32 



UNIO. 



L 



OVAL. 



*Egyptiacus. Caill. Fer. Desk. 

 Potier. 



Caffer. Krauss. (South Africa.) 



Guadechaudii. Eyd. (Bengal.) 



Bonneaudii. Eyd. (India.) 



OBLONG. 



*brevidens. Lea. Chenu. 

 Unio interruptus. Con. 



tetralasmus. 1 Say. Desh. Con. 



*camptodon. 2 Say. 

 Unio declivis. 3 Con. 

 Unio Sayii. Tappan. Con. 

 Unio rhomboidius. Dr. Ward's MSS. 



*obesus. Lea. 



*Hopetonensis. Lea. Chenu. 



*fraternus. Lea. 



*Cuverianus. Lea. 



*Roanokensis. Lea. Chenu. 



exolescens. Gould. 



OBLONG. 



*jejunus. Lea. Chenu. 



Lea. Grould. Adams. 

 Dekay. Stimpson. 



*complanatus. 



Linsley. 



Migh. 

 Mya complanata. Soland. Dill. 

 Mya rigida. Wood. 

 Unio violaceus." Spongier. 

 Unio purpureus. 5 Say. Bar. Con. 

 Unio rarisulcata. Lam. Menke. 

 Unio coarctata. Lam. Menke. 

 Unio purpurascens. Lam. Desh. 6 



Menke. Potier. 

 Unio rhombula. Lam. 

 Unio carinifera. Lam. 

 Unio Georgina. Lam. 

 Unio glabrata. Lam. 

 Unio sulcidens. Lam. Chenu. 

 Unio fluviatilis. Green. 

 Unio subinflata. Con. 

 Unio planilaterus. Con. 



cultelliformis. Con. 7 

 *symmetricus. Lea. 



lutulentus. Gould. 



limatulus. Con. 

 *Buddianus. Lea. 



1 Tetralasmus will, I think, prove to be a large and perfect declivis, Say. 



2 This fine shell, as well as the preceding one, both of which are Mr. Say's, seem to have been overlooked in 

 the formation of his catalogue. They are described in his Amer. C'onchology. I have never seen the shell he 

 calls tetralasmus — they may possibly prove to be the same. 



3 The shell in the Academy of Nat. Sci., described and figured by Mr. Conrad, in his Monography, p. 45, as 

 declivis, Say, I consider to be a middle-aged camptodon, Say. This, however, is not the opinion of all our con- 

 chologists. Professor Kirtland, in his Ohio Report, says that a shell answering Say's description of declivis is 

 found in some of the tributaries of the Scioto River. This is the shell since described by Judge Tappan as U. Sayii. 



4 Fide Ferussac. 



5 Mr. Conrad is wrong, in his " Synoptical Table," in giving Mr. Say's name precedence, making complanatus 

 a synonym. 



6 Deshayes, in Ency. Meih. Vers. t. 2, p. 381, No. 9. 



7 Unio cultelliformis is described as coming from Australia. It is so much like one of our varieties of com- 

 planatus, that I am induced to believe that some error of locality must have occurred. 



