CYPRINID^. 51 



Gemis: Notropis. 



Key to Species. 



A. Teeth 4-4, 1, 4-4, o, or 1, 4-4, 1 (sometimes 2 teeth in one or both inner rows in JV. 

 hudsonius and N. heterodon). 

 B. Scales not very closely imbricated, not notably deeper than long; dorsal in- 

 serted nearly over the ventrals; no black spot on dorsal fin. 

 C. Teeth one-rowed, 4-4 (sometimes 2, 4-4, 2 in N. heterodon). 



D. lateral line usually more or less incomplete; small species, usually 

 with a dusky lateral band. 



E. Mouth very small, chin pale. — caynga. 

 EE. Mouth moderate; chin black. — heterodon. 



DD. lateral line always complete; small, weak species. 



F. Fins all small and low, pectorals not reaching ventrals. — 



blennius. 

 FF. Fins high, pectorals reaching ventrals. — volucellas. 



CC. Teeth two-rowed, 1, 4-4, o; 1, 4-4, 1; or 1, 4-4, 2, the grinding surface more 

 or less developed. 

 G. No distinct dark spot at base of caudal. — shumardi. 



GG. A distinct dark spot present at base of caudal fin. — hudsonius. 

 BB. Scales deeper than long, closely imbricated along side of body. Usually a dis- 

 tinct black spot on last rays of dorsal. — whipplii. 

 _AA. Teeth 2, 4-4, 2 (2, 4-4, 1 in N. jejunus). 



H. Anal fin short, of 7 to 9 developed rays. 



I. Teeth with the grinding surface developed. 



J. Scales closely imbricated along the sides, no dark spot at base of 



caudal. — cornutus. 



JJ. Scales not closely imbricated, a dark spot at base of caudal at least 

 in young. 

 K. 13 scales before dorsal fin. — heterodon. 



KK. 18 scales before dorsal. — hudsonius. 



II. Teeth without evident grinding surface, scales not closely imbricated. 

 Iv. Eye very large, 2% in head; teeth 2, 4-4, 2. — ariommus. 

 lit,. Eye z% i n head, teeth 2, 4-4, 1.— jejunus. 



HH. Anal fin long, of 11 or 12 rays; dorsal inserted behind ventrals. 



M. Scales not closely imbricated on sides, not crowded anteriorly. 



N. Eye very large, 2% to 3.— arge. 



NN. Eye smaller, 3% to 4- 



O. Front of dorsal midway between snout and base of caudal fin; 



eye 3% — atherinoides. 



OO. Front of dorsal nearer to base of caudal than to snout; eye 4. — 



rubrifrons. 

 MM. Scales small and crowded anteriorly, closely imbricated; a black spot at 

 base of caudal. — umbratilis. 



Notropis cayuga Meek. 



Head 4 or a little over; depth 4^; eye 3^. D. 8; A. 8; scales in lateral 

 line about 36, 14 before dorsal; teeth 4-4. Close to N. heterodon, from 

 •which it can be distinguished most readily by the absence of any black on 

 the chin. Lateral line wanting on some scales. Jaws nearly equal. A black 

 band along lateral line, continued forward along sides of head and around 

 snout on upper jaw. Length 2^ inches. 



