8 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY 1. 



la all cases where the recognition of Rafinesque's genera or species 

 will render necessary a change in the current nomenclature, I have 

 added Rafinesque's description as a foot-note, that the reader may see 

 the grounds on which the identification is based. In such cases, I have 

 usually italicized the salient points. 



Finally, a list of the species now found in the valley of the Ohio, 

 which do not appear to have been known to Eafinesque, completes the 

 memoir. 



This paper was originally prepared for the press in the spring of 1876. 

 Most of the changes in nomenclature here discussed have been adopted 

 by the author in different papers on fishes, and they have generally 

 received the sanction of American workers in ichthyology. The manu- 

 script of the paper has been since retouched, some untenable positions 

 have been abandoned, and some further changes suggested by Profess- 

 ors Cope and Gill have been introduced. 



