The following three genera are fresh water clams or mus- 

 sels. Unio has cardinal and lateral teeth; Margaritana, 

 cardinal teeth; Anodonta is toothless. All crawl and bur- 

 row with the long foot, and when thrown ashore by waves 

 at Onondaga lake, I have seen them raise themselves and 

 get back to the water. 

 Unio alatus. Say. Brown, winged, variable. 



cariosus. Say. Yellowish, inflated, rare. Oswego 



river. 



complanatus. Sol. The common flat species. 



gracilis. Barnes. Resemble alatus, lighter, thinner. 



iris. Lea. Resembles IT. Novi-Eboraci. Canal. 



Liebii. Lea. A curious dead shell from Onondaga 



lake, thus identified by Dr. Newcomb. Rare. 



ligamentinus. Lam. Coarse, oval, brown, rare. 



Cross lake. 



luteolus. Lam. Ova\, teeth compressed, variable. 



It is often difficult to distinguish this shell from IT. 



radiatus. 



Novi-Eboraci. Lea. Small, yellow, interrupted 



rays. 



occidens. Lea. Large, ovate, polished. Seneca 



river. 



parvus. Barnes. Small, cylindric. Erie canal. 



pressus. Lea. Green, compressed, winged. Seneca 



river. 



radiatus. Lam. Oval, variable, teeth erect, common. 



rectus. Lam. Long, black. Rifts of rivers. 



rosaceus. DeKay. Like radiatus and luteolus. 



Rosy within. Rare. 



rubiginosus. Lea. Reddish, heavy, angular. Erie 



canal. 



siliquoideus. Barnes. Polished, inflated. 



Tappanianus. Lea. Small, compressed. Canal and 



Seneca river. 



undulatus. Barnes. Large, brown, plicate, quad- 

 rate. Canal, rare. 



ventricosus. Barnes. Large, oval, inflated. Seneca 

 river. 



Margaritana marginata. Say. Inflated, truncated, com- 

 mon. 



rugosa. Barnes. Compressed, one end wrinkled. 

 Rivers and canals. Occurs in Onondaga lake. 



