MOLLUSCA OF OHIO. 393 



Unio tetralasmus sayi Ward. 



Scioto River, e. g. at Circleville (type locality). 

 Unio complanatus (Solander) Dillwyn. X 



St. Lawrence drainage; (among numerous Unionidae col- 

 lected from Lake Erie, at Sandusky and Vermilion, at 

 various times, no specimens were seen, St.). One was 

 found in a race on the Tuscarawas River, at New Phil- 

 adelphia; evidently the mussels have migrated from 

 Lake Erie, over the divide, probably by way of the 

 Ohio canal. 

 Margaritana monodonta (Say, Unio). 



Ohio River at Cincinnati (still!), but not common. 

 Proptera alata (Say Unio). 



Both drainages; large e. g. in the Great Miami River; com- 

 mon in Lake Erie, rather small. 

 Proptera lsevissima (Lea, Symphynota), U. ohioensis Say. 



Ohio River, and tributaries — ? 

 Proptera gracilis (Barnes, Unio). 



Both drainages; common in Lake Erie. 

 Proptera leptodon (Rafmesque, Unio), Symphynota tenuissima 

 Lea. 

 Both drainages, not common; a specimen from "Cleveland" 



is in the Oberlin collection. 

 None of the four Proptera species have been found in the 

 Tuscarawas River. 

 Symphynota compressa Lea (known as Unio pressus Lea). 



Over the state. 

 Symphynota costata (Rafmesque, Alasmidonta), Al. rugosa 

 Barnes. 

 Over the state; the Lake Erie form is quite small and of 

 somewhat different shape. 

 Symphynota complanata (Barnes, Alasmodonta). 



Over the state, in rivers, creeks, canals, lakes. 

 Alasmidonta marginata Say, Al. marginata var. truncata B. H. 

 Wright, Al. truncata Simpson, Synopsis. 

 Over the state, both drainages; a small, slight form in Lake 



Erie. 

 Alasmidonta — - (the eastern, or Atlantic drainage form, 

 or species): Lake Erie and tributaries (?). X 

 Alasmidonta calceolus (Lea, Unio), Margaritana deltoidea Lea. 



Over the state, common. 

 Arcidens confragcsus (Say, Alasmodonta.) 



Ohio River at Cincinnati. 

 Lastena lata (Rafmesque, Anodonta — Lastenai, U. dehiscens Say.. 

 Ohio drainage, not common. 



