CYP&INID.E. XXVI. 55 



(Hylopsis tuditanus Cope ; Alburnops taurocephalus Hay.) (Lat., 

 watchful.) 



56. NOTROPIS Rafinesque. (AMERICAN MINNOWS.) 

 (MINNILUS Rafinesque, etc., etc.) 



(As now understood, this genus contains upwards of a hundred 

 species of small Cyprinoids, all of them confined to the waters of 

 E. N. A. They are feeble fishes, of rather low organization, none 

 of them of any value as food to man, but of great importance as 

 food for the larger predatory fishes. The species are highly vari- 

 able, readily affected by surrounding conditions, while the per- 

 manently distinctive characters are few. The identification of 

 species in this group is therefore very difficult, and in the case 

 of young specimens often impossible. The following analysis must 

 be used with caution, as all characters are subject to occasional 

 or individual variations.) (i/wros, back; TpoVty, keel; but the 

 back is not keeled. Rafinesque's types had been shrivelled by 

 drying.) 



a. Teeth 4, 4, or 1, 4-4, 0, or 1, 4-4, 1 (sometimes 1, 4-4, 2 in N. Jiudsonius). 

 b. Scales not closely imbricated, not notably deeper than long; D. inserted 



nearly over V. ; A. short, its rays 7 or 8. 

 c. Teeth 4-4, the grinding surface more or less developed. 

 d. Lateral line usually incomplete ; scales before D. large, 13 in num- 

 ber. (Hemitremia Cope.) 

 e. Snout very obtuse ; lower jaw not projecting. 



97. N. bifrenatus (Cope). Body slender, the tail contracted; 

 upper lip on level of lower part of pupil; jaws subequal, eye large, 

 3 in head; lateral line very short. Straw-color, with jet-black 

 lateral band, bordered with orange on snout. Head 4 ; depth 4. 

 D. 8. A. 7. Scales 5-36-3. L. 2. Mass, to Md. (Lat., two- 

 bridled.) 



98. N. anogenus Forbes. Very similar to N. heterodon, but 

 with lateral line usually complete ; the mouth very small and very 

 oblique, the lower jaw included, the upper lip above level of pupil; 

 snout short, blunt. Dusky, a very distinct lateral band and a black 

 spot at base of C. ; a black speck on each pore of lateral line. 

 Head 4^; depth 4|. A. 7. Lat. 1. 34 to 37. L. 1. W. N. Y. 

 (Ithaca, Meek) to 111. (a, without; yews, chin.) 



ee. Snout pointed ; lower jaw projecting. 



99. N. heterodon Cope. Body rather stout; eye 3 in head; 

 lateral line usually developed about half-way, sometimes nearly per- 

 fect. Olive, sides with dusky plumbeous band, fainter than in 

 preceding. Head 4 ; depth 4. A. 8. Scales 5-36-3. L. 2J. 

 Teeth crenate. W. N. Y. to Kans. ; common. (Other specimens 

 from Ind. and HI. have lateral line complete, and teeth 2, 4-4, 2. 



