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OF THE CUSPIDATUS. 75
the f\mg differs from that of an Incisor, only in being much
larger.
The outside of the body of a Cuspidatus projects most at

are equally wanting. In those which possess them, they are frequently
confined to the male sex, and when present in both sexes, they are
always of minor development in the female. Amongst the deer tribe,
upper canines reach their largest size in the small musk-deer, especially
in the typical species (Moschus moschiferus), in the males of which the
proportions attained by these teeth are intermediate between those in
the Machairodus and in the Walrus. It is interesting to notice that,
although these teeth are not present in the upper jaw in the more
typical Ruminantia, that yet they existed in those extinct forms which
appear to have been replaced by them. Thus, amongst the fossil remains
of the eocene tertiary period, we find canines present in both jaws in the
Dichodon cuspidatus, an animal which, as respects its dentition, appears
to have formed a connecting link between another eocene tertiary form
—the Anoplotherium and existing Ruminantia. In the Dichodon, these
teeth closely resemble the incisors. Although a little larger, and having
a low point, they are yet more trenchant than piercing. The presence
and development of upper canines in the Ruminants appear to bear an in-
verse relationship to the presence and growth of horns. Those ruminating
animals which have typical horns are unprovided with these teeth. First
present in the periodically hornless deer, they attain their largest dimen-
sions in the absolutely hornless Musks ; whilst, in the Camelidoe, the
upper canine is not only of formidable dimensions itself, but, as we have
already seen, it is accompanied by an upper laniariform incisor. In the
Llamas of the New World, the upper canines are more feeble than in
the camels and dromedaries. The inferior canines in the ordinary
Ruminants are procumbent, and appear to form part of the same series
with the lower incisors. They may, however, be distinguished by the
lateness of their eruption, and frequently by their form. Thus, in the
Musk-deer, they are smaller and more pointed than the incisors ; in the
Giraffe they have a much larger crown, which is bilobed. In the
Camelidoe, they are more erect in position, and present a laniariform
configuration. In the Auchenioz, a short diastema separates them from
the incisors.
On turning to the non-runiinant, even-toed Ungulates, we find, in the
Hog tribe, a remarkable development of the upper canine teeth. The
tusks or upper canines of the Wild Boar curve forwards, upwards, and
outwards ; their sockets having a similar direction, and being strengthened
above by a ridge of bone, which is remarkably developed in the African
Masked Boar. The enamel on the inferior side of the tusk is ribbed
longitudinally ; a narrow strip of hard enamel is also laid upon the
anterior part, and another upon the posterior concave angle forming the
point of the tusk, which is worn obliquely upwards from before, and