31. CYPRINID^ PTYCHOCHILUS. 225 
chiefly west of the Cascade Kaiige, from Cciliforiiia to British Columbia, 
often entering the sea; abundant. 
{Cuprinns (Leuciscns) caurinus IJichardsou, Fauna Bor.-Amer. Fisbos, 1836, 304: M;/- 
locheilus lateralis, caurbnis, imd fratcrciilus Girard, S. Pac. K. K. Surv. x, 213-215: 
Lcucosomm caurinus Giiutlier, vii, 270.) 
99.— I«¥JL0PIIAK03>©]V Ayi-es. 
(Ayres, Proc. Cal. Acad. Nat. Sci. 1855, 33: type Mylopharodon robustus Ayres — Gi7a 
conocepliala B. & G. ) 
Body elongate. Head large, pike-like, the upper jaw not protrac- 
tile; no barbel. Teeth 2, 4-5, 2; two or three of the teeth in the main 
row molar, truncate or bluntly rounded at the apex, much enlarged. 
Mouth terminal, rather large, with thickened lips. Scales rather small. 
Lateral line continuous. Dorsal tin inserted behind the ventrals. Anal 
basis short. Size very large. This genus has been confounded with 
Mylochilus, from which it differs in the non-protractility of the uiiper 
jaw. (Shortened from Mylopliarijngodon — ixu/.o^, grinder; <pdpu'p^, pha- 
rynx; oda»^ tooth.) 
354. M. coBioceplialus (Baird & Girard) Grd. 
Body elongate, subfusiform, compressed. Head broad and depressed, 
the snout tapering, almost wedge-shaped. Mouth horizontal, the jaws 
about equal, the maxillary extending to eye. Eye small, about 7 in 
head, 2.t in snont ; preorbital elongate. Interorbital space as long as 
maxillary, 3 in head. Scales rather small, of the type usual in the 
Pacitic coast Cyprinidw. Dorsal lin a little behind ventrals. Caudal 
fin 1^ in head ; caudal peduncle very long, 44 in length. Color dark, 
paler below. Head 34; depth 4§. D. 8; A. 8; scales 17-74-7. L. 48 
inches. liivers of California. Next to the species of Ptychochilus the 
largest of our Cyprinidcc. 
{(dila conocepliala B. & G. Proc. Acad. Nat. Sci. Pbila. 1854, 134: Mylopharodon ro- 
hustus Ayven, Proc. Cal. Acad. Nat. Sci. 1855, 33: Mylopharodon conocephalus androhustus 
Grd. U. S. Pac. R. R. Surv. x, 216; Giiiitber, vii, 262.) 
100.— PTYCIIOCIIBI.5JS Agassiz. 
{Ptychoclieilus Agassiz, Ainer. Jouru. Sci. Arts, 1855, 229: tjqie Ftychocheilus gracilis 
Agas.siz = Leuciscus oregonensis Ricb. ) 
Body elongated, little elevated, the caudal peduncle not contracted. 
Head long, slender, i)ike-like. Mouth nearly horizontal, widely cleft, 
the maxillary extending to below the eye, the upper lip rather below 
the level of the eye, the lower jaw included both anteriorly and later- 
ally; no barbel; lips thick. Scales small, little imbricated, mostly 
Bull. Nat. Mus. No. 10 15 
