64 



U. S. p. R. R. EXP. AND SURVEYS — ZOOLOGY — GENERAL REPORT. 



evenly as far as the insertion of the caudal ; thehase of the anal, as usual, ending before that of 

 its opposite fin. The rays are all undivided. 



Br. VI— VI ; D IX, 18 ; A U or 15 ; C 3, 1, 5, 4, 1, 2 ; V I, 4 ; P 15. 



The skin is smooth all over, except on a space immediately behind the pectorals, where the 

 characteristic prickles of the genus may be seen, of a minuteness to deceive a superficial observer. 

 The lateral line runs straightway from the upper part of the thoracic arch to opposite the last 

 ray of the second dorsal, where it makes a sudden fall to reach the middle of the peduncle of 

 the tail ; hence straight again towards the base of the caudal. Along the flanks it is much 

 nearer the dorsal than the abdominal outlines. Large mucous pores are observed along the 

 inferior surface of the dentarif s and along the lateral line also. 



The ground color of the upper regions is of a reddish brown, dotted or maculated, and some- 

 times even transversally banded with black. Beneath, unicolor, whitish, or dull yellowish. 

 Fins blackish brown ; caudal and pectorals variegated with black ; external edge of ventrals 

 whitish ; upper margin of dorsal yellowish. 



The species inhabits the fresh waters of California. 



List of specimens. 



3. COTTOPSIS PARVUS, Grd. 



Spec. Char. — Origin of first dorsal situated posteriorly to the insertion of the upper ray of pectorals. First ray of anal 

 placed under the fourth of second dorsal. Extremities of pectorals extending to the anterior margin of the anal. Skin 

 generally prickly ; lateral line slightly deflected upon the peduncle of the tail. Olivaceous, maculated with blackish. 



Syn. Cottopm partna, Gun. Proc, Acad. Nat. Sc. Philad. VII, 1854, 144. 



This species may readily be distinguished from C. gulosus by a body more fusiform and a head 

 more depressed, in which particulars it resembles C. asper most. The head forms exactly the 

 fourth of the total length ; its upper surface is gradually sloi)ing towards the snout, which is 

 obtusely rounded. The jaws are equal in length, and the cleft of the mouth oblique upwards ; 

 the posterior extremity of the maxillary reaching a vertical line intersecting the pupil nearly 

 through its middle. The eye is of medium size, elliptical in shape ; its horizontal and greatest 

 diameter entering nearly five times in the length of the side of the head. The preopercular 

 spines are quite inconspicuous. 



The origin of the first dorsal is situated a little backwards of the insertion of the upper ray 

 of the pectorals ; its upper margin forms a depressed convexity ; it is connected by a membrane 

 to the second dorsal. The rays are eight in number, inserted upon a base entering twice and a 

 half in the length of the second dorsal. The latter is composed of twenty or twenty-one 

 undivided rays, the tips of the posterior ones not reaching the insertion of the caudal. It is 



