112 THE MAMMALIA. 



Ground-pig, and the American Ant-bears, Sloths, 

 and Girdled-animals were at one time allied, we 

 should also have to assume a connection between 

 the three continents. There has been no lack of 

 very bold combinations to bridge over the gap to our 

 undiscoverable friends who, it is to be hoped, were 

 better equipped for a wandering life than they are 

 nowadays, and have been since the Tertiary, at 

 least and also to the ostriches, which, owing to a 

 similar geographical distribution, are equally enig- 

 matical. But geology has, as yet, not been able to 

 say her yea to this. America alone shows a rich past 

 for the Edentata of the earth's most remote periods. 

 In Europe traces, at least, have been found which 

 justify the conclusion that where single individuals 

 of the modified forms lived, others also of the same 

 group must have existed contemporaneously or in 

 the preceding periods. 



The comparatively large variety of Edentates 

 in South America is accounted for by the still 

 larger number of Diluvial species, some of which 

 were of gigantic size. Many inhabited the same 

 tracts of land which are at present the abode 

 of their evident successors, if not descendants. 

 Others we find pushed farther northwards, but we 

 cannot with certainty determine whether their 



