SOUTH-AMERICAN MAMMALS 



389 



On the contrary, most of the fossil Mammalia from those 

 formations are as distinct from the Enropa?o-Asiatic forms as 

 they are closely allied to the peculiarly South American 

 existing genera of Mammalia. 



The genera Equus, Tapirus, and the still more ubiquitous 

 Mastodon, form the chief, if not sole exceptions. The repre- 

 sentation of Eguus during the pliocene period by distinct 

 species in Asia (E. primigenius) and in South America (E. 

 curvidens), is analogous to the geographical distribution of 

 the species of Tapirus at the present day. 



South America alone is now inhabited by species of 

 sloth, of armadillo, of cayy, aguti, ctenomys, and platyrrhine 

 monkey ; but no fossil remains of a quadruped referable to 

 any of these genera have yet been discovered in Europe, Asia, 

 or Africa. The types of Bradypus and Dasypus were, how- 

 ever, richly represented by diversified and gigantic specific 



Fig. 134. 

 Extinct Terrestrial Sloth, Mylodon robustus (Pleistocene, S. America). 



forms in South America during the geological periods imme- 

 diately preceding the present. The skeleton of one of these 

 forms of the sloth tribe is represented in fig. 134 ; it measures 



