262 
U. S. P. E E. EXP. AND 8UEYEYS-ZOOLOGY—GENEEAL EEPOET. 
The general appearance is the same as that of the preceding species. The snout is more conical, 
the mouth larger and more deeply cleft. The head constitutes likewise the fifth of the total 
length, which measures three inches and a half. The eye is well developed, sub-circular ; its 
diameter entering a little over three times in the length of the side of the head. 
The anal fin is deeper than long, its anterior margin being nearer the tip of the lower lobe of 
the caudal than the extremity of the snout. The dorsal is higher than in the preceding species. 
The pectorals being slender. The formula of the fins reads thus: 
D 2, 8 + 1 ; A 2, 8 + 1 ; C 6, 1, 9, 8, 1, 7 ; V 1, 8 ; P 15. 
The scales are large, deeper than long, sub-elliptical on the back, elsewhere anteriorly 
sub truncated and posteriorly rounded, with radiating grooves upon the posterior section only. 
There are but nine rows of scales, five above and three below the lateral line. 
The color is reddish brown, lighter beneath than above ; the middle of the flanks appearing 
as though streaked with silver ; the fins being unicolor, of a light yellow or straw tint. 
References to the figures. —Plate LYII, fig. 1, represents Alburnops shumardi, size of life. 
Fig. 2, a scale from the dorsal region. Fig. 3, a scale from the lateral line. Fig. 4, a scale 
from the abdominal region. 
List of specimens. 
Catal. 
No. 
Cor. No. 
of teeth. 
No. of 
spec. 
Age. 
Locality. 
When 
collected. 
Whence obtained. 
Nature of 
specimen. 
Collected by— 
68 
2675 
2 
Adult. 
Arkansas river, near 
Fort Smith. 
1853 
Lt. A. W. Whipple. 
Alcoholic . 
Dr. Geo. G. Shumard. 
3. ALBURNOPS 1LLECEBROSUS, Grd. 
Plate LVII, Figs. 5—8. 
Sped. Char. —Head contained five times and a half in the total length. Snout sub-conical; lower jaw shorter than the upper 
Posterior extremity of maxillar bone extending to a vertical line drawn in front of the orbit. Anterior margin of dorsal fin 
equidistant between the extremity of the snout and the insertion of the caudal. Insertion of ventrals situated somewhat in 
advance of the anterior edge of the dorsal; their tips reaching the vent. Eeddish brown, lighter beneath than above, with the 
middle of the flanks silvery; fins unicolor. 
Syn. —Alburnops illecebrosus, Gun. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 194. 
This is perhaps the most graceful of the three species so far known of this genus. The snout 
is less prominent than in A. shumardi , and more so than in A. hlennius. The eyes are larger 
than in either of the two species just alluded to ; their diameter entering about three times in 
the length of the side of the head. The head is contained five times and a half in the total 
length, which averages about three inches. 
The dorsal fin is much higher than long, and not well represented on the accompanying 
figure: it being much lower posteriorly, hence its upper edge a good deal more inclined 
backwards. The anal is, as usual, deeper than long ; its anterior margin being equidistant 
between the isthmus and the tip of the inferior lobe of the caudal. 
The scales are large, much deeper than long, and proportionally more so than in the fore¬ 
going two species. Their anterior margin is sub-truncated, the posterior edge being rounded, 
with radiating grooves upon the latter section only. There are ten rows of scales as in A. 
hlennius. 
