NAIADES. 91 



IN Mr. Rafinesque's Monograph, and in his subsequent Papers, are inserted 

 descriptions under the following names. Not being able to identify them, I have 

 deemed it better simply to give a catalogue of them. Those which I suppose I have- 

 identified will be found in the foregoing table. In this list, I have not divided the 

 Uhionidce into his numerous genera. The want of adequate figures, and an absence 

 of sufficiently accurate description, together with Mr. Rafinesque's well-known 

 proclivity to make species out of imaginary forms and specimens, induced me, after 

 repeated and vain attempts to recognize his species, to follow the example of Mr. Say, 

 Mr. Barnes, and all the other American malacologists up to the time of commencing 

 my memoirs on this subject, to avoid any farther attempt to elucidate a mass of 

 confusion which was considered beyond the pale of science. The views of the late 

 Dr. Binney, in his Terrestrial Molluscs of the United States, Prof. A. Gray, in Amer. 

 Journal of Science, and Major Le Conte, in the Proc. Acad. Nat. Sciences, in relation 

 to the claims of this writer, are so conclusive that it is only necessary for any unpre- 

 judiced mind to examine the facts and be perfectly satisfied that Mr. R. has, so far 

 from advancing science by his writings in this branch, been the cause of inextricable 

 confusion, from the embarrassment of which we can only be relieved by altogether 

 avoiding any further attempt to make out his imaginary species. M. Ferussac, who 

 made vain attempts to understand his division and species, says that the shells he 

 sends away augment the difficulties in knowing his own species, and that he had 

 received the same shells under different names, and others with the names evidently 

 different from those given in his monography; that the difficulty, therefore, is inex- 

 tricable in the determination of his species, &c. 



Alasmodonta atropurpureum ? Unio antrosa ? Unio cyclips ? 



badium? argyratus? cyphia? 



costata? atroviolacea? decorticata? 



hians? attenuata? depressa? 



papyraceum ? aurata? diaphanus? 



ponderosum? bicolor? dilatata? 



rugosum? biloba? diploderma? 



scriptum? bullata? ellipsaria? 



sulcatum? calendis? elliptica? 



viridis? cardium? fasciata? 



castaneus ? fasciola ? 



Anodonta aperta? chloris? fasciolaris? 



atra? cinerescens? flava? 



cuneata? Cliffbrdiana ? flexuosa? 



digonota? cordata? flexus? 



inflata? costata? fontinalis? 



lata? crassa? fragilis? 



Ohiensis? cuneata? fulgens? 



solenoides? cuprea? fulvus? 



