366 O. C. Marsh— Vertebrate Life in America. 
Returning once more to the upper Eocene, we find another 
line of descent starting from Oromeryz, which, as we have 
seen, had apparently then just become differentiated from the 
and its near allies, which resemble so strongly the Pliocene 
Cervide that they may fairly be regarded as their probable 
progenitors. Possibly some of these forms may be related to 
the Tragulide, but at present the evidence is against it. 
The Deer family has representatives in the upper Miocene of 
Europe, which contains fossils strongly resembling the fauna of 
our lower Pliocene, a fact always to be borne in mind in com- 
paring the horizon of any group in the two continents. Several 
species of Cervide, belonging to the genus Cosoryx, are known 
from the lower Pliocene of the West, and all have very small 
antlers, divided into a single pair of tynes. The statement 
recently published, that most of these antlers had been broken 
during the life of the animals, is unsupported by any evidence, 
and is erroneous. These primitive Deer do not have the orbit 
closed behind, and they have all the four metapodial bones 
eat although the second and fifth are very slender. In the 
liocene, a true Cervus of large size has been discovered. 
In the Post- ‘Tertiary, Cervus, Alces, and Zarandus have been met 
with, the latter far south of its present range. In the caves of 
outh America, remains of Cervus have been found, and also two 
gt of Antelopes, one referred to a new genus, ‘Leptothert tum. 
ollow-horned Ruminants, in this country, appear to 
date pack no further than to the lower Plioce ene, and here only 
two species of Bison have as yet been discovered. In the Post- 
Sacre this genus ~ represented by numerous individuals 
and several species, e of large size. The Musk Ox agen’ 
was et naty ete per ing some parts of this epoch, and 
its remains are widel) Sieibaes d. 
No authentic fossil remains of true Sheep, Goats, or Giraffes 
have as yet been found on this continent. 
roboscideans, which are now separated from the typi- 
Uoguletes as a distinct order, make their first appearance In 
upper Pliocene, and in the Post-Tertiary ; although some of 
the remains attributed to the latter are undoubtedly older. 
The Pliocene species all have a band of enamel on the tusks, 
and some other fam Aone observed in. the oldest Mastodons 
of ht which are from essentially the same horizon. Two 
species of this genus have been found in South America, in 
S. 
The genus Hlephas is a later form, and has not yet been iden- 
