The Porpoises differ from the Dolphins in having their snout short and
uniformly rounded, without a beak-like projection. Their teeth are
compressed, sharp-edged, and rounded, their number from twenty-two to
twenty-five in each jaw. Their skin is smooth and shining, black above
and white below, and as they never attain a greater length than four or
five feet from the tip of the muzzle to the extremity of their flat
horizontal tail, they may be regarded as the smallest of the Cetacean
Order. These animals abound in every sea, and many people have witnessed
their unwieldy gambollings, the character of which is by no means badly
expressed by their name (porc-poisson, hog-fishes). They have, in fact,
somewhat the appearance of floating pigs, as they wallow in the trough
of the sea and roll over each other amid the foaming waves.
Their food consists entirely of Fishes, of which they destroy great
quantities. They follow the shoals of Herrings and of Mackerel, and when
pursuing their prey, not unfrequently venture into the estuaries of
rivers, and make excursions up the rivers themselves.