220 
U. S. P. E E. EXP. AND SUEVEYS—ZOOLOGY—GENEEAL EE POET. 
D 13 ; A 10-; C 4, 1, 8, 8, 1, 3 ; V 9 ; P 15. 
The scales are sub-elliptical in general shape, presenting no grooves upon their lateral 
sections, but few upon the anterior section, and numerous posteriorly upon that section of the 
scale that is exposed. 
The color is yellowish brown, lighter beneath than above, where a dusky hue sometimes 
prevails. • The sides and inferior surface of the head are likewise rather yellowish olive. 
References to the figures. —Plate XLVIII, fig. 5, represents Moxostoma claviformis, size of 
life. Fig. 6, an outline from above. Fig. 7, a section of the body, taken across the line of 
greatest depth. Fig. 8, a scale from the dorsal, region. Fig. 9, a scale from the abdominal 
region. 
List of specimens. 
Catal. 
No. of 
Age. 
Locality. 
When 
Whence obtained. 
Orig. 
Nature of 
Collected by— 
No. 
spec. 
collected. 
No. 
specimen. 
165 
5 
Adult & 
Coal Creek, tributary of south 
1853 
Lt. A. W. Whipple 
VI 
Alcoholic. 
H. B. Mollhausen. 
Young. 
fork of Canadian river. 
PTYCHOSTOMDS, Agass. 
Gen. Char. —Head short and stout. Mouth protractile and directed downwards. Transverse folds or ridges upon the lips. 
Inferior lip but slightly lobed. Body sub-fusiform, elongated, covered with well developed scales, as large anteriorly as 
posteriorly. 
Syn. — Ptychostomvs, Agass. in Amer. Journ. of Sc. 2d series, XIX, 1855, 88.—Grd. in Proc. Acad. Nat. Sc. Philad. 
VIII, 1856, 172. 
Resembles- Gatostomus in its general appearance. The height of the dorsal may be either 
equal to its length or somewhat higher than long. The wing-like expansions of the pharyngeals 
is anything but characteristic of this genus. The conspicuous lateral line will at once dis¬ 
tinguish it from Moxostoma. The mouth is much more protractile, and directed more down¬ 
wards than in the latter mentioned genus. 
PTYCHOSTOMUS HAYDENI, Grd. 
Plate XLIX, Figs. 1—4. 
Spec. Char. —Body sub-fusiform. Head contained five times and a half in the total length. Eye sub-circular, moderate 
sized; its diameter entering five times in the length of the side of the head. Dorsal fin higher than long ; its anterior margin 
being much nearer the tip of the snout than the insertion of the caudal. The latter is furcated. Insertion of ventral fins 
situated opposite the middle of the dorsal. Anal much deeper than broad. Pectoral moderate sized. Scales longer than 
deep, furrowed upon their anterior and posterior sections. 
Syn. —Ptychostomus haydeni, Grd. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 172. 
The head is contained five times and a half in the total length. The body is sub-fusiform, 
very regular in its outline. The eye is sub-circular and moderate in its development; ifcs 
diameter being contained five times in the length of the side of the head. The opercle is 
largely developed, whilst the sub-opercle is small, a character which is more or less generical. 
The dorsal fin is somewhat higher than long ; its upper margin is sub-concave, its anterior 
margin being nearer the tip of the snout than the base of the caudal. The caudal is furcated. 
