ara and Surinam, with a prominent
ridge along each lateral margin of the tail. In two small species the
feet are only slightly webbed; claws exceedingly small or altogether
wanting on some of the toes; the first upper premolar very small,
sometimes wanting; and the molars very broad and massive. The species
in question are _L. inunguis_ of South Africa, and _L. leptonyx_ or
_cinerea_ of India, Java and Sumatra, and have been separated as a
distinct genus, Aonyx.

The sea-otter, _Latax_ (or _Enhydra_) _lutra_, with a dentition of i.
3/2, c. 1/1, p. 3/3, m. 1/2, total 32, differs from other Carnivora in
having but two incisors on each side of the lower jaw, the one
corresponding to the first (very small in the true otters) being
absent. Though the molar teeth generally resemble those of _Lutra_ in
their proportions, they differ in the exceeding roundness and
massiveness of their crowns and bluntness of their cusps. Feet webbed;
fore-feet short, with five subequal toes, with short compressed claws;
hind-feet very large, depressed and fin-like, their phalanges
flattened as in seals. The fifth toe the longest and stoutest, the
rest gradually diminishing in size to the first, all with moderate
claws. Tail moderate, cylindrical (see OTTER).

II. PINNIPEDIA

The second suborder is formed by the seals, walruses and eared seals,
which differ from the rest of the Carnivora mainly in the limbs being
modified for aquatic progression; the two upper segments being very
short and partially enveloped in the general integument of the body,
while the third, especially in the hind extremities, is elongated,
expanded and webbed. There are always five well-developed digits on each
limb. In the hind-limb the two marginal digits (first and fifth) are
stouter and generally larger than the others. The teeth also differ from
those of the more typical Carnivora. The incisors are always fewer than
3/3. The chsek series consists generally of four premolars and one molar
of uniform characters, with never more than two roots, and with conical,
more or less compressed, pointed crowns, which may have accessory cusps,
placed before or behind the principal one, but are never broad and
tuberculated. The milk-teeth are small, simple and shed or absorbed at
an early age, usually either before or within a few days after birth.
The brain is relatively large, the cerebral hemispheres broad in
proportion to their length