in the numerical characters of their dentition, to the more typical
Carnivora.
The alternate interlocking of the crowns of the teeth of the
upper and lower jaws, which is their general relative position in
the Carnivora, is well marked in regard to the premolars of the
Viverride (fig. 4): as the lower canine is in front of the upper,
so the first lower premolar rises into the space between the
upper canine and first upper premolar, the fourth lower premolar
in like manner fills the space between the third upper premolar
and the sectorial tooth (p 4), playing upon the anterior lobe of the
blade of that tooth which indicates by its position, as by its mode
of succession that it is the fourth premolar of the upper jaw. The
first true molar below, modified as usual in the Carnivora to form
the lower sectorial, sends the three tubercles of its anterior part
to fill the space between the sectorial and the first true molar
above. In the Musangs the lower sectorial is in more direct opposition
to its true analogue, the first tubercular molar in the
upper jaw ; and these Indian Viverride (Paradoxuri) are the least
carnivorous of their family, their chief food consisting of the fruit
of palm-trees, whence they have been called ‘Palm-cats.’
181. Hyena.—The dentition of this genus presents a nearer approach
to the strictly carnivorous type by the reduction of the tubercular
molars to a single minute tooth on each side of the upper
jaw, the inferior molars being all conical or sectorial teeth: the
molar teeth in both jaws are larger and stronger, and the canines
smaller in proportion than in the Feline species, from the formula
of which the dentition of the Hyaena differs numerically only in
the retention of an additional premolar tooth on each side of
both jaws. The dental formula of the genus Hyena (PI. 126,
fig. 6) is :—
c. —1—1 ; pm. p4i-l4r : m. l—i 34.
The crowns of the incisors form almost a straight transverse line
in both jaws; the exterior ones, above, being much larger than
the four middle ones, and extending their long and thick inserted base
further back : the crown of the upper and outer incisor is strong,
conical, recurved, like that of a small canine, with an anterior
and posterior edge, and a slight ridge along the inner side of the
base. The four intermediate small incisors are divided by a
transverse cleft into a strong anterior conical lobe, and a posterior
ridge, which is notched vertically; giving the crown the figure
of a trefoil. The lower incisors gradually increase in size from
the first to the third; this and the second have the crown indented
externally, but they have not the posterior notched ridge
like the small upper incisors ; the apex of their conical crown fits
into the interspace of the three lobes of the incisor above. The
canines have a smooth convex exterior surface, divided by an anterior
and posterior edge from a less convex inner side : this surface
is almost flat and of less relative extent in the inferior canines. The
first premolar above (p 1) is very small, with a low, thick conical
crown: the second presents a sudden increase of size with an additional
posterior and internal basal ridge to the strong cone.
The third premolar exhibits the same form on a still larger scale,
and is remarkable for its powerful aspect. The posterior part of
the cone of each of these premolars is traversed by a longitudinal
ridge. The fourth premolar (p 4) is the carnassial tooth and has
its long blade divided by two notches into three lobes, the first a
small thick cone, the second a long and compressed cone, the
third a horizontal sinuous trenchant plate: a strong trihedral tubercle
is developed from the inner side of the base of the anterior
part of the crown. The single true molar of the upper jaw
(fig. 7, m 1) is a tubercular tooth of small size: it is transversely
oblong in the Hyena vulgaris and H. fusca; smaller and sub-circular
in the Hyena crocuta; still smaller and implanted by a single
fang in the Hyena spelea: in all the existing species of Hyaena it
has two fangs. The first premolar of the lower jaw (fig. 6, p 2)
fits into the interspace between the first and second premolars
above, and answers, therefore, to the second lower premolar in the
Voverride : it is accordingly much larger than the first above ; it
has a ridge in the forepart of its cone, and a broad basal talon
behind. The second (p 3) is the largest of the lower premolars,
and has an anterior and a posterior basal ridge, with a vertical ridge
i i 2