ORTMANN: UNIONID©® OF WESTERN PENNSYLVANIA. 198 
from any one locality was secured in Neshannock Creek at Eastbrook, 
Lawrence County. 
35. Pleurobema zsopus (Green). 
The type-locality is Pittsburgh (Green). Recorded in Harn’s list 
from western Pennsylvania ; in Rhoads’ list from the Ohio and Beaver. 
There is a specimen in the Carnegie Museum from the Mononga- 
hela at Charleroi, Washington County (Ehrmann Collection), and the 
writer has found it sparingly in the Ohio in Beaver County, and more 
abundantly in the Allegheny in southern Armstrong County. 
36. Quadrula undulata (Barnes). 
It is not mentioned in Harn’s list, but occurs in Clapp’s list from 
Allegheny County. Rhoads’ / p/icatws from the Ohio and Beaver is 
this species. 
It is abundant all over the Beaver drainage, chiefly so in. the Mahon- 
ing and Shenango Rivers, and formerly occurred in Connoquenessing 
Creek. It is rather frequent in the Ohio in Beaver County. It is 
unknown from the Monongahela, but a single half shell was found in 
the Cheat River in Fayette County. It is present in the upper Mo- 
nongahela drainage in West Virginia, judging from specimens in the 
Carnegie Museum. In the Allegheny River in Armstrong and 
Venango Counties it is very rare, but becomes again abundant in 
French Creek in Venango and Crawford Counties, as far up as Le- 
boeuf Creek in Erie County. It is absent from the whole Kiski- 
minetas drainage and the upper Allegheny above Venango County. 
37. Quadrula cylindrica (Say). 
Cited in Harn’s list from western Pennsylvania and in Rhoads’ list 
from the Ohio and Beaver. 
There is a dead shell in the Carnegie Museum from the Monon- 
gahela at Charleroi, Washington County (Ehrmann Collection), and 
the writer has found a dead specimen in the Ohio in Beaver County. 
Living specimens have been found repeatedly in the Mahoning and 
Shenango Rivers, and in Pymatuning Creek in Lawrence and Mercer 
Counties, in the Allegheny in Armstrong County, and in French 
Creek in Venango and Crawford Counties. 
38. Quadrula metanevra (Rafinesque). 
Not mentioned in the lists of Harn, Stupakoff, and Clapp. Reported 
by Rhoads from the Ohio. 
It is restricted to the larger rivers, occurring in the Ohio in Beaver 
County (formerly in Allegheny County), the Monongahela (Charle- 
roi), and the Allegheny, Armstrong County. 
