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, PL, “ Formations s£dimentaires de Patagonie,” p. 289. 
