364 UNGULATA. 



of the Cavicornia, comprising the Oxen, Sheep, Goats, and 

 Antelopes. This family includes the most typical Eumi- 

 nants, and those of most importance to man. The upper 

 jaw in all the Cavicornia is wholly destitute of incisors and 

 canines, the place of which is taken by the hardened gum, 

 against which the lower incisors bite. There are six in- 

 cisors and two canines in the lower jaw, placed in a con- 

 tinuous series, and the molars are separated by a wide gap 

 from the canines. There are six molars on each side of 

 each jaw. Both sexes have horns, or the males only may 

 be horned, but in either case these appendages are very dif- 

 ferent to the " antlers " of the Cervida^.. The horns, namely, 

 are persistent, instead of being deciduous, and each consists 

 of a bony process of the frontal bone — or " horn-core " — 

 covered by a sheath of horn. In the Prong-buck (Antilo- 

 capra), however, the sheath of the horn is slied annually. 

 The feet are cleft, but are mostly furnished with accessory 

 hoofs placed on the back of the foot. 



The Cavicornia comprise the three families of the Antilo- 

 pidce, Ovidm, and Bovidce. The Antelopes form an extremely 

 large section, with very many species. They are character- 

 ised by their slender, deer-like form, their long and slender 

 legs, and their simple, cylindrical, annulated, or t-s\nsted 

 horns, which are somethnes confined to the males, but often 

 occur in the females as well. 



The above definition will not apply in all points to some 

 singular extinct forms usually referred to the Antilojjidce, 

 nor to one aberrant existing form — viz., the Prong-buck 

 (Antilope ficrcifer, or Antilocapra Americana). This extra- 

 ordinary and unique species differs from the typical Ante- 

 lopes in having no lateral toes, in having horns which 

 have a snag in front, and in the fact that the outer sheath 

 of the horn is deciduous, and not permanent. For these 

 reasons, it has been proposed to place the Prong-buck in a 

 separate family (the Antilocapridce) ; but it is more con- 

 venient here to consider it as an aberrant member of the 

 Antilopidcc. 



The Antelopes do not appear to have a high antiquity, 

 the oldest known forms being from the Upper Miocene of 



