66 TELEOSTEI : EVENTOGNATHI. — XII. 



young with dusky lateral shade. Head 4 J; depth 4f. D. 8. A. 8. 

 Scales 6-50-5. L. 12. Missouri Basin, abundant in river chan- 

 nels, N. to Saskatchewan, S, to Cairo, 111. (Lat., slender.) 



63. SEMOTILTTS Rafinesque. (crrjiia, banner; the remainder, 

 according to Kafinesque, means " spotted.") 



a. Scales scarcely crowded anteriorly, about 8-45-5 ; no black spot at base 

 of dorsal in front. 



148. S. buUaris (Rafinesque). Fall-fish. Chub. Roach. 

 D. inserted midway between nostril and base of C, ; barbel very 

 small; eye 4^ in head; 22 scales before D. Bluish above, sides 

 silvery ; fins plain. Head 4 ; depth 4. D. 8. A. 8. L. 18. Quebec 

 to Va., abundant E., the largest of the Cyprinidce E. of the Rocky 

 Mts. On the Pacific slope are species (^Ptycliocheilus, Mylopharo- 

 don, etc.) 5 to 6 feet in length. " The chub is a soft fish ; it tastes 

 like brown-paper salted." [Thoreau.) (Lat., 6uHa, bubble.) 



aa. Scales small, crowded anteriorly, about 10-54-7; lat. 1. 52 to 65; a round- 

 ish black spot at base of D. in front. 



149. S. atromaculatus (Mitchill). Horxed Dace, Ckeek 

 Chub. D. inserted midway between pupil and base C; body 

 robust; head large and broad; barbel minute, not evident in the 

 young; mouth large, lower jaw included ; eye small; 30 scales be- 

 fore D. Dusky, little silvery, a dark bar at shoulder ; young with 

 dark lateral band ; $ more or less red and with coarse tubercles 

 in spring. Head 3|; depth 4. D. 7. A. 8. L. 12, or less. W. 

 Mass. to Dakota, Va. and La., very abundant, especially in small 

 clear brooks. Variable. (Semotilux corporalis of authors, not of 

 MitchiU.) (Lat. ater, black; maculatus, spotted.) 



64. PHOXINUS Agassiz. Dace. 



(As here understood, a very large genus, one of the largest in 

 Ichthyology, comprising a great number of species, mostly of 

 Europe, Asia, and Western North America, distinguished from 

 Notropis, in general by the better developed dentition ; the teeth 

 2, 4 - 5, 2, or 2, 5 - 5, 2, and by the larger size of the body ; the 

 scales being in general smaller than in Notropis. We here unite 

 Squalius (lat. 1. complete) with Plioxinm (lat. 1. incomplete). 

 When we consider European species only, the two genera appear 

 to be widely separated, but the intergradation is almost perfect 

 when American species are taken into account. (Old name from 

 (jiO^Ss, tapering.) 



a. Lateral line complete (Squalitis Bonaparte). 

 b. Teeth without grinding surface; caudal peduncle rather slender; anal 

 basis short. 



