ar to be
always wanting in the upper jaw. The upper sectorial is much larger in
proportion to the other teeth; and the upper molar about the same size
as the sectorial, triangular, with the apex turned backwards. Heel of
lower sectorial less than half the length of the tooth. Skull very
wide in the occipital region; the lambdoidal crest greatly developed,
and the sagittal but slightly, contrary to what obtains in _Meles._
Vertebrae: C. 7. D. 15. L. 5, S. 3, Ca. (?). Body stoutly built and
depressed. Tail short. The animals of this genus are peculiar to North
America, where they represent the badgers of the Old World, resembling
them much in appearance and habits. _T. americana_ is the common
American badger of the United States, _T. berlandieri_, the Mexican
badger, being a local variety.

Otter tribe.

The third and last subfamily is that of the otters, or _Lutrinae_, in
which the feet (with the exception of the hind pair in the sea-otter)
are short and rounded, with the toes webbed, and the claws small,
curved and blunt. The head is broad and much depressed. The upper
posterior cheek-teeth are large and quadrate. The kidneys are
conglomerate. Habits aquatic.

In the true otter of the genus _Lutra_ the dentition is i. 3/3, c.
1/1, p. 4/3, m. 1/2; total 36. Upper sectorial with a trenchant
tricusped blade, and a very large inner lobe, hollowed on the free
surface, with a raised sharp edge, extending along two-thirds or more
of the length of the blade. Upper molar large, with a quadricuspidate
crown, broader than long. Skull broad and depressed, contracted
immediately behind the orbits; with the facial portion very short and
the brain-case large. Vertebrae: C. 7, D. 14-15, L. 6-5, S. 3, Ca.
20-26. Body very long. Ears short and rounded. Limbs short. Feet
completely webbed, with well-developed claws on all the toes. Tail
long, thick at the base and tapering, rather depressed. Fur short and
close.

Otters are more or less aquatic, living on the margins of rivers,
lakes, and in some cases the sea; are expert divers and swimmers, and
feed chiefly on fish. They have an extensive geographical range, and
so much resemble each other in outward appearance, especially in the
nearly uniform brown colouring, that in some cases the species are by
no means well-defined. The Brazilian otter (_L. brasiliensis_) is a
very large species from Brazil, Demer