CYPRINID^E. XXVI. 5 3 



back and sides dusted with dark specks. Head 4 ; depth 5. 

 D. high, 8. A. 7 Lat. 1. 63. L. 2J. Illinois R. (Lat., dusted). 



51. CHROSOMUS Rafinesque. (xpws, color; o-oi/za, body.) 



89. C. erythrogaster Rafinesque. RED-BELLIED MINNOW. 

 Brownish olive, with black spots on the back, a blackish band from 

 above eye, straight to the tail, sometimes breaking up in spots be- 

 hind ; another below, broader, running through eye, decurved 

 along the lateral line, ending in a black spot at base of C. ; belly 

 and space between bands bright silvery, brilliant scarlet red in 

 spring males, as are the bases of the vertical fins; females ob- 

 scurely marked. D. 8 ; A. 9. Scales 16-85-10. L. 2. Penn. to 

 Dakota and Tenn., abundant in small clear streams; one of the 

 most beautiful of our fishes ; in high coloration the fins are bright 

 yellow. It is the most desirable of all our minnows for aquarium 

 purposes, being hardy, graceful, and gaily colored, (epvtipos, red ; 

 yaa-rrjp, belly.) 



52. HYBOGNATHUS Agassiz. (vjSo'y, gibbous ; yvdQos, jaw.) 



a. Teeth comparatively long, and scarcely hooked; silvery species. (Hybo- 



gnathus.) 



b. Suborbitals broad, the anterior, about twice as long as deep. 

 c. Mouth narrow, its cleft not reaching nearly to eye ; lower jaw shorter 

 than upper, obtuse at tip. 



90. H. nuchalis Agassiz. Body rather slender; head rather 

 short, the profile evenly curved ; eye moderate, 4 in head ; lateral 

 line decurved; 13 large scales in front of D. ; intestine 7 to 10 

 times length of body. Silvery green, sides bright silvery, with an 

 underlying plumbeous shade ; fins all pale. Head 4| to 5 ; depth 4-|. 

 D. 8, A. 7. Scales 5-38-4. L. 4 to 9. N. J. to S. C., Dakota, and 

 Texas, common near large rivers. Variable ; notable varieties are 

 placita Girard, Arkansas and Missouri rivers, the eye smaller, 

 5 in head, the snout depressed and blunt, with very small mouth ; 

 var. regia Girard, Potomac River, larger (7 inches long), with 

 deeper body and larger eye, 3f in head. (Lat., pertaining to the 

 nape.) 



cc. Mouth wide, its cleft reaching about to eye ; jaws subeqnal, the lower 

 acutish at tip. 



91. H. argyritis Girard. Silvery. Upper Missouri and Red 

 R. of North. (Lat., silvery.) 



aa. Teeth comparatively short, distinctly hooked; suborbitals very narrow; 

 plumbeous species. (Dionda Girard.) 



92. H. nubila (Forbes). Maxillary 3 in head ; snout short, not 

 very blunt ; eye 3 in head ; 12 scales before D. Head 4J ; depth 

 4^. Scales 5-37-3. Olivaceous with plumbeous or dusky lateral 



