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 Unionide 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 levissima (Lea, Symphynota), U. oluoensis Say. 
Ohio River, and tributaries—? 
Proptera gracilis (Barnes, Unio). 
Both drainages; common in Lake Erie. 
Proptera leptodon (Rafinesque, Unio), Symphynota tenutssima 
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 Unto pressus Lea). 
Over the state. 
Symphynota costata (Rafinesque, Alasmidonta), Al. rugosa 
Barnes. 
Over the state; the Lake Erie form is quite small and of 
somewhat difierent 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 (7). x 
Aiasmidonta calceolus (Lea, Unio), Margaritana deltoidea Lea. 
Over the state, common. 
Arcidens confragosus (Say, Alasmodonta.) 
Ohio River at Cincinnati. 
Lastena lata (Rafinesque, Anodonta—Lastena), U. dehiscens Say. 
Ohio drainage, not common. 
