142 



priority, even though it is now recognized that the species falls in Margaritana 

 rather than in Unio. 



In habit the species resembles Margaritana dehiscens in that it is often deeply 

 buried in the gravelly banks it affects, in rather swiftly flowing water. Most 

 commonly, however, it may be found buried deeply under large Hat rocks, and 

 between clefts in rocky bottoms. It is a rather rare shell in collections. 



* Margaritana rugosa Barnes. 



Wabash River, White River, Blue River, Fourteen Mile Creek. 



* Unio (Bsopus Green. 



Wabash River, Ohio River. 

 "■■■" Unio alatus Say. 



White River, Ohio River, Wabash River. 



* Unio anodontoides Lea. 



Wabash River, Ohio River, Bruisett's Creek, Vigo County. 



* Unio asperrimus Lea. 



Wabash River, Ohio River, at the Falls; this form is equivalent to Unio 

 laihrymosus Lea. 



* Unio camelus Lea. 



Ohio River; this is an old and heavy Unio phaseolus, of which it is a 

 synomym, 



* Unio camptodon Say. 



Wabash River, Ohio River. 



* Unio capax Green. 



Wabash River, Ohio River. 



* Unio cicatricosus Say. 



Wabash River, Ohio River. 



* Unio circulus Lea. 



St. Mary's River, Ohio River, Wabash River, Peru. 



* Unio clavus Lamarck. 



Wabash River, very abundant ; St. Joseph River. 



* Unio coccineuH Hildreth. 



Wabash River, Ohio River. 



* Linio cooperianug Lea. 



Wabash River, Ohio River. 



* Unio cornutus Barnes. 



Ohio River, Wabash River. 



