240 CTPRIMID^. 



the head thrice and three-fourths. Head not quite twice as long as 

 deep, the width of the interorbital space (which is flat) being equal 

 to the length of the snout. Eye of moderate size, its diameter being 

 one-half of the length of the snout, and one-third of that of the 

 postorbital part of the head. Mouth subhorizontal, large, the max- 

 illary extending to behind the vertical from the front margin of the 

 eye. Jaws nearly even in front. Lips well developed. Suborbital 

 bones narrow, the prteorbital being longer than the eye and nearly 

 twice as large as the postorbital. The origin of the dorsal fin is 

 nearly oj)posite to the middle of the root of tlae ventral fin and some- 

 what nearer to the prfeoperculum than to the base of the caudal. 

 Caudal fin forked. There are eight longitudinal series of scales 

 between the lateral line and ventral fin. Coloration uniform. 



Pharyngeal bones narrow, but stoutly built, with two series of 

 subcorneal teeth, pointed, and slightly hooked at the extremity, 

 5 . 2 — 2 . 5. Gill-rakers very short, few in number. The attachment 

 of the giU-merabrane to the isthmus takes place opposite to the hind 

 margin of the prijeoperculum. 



Oregon. 



a. Type of the species, 13 inches long. Oregon. From the Haslar 



Collection. 



b. Young. Eraser's Eiver. Voyage of H.M.S. ' Plumper.' 



Ptychocheilus vorax, Girard, Proc. Ac. N'at. Sc. Philad. 1856, 

 p. 209, and U. S. & Pac. E. E. Exped. Fish. p. 301, appears to 

 belong to the same group as L. cjrandis and L. oregonensis ; it is 

 described thus : — The greatest depth of the body is nearly equal to 

 the length of the head, which is nearly one-fifth of the total (with 

 the caudal). Peduncle of the tail very slender. The diameter of 

 the eye is two-thirteenths of the length of the head. The max- 

 illary extends to the vertical from the front margin of the eye. 

 Origin of the dorsal somewhat nearer to the root of the caudal than 

 to the end of the snout. 



38. Leuciscus gracilis. 



Cyprinus (Leuciscus) gracilis, Richardson, Fmm. Bor.-Amer. Pise. 

 p. 120, pi. 78. 



D. 9. A. 10. V. 8. L. lat. 55. L. transv. 7/9. 

 The height of the body is about equal to the length of the head, 

 which is contained four times and three-fourths in the total (with- 

 out caudal). Crown of the head broad and flat ; nape gibbous. The 

 diameter of the eye is one-half of the length of the snout, and one- 

 third of that of the postorbital portion of the head. Upper jaw 

 overlapping the lower ; mouth subhorizontal. The origin of the 

 dorsal fin is opposite to that of the ventrals and somewhat nearer to 

 the end of the snout than to tbe root of the caudal fin, which is 

 deeply forked. Coloration uniform. {Rich.) 

 Saskatchewan Eiver. Length 12 inches. 

 The pharyngeal teeth of this fish are not known, but it appears 



