O. C. Marsh— Vertebrate Life in America. 371 
ities with the South American Marmosets. This genus had 
forty teeth. The brain was nearly smooth, and the cerebellum 
generalized forms, with characters in the teeth, skeleton and 
feet that suggest relationships with the Carnivores, and even 
with the Ungulates. These resemblances have led palzontolo- 
gists to refer some imperfect specimens to both these orders. 
_In the Miocene lake basins of the West, only a single spe- 
cies. of the Primates has been identified with certainty. This 
was found in the Oreodon Beds of Nebraska, and belongs to 
the genus Laopithecus, apparently related both to the Zimno- 
theride and to some existing South American Monkeys. In 
the Pliocene aud Post-Pliocene,of North America, no remains 
f ; 
In the Post-Pliocene deposits of the Brazilian caves, remains 
of Monkey 
cies of Callithrix, Cebus and Jacchus, all living South American 
enera. Only one extinct genus, Protopithecus, which embraced. 
existence of Man in our Pliocene. All the remains yet dis- 
Ip this rapid review of Mammalian life in America, from its 
first known appearance in the Trias down to the present time, I 
have endeavored to state briefly the introduction and succes- 
sion of the principal forms in each natural group. If time per- 
mitted, I might attempt the more difficult task of trying to 
indicate what relations these various groups may possibly bear 
to each other; what connection the ancient Mammals of this 
continent have with the corresponding forms of the Old World;. 
and, most important of all, what real progress Mammalian life 
has here made since the beginning of the Eocene. As it is, 
