PISHES—CYPRINIDAE—MOXOSTOMA CLAYIFORMIS. 
219 
List of specimens. 
Catal. 
No. 
Corr. No. 
of teeth. 
No. of 
spec. 
Age. 
Locality. 
When 
collected. 
Whence obtained. 
Nature of 
specimen. 
Collected by— 
178 
2742 
i 
Adult. 
Milk river, affluent of 
1853 
Gov. 1.1. Stevens... 
Alcoholic. 
Dr. Geo. Suckley... 
Upper Missouri. 
178 
2742 
12 
Young 
1853 
179 
1 
Fort Pierre, Neb. 
1854 
MOXOSTOMA, Rafin 
Gen. Char. —The body is elongated, compressed ; the head small; the mouth small also, opening obliquely forwards and 
downwards. The lips are small and transversely ridged; the inferior one being slightly bilobed. The anterior margin of 
the dorsal is situated in advance of the insertion of the ventrals. The dorsal fin itself is either higher than long, or else its 
length is equal to its height, varying somewhat according to the sexes, as well as the anal, which is, however, always deeper 
than long. The shaft of the pharyngeal bones constitutes a very open curve, the convex margin of which is regular and entire. 
The teeth themselves are very much compressed, strongly curved inwardly, and much larger inferiorly than superiorly. 
Svn.— Moxostoma, Rafin. Ichth. Ohiens. 1820, 54—Agass. in Amer. Journ. of Sc. 2d series, XIX, 1855, 84.— Grd. in 
Proc. Acad. Nat. Sc. Philad. VIII, 185(1, 170. 
The most striking character by which this genus may be recognized amongst the other 
cyprinoids, it must be conceded, is the absence of that lateral line possessed by almost every 
fish. In other respects it resembles Ptychostomus and Catostomus, from which it, however, 
differs by the structure of the pharyngeal bones and the teeth. 
The scales are longer than deep, and so very much imbricated that they appear deeper than 
long. They are furrowed upon their anterior and posterior sections ; the grooves being much 
more numerous posteriorly than anteriorly, giving often the body a striated appearance. 
MOXOSTOMA CLAYIFORMIS, Grd. 
Plate XLYIII, Figs. 5—9. 
Spec. Char. —Head constituting the fifth of the total length. Mouth rather small ; lips conspicuously plaited or ridged. 
Eye moderate sized, circular ; its diameter contained about four times in the length of the side of the head. Anterior margin 
of dorsal fin nearer the snout than the base of the caudal. Ventrals inserted opposite the fifth ray of the dorsal. Caudal fin 
posteriorly concave. Anal fin narrow and deep. Scales much longer than deep, very much imbricated. Yellowish brown, 
rather dusky along the dorsal region. 
Syn.— Moxostoma claviformis, Grd. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 171. 
Its general outline has a club-shaped appearance, a trait, though more or less generical, is 
especially characteristic here. The largest specimens which we have examined are four inches 
in total length, and in all prohability not very immature. The greatest depth, taken across 
the pectoral region, is contained four times and a half in the total length, in which the head 
enters five times. The eye is circular and moderate in development, contained a little over 
four times in the length of the side of the head. The upper margin of the dorsal fin is sub- 
convex ; its anterior margin is nearer the tip of the snout than the insertion of the caudal fin. 
The caudal is concave posteriorly; the anal narrow and deep. The ventrals are inserted opposite 
the fifth ray (or third developed one) of the dorsal, and their tips do not extend as far back as 
the tips of the posterior rays of the dorsal fin when bent along the dorsal line. 
