ing the fossil forms from one another. Of the
seven Miocene Elephants of India, as judged by the characters of
the molar, teeth, two are allied to the existing Indian Elephant,
one is related to the living African Elephant, and the remaining
four are in some respects intermediate between the true Elephants
and the Mastodons.

[Illustration: Fig. 247.--A, Molar tooth of _Elephas planifrons_,
one-third of the natural size, showing the grinding surface--from
the Upper Miocene of India; B, Profile view of the last upper molar
of _Mastodon Sivalensis_, one-third of the natural size--from
the Upper Miocene of India. (After Falconer.)]

The _Mastodons_, lastly, though quite elephantine in their general
characters, possess molar teeth which have their crowns furnished
with conical eminences or tubercles placed in pairs (fig. 247, B),
instead of having the approximately flat surface characteristic
of the grinders of the Elephants. As in the latter, there are two
upper incisor teeth, which grow permanently during the life of
the animal, and which constitute great tusks; but the Mastodons,
in addition, often possess two lower incisors, which in some
cases likewise grow into small tusks. Three species of _Mastodon_
are known to occur in the Upper Miocene of the Siwalik Hills
of India; and the Miocene deposits of the European area have
yielded the remains of four species, of which the best known are
the _M. Longirostris_ and the _M. Angustidens_.

Whilst herbivorous Quadrupeds, as we have seen, were extremely
abundant during Miocene times, and often attained gigantic
dimensions, Beasts of Prey (_Carnivora_) were by no means wanting,
most of the principal existing families of the order being
represented in deposits of this age. Thus, we find aquatic Carnivores
belonging to both the living groups of the Seals and Walruses;
true Bears are wanting, but their place is filled by the
closely-allied genus _Amphicyon_, of which various species are
known; Weasels and Otters were not unknown, and the _Hyoenictis_
and _Iditherium_ of the Upper Miocene of Greece are apparently
intermediate between the Civet-cats and the Hyaenas; whilst the great
Cats of subsequent periods are more than adequately represented by
the huge "Sabre-toothed Tiger" (_Machairodus_), with its immense
trenchant and serrated canine teeth.

Amongst the _Rodent_ Mammals, the Miocene rocks have yielded
remains of Rabbits, Porcupines (such as the _Hystrix primigenius_
o