22 



U N 10. 



QUADRATE. 



*fragosus. 1 Con. 



*Phillipsii. Con. Kiist. 



*Cincinnatiensis. Lea. Chenu. 



*pustulatiis. Lea. Chenu. 

 TJnio undulatus. Con. 



*Schoolcraftensis. 2 Lea. 

 TJnio prasinus. Con. 

 JJnio nodiferus. Con. 



TRIANGULAR. 



*apiculatus. Say. Con. 



r. Lea. Chenu. 



*Dorfeuillianus. Lea. Chenu. 



*stapes. Lea. Con. Chenu. 



*tuberosus. Lea. Chenu. 



*sparsus. Lea. Chenu. 



*metanevrus. Raf. Con. Kiist. 

 TJnio nodosus. Bar. Hild. 

 Unto rugosus (Flat). Bar. Hild. 

 Telederma metanevra. Swain. 



intermedins. Con. 

 *cornutus. Bar. 



f TRIANGULAR. 



TJnio reflexa? Raf. 

 TJnio reflexus. Con. 



SUBROTUND. 



*pustulosus. Lea. Chenu. 



TJnio verrucosus. Bar. Var. b. 



TJnio verrucosa. Valen. 



TJnio verrucosus albus. Say; but not 



of Hildreth. 3 

 TJnio bullatus. Con. 



*Keinerianus. Lea. 



*turgidus. Lea. Chenu. 

 TJnio Mortoni. Con. 



*Cooperianus. Lea. Kirtl. 



"Verrucosus. Bar. Eat. 

 TJnio tuberculata? Raf. 

 TJnio tuberculosa. Valen. 

 TJnio verrucosus purpureus. Hild. 

 TJnio tuberculatus. Con. 



*graniferus. Lea. Chenu. 



nodulosus. Lea. 



Mya nodulosa. 4 Wood. Bill. 



*irroratus. Lea. Baton. Desh. 

 Chenu. 

 TJnio verrucosus albus. Hild. 

 TJnio stegarius. Con. 



*caperatus. Lea. 



TJnio abacoides. Hald. 



1 This shell has been considered the female of asperrimus (nobis), but I have no doubt of its being distinct. 

 Some of our best western naturalists think it to be the true rugosus of Barnes. 



2 Prof. Kirtland thinks this may prove only a variety of pustulosus (nobis), but I am not of that opinion. 



3 A specimen sent to me by Dr. Hildreth as Unio verrucosus albus, proved to be a true irroratus (nobis). 



4 This shell, as figured by Wood in his " General Conchology," seems to me to be distinct from the pustulostis 

 (nobis), with which it has been confounded. The figure of Wood is longer than any pustuloses I have seen, and the 

 epidermis is much darker ("bottle-green"). The nodules are more numerous about the beaks, and the lateral tooth 

 is longer and thicker. It approaches still closer to graniferous, but is a longer shell. I doubt if nodulosus be an 

 American species. 



