o I am indebted to the politeness of Mr. Poutson, for 
an opportunity to consult his library and collection, 
° in order to prepare the following Table of the spe- 
cies of Naiades, inhabiting the North American 
rivers. Most of those which have been described by 
Rarinesqaue, have been added by that author to Mr. 
Pou.son’s valuable collections, with the names at- 
tached to each; but I have considered some of these 
as merely appertaining to varieties, and have given 
them among the synonymes of the different species, 
to which I think they properly belong. Mr. PouLson 
deserves the thanks.of Conchologists for the pains 
he has taken to rectify the confused nomenclature 
of American Naiades, a task which has been attend- 
ed with considerable labour and expense. 

, a ee Re cai is 
te ES ae 
\ 
F2 

