Vertebrae: C. 7, D. 15, L. 5, S. 4, Ca. 11. Nose of adult male
produced into a short tubular proboscis, ordinarily flaccid, but
capable of dilatation and elongation under excitement. One species,
_M. leoninus_, the elephant-seal, or "sea elephant" of the whalers,
the largest of the whole family, attaining the length of nearly 20 ft.
Formerly abundant in the Antarctic Seas, and also found on the coast
of California.

Walrus

The next family is that of the walruses, or _Odobaenidae_, the single
generic representative of which is in some respects intermediate
between the _Phocidae_ and _Otariidae_, but has a completely aberrant
dentition. Walruses have no external ears, as in the _Phocidae_; but
when on land the hind-feet are turned forwards and used in
progression, though less completely than in the _Otariidae_. The upper
canines are developed into immense tusks, which descend a long
distance below the lower jaw. All the other teeth, including the lower
canines, are much alike, small, simple and one-rooted, the molars with
flat crowns. The skull is without post-orbital process, but has an
alisphenoid canal. In the young the dentition is i. 3/3, c. 1/1, p.
and m. 5/4, but many of these teeth are, however, lost early or remain
through life in a rudimentary state, concealed by the gums. The teeth
which are usually developed functionally are i. 1/0, c. 1/1, p. 3/3,
m. 0/0; total 18. Vertebrae: C. 7, D. 14, L. 6, S. 4, Ca. 9. Head
round. Eyes rather small. Muzzle short and broad, with a group of
long, very stiff, bristly whiskers on each side. The remainder of the
hair-covering very short and closely pressed. Tail rudimentary.
Fore-feet with subequal toes, carrying five minute flattened nails.
Hind-feet with subequal toes, the fifth slightly the largest, with
cutaneous lobes projecting beyond the ends as in _Otaria_; first and
fifth with minute flattened nails; second, third and fourth with
large, elongated, subcompressed pointed nails. The two species are
_Odobaenus rosmarus_, of the Atlantic, and the closely allied _O.
obesus_, of the Pacific. (See WALRUS.)

[Illustration: FIG. 7.--Skull and dentition of Australian Sea-Bear
(_Otaria forsteri_).]

Sea-lions

The third and last family of the Pinnipedia, and thus of existing
Carnivora, is the _Otariidae_, which includes the eared seals, or
sea-lions and sea-bears. In all these animals,