ing
always seized by the teeth.

The skull partakes of the characteristics of both cat and bear. It
departs from the simple cutting dentition of the former by the
addition of two tuberculated molars in each upper jaw, or one more
than the rudimentary molar in the cat, whilst the lower jaw has two
extra molars on each side; the premolars are also in excess, being
four in number on each side of the upper and lower jaws, whereas in
the feline there are three above and two below.

There is also a difference in the lower carnassial or first molar,
which impinges on the upper carnassial or fourth premolar; it has
a protuberance behind, termed the heel, which is prominently marked,
but it is in the molars in which the greatest deviation from the
specially carnivorous dentition occurs. The incisors are somewhat
larger than, but the canines and premolars approximate to, those of
the felines; the crown of the incisors is cuspidate, and the
premolars increase gradually in size, with the exception of the
fourth in the upper jaw, the carnassial, which is treble the size
of the one next to it.

But it is in the molars that we find the similarity to the
semi-herbivorous bears. The last two molars on each side of the upper
and lower jaws are true grinders, divided into four cusps, which
suits the dog to a mixed diet.

Of course the increased number of teeth (the dog has forty-two
against thirty of the cat) necessitates a prolonged muzzle, and
therefore the skull has more of the bear than the cat shape. The nasal
bones are long, the zygomatic arch smaller, but it has the ear-bulb
or _bulla tympani_, so conspicuous in the cat and wanting in the bear,
yet the character of the aperture of the ear or _auditory meatus_
approaches that of the latter, as the margins of its outer aperture
are somewhat prolonged into a short tube or spout, instead of being
flush, as in the felines. Then the bony clamp or par-occipital
process, which in the cats is fixed against the hinder end of the
bulla, is in the dogs separated by a decided groove.

The intestinal peculiarities of this section consist of a very large
caecum or blind gut, which is small in the cats and wholly absent
in the bears, and in the very long intestines. Some have a sub-caudal
gland secreting a pungent whey-like matter.

_GENUS CANIS--THE DOG_.

Muzzle obtuse; tail short; no caudal gland.

Dental formula: inc., 6/6; can., 1--1/1--1; premolar, 4--4/4--4;
molar, 2--2/3--3.