224 
U. S. P. R. R. ESP. AND SURVEYS-ZOOLOGY-GENERAL REPORT. 
1. CATOSTOMUS OCCIDENTALIS, Ayres. 
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 occidentalism 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 rounde , anteriorly 
obtuse angled and laterally linear. Numerous radiating grooves may he observed upon the 
anterior and posterior sections. 
List of specimens. 
Catal. 
No. 
Corresponding 
No. of teeth. 
No. of 
spec. 
Age. 
Locality. 
When 
collected. 
Whence obtained. 
Nature of 
specimen. 
Collected by— 
241 
2794 
2 
Adult. 
San Francisco, Cal. 
1855 
Lt. R S. Williamson 
Alcoholic. 
Dr. John S. Newberry. 
2. CATOSTOMUS LABIATUS, Ayres. 
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. —Catostomns labia/us, 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 ; V 1, 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 ; 
