THE FAMILY NAIADES. 9 



sence of the individual specimens noted. In the absence of 

 these specimens, which no naturalist has, I believe, ever seen 

 but the Professor, I feel myself compelled to prefer other au- 

 thorities which are now almost universally received by our 

 men of science. I am the more fortified in this conclusion, 

 when I see that his most ardent advocate acknowledges that 

 he has made six species from a single one ;* and the absurdity 

 is still stronger when we turn to Prof. R.'s monograph, and 

 find that this single species has furnished several genera, and 

 is placed in fact in tioo different sub-families! ! ! 



In regard to the Catalogue published last year by Baron 

 Ferussac, in which he gives precedence to many of Professor 

 Rafinesque's names, it must be remembered that this has been 

 done on the authority of others, and not from the inspection 

 of the subjects themselves. Had he known the manner in 

 which these claims had now been brought forward, he certainly 

 would have admitted them with doubt. It will be observed 

 that I have inserted in this '-Synopsis" many new species which 

 may not be recognized at once as mine. These are contained 

 in my late Memoirs read at various times before the American 

 Philosophical Society, and will, I hope, shortly appear in its 

 Transactions. 



* Conrad's Synoptical Table on New Fresh Water Shells of the United 

 States, p. 72. U. triangxdaris. 



