FISHES—CYPRINIDAE —LUXILUS SECO. 
281 
Numerous immature specimens of this species were collected, together with one about five 
inches in length. The body is very much compressed, deepest upon the middle of its length, 
and tapering towards both extremities ; the greatest depth being contained four times in the 
total length. The snout is sub-conical, the head rather small, and forming about the fifth of 
the total length, it being slightly depressed above the eyes. The anterior margin of the dorsal 
fin is nearer the base of the caudal than the extremity of the snout. The caudal is furcated. 
Both the anal and dorsal are anteriorly elevated. The insertion of the ventrals is situated in 
advance of the anteriqf margin of the dorsal. The pectorals and the ventrals are of medium 
development. 
D 2, 10 + 1 ; A 2, 11 + 1; C 8, 1, 9, 8, 1, 9 ; Y 10 ; P 15. 
The scales are of medium size, anteriorly sub-truncated, elsewhere rounded, and provided 
with radiating furrows upon their posterior section only. The lateral line is bent downwards 
upon the abdomen, constituting a curve, the convexity of which is nearer the ventral than to 
the dorsal outline. 
The color of the upper region is dark greyish brown, the middle of the flanks being silvery, 
and the belly yellowish, speckled with grey. The fins are unicolor, of a greyish olive tint. 
List of specimens. 
Catal. 
No. 
Cor. No. 
of teeth. 
No. of 
specs. 
Age. 
Locality. 
When 
collected. 
Whence obtained. 
Nature of 
specimen. 
Collected by— 
57 
10 
Young. 
Pose, or O-co-ya creek, Cal. 
1853 
Lt. R. S.Williamson. 
Alcoholic. 
Dr. A. L. Heermann. 
58 
10 
•..do.•• 
Four creeks, Tulare valley. 
1853 
Cal. 
59 
2667 
2 
Adult. 
1853 
.do. 
2. LUXILUS SECO, Grd. 
Spec. Char. —Body rather elongated, sub-fusiform in its outlines. Head small, contained five times and a half in the total 
length. Snout sub-conical, rather abbreviated. Gape of the mouth slightly oblique ; posterior extremity of maxillary 
extending to a vertical line intersecting the anterior nostril. Eye very large, sub-circular ; its diameter entering about three 
times in the length of the side of the head. Anterior margin of dorsal fin equidistant between the extremity of the snout and 
the fork of the caudal. Vertical fins moderately developed ; pectorals and ventrals rather small. Light reddish brown above ; 
yellowish white beneath. Fins light olive. 
Syn. —Luxilus seco, Grd. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 203. 
The body is deeper than in L. leptosomus, figured and described in the Report of the United 
States and Mexican Boundary Commission. Its depth is equal to the fourth of the total length. 
The head is contained five times and a half in the same dimension. The eye is very large ; 
its diameter entering three times only in the length of the side of the head. The mouth is 
small. The dorsal is much higher than long, superiorly sub-convex, whilst the anal is nearly 
as long as deep and interiorly sub-concave. The anterior margin of the latter is somewhat 
nearer the tip of the lower lobe of the caudal fin than the isthmus. The caudal is longer than 
the head. The origin of the ventrals is nearer the extremity of the snout than the insertion of 
the caudal; their external edge is sub-convex, and, when extended backwards, their tips scarcely 
reach the vent. The pectorals are sub-ovate and far from reaching the insertion of the ventrals. 
D 2, 8 + 1; A 2, 14 + 1; C.5, 1, 9, 8,1,6; Y 9 ; P 14. 
The scales are of moderate development, and the lateral line very much deflexed upon the 
abdomen. 
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