CYPEiNiD^. — cvni. 2S9 



2. H. superciliosus. Cope. Head broader; a distinct 

 barbel at each angle of the mouth; scales on sides high 

 and narrow. With the preceding, of which it is perhaps 

 a variety. 



4. COUSOUS, Cope. Coliscus. 



1. C. parietalis, Cope. Silvery; D. I, 7; A. I, 8; lat. 

 1. 42. Missouri. 



5. HYBOGNATHUS, Agassiz. Blunt- Jawed Minnows. 



1. H. nuchalis, Ag. Blunt - Jawed Minnow. Sub- 

 orbital bones broad and short, not long and narrow as 

 in the next; head 4f in length; eye small, shorter than 

 snout, 4 to 4J in head; depth 4J in length, -about equal 

 to length of head; D. I, 8; A. I, 8; lat. 1. 38; L. 2 J. 

 Ohio Valley and W. This and the next may be readily 

 known from the Syhopses, which they strongly resemble 

 externally, by the peculiarities of the intestines. 



2. H. argyritis, Grd. Silvery Minnow. Olivaceous 

 green above, sides clear silvery with bright reflections; 

 fins unspotted; eye large, longer than muzzle, 3 to 4 in 

 head; depth 4^ in length; scales in front of dorsal quite 

 large; lateral line decurved; head large, upper jaw 

 heavy; D. I, 8; A. I, 8; lat. 1. 38; L. 5. N. J. to S, C. 

 and W. to the Upper Missouri; abundant in the larger 

 streams; one of our handsomest dace. {JS, Qsm&riwus, 

 Cope, not in the least different.) 



3. H. regius, Grd. Rotal Minnow. Head 5 in 

 length; mouth small; bright silvery; D. I, 9; A. I, 9; 

 L. 7; lat. 1. 38. Maryland and Virginia; a species 

 similar to the preceding but apparently much larger; 

 the two need further comparison. 



