30 PROCEEDINGS OF THE ACADEMY OF [1894. 



S. fabale Prime. 



Town Creek, Allegheuy Co., Md. , 64,884. Warm Spring Creek, 

 Morgan Co., W. Va., 64,843. 



Family UNIONIDJE. 



Genus UNIO Retz. 



TJ. complanatus Sol. 



Conecocheague River, westof Hagerstown, Md., 64,824. Sideling 

 Creek, between Allegheny and Washington Counties, Md., 64,825. 

 Potomac River at Hancock, Md., 64,822. Potomac River at 

 Cherry Run, W. Va., 64,823. 



U. productus Con. 



Sideling Creek, between Allegheny and Washington Counties, 

 Md., 64,827. 



U. tappanianus Lea. 



Sideling Creek, Md., 64,820. 



Sideling Creek, at the time ot our visit (Sept. 1892) was merely 

 a chain of pools connected by a slender stream of water running 

 among, rather than over, the rocks of dry intervals. The pools had 

 rocky and muddy bottoms, and in them no less than five species of 

 Unionidae were found, represented by many individuals. No Ancu- 

 losa were found here. 



Stone found U. cariosus and U. radiatus at York Furnace, York 

 Co., Pa. 



Genus MARGARITANA Schum. 

 M. marginata Say. 



Conecocheague River, westof Hagerstown, Md. , 64,820. Potomac 

 River at Hancock, Md., 64,819. Sideling Creek, Md., 64,821. 

 Potomac River at Cherry Run, Morgan Co., W. Va., 64,818. 



M. undulata Say. 



Sideling Creek, Md., 64,828. 



Genus ANODONTA. 



Mr. Witmer Stone found A. fluvlatiUs Dillw. and A. suhcylindrica 

 Lea at York Furnace, York Co. , Pa. 



