and/or small schooling fish, by taking
water into the mouth and forcing it out through the overlapping fringes
of the baleen plates. Baleen whales are externally distinguishable from
toothed whales by having paired blowholes. There are eight species of
baleen whales in the western North Atlantic, ranging in size from the
minke whale (just over 30 feet [about 9.1 m])[5] to the blue whale (85
feet [25.9 m]).

[Footnote 5: Throughout this guide, measurements are given first in feet
or inches, followed in parentheses by their equivalents in meters or
centimeters. It is recognized that field estimates cannot be as precise
as most of the conversions used.]

TOOTHED WHALES. Unlike the baleen whales, the toothed whales do have
teeth after birth. The teeth vary in number from 2 to over 250, though
they may sometimes be concealed beneath the gum. In addition, toothed
whales have only a single blowhole. This group includes the animals
commonly called dolphin or porpoise as well as some commonly called
whales (for example, the sperm whale). There are currently about 30
species of toothed whales known from the western North Atlantic, ranging
in maximum adult size from the common or harbor porpoise, which is
approximately 5 feet (1.5 m) long, up to the sperm whale which reaches a
length of 68 feet (20.7 m). Several other species which are expected to
be found in this region, though they have not yet been reported, are
also included in this guide.

CLASSIFICATION OF CETACEANS

In addition to the two suborders (Mysticeti and Odontoceti), the
cetacean order contains numerous families, genera, and species. Each of
these groupings represents a progressively more specialized division of
the animals into categories on the basis of similarities in their
skulls, postcranial skeletons, and external characteristics. The
discipline which concerns itself with naming an animal and assigning it
to its appropriate scientific category is known as taxonomy. An example
of the classification of a cetacean species is shown in the following:

SCIENTIFIC CLASSIFICATION OF THE
ATLANTIC BOTTLENOSED DOLPHIN

Kingdom: Animalia all animals

Phylum: Chordata having at some stage a notochord,
the precursor of the backbone

Subphylum: Vertebrata animals with backbones--fishes,
amphibians, reptiles, birds,
and mammals

Class: