228 
U„ S. P. R. R. EXP. AND SURVEYS—ZOOLOGY—GENERAL REPORT. 
in advance of the orbit. The fins are of hut moderate development; the insertion of the 
ventrals is situated a little posteriorly to the anterior margin of the dorsal. The formula of the 
rays read as follows: 
D 2, 8; A 2, 8 ; C 8, 1, 9, 8, 1, 7 ; V 8 ; P 14. 
The scales are large, deeper than long/with radiating furrows upon their posterior section 
only; the lateral line following the middle of the flanks. 
The dorsal region is "blackish brown ; a black streak is observed along the flanks, just above 
the lateral line, extending from a black spot at the base of the caudal, to the extremity of 
the snout. The inferior region is yellowish white ; minute black dots being spread all over the 
body. 
List of specimens. 
Catal. 
No. 
Cor. No. 
of teeth. 
No. of 
epee. 
Sex. 
Locality. 
When col¬ 
lected. 
Whence obtained. 
Nature of 
specimen. 
Collected by— 
45 
2658 
12 
<? Q 
Head waters of Rio Pecos... 
1854 
Capt. John Pope. 
Alcoholic 
Capt. Pope_ 
2. DIONDA PAPALIS, Gird. 
Spec. Char. —Body anteriorly thickish, sub-fusiform. Head sub-conical, abbreviated, forming a little more than the fifth of 
the total length. Eye sub-circular. Gape of the mouth slightly arched; its angle not reaching a vertical line drawn in advance 
of the orbit. Caudal fin entering five times and a half in the entire length. Insertion of ventrals situated under the anterior 
margin of the dorsal. Scales moderate, deeper than long. 
Syn. —Dionda papulis, Grd. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 178. 
The head in this species is rather small, but rounded off upon the snout; it forms a little 
more than the fifth of the entire length. The eye is sub-circular ; its diameter entering four 
times in the length of the side of the head. The body is thickish anteriorly, sub-cylindrical, 
tapering posteriorly. The dorsal and anal fins are proportionally well developed. The caudal 
is furcated ; the ventrals are inserted under the anterior margin of the dorsal. The scales are 
moderate sized, deeper than long. The coloration has been altered to a uniform black subse¬ 
quently to its immersion in alcohol with sundry other specimens. 
List of specimens. 
Catal. 
Cor. No. 
No. of 
Locality. When col¬ 
Whence obtained. 
Nature of 
Collected by— 
No. 
of teeth. 
spec. 
lected. 
specimen. , 
39 
2653 
2 
Delaware creek, trib. of Rio Pecos.. 1854 
Capt. John Pope. 
Alcoholic . 
Capt. Pope. 
3. DIONDA PLUMBEA, Grd. 
Plate LII, Figs. 21—25. 
Spec. Char. —Body elongated, sub-fusiform, compressed. Head sub-pyramidal, anteriorly blunt, constituting the fifth of the 
total length. Gape of mouth slightly arched, its angle not extending as far as a vertical line drawn in front of the orbit. The 
eye is large, sub-circular. The caudal fin enters about six times in the total length. Insertion of ventrals situated slightly back¬ 
wards of the anterior margin of the dorsal. Scales moderate sized, deeper than long. Greyish brown above ; whitish or 
yellowish beneath, with a black spot at the base of the caudal. 
Syn. —Dionda plumbea, Grd. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 178. 
