MOLLUSCA OF OHIO. 391 



Quadrula fragosa (Conrad, Unio). 



Ohio River at Cincinnati, seems rare; Scioto River. 

 Quadrula pustulosa (Lea, Unio). 



Ohio River and most of its tributaries; decidedly variable in 

 regard to size, shape, and surface sculpture: from 

 smooth to covered with tubercles all over. — A form 

 from the lake drainage, e. g. the Tiffin River (St.), is 

 considerably different from the high, cooperiana-like 

 form of the Ohio River and tributaries: more elongate, 

 "quadrate," approaching lachrymosa in outlines; the 

 same is known from Michigan, Indiana (Kankakee 

 River, St.), Illinois and Iowa (t. Walker), and seems to 

 represent a variety, may be = schoolcrajtensis Lea. X 

 Quadrula pustulosa kleineriana Lea. 



"Entire Mississippi drainage; Lake Erie," t. Simpson. 

 Quadrula cooperiana (Lea, Unio). 



Ohio River; tributaries? 

 Quadrula pustulata (Lea, Unio). 



Ohio River at Cincinnati; Mahoning River (Dean, Streator) ; 

 cited from the Tuscarawas River, by Dean; I was not 

 able to find a trace of it and suppose some form of 

 pustulosa was mistaken for it. 

 Quadrula subrotunda (Lea, Unio). 



Ohio River; Scioto River; Tuscarawas River, a form with 

 very heavy shell, the beaks quite anterior, the shape of 

 the mussel being much like that of PI. clava, the lines 

 of growth coarse and markedly regular; a very small, 

 slight form seems to be in Lake Erie. 

 Quadrula kirtlandiana (Lea, Unio). 



Ohio River and some tributaries: Mahoning River, from 

 which Lea had his types; Tuscarawas River, common 

 and very variable, from the subrotunda form to much 

 elongate, and some specimens much resembling (old) 

 cesopus ; one large and heavy specimen has numerous 

 small muscle scars scattered all over the inner surface 

 within the pallial line. It seems that kirtlandiana is 

 doubtfully distinct from subrotunda, and half grown 

 specimens agree with Lea's description and figure of 

 the last named species. 

 Quadrula sesopus (Green, Unio). 



Ohio River and tributaries, Scioto, Mahoning, Tuscarawas. 



Note. — cesopus certainly ranges nearer the Quadrula of 

 this group than with Pleurobema ; it closely resembles 

 kirtlandiana in features of the shell and soft parts. 

 [Simpson himself was in doubt where to range this and 

 the following species.] 



