NORTH AMERICAN CONCHOLOGY. 



159 



Amnicola grana Say. 

 Paludina ponderosa Say. 

 Melania livescens Menke. 

 31. Niagarensis Lea. 



subulata. 

 Cyclas similis Say. 



partumeia Say? 

 Pisidium dubium S. (notes). 

 Unio radiatus Gmel. 

 Anodonta Pepiniana Lea. 



Agassiz. — On the Embryology of Ascidia and the Character- 

 istics of New Species from the Shores of Massachusetts : by 

 Prof. Louis Agassiz. (Proc. American Assoc, for Advance- 

 ment of Science, vol. ii, p. 15T, 1850.) 



Page. 



159 



159 

 159 

 159 



Ascidia amphora Ag. 

 psammophora Ag. 

 ocellata Ag. 

 carnea Ag. 



159 Ascidia hirsuta Ag. 



159 rugosa Ag. 



159 Boltenia microcosmus Ag. 



dewberry. — Geographical Distribution of certain Species of 

 Fluviatile and Terrestrial Shells: by J. S. Newberry, M. D. 

 (Proc. American Assoc, for Advancement of Science, vol. v, p. 

 105, 1851.) 



