172 



BULLETIN 56, UNITED STATES NATIONAL MUSEUM. 



Type-locality. — Fort Clark, Kinney County. Texas. (Type, skull 



ami skin. No. 84794, I'.S.X.M.) 



Geographical range. — Inhabits the Rio Grande region of Texas. 

 extending south through Mexico as far as San Luis Potosi. 



General characters. — Size small; ears relatively small, with black 

 on cdo'cs and tip; horns small and strongly incurved; limbs rela- 

 tively short; molar and premolar teeth very large; general color 

 pale; coat line and long. 



Color. — In the type, which is in complete winter coat, the upper 

 surface is superficially a pepper-and-salt mixture of black, yellowish 

 white, and gray. A distinctly blackish area begins anteriorly on the 

 crown, between the horns and ears, and extends posteriorly almost to 

 the root of the tail. The color gradually pales to light yellowish 

 ash on the sides. All of the hairs of the upper surface are white at 

 extreme base, plumbeous ash in the middle, black apically, and sub- 

 terminally ringed with yellowish white, these whitish annul] increas- 

 ing in width from the vertebral area downward. Under surface 



Fig. 9.— Onocon.Ei's americanus. (Cat.No.912, U.S.N.M., Virginia.) a, skci.i.: u, a«ditalregion 



pure white on the axillae, inner surface of thighs, and abdomen: 

 fuliginous on the chest. Tail white below, black above, the black of 

 the upper surface much obscured by broad yellowish brown subter- 

 minal annuli to the hairs. Head, with naked nose-pad, and front of 

 under lip. plumbeous black. Iris yellowish hazel. Upper jaw white 

 anteriorly, next to the naked inutile, becoming light ash farther back, 

 with an intervening area of black, which latter forms a triangular 

 area, with its base applied to the posterior margin of the nostril and 

 its apex crossing the middle of the upper lip and extending over the 

 under jaw to form a small black -pot behind the pure white chin. 

 Throat white, mixed with ash where the basal coloring of the hair is 

 exposed, between the white tips. Upper side of head black, much 

 obscured on the forehead by dirty white and reddish subterminal 

 annuli. Orbits and base of ear externally whitish. Concavity of 

 ear densely clothed with long white hair: convexity tipped and 

 bordered by black, except at base anteriorly, the black inclosing an 

 area of pepper-and-salt gray; base of ear posteriorly clear ash gray. 



