224 



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



1. CATOSTOMUS OCCIDENTAL-IS, Ay res. 



SPEC. CHAK. Head constituting less than the fifth of the total length. Eye of medium size ; mouth rather small ; labial 

 papillae small and rather inconspicuous. Isthmus very broad. Dorsal fin longer than high ; its anterior margin nearly equi 

 distant between the extremity of the snout and the insertion of the caudal. The anterior margin of the ventrals corresponds to 

 the middle of the dorsal, and is nearer the extremity of the snout than the tip of the lower lobe of the caudal. Posterior 

 extremity of anal fin reaching the rudimentary rays at the inferior lobe of the caudal, which is moderately emarginated. 

 Scales moderate. Upper regions of a greyish lead tint ; beneath of a soiled yellow or white. 



SYN. Catostomus occidentalis, AYRES, in Proc^Cal. Acad. Nat. Sc. I, 1854, 18. AGASS. in Amer. Journ. of Sc. 2d Ser .XIX, 

 1854, 94. GRD. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 174. 



This species has been described under the same name almost simultaneously by two different 

 naturalists, one in the west, the other in the east. It is brought to the market of San Francisco, 

 and said to be quite common in the Sacramento and San Joaquin rivers. The largest specimen 

 we have examined measures twelve inches and a half ; we have counted the rays of the fins as 

 follow : 



D 2, 13 + 1 ; A 2, 8 ; C 7, 1, 8, 8, 1, 6 ; V 1, 11 ; P 18. 



The scales are moderate sized, somewhat longer than deep, posteriorly rounded, anteriorly 

 obtuse angled and laterally linear. Numerous radiating grooves may be observed upon the 

 anterior and posterior sections. 



List of specimens. 



2. CATOSTOMUS LABIATUS, Ay res. 



SPEC. CHAR. Head constituting the fifth of the total length. Eye small. Mouth of medium size ; labial papillae conspicuously 

 developed. Dorsal fin higher than long ; its anterior margin nearer the extremity of the snout than the base of the caudal. 

 Pectoral fins quite elongated and well developed. Insertion of ventrals situated opposite the posterior third of the base of the 

 dorsal, and nearer the extremity of the snout than the tip of the lower lobe of the caudal. Posterior extremity of anal fin 

 extending to the rudimentary rays of the caudal. The scales are large. The upper regions are black, the lower half of the 

 sides clouded black and yellow, whilst the belly and the inferior surface of the head are yellow, almost unicolor. 



SYN. Oatostamus labiaius, AYRES, in Proc. Cal. Acad. Nat. Sc. I, 1855, 32. GRD. in Proc. Acad. Nat. Sc. Philad. VIII, 

 1856, 175. 



Is easily distinguished from the preceding species by its dorsal fin, which is higher than long, 

 its larger mouth, larger lips, and more conspicuous labial papillae. The eye is smaller, since its 

 diameter enters somewhat over seven times in the length of the head. We count the rays as 

 follow : 



D 2, 11 + 1 ; A 1, 8 ; C 4, 1, 9, 8, 1, 5 ; VI, 10 ; P 17. 



The scales are large, deeply imbricated, longer than deep, sub-elliptical in their outline, laterally 

 almost linear, with numerous radiating grooves upon their anterior and posterior sections, 

 extending even sometimes to the lateral sections with a proclivity of being directed towards the 

 anterior margin. 



The color is dark blackish brown above, becoming lighter on the sides, which are blotched ; 



