 

 winkleyi, Sterki. 

 declive, Sterki. 



Pisidium. 



virginieum, Gm. 

 compressum, Prime, 

 abditum, Hald. 

 ventricosum. Prime, 

 rotundatum, Prime, 

 aequilaterale. Prime, 

 afhne, Sterki. 

 glabellum, Sterki. 

 milium, Held, 

 minus, Adams, 

 noveborascense, Sterki. 

 ohioense, Sterki. 

 pauperculum, Sterki. 

 politum, Sterki. 

 rotundatum, Prime, 

 sargenti, Sterki. 

 splendidulum, Sterki. 

 streatori, Sterki. 

 strengi, Sterki. 

 subrotundum, Sterki. 

 succineum, Sterki. 

 variabile. Prime, 

 walkeri, Sterki. 



There is a quantity of material still under consideration 

 and much more will, it is hoped, be secured during next summer. 

 Several additions will, I think, be made to the list of Sphaeria 

 and Musculia, and many to the already lengthy catalogue of our 

 Pisidia. These minute shells occur everywhere throughout the 

 district in such great numbers and variety that their determina- 

 tion is a matter of extreme difficulty. When Dr. Sterki has 

 further studied the specimens now before him and the collections 

 of 1913, a fairly complete list might be published, with the 

 localities in which they are found, and figures of the larger or 

 more beautiful species. L. 



