THE NAUTILUS. 137 



that my series represents two species, but the task of separating them 

 must be left to a specialist. 



Unio ovatus Say. Ohio R., Coraopolis, 29 ; Beaver, 1 ; Beaver R.,. 

 Wampum, 3. 



Unio parvus Bar. Beaver R., Wampum, 1. 



Unio phaseolus Hild. Beaver R., Wampum, 37. 



Unio pilaris Lea. Ohio R., Coraopolis, 1. 



Unio plicatus Lesueur. Ohio R., Beaver, 1 ; Beaver R., Wam- 

 pum, 10. A more careful examination may show some of these to be 

 andulatas. The distinction between these two species as identified 

 in the Academy collection is not correlated by constant differences. 



Unio pressus Lea. Beaver R., Wampum, 3. 



Unio pustulosus Lea. Ohio R., Coraopolis, 1; Beaver R., Wam- 

 puni, 8. 



Unio rectus Lam. Ohio R., Coraopolis, 4; Beaver, 5. 



Unio rubiginosus Lea. Ohio R., Coraopolis, 5. 



Unio securis Lea. Ohio R., Coraopolis, 1. 



Unio triangularis Bar. Ohio R., Coraopolis, 17; Beaver, 10; 

 Beaver R., Wampum, 15. 



Unio trigonus Lea. Ohio R., Coraopolis, 3. These specimens are 

 so young that their identification is not satisfactory. 



Unio tuberculatus Bar. Ohio R., Coraopolis, 1 ; Beaver, R. 

 Wampum, 2. 



Unio verrucosus Bar. Ohio R., Coraopolis, 2 ; Beaver, I ; Bea- 

 ver R., Wampum, - 2. 



Family CYRENID/E. 



Sphaerium stamineum Conr. Ohio R, Coraopolis, 20; Raccoon 

 Creek, Beaver Co., 4. 



Sphaerium striaiinum Lani. Ohio R., Coraopolis, 15; Raccoon 

 Creek, Beaver Co., 3; Beaver R., Wampum, 2. 



Family PLEUROCERID^E. 



Goniobasis depygis (Say). Ohio R., Coraopolis, 150; Beaver r 

 10 ; Beaver R.. Wampum, 60 ; 



t-leurocera canahcul atum Say. Ohio R., Coraopolis, 50; Beaver^ 

 16. 



Family VIVIPARID.E. 



Campeloma subsolidum (Anth). Beaver R., Wampum, 20. 



Family PHYSIDJE. 



Physa heterostropha Say. Ohio R., Coraopolis, 3; Beaver, 20; 

 Allegheny R., 6 m. Isl., Pittsburgh, 60; Beaver R., Wampum, 27. 



