CYPRINIDA. — XXVI. 53 
back and sides dusted with dark specks. Head 44; depth 5. 
D. high, 8. A.7 Lat. 1.63. L. 24. Illinois R. (Lat., dusted). 
51. CHROSOMUS Rafinesque. (xpos, color; capa, body.) 
89. C. erythrogaster Rafinesque. Rep-BeLLizp 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. (épuOpds, red; 
yaornp, belly.) 
52. HYBOGNATHUS Agassiz. (ds, gibbous ; yvdéos, 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. 0 Uda W 
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 44 to 5; depth 4}. 
D. 8, A. 7. Scales 5-38-4, L.4to9. N.J.to 8. 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, 3} in head. (Lat., pertaining to the 
nape.) 
cc. Mouth wide, its cleft reaching about to eye; jaws subequal, 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 44; depth 
44. Scales 5-37-3. Olivaceous with plumbeous or dusky lateral 
