FISHES—CYPRINIDAE—CLIOLA YIGILAX. 
257 
1. CLIOLA YIGILAX, Grd. 
Spec. Char. —Head constituting the fifth of the total length. Eye moderate, its diameter entering about three times and a 
half in the length of the side of the head. Posterior extremity of maxillar bone not extending quite as far back as a vertical line 
drawn at the anterior rim of the orbit. Anterior margin of dorsal fin equidistant between the extremity of the snout and the 
insertion of the caudal. Yellowish brown, with a blackish streak along the lateral line, a black spot at the base of the caudal, 
and one at the anterior edge of the dorsal. 
Svn. — Ceratichthys vigilax, B. & G. in Proc. Acad. Nat. Sc. Philad. VI, 1853, 391. 
Leuciscus vigilax, B. & G. in Marcy’s Expl. of Red Riv. of La. 1853, 248, Zool. pi. xxiv, figs. 1—4. 
Cliola vigilax, Grd. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 192. 
The body is sub-fusiform, compressed. The bead forms one-fifth of the entire length ; it is 
contained three times in the length of the body : the caudal fin being about one-fifth of the entire 
length. The head itself has the shape of a truncated cone. The eyes are sub-elliptical, their 
longitudinal diameter being contained three times and a half in the length of the sides of the 
head. The mouth is rather small, its angle not extending to a vertical line drawn at the 
anterior rim of the orbit. The opercle is considerably large and almost trapezoidal in shape. 
The subopercle and preopercle are comparatively small. The isthmus beneath is about three- 
tenths of an inch wide. 
The dorsal fin is longer than high, and is composed of nine rays, bifurcated from about their 
middle, some of the middle rays showing another subdivision upon their extremity. The caudal 
fin is furcated, its angles being acute. It contains eighteen well developed rays, and several 
rudimentary ones above and below ; the central ones bifurcate twice. The base of the caudal 
fin is considerably broader (higher) than the central portion of the peduncle of the tail. The 
anal fin is situated behind the dorsal, is higher than long, suh-trapezoidal, and composed of 
eight bifurcated rays ; the central ones subdivided towards their extremity. The ventrals are 
inserted somewhat behind the anterior margin of the dorsal ; they are rather slender, posteriorly 
rounded, composed of eight bifurcated rays, the middle ones subdivided towards their extremity; 
and when bent backwards the fin does not reach quite to the vent, which is situated immediately 
in advance of the anterior margin of the anal fin. The pectorals are slender ; when bent back¬ 
wards they do not reach the insertion of the ventrals. They are composed of fourteen bifurcated 
rays, the central ones subdividing upon their last third. Formula : 
D 9 ; A 8 ; C 3, 1, 8, 8, 1, 3 ; Y 8 ; P 14. 
The scales are proportionally large, somewhat higher than long, rounded at both extremities, 
more abruptly anteriorly, with radiating furrows upon their posterior half. There are sixteen 
rows of them on the line of greatest depth, and eight on the peduncle of the tail. The lateral 
line, in which thirty-eight to forty scales may he counted, runs along the middle of the flank, 
slightly bent downwards on the abdomen. 
The ground color is yellowish brown ; a blackish stripe composed of crowded dots follows the 
lateral line on the sides. A black spot may be seen at the base of the caudal, and one also at 
the anterior margin of the dorsal. 
List of specimens. 
Catal. 
No. 
Cor’g. No 
of teeth. 
No. of 
spec. 
Locality. 
When col¬ 
lected. 
Whence obtained 
Nature of 
specimen. 
Collected by— 
31 
2645 
i 
Otter creek, trib. of Red 
river, Arkansas. 
1852 
Capts. R. B. Marcy 
and McClelland. 
Alcoholic. 
Sapt.G B. McClelland 
33 a 
