322 U. 8. p. R. R. EXP. AND SURVEYS — ZOOLOGY GENERAL REPORT. 



equal, tlie upper one protruding slightly over the lower. Tlie mouth is deeply cleft ; the 

 posterior extremity of the maxillary extending considerably beyond the orbit ; it is a slender 

 and slightly curved bone. The teeth are, generally sjjeaking, of a moderate development ; those on 

 the shaft of the vomer are the stoutest ; tlie next in size are on the dentary and tongue ; the 

 smallest of all are the maxillary proper. The nostrils are nearer the orbit than the end of the 

 snout. The orbit is large, sub-elliptical, its horizontal diameter entering about five times iu 

 the length of the sides of the head, nearly once and a half in advance of its anterior rim. The 

 branchiostegal rays are ten on either side. The opercle is well developed, and but a little nar- 

 rower above than below. 



The fins are all well developed ; the anterior margin of the dorsal fin is equidistant between 

 the insertion of the caudal and the extremity of the snout ; its height is a little more than its 

 len<Tth, and its posterior ray is but one-fourth shorter than the third, which is the highest ; the 

 anterior two being mere rudiments. The adipose is situated opposite the posterior portion of 

 the anal, although its terminal margin is not quite even with the tip of the anal. The caudal 

 is broad, deeply emarginated, not to say furcated, constituting a little less than the sixth of the 

 entire length. The anal is much deeper than long ; its anterior margin is slightly convex, and 

 its posterior margin less than the third of its depth. Tlie insertion of the ventrals is placed 

 opposite the base of the third developed ray of the dorsal ; their tips do not extend as far 

 posteriorly as the tip of the dorsal. The pectorals are sub-lanceolate, oval ; their rays, as in all 

 the other fins, are bifurcated or branched. 



Br. 10 : 10 ; D 14 ; ; A 14 ; C 7, 1, 9, 8, 1, 6 ; V 9 ; P 14. 



The scales are of but moderate development, sub-elliptical in the lateral line, being a little 

 longer than deep, (fig. 4), but deeper than long elsewhere, considerably more so on the abdom- 

 inal region (fig. 5) than on the dorsal (fig. 3). They are deeply imbricated, and largest upon 

 the middle of the flanks. 



The ground color of the upper region is greyish green, the middle of the flank of a coppery 

 hue, and the belly olivaceous grey. The upper surface of the head having the same hue as 

 the back, and the sides coppery like the flanks ; but the upper part of the body is scattered all 

 over with irregular black specks and dots, extending somewhat beneath the lateral line. The 

 dorsal and caudal fins are densely covered with roundish black spots. The lower fins are uni- 

 color, like the abdomen. 



The specimen above described, being the male sex, was collected in Chico creek, Sacramento 

 valley, by Dr. John. S. Newberry, under Lieutenant R. S. Williamson. 



The following refers to the female sex : The snout is obtusely rounded, and the jaws nearly 

 even. The proportions of the head towards the body are the same as in the male ; the mouth 

 is horizontal upon its anterior half and slightly oblique posteriorly. The teeth are moderate 

 in development, very slightly larger on the tongue than on the dentary ; the rest of them are 

 pretty nearly equal, except those on the maxillary, which are quite exiguous. The posterior 

 free extremity of the maxillary extends to a vertical line drawn posteriorly to the orbit. The 

 eye is large and sub-circular, its diameter being contained about five times in the length of the 

 sides of the head, exactly once in advance of the anterior rim of the orbit. The opercle is much 

 narrower above than below and overlaps considerably the subopercle, which is well developed. 

 There are eleven branchiostegal rays on either side, one more than in the male. 



The greatest depth of the body, taken in advance the dorsal fin, is equal to the fifth of the 

 entire length ; and the least depth on the peduncle of the tail is less than the half of the greatest. 



