Ortmann : Unionid.t: of Western Pennsylvania. 199 



39. Quadrula lachrymosa (Lea). 



Never reported before. A single living individual was found by the 

 writer in the Ohio River at Cook's Ferry, Beaver County. 



40. Quadrula pustulosa (Lea). 



Cited in Harn's list from western Pennsylvania. Rhoads records it 

 from the Ohio and Beaver. 



It occurs in the larger rivers, but is now rather scarce. It goes up 

 in the Monongahela as far as the Cheat River in Fayette County, in 

 the Allegheny to southern Armstrong County, and in the Beaver to the 

 Mahoning River in Lawrence County. 



41. Quadrula cooperiana (Lea). 



Reported by Rhoads from the Ohio in Allegheny and Beaver 

 Counties. 



The writer has found only one living and two dead shells of this 

 species in the Ohio in Beaver County. 



42. Quadrula rubiginosa (Lea). 



Not mentioned in Harn's list; reported by Clapp from Allegheny 

 County, and by Rhoads from the Ohio River in Allegheny County. 



Typical specimens of this species are found in the smaller creeks of 

 the southwestern section of the state. It occurs in Raccoon Creek, 

 Beaver ('ounty, and was formerly found in Chartiers Creek, Allegheny 

 County. It exists in the Monongahela drainage. Ten Mile Creek, 

 Washington and Greene Counties, Dunkard Creek, Greene County, 

 and also in the Allegheny River in Armstrong County, and in Crooked 

 Creek, Armstrong and Indiana Counties. Specimens from the larger 

 rivers (Monongahela and Ohio) are not typical, and approach more 

 or less Q. trigona (Lea). Nevertheless no typical /rigoiia has ever 

 been found, the specimens reported by Stupakoff as trigona being 

 probably, and those reported by Rhoads surely this intermediate form. 



43. Quadrula obliqua (Lamarck). 



Call and Harn record obliquus and mytiloides from western Pennsyl- 

 vania, Stupakoff gives U. pyramidafus from Allegheny County, Clapp 

 U. obliqmts ^rom Allegheny County, and Rhoads has U. obliquus from 

 the Ohio. Of Rhoads' specimens only a few belong here. 



This form is quite frequent in the Ohio River in Beaver County, 

 and it used to be abundant in the Ohio in Allegheny County, and in 

 the Monongahela at Charleroi, Washington County (Ehrmann Collec- 

 tion). It is present in the Allegheny in Armstrong County, and a 

 single specimen was found in the Beaver at Wampum, Lawrence 

 County (Clapp &: Smith Collection). 



