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OF THE CUSPIDATUS. 71
thicker than the Incisores, and considerably the longest of all
the Teeth.

tooth in both jaws of larger size than the succeeding ones and, from
;
the peculiarity of their shape, these larger teeth have received the
name of canine. An interval, which is wider in the upper jaw, separates
the so-called canine from the succeeding tooth ; hut, in consecpience
of the greater interspace above, the upper tooth plays upon the
anterior surface of the lower, thus the relative position which charac-
terises the true canines in Carnivora and Quadrumana is reversed. These
teeth are three-sided, with the margins of the abraded surfaces leading
to the point, trenchant.
The presence and devolopment of canines in the Marsupial order,
evidently present a close connection with the food and habits of its
different genera. Thus, in the predaceous Thylacinus and Dasyurus,
these teeth resemble closely in shape and proportions, the same weapons
in the typical Carnivores. In the Dog-headed Opossum (Thylacinus)
the canines are long, strong, curved, and pointed : the apices of the
lower canines are received in depressions in the pre-maxillary palatal
plate when the mouth is closed, and do not, as in the placental car-
nivores, project beyond the margin of the upper jaw. In Dasyurus, the
canines are of equal, or even greater development than in the Thylacine.
In an extinct animal of this genus, they resembled in form and propor-
tions the same teeth in the Leopard. The canines present a diminished
relative size in the Phascogale and other smaller species of the car-
nivorous group. The Opossums (Didelphys), present a dentition
adapted to the mixed nature of their diet. Canines of considerable
development are present in botb jaws but tbe molars indicate a
;
departure from the conformation characteristic of the true flesh-feeders.
The smaller species of Opossums are insectivorous ; whilst tbe larger
prey on small quadrupeds and birds, as well as on reptiles and insects,
and even fruits. One species prowls along the sea-shore in search of
crabs and other Crustacea; another, Otter-like, subsists almosts exclu-
sively on fresh-water fish. Canines are feebly represented in the
Phalangers and Petaurists, which feed principally on fruits, buds, and
leaves, together with insects, eggs, &c. In the herbivorous Potoroos and
in the Koala, they are absent in the lower jaw; whilst they are wanting
in both jaws in the Kangaroos and Wombat.
The large tailless Hedgehogs, or Tenrecs of Madagascar, have the most
formidably-developed canines to be found in the whole Insectivorous
order. In the Tenrec, these teeth present all the characters of the canines
of Carnivora : they are large and long, pointed, trenchant, recurved, and
single-fanged. A wide space separates them in both jaws from the pre-
molars. In the European Hedgehog, no canine teeth are present. The
first tooth which succeeds the incisors in the Gymnura, in both jaws,