336 



BACKBONED ANIMALS. 



FIG. 359. Rocky Mountain sheep (Capra 

 montana). 



head (frontal) bone 

 of the skull form the 

 cores that are cov- 

 ered by the horns, 

 that are special de- 

 velopments' of the 

 outer skin or epi- 

 dermis. 



Goats and 

 Sheep. In the 

 Rocky Mountain 

 sheep, or big-horn 

 (Fig. 359), the horns 

 are extremely pow- 

 erful. In the fe- 

 male, the horns are 



straight, and similar to those of a goat. Their height at 



the shoulder is about three feet, and their weight three 



hundred and fifty pounds. They are now confined to the 



country west of the Missouri, and are fast becoming extinct. 

 About forty varieties of the domestic sheep are known. 



Its origin is obscure, 



but it is possibly a 



descendant of an 



Asiatic sheep (Ovis 



argali). The Bar- 



bary sheep, or Mou- 



flon, has soft hair 



of a reddish tinge. 



From it and the Si- 

 berian Argali spring 



the merino sheep of 



the East ; their tails 



attain a weight of 



one hundred pounds, 



and have to be Sup- FlG - 360. -Musk-sheep (Ovibos moschatus\ 



