176 THE MAMMALIA. 



animal belonging to the genus Bos (Fig. 26). Here 

 the parietals are pushed completely back from the 

 top, or all but a small portion, to the abrupt 

 incline at the back of the head. From a front 

 view, or looked at from above, they cannot be 

 seen at all. On the other hand, the frontal 

 bones (Fig. 26) form great plate- shaped cover- 



FIG. 27. Skull of the Gazelle (Antelope arabica). 

 *, Parietal ; /, frontal bone ; z, mid jawbone. 



ings to the forehead, and the bony processes rise 

 upon their outer edge. As compared with the 

 skull of an antelope (Fig. 27), the skull of our 

 domestic ox has reached the extreme of a formation 

 which is still repeated pretty perfectly in the 

 individual development of the calf to the cow. It 

 consists in this : that in the calf the skull is still 



