272 



U. S. P. R. R. EXP. AND SURVEYS ZOOLOGY GENERAL REPORT. 



The scales are large, and trie lateral line gently deflexed upon the abdominal region. The 

 color is reddish brown above, rather more yellowish beneath, with the middle of the flanks 

 silvery, and black dots along the track of the lateral line. The fins are unicolor. 



List of specimens. 



MONTANA, Girard. 



GEN. CHAR Body compressed, sub-fusiform. Head rather small, sub-conical or rounded. Snout occasionally protruding 

 slightly. Mouth sub-oblique, terminal ; both jaws generally equal. No barbels. Isthmus narrow. Eyes moderate. Caudal 

 fin furcated. Scales deeper than long, with radiating furrows upon their posterior section alone. These characters, so far, are 

 found in Plargyrus. But now for the differences. The insertion of the ventrals is situated in advance of the anterior margin 

 of ihe dorsal, which is higher than long. The pharyngeal teeth are compressed, of the raptatorial kind, of the hooked type, 

 without grinding surface, instead of which a sharp ridge is observed, very minutely crenated. They are disposed upon a single 



row of four, thus : 4 4. 



*&amp;gt; 



STN. Moniana, GRD. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 199. 



This genus is composed of small species, all of which being provided with scales similar in 

 their general outline to those of Plargyrus and Cyprinella. 



1. MONIANA LUTEENSIS, Grd. 



SPEC. CHAR. Body sub-fusiform, elongated; back slightly convex. Head contained three times and a half in the total length. 

 Eye moderate, sub-circular ; its diameter entering four times in the length of the side of the head. Jaws equal ; posterior 

 extremity of maxillar bone not reaching a vertical line drawn at the anterior rim of the orbit. Anterior margin of dorsal fin 

 equidistant between the tip of the snout and the base of the caudal. Insertion of ventrala situated in advance of the anterior 

 edge of the dorsal. Pectorals slender; their tips not reaching quite the origin of the ventrals. Bluish black or brown; dorsal 

 fin yellowish brown ; other fins reddish. 



STN. Leuciscus lutrcnsis, B. & G. in Proc. Acad. Nat. Sc. Philad. VI, 1853, 391 ; &, in Marcy s Expl. of Red Riv. of La. 



1853, 251, Zool. pi. xiv. figs. 912. 

 Moniana lutrensis, GRD. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 199. 



The body is very mucli compressed and sub-fusiform in general appearance, somewhat tapering 

 from the posterior margin of the dorsal and anal fins to the caudal, the base of which is broader 

 than the peduncle of the tail. The greatest depth is equal to the length of the head, which is 

 contained three times and a half in the total length, the caudal fin included. The greatest 

 thickness is nearly equal to half of the depth. In general aspect it resembles Luxilus ken- 

 tuckicnsis of Dr. Kirtland. The eyes are of medium size, sub-circular ; their diameter being 

 contained four times in the length of the sides of the head. The nostrils, situated towards the 

 upper surface of the head, are nearer the eyes than the tip of the snout. The posterior 

 extremity of the maxillary does not reach a vertical line drawn at the anterior rim of the orbit. 



The upper and posterior margins of the opercle constitute a uniform curve, whilst the anterior 

 and inferior margins are straight, forming together a rather acute angle. The sub-opercle and 

 inter-opercle are comparatively small. 



