THE MONKEYS OF SOUTH AMERICA 365 



the views of Dr. Ameghino * as to the age of these beds have 

 received a considerable amount of adverse criticism. Still, 

 if we assume the correctness of his arguments and the former 

 existence of a land bridge between South America and Africa, 

 these lemuroid mammals might have passed from Patagonia, 

 as Dr. Ameghino supposes, to Africa and thence to Europe, 

 and lastly, from there to North America. I do not think that 

 this was the history of events. One distinct branch may 

 have travelled from Patagonia to Chile, and thence direct to 

 North America by a western land connection (compare 

 Fig. 14), which I have already mentioned and which will be 

 further discussed in the next chapter. From North America it 

 may have passed into Europe by the mid- Atlantic land bridge. 

 I doubt whether a separate branch reached Africa from South 

 America by a land bridge, which Dr. Ameghino contends 

 joined these two continents. However, it is this very problem 

 of the zoological affinity between South America and Africa 

 and its origin which will be dealt with in this chapter. 



What we have to consider principally, therefore, is 

 whether there are really such affinities between the living 

 faunas of the two continents as to make it probable that 

 the latter were once connected with one another by land. 

 The capuchin and marmoset families, which are quite con- 

 fined to South and Central America, have probably originated 

 there in the remote past and have not been able to pass into 

 any other continent. All we know of their immediate ancestry 

 is that in the Eocene deposits of Patagonia a new family 

 of monkey-like creatures arose, possessing certain marks of 

 resemblance to the two recent South American families. They 

 were named " Homunculidae " by Dr. Ameghino. As these 

 also are quite unknown outside South America, it would 

 appear as if Patagonia had become isolated during the course 

 of the Eocene Period from the rest of the world. We cer- 

 tainly have no evidence of any Tertiary land connection 

 between the southern portions of South America and Africa 

 from the distribution of monkeys. 



Another typically Brazilian arboreal mammal is the sloth, 

 which lazily and cautiously moves from branch to branch 



* Ameghino, Fl., " Formations s6dimentaires de Patagonie," p. 289. 



