212 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY — [V. 



** Species of small size, with the mouth subiuferior aud horizontal ; the dorsal fin in- 

 serted slightly in front of the ventrals, and the scales generally large and sil- 

 very (? Hybopsis Agassiz). 



b. Teeth two-rowed cumiiigi, lucens, am hlops, ruhrifrons, hi/jjsinotus. 



bb. Teeth one-rowed dissimilis, sterlefus, cestivalis, gelidun. 



*** Species of small size, with the month subinferior and horizontal, with thickened 

 lips ; the dorsal fin inserted slightly behind the ventrals, usually with a black 

 blotch on its last rays; scales rather large, silvery. 



labrosus, zanemus, monaohuH. 

 * Species of large size, with the month anterior, the lower jaw included; the dorsal 

 fin slightly behind the ventrals. (Ceratichihys.) 



326. ChisnttatusiKirt.) Grd.— Horny Head; River Chub ; Jerker. 



Body rather robust, little elevated, little compressed. Head large, 

 rather broadly rounded above; the snout conical, bluutish. Mouth 

 rather large, subterminal, little oblique, the lower jaw somewhat the 

 shorter, the upper lip rather below the level of the eye, and the maxil- 

 lary not reaching to the front of the eye. Eye small, median, high up. 

 Suborbitals very narrow; preorbital large. Fins moderate; the dorsal 

 rather posterior, slightly behind the insertion of the ventrals ; caudal 

 broad, little forked. Scales large, not crowded anteriorly, 18 rows in 

 front of the dorsal. Lateral line somewhat decurved. Color bluish 

 olive; sides with bright green and copjier^- reflections; a curved 

 dusky bar behind the opercle ; scales above with dark borders ; belly 

 l>ale, but not silvery, rosy in spring males ; tins all pale orange, with- 

 out black spot. Males in spring with a crimson spot on each side of 

 the head; the adults with the top of the head swollen, forming a sort 

 of crest, which is sometimes a third of an inch higher than the level of 

 the neck and is covered with large tubercles ; young with a dark caudal 

 spot. Barbel well developed. Head 4; depth 4i. D. 8; A. 7; scales 

 6-41-4; teeth 1, 4-4, 1, or J, 4-4, 0, sometimes 4-4. L. 6-9 inches. 

 Pennsylvania to the Great Basin of Utah and southward; everywhere 

 abundant. The most widely diffused of our Cyprinida'. Western speci- 

 mens usually have the teeth in two rows. 



{Semotilus bigtiUatus Kirtland, Bost. Jouru. Nat. Hist. 1840, iii, 344; Cope, Cypr. 

 Penn. 1866, 366 ; Guuther, vii, 178 : Nocomls nehrascensis and fNocomis bellicus Girard, 

 Proc. Acad. Nat. Sci. Phila. 1858, 213: Ceratichthys cyclotis and stigmaticus Cope, Proc. 

 Acad. Nat. Sci. Phila. 1864,277,278: Ceratichthys cycloiifi Giinther, vii, 178: Ceratich- 

 thys stigmaiieus Giinther, vii, 179.) 



337. C. iiiJcro|>og:oii Cope. 



Body moderately stout. Head much as in Minniliis cornutus, broad, 

 the muzzle obtuse, the profile rounded, descending. Mouth slightly 

 oblique, its angle opi)osite front of the orbit. Eye 3^ in head. Barbel 

 minute. Caudal peduncle slender. Yellowish brown, with brown ver- 



