202 LAND MAMMALS IN THE WESTERN HEMISPHERE 



by two genera, now extinct, one of which (^Platygonus) had 

 crested grinding teeth and much longer legs than the modern 

 peccaries. Another indigenous group, strange as that may seem, 

 is the suborder (Tylopoda) of the camels and llamas, both of 

 which are represented in the North American Pleistocene, the 

 descendants of a very long American ancestry. Some of 

 these tylopodans were far larger than existing forms, and at 

 least one species extended its range to Alaska. 



Of ultimately Old World origin, but through a considerable 

 line of descent in America, were the typically American deer 

 (Odocoileus) of which the Virginian and Black-tailed species 

 are familiar modern instances. Whether or not the Old 

 World types, the Caribou (Rangifer) and Wapiti (Cerms 

 canadensis) had reached the western hemisphere, is a matter 

 of some doubt ; if present at all, they must have been com- 

 paratively rare. The Moose (Alee americanus), on the other 

 hand, had already appeared, but seems to have been confined 

 to the western half of the continent, its presence in the east 

 being questionable. The mistakenly named ' ' Rocky Mountain 

 Goat" (Oreamnos montanus), which is an antelope of the 

 chamois group, was an apparently late arrival in the Pleistocene, 

 while the peculiar Prong-Buck (Antilocapra americana), which 

 is very different from any of the Old World antelopes, was 

 present in the early part of the epoch. The descent of this 

 remarkable animal is still a problem, but not improbably it 

 was derived from the "deer-antelopes" of the Miocene and 

 Pliocene, the last of which occurred in the early Pleistocene. 

 Mr. Gidley has announced the surprising discovery in Mary- 

 land of a large antelope hardly distinguishable from the 

 African Eland (Taiirotragus) . Other late arrivals from the 

 Old World were several forms allied to the existing Musk Ox 

 (Ovibos), at least two genera of which ('\Preptoceras and '\Eucera- 

 therium) have been found in California. A surprising number 

 of species of Bison occurred in the Pleistocene, no less than 

 seven of which are recognized as distinct, ranging from Florida 



