100 Cockerell and Callaway — Fishes of the Genus Notropis. 



adaptation to smaller streams, enal)ling the fishes to populate 

 waters unsuitable to the stem-form. 



Tlie accompanying table shows the number of apical radii on 

 the scales of the species of Notropis examined by us. It must be 

 noted that the scales are all taken from the same part of the fish, 

 namely, the immediate vicinity of the lateral line, at the level of 

 the beginning of the dorsal fin. There is no doubt whatever that 

 by examining a larger number of scales, especially from large 

 series of the fish, the recorded ranges of variation would in al- 

 most every case be sensibly increased. At the same time, we 

 are satisfied that with this caution the table may be regarded as 

 of significance in relation to the evolution of the species. It 

 will be observed that two subgenera, as currently interpreted, 

 are in the table separated into divergent parts. In the case of 

 Cyprinclla we do not believe that a second group is indicated, 

 but in Hydrophlox it appears to be necessary to separate N. coc- 

 cogenis as the type of a new subgenus. 



NoTRdPis Rafinesque. 

 Number of apical radii (counting those only partly developed). 



Coccogenia, subgen. nov. 

 Type, Notropis coccogenis (Cope). 

 "Mouth large, very oblique, . . . lower jaw projecting beyond upper, 



