184 Annals of the Carnegie Museum. 



10. Unio cornutus Barnes = Obliquaria reflexa Rafinesque. 



11. *' undulatus Barnes = Quadrula undulata (Barnes). 



12. *' obliquus Lamarck = Quadrula obliqua (Lamarck). 



These species, as well as the seven of Stupakoff's list, are yet present 

 in the Ohio River below Pittsburgh in Beaver County. In Allegheny 

 County they now seem to be extinct, only Unio crnssidens being 

 found in the northeastern corner of the county, together with the four 

 species mentioned above. 



In 1899, S. N. Rhoads (Nautilus, 12, 1899, pp. 133 ff. ) published 

 a list of shells collected by himself in the Ohio River at Coraopolis, 

 Allegheny County, and at Beaver, Beaver County, and in the Beaver 

 River, at Wampum, Lawrence County. The collections were made 

 in September, 1898. A number of the duplicate specimens were 

 secured by the Carnegie Museum, while the main collection went to 

 the Academy of Natural Sciences in Philadelphia. I have gone over 

 both collections, and am able to correct certain misidentifications. 

 The collection from Wampum is controlled by a much larger collec- 

 tion from the same place in the Carnegie Museum, secured in Septem- 

 ber, 1897, by G. H. Clapp and H. H. Smith. 



The following species are recorded by Rhoads, and I append the 

 necessary remarks : 



1. Anodonta edentula Say = Strophitus undulatus (Say). 



Three specimens from Coraopolis in the Philadelphia Academy are 

 this species. In the same tray were several specimens of Symphynota 

 viridis, which probably were put in by mistake, since this species is 

 not found in the Ohio drainage. From Wampum in the Philadelphia 

 Academy and Carnegie Museum. Also recorded from Beaver, but no 

 specimens could be found in either collection. 



2. Anodonta gracilis Lea = Proptera gracilis (Lea). 



From Coraopolis and Beaver in the Philadelphia Academy. 



3. Anodonta marginata Say = Alasmidonta marginata Say. 



From Coraopolis in Philadelphia Academy, from Wampum in Phila- 

 delphia Academy and Carnegie Museum. 



4. Margaritana rugosa Barnes = Symphynota costata (Rafinesque). 

 From Coraopolis and Beaver in Philadelphia Academy ; from Wam- 

 pum in Philadelphia Academy and Carnegie Museum. 



5. Unio aesopus Green = Pleurobema cesopus (Green). 

 From Coraopolis and Wampum in Philadelphia Academy. 



