220 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



orbital width being nearly half the length of the head. Mouth rather 

 large, slightly oblique, the upper lip on the level of the lower ijart of the 

 eye, the maxillary reaching the line of the front of the eye, the upi)er jaw 

 very protractile, the lower jaw included. Eye small, rather high up 

 and anterior, 6 in head. Fins rather large ; dorsal in advance of the 

 middle of the body; caudal peduncle rather stout. Scales large and 

 silvery; lateral liue decurved; 23 scales in front of dorsal. Coloration 

 pale; back bluish; sides and below silvery; head mostly white; fins 

 pale. Head i^ ; depth 4|. I). 8 ; A. 8 ; scales 6-50-5 ; teeth 2, 4-4, 2. 

 L. 12 inches. Rocky Mountain region from the Kansas and Yellow- 

 stone Elvers to the Saskatchawan ; abundant. 



(Cijprinus {Leuciscus) gracilis Rich, Fauna Bor.-Amer. Pise. 1836, 120: rogonichthy^ 

 communis Grd. Proc. Acad. Nat. Sci. Phila. 1856, 188, and U. S. Pac. R. R. Surv. x, 

 247: Pogonichthys communis Gill, Ichtli. Captain Simpson's Surv. 408: Pogoniehthys {Pla- 

 iygobis) gulonellns Cope, Proc. Acad. Nat. Sci. Phila. 1864, 277 : Leuciscus gracilis Giin- 

 ther, vii, 240: Leitcosomus communis and gulonellus Giinther, vii, 267, 268.) 



346. P. pallidiis Forbes, sp. nov. 



"The depth is contained 4§ times in length, and the head 4. The eye 

 equals the snout, and enters length of head 3f times and the interor- 

 bital space twice. The head is tiat above and the snout overhangs the 

 mouth, which is large and wide, with a maxillary barbel about one-third 

 as long as the eye. The mandible reaches a vertical line drawn through 

 the middle of the iris in front. The greatest depth of the head enters 

 its length 1| times. The scales are 6-55-5, with 22 rows before dorsal, 

 where they are much smaller than elsewhere. The lateral line is straight, 

 except for a few scales in front. The pectoral fins are large and pointed, 

 reaching the ventrals, and the latter attain the vent. The front of the 

 dorsal is situated a trille before the ventrals and a little nearer snout 

 than caudal. D. 8; A. 8. The color in alcohol is plain, with a 

 plumbeous lustre along sides, and traces of a dnskj' lateral stripe behind 

 dorsal. The iiharyngeal teeth are stout, 2, 4-4, 2, hooked,. with masti- 

 catory surface. L. 2J inches. One specimen from the Ohio River at 

 Cairo, i>robably adult, as the snout is tuberculate." [Forbes, MSS.) 



95.— SEMOTIJLUS Rafinesque. 



Chubs. 



{Leucosomus Heckel ; Chilonemus Baird.) 



(Rafinesque, Ichth. Oh. 40, 1820 : type Semotilus dorsalis Raf. = Cyprinus corporalis 



Mitch.) 



Body robust. Head large. Mouth terminal, the upper jaw pro- 

 tractile, a small barl)el on the maxillary just above its extremity. In. 



