(possibly with exception of the Dog and a Rodent or
two, as at present). In Austro-Columbia the later
Tertiary fauna exhibits numerous and varied forms of
Platyrrhine Apes, Rodents, Cats, Dogs, Stags,
Edentata,
and Opossums; but, as at present, no Catarrhine Apes,
no Lemurs, no
Insectivora, Oxen, Antelopes,
Rhinoceroses, nor
Didelphia other than Opossums.
And in the wide-spread Arctogaeal province, the Pliocene
and later mammals belong to the same groups as those
which now exist in the province. The law of succession
of types, therefore, holds good for the present epoch
as compared with its predecessor. Does it equally
well apply to the Pliocene fauna when we compare it
with that of the Miocene epoch? By great good
fortune, an extensive mammalian fauna of the latter
epoch has now become known, in four very distant portions
of the Arctogaeal province which do not differ greatly
in latitude. Thus Falconer and Cautley have made
known the fauna of the sub-Himalayas and the Perim
Islands; Gaudry that of Attica; many observers that
of Central Europe and France; and Leidy that of Nebraska,
on the eastern flank of the Rocky Mountains.
The results are very striking. The total Miocene
fauna comprises many genera, and species of Catarrhine
Apes, of Bats, of
Insectivora; of Arctogaeal
types of
Rodentia; of
Proboscidea; of
equine, rhinocerotic, and tapirine quadrupeds; of
cameline, bovine, antilopine, cervine, and traguline
Ruminants; of Pigs and Hippopotamuses; of
Viverridae
and
Hyaenidae among other
Carnivora;
with
Edentata allied to the Arctogaeal
Orycteropus
and
Manis, and not to the Austro-Columbian Edentates.
The only type present in the Miocene, but absent in
the existing, fauna of Eastern Arctogaea, is that
of the
Didelphidae, which, however, remains
in North America.
But it is very remarkable that while the Miocene fauna
of the Arctogaeal province, as a whole, is of the
same character as the existing fauna of the same province,
as a whole, the component elements of the fauna were
differently associated. In the Miocene epoch,
North America possessed Elephants, Horses, Rhinoceroses,
and a great number and variety of Ruminants and Pigs,
which are absent in the present indigenous fauna;
Europe had its Apes, Elephants, Rhinoceroses, Tapirs,
Musk-deer, Giraffes, Hyaenas, great Cats, Edentates,
and Opossum-like Marsupials, which have equally vanished
from its present fauna; and in Northern India, the
African types of Hippopotamuses, Giraffes, and Elephants
were mixed up with what are now the Asiatic types
of the latter, and with Camels, and Semnopithecine
and Pithecine Apes of no less distinctly Asiatic forms.