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 
undulatus. 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- 
pum, 8. ; 
Unio rectus Lam. Ohio R., Coraopolis, 4; Beaver, 5. 
Unio rubiginosus Lea. Ohio R., Coraopolis, 5. 
Unio securis Lea. Ohio K., Coraopolis, 1. 
Unio triangularis Bar. Ohio R., Coraopolis, 17; Beaver, 10 ; 
Beaver R., Wampum, 15. 
Unio trigonus Lea. Ohio R., Coraopolis,5. These specimens are 
so young that their identification is not satisfactory. 
Unio tuberculatus Bar. Ohio R., Coraopolis, 1; Beaver, Ris 
Wampum, 2. 
Unio verrucosus Bar. Ohio R., Coraopolis, 2; Beaver, | ; Bea- 
ver R., Wampum, 2. 
Family CYRENID&. 
Sphaerium stamineum Conr. Ohio R,, Coraopolis, 20; Raccoon 
Creek, Beaver Co., 4. 
Sphaerium striatinum Lam. Ohio R., Coraopolis, 15; Raccoon 
Creek, Beaver Co., 3; Beaver R., Wampum, 2. 
Family PLEUROCERID®. 
Goniobasis depygis (Say). Ohio R., Coraopolis, 150; Beaver, 
10; Beaver R., Wampum, 60 ; ; 
Fleurocera canaliculatum Say. Ohio R., Coraopolis, 50; Beaver, 
16. 
Family VIVIPARIDA. 
Campeloma subsolidum (Auth). Beaver R., Wampum, 20. 
Family Paysip a. 
Physa heterostropha Say. Ohio R., Coraopolis, 3; Beaver, 20 ; 
Allegheny R., 6m. Isl., Pittsburgh, 60; Beaver R., Wampum, 27. 
