FOSSIL AMERICAN MONKEYS. 
187 
Mantled Howler. 
northerly regions of Brazil are rufous or ferruginous in colour, while the females 
and those from the more southern regions are brown or blackish-brown. This 
species is very closely allied to the red howler. 
In Costa Rica, and probably also in other districts of Central 
America, the howling monkeys are represented by a very well- 
marked species, known as the mantled howler (M. palliatus). This animal is 
characterised by the presence of a fringe of long brownish-yellow hair running 
along the lower part of the flanks, so as to form a kind of mantle on each 
side of the body. The general colour of the fur is blackish-brown, the hairs 
on the middle of the back, as well as on the upper parts of the sides, being 
yellowish-brown, with black tips. 
Fossil American Monkeys. 
In previous chapters we have seen how all the fossil monkeys of the Old World 
are more or less closely allied to the recent monkeys of that half of the 
globe, none of them showing any signs of closer 
affinity with their western cousins. The same holds 
good with regard to the extinct monkeys which have 
left their remains in the great caverns of Brazil, or 
in the fresh-water superficial deposits which cover 
such large areas of country in Argentina and other 
parts of South America; all these belonging either to 
existing genera, and in some cases even species, of 
American monkeys, or to extinct types of the same 
great family. 
At the time when the huge ground-sloths known 
as megatheres and mylodons roamed over the pampas 
of South America, the forests of Brazil re-echoed as 
now with the cries of howling monkeys, apparently 
identical with the species still living; while titis and 
sapajous are known to have existed at the same 
epoch, and remains of other living genera will doubtless also be found in the same 
deposits, which belong to what geologists term the Pleistocene period. At the same 
time, with these existing genera there also lived a totally extinct genus of monkeys, 
known by the name of Protopitheeus. These monkeys appear to have been nearly 
related to the modern howlers, but were considerably larger than any living 
American monkey. In Argentina and Patagonia remains of monkeys, apparently 
belonging to this family, occur in much older strata, which have been correlated 
with the Eocene rocks of Europe. Marmosets are likewise represented in the 
superficial South American deposits. 
UPPER AND SIDE VIEWS OF LOWER JAW 
OF AMERICAN TERTIARY MONKEY 
(Homunculus .)—After Ameghino. 
