154 THE MAMMALIA. 



we come to understand the great variety which dis- 

 tinguishes the Selenodonts among one another, and 

 which becomes all the more marked, the more ob- 

 stinately the characteristic form is preserved. 



But since Kowalewsky's classic works there can 

 be no question that the peculiarities, connected with 

 the reduction of the limbs, are testimonies at least 

 as distinctive and trustworthy for the Present and 

 the Past. 



The majority of the living Ruminants are divided 

 into the large families of the Deer, the Antelopes, 

 and the Oxen. The last two, as horned animals, 

 are more closely allied to one another than to the 

 deer. The goats and sheep are closely allied to 

 the antelopes. Apart from all these we have the 

 Camels, to which we shall first direct our attention, 

 for, at least as regards dentition, they have pre- 

 served a higher geological antiquity than the others. 



4. THE CAMELID^, OE CAMELS. 



When Riitimeyer calls the llama ' a late offshoot 

 of the Eocene Anoplotherise, and as originating first 

 in America,' he gives a proof of the utter uncer- 

 tainty which prevailed about ten years ago as to 

 the position and historical development of the two 

 species which, since Buffon's day, had been regarded 



