264 



U. 8. P. R. R. EXP. AND SURVEYS — ZOOLOGY GENERAL REPORT. 



The species is gracefully sub-fusiform in its profile, the depth, in advance of the dorsal, being 

 equal to the fifth of the entire length, in wliicli the head itself enters about five times. The eye 

 is very large, its diameter entering three times and a lialf in the length of the aide of the head. 

 D 2, 8 4- 1 ; A 2, 9 ; C 8, 1, 9, 8, 1, 9 ; V 1, 8 ; PI, 14. 



The tips of the pectoral fins are nearly at the same distance from the insertion of the ventrals 

 as the tips of the latter are from the origin of the anal fin. 



The dorsal region is reddish brown, the sides being silvery and the abdomen yellowish. A 

 black streak may be seen along the upper edge of the silvery zone of the flanks. Fins oliva- 

 ceous ; rays tinged with greyish. 



References to the figures. — Plate LIX, fig. 1, represents Plargyrus hotomani, size of life. Fig. 

 2, a section of the body across the line of greatest depth. Fig. 3, a dorsal scale. Fig. 4, a scale 

 from the lateral line. Fig. 5, a scale from the abdominal region. 



List of specimens. 



CYPRINELLA, Girard. 



Gen Char. — Body very much compressed, either elongated and sub-fusiform, or else with the dorsal and abdominal outlines 

 rather arched. The licad isof moderate size, sub-conical, tho snout generally protruding beyond the lower jaw. Mouth small, 

 its gape slightly oblique, and sub-terminal. No barbels. Eyes moderate. Isthmus narrow. Tail tapering ; caudal fin furcated. 

 Insertion of ventrals opposite or slightly in advance of the anterior margin of dorsal fin. Scales large, else of moderate develop- 

 ment, imbricated, much higher than long, with radiating furrows upon their posterior section only. Lateral line forming a 

 downwards curve bencatli the middle of tlie flanks. Pliaryngeal bones resembling those of i'(orgi/' us. The teeth are slender and 

 compressed, of the raptatorial kind of the hooked type, slightly hooked, witliout grinding surface, instead of which, a sharp ridge 

 inconspicuously crenaled, and disposed upon a double row of oue and four in the following manner : 1 | 4 — 4 | 1. 



Sxs.— Cypnndla, Grd. in Proc. Acad. Nat. Sc. Pliilad. VllI, 1856, 19G. 



Had the name of Hypsolepis not been preoccupied to designate another genus, it might have 

 been applied with great propriety to tlie species of tlie present genus, since the fishes herein 

 included possess that curious character of having the scales higher than long. They replace in 

 the southwest the Plargyri of more nortliern climes. Though generally smaller than the species 

 of Plargyrus, some do resemble the latter in a very striking manner, whilst others are much 

 shorter and deeper in proportion. The chief differences between the present genus and Plar- 

 gyrus is to be found in the pharyngeal teeth and the position of the ventrals. 



To 3Ioniana it bears more striking resemblances and real affinities. The position of the 

 ventral fins is the same ; the jdiaryngeal bones are alike also ; the teeth are of the same general 

 pattern, but disposed upon a double series in Cyprinella, and upon one only in Moniana. More- 

 over, in Cyprinella the snout generally protrudes beyond the lower jaw, though the mouth is 

 sub-terminal and its gape slightly oblique. 



