ORTMANN: UNIONID2 OF WESTERN PENNSYLVANIA. 188 
collection, there is a collection made by G. A. Ehrmann in the Mo- 
nongahela River at Charleroi, Washington County, acquired in 1897 ; 
a collection made by Miss Vera White in Little Beaver Creek at 
Cannelton, Beaver County, acquired in 1897 ; and a collection made 
by H. H. Smith at the same locality in September, 1897. Besides 
there are single species from various places collected by others, which 
need not be mentioned here. 
The list is arranged according to Simpson’s Synopsis ( Proceedings 
United States National Museum 22, 1900). Ina final treatise on the 
Unionide of Pennsylvania, this system will be considerably changed. 
The alterations introduced here relate chiefly to the nomenclature. 
A. Onto RIVER DRAINAGE. 
1. Truncilla triquetra Rafinesque. 
Not reported by Harn, Stupakoff, and Clapp; reported from the 
Ohio and Beaver Rivers by Rhoads. 
Generally distributed in the Ohio, Beaver, and Allegheny drainages, 
and going up into the smaller tributaries: Shenango River and Pyma- 
tuning Creek in Mercer County ; French Creek in Venango and Craw- 
ford Counties ; Conneaut Outlet in Crawford County ; Leboeuf Creek, 
Erie County. It has not been recently found alive in the Ohio River 
below Pittsburgh. It is rather abundant in the Allegheny River in 
Armstrong County, but never found in the Monongahela drainage. 
2. Truncilla (Pilea) perplexa rangiana (Lea). 
Not reported previously. Rather abundant in the Allegheny River 
from southern Armstrong County up through Venango and Forest into 
Warren Counties (here also in Connewango Creek), and further in 
French Creek in Venango and Crawford Counties. A-single specimen 
has been found in the Shenango River in Lawrence County. 
3. Micromya fabalis (Lea). 
Reported by Harn from western Pennsylvania. Rhoads’ Uno par- 
vus from the Beaver at Wampum is probably this species. 
Found rather sparingly in the Beaver and Allegheny drainages ; in 
the Mahoning River in Lawrence County ; in the Shenango River and 
Pymatuning Creek in Mercer County ; in Crooked Creek in Armstrong 
County ; French Creek in Venango and Crawford Counties ; in the 
upper Allegheny in Venango County, as far up as Connewango Creek 
in Warren County. It is nowhere abundant, and is missing in the Mo- 
nongahela drainage. © 
