_Phocidae_
themselves. The stomach is simple, but the intestines are
considerably longer than in the _Felidae_, averaging about fifteen
times the length of the body; the digestion is rapid. The bones are
light and spongy, and the spine particularly flexible, from the
amount of cartilage between the bones. They have a large venous
cavity in the liver, and the lungs are capacious, the two combining
to assist them in keeping under water; the blood is dark and abundant.
The brain is large, and in quantity and amount of convolution exceeds
that of the land Carnivores. Their hearing is acute, but their sight
out of water is defective.

Their external features are an elongated pisciform body, the toes
joined by a membrane converting the feet into broad flippers or fins,
the two hind ones being so close as to act like the caudal fin of
a fish. The head is flattish and elongated, or more or less rounded,
but in comparison with the body it is small. Except in the _Otaridae_
there are no perceptible ears, and in them the ear is very small.
The fur is of two kinds, one long and coarse, but the other, or under
fur, is beautifully soft and close, and is the ordinary sealskin of
commerce. The roots of the coarse hair go deeper into the skin than
those of the under fur, so the furrier takes advantage of this by
thinning the skin down to the coarse roots, cutting them free, and
then the hairs are easily removed, leaving the soft fur attached to
the skin.

The Pinnigrada are divided into three families--the _Trichechidae_,
or walruses; the _Otaridae_, or sea-lions or eared seals; and the
_Phocidae_, or ordinary seals.

As none of these animals have been as yet observed in the Indian seas,
being chiefly denizens of cold zones, I will not attempt any further
description of species, having merely alluded to them _en passant_
as forming an important link in the chain of animal creation.

We must now pass on to the next order, a still more aquatic one.

ORDER CETACEA--THE WHALES.

These curious creatures have nothing of the fish about them, save
the form, and frequently the name. In other respects they are
warm-blooded, viviparous mammals, destitute of hinder limbs, and
with very short fore-limbs completely enclosed in skin, but having
the usual number of bones, though very much shortened, forming a kind
of fin. The fin on the back is horizontal, and not rayed and upright
like that of a fish; the tail resembles that of a fish