eth and the feet. They
are all inhabitants of the shores of the southern hemisphere.

In _Ogmorhinus_ all the teeth of the cheek-series have three distinct
pointed cusps, deeply separated from each other, of which the middle
or principal cusp is largest and slightly recurved; the other two are
nearly equal in size, and have their tips directed towards the middle
one. Skull much elongated. One species, _O. leptonyx_, the
sea-leopard, widely distributed in the Antarctic and southern
temperate seas. In _Lobodon_ the molars have compressed elongated
crowns, with a principal recurved cusp, rounded and somewhat bulbous
at the apex, and one anterior, and one, two or three posterior
distinct accessory cusps. One species, _L. carcinophagus_, the
crab-eating seal. In the third genus, _Leptonychotes_, represented by
_L. weddelli_, the molars are small, with simple, subcompressed,
conical crowns, and a broad cingulum, but no distinct accessory cusps.
Finally in the white seal (_Ommatophoca rossi_) all the teeth are very
small, those of the cheek-series with pointed, recurved crowns, and
small posterior and still less developed anterior accessory cusps.
Orbits very large. Nails rudimentary on front and absent on hind-feet.
The skull bears a considerable resemblance to that of the next
subfamily.

The presence of two pairs of upper and one pair of lower incisors is
characteristic of the members of the subfamily _Cystophorinae_, in
which the teeth of the cheek-series are generally one-rooted. The nose
of the males has an appendage capable of being inflated. First and
fifth toes of hind-feet greatly exceeding the others in length, with
prolonged cutaneous lobes, and rudimentary or no nails. In the typical
genus _Cystophora_ the dentition is i. 2/1, c. 1/1, p. 4/4, m. 1/1;
total 30; the last molar having generally two distinct roots. Beneath
the skin over the face of the male, and connected with the nostrils,
is a sac capable of inflation, when it forms a kind of hood covering
the upper part of the head. Nails present, though small on the
hind-feet. Represented by _C. cristata_, the hooded or bladder-nosed
seal of the Polar Seas. In _Macrorhinus_ the dentition is numerically
the same as in the last, but the molars are of simpler character and
all one-rooted. All the teeth, except the canines, very small
relatively to the size of the animal. Hind-feet without nails.