BOVID^E 9 



the direction of the crescents in the lower jaw is the reverse 

 of that in the upper. The metacarpals of the main pair of 

 toes in the fore-foot and the corresponding metatarsals in 

 the hind -foot respectively unite into a cannon-bone ; while 

 the metacarpals and metatarsals of the small lateral toes 

 (which may be absent) are never complete, but represented 

 either by their upper or lower ends (fig. 1 B). The pair of 

 condyles in which each cannon-bone terminates inferior! y are 

 parallel to one another and severally carry a pulley -like ridge. 

 The navicular and cuboid bones of the tarsus are united. 

 With a few exceptions, either horns or antlers are developed, 

 at least in the males. The stomach has four complete 

 cavities (fig. 7) ; and the placenta is of the cotyledonous 

 type. 



FAMILY I. BOVHLE. 



The cranial appendages take the form of hollow, 

 permanent (i.e. non-deciduous) sheaths of horn supported on 

 bony cores, containing numerous air-cells, which arise from 

 the frontal bones of the skull; such appendages being 

 common in the majority of the genera to the two sexes, but 

 in others restricted to the male. Upper canines wanting; 

 lower canines with simple crowns (fig. 4 A) ; cheek- teeth 

 frequently hypsodont. Lateral toes always incomplete, 

 being sometimes entirely absent, but more generally repre- 

 sented either by the hoofs alone, or by these and vestiges of 

 the skeleton, the phalanges being replaced by irregular bony 

 nodules ; lower ends of lateral metacarpals invariably absent. 

 Gall-bladder nearly always present. Placenta with numerous 

 cotyledons. 



The horns of the Bovidoe vary in the direction of their 

 twist ; the right horn in some cases forming a right-handed 

 spiral, and the left horn a left-handed spiral, whereas in 

 other instances the reverse condition obtains. 



Taking a screw, or corkscrew, as a right-handed spiral, 

 the same spiral obtains in the right horn of the extinct 

 antelopes of the genus Oioceros ; the left horn forming a 

 left-handed spiral. The same condition obtains in the horns 

 of cattle, and the more typical sheep, both wild and tame, in 



