NORTH AMERICA AND THE WEST INDIES 323 



World, they differ in that the horn sheaths are forked instead 

 of simple and are shed and renewed annually instead of being 

 permanently retained. In many of the fossil forms, the bony 

 core of the horns was forked to correspond to the forked sheath, 

 but in the living species this front branch of the horn core is 

 represented by a slight bulge only. In some of the extinct 

 species the horns showed a twisted core recalling that of the 

 Old World bushbucks. Only a single species is known to have 

 lived down to the Recent period, but smaller forms, such as 

 Capromeryx, with a forked horn core, must have persisted to no 

 very distant period, and have left their remains in the tar pits 

 of Rancho La Brea, California, and elsewhere in the Southwest. 

 Four races of the pronghorn have been described, but they 

 differ in such slight characters that they may be best con- 

 sidered together. 



PRONGHORN ANTELOPE; PLAINS PRONGHORN 

 ANTILOCAPRA AMERICANA AMERICANA (Ord) 



Antilope americana Ord, Guthrie's Geography, 2d Amer. ed., vol. 2, pp. 292, 308, 1815 



("Plains and highlands of the Missour^"). 

 FIGS.: Stone and Cram, 1902, pi. facing p. 64 (photographs); Nelson, 1916, p. 451, 



upper fig. (col.); 1925, pis. 1-6 (photographs and habitat). 



MEXICAN PRONGHORN 

 ANTILOCAPRA AMERICANA MEXICANA Merriam 



Antilocapra americana mexicana Merriam, Proc. Biol. Soc. Washington, vol. 14, p. 31, 

 Apr. 5, 1901 ("Sierra en Media, Chihuahua, Mexico"). 



OREGON PRONGHORN 

 ANTILOCAPRA AMERICANA OREGONA V. Bailey 



Antilocapra americana oregona V. Bailey, Proc. Biol. Soc. Washington, vol. 45, p. 45, 

 Apr. 2, 1932 ("Hart Mountain (Warner Mts.), Oregon"). 



LOWER CALIFORNIA PRONGHORN 

 ANTILOCAPRA AMERICANA PENINSULARIS Nelson 



Antilocapra americana peninsularis Nelson, Proc. Biol. Soc. Washington, vol. 25, p. 

 107, 1912 ("Forty-five miles south of Calmalli, Lower California"). 



Light of body and limb, the pronghorn stands about 34 to 

 36 inches at the shoulder, with a total length of about 54 inches 

 in adult males, females slightly less (Anthony). The forehead, 



