animals are usually dark.

MAXIMUM SIZE

To 9 feet (2.7 m). To 10 feet (3.1 m).

DORSAL FIN

Often part black, part lighter Uniformly dark.
gray.

Distribution

Atlantic white-sided dolphins are distributed, primarily offshore, in
the cool waters between the Gulf Stream and the Labrador Current. They
have been observed from Hudson Canyon, off New York City, north to
southern Greenland and perhaps Davis Straits. Their normal range shares
a southern boundary with the white-beaked dolphin but does not extend as
far to the north.

Stranded Specimens

In addition to the features described above for living animals at sea,
stranded Atlantic white-sided dolphins can be distinguished from
white-beaked dolphins by the following:

ATLANTIC WHITE-SIDED
DOLPHIN WHITE-BEAKED DOLPHIN

NUMBER OF TEETH

30-40 per side per jaw, 22-28 per side per jaw; have
sometimes more in upper. larger individual teeth--to 6
mm in diameter.

FLIPPERS

Lower portion of forward Lower portion of forward
margin more curved. margin less acutely curved.

VENTRAL COLOR

White coloration of belly White coloration of belly
extends high onto sides of extends to lower jaw but not
body. above flippers on sides.

CAUDAL CRESTS

Tail stock strongly compressed Tail stock less laterally
laterally; taller, narrows compressed, tapers more
rapidly just in front of flukes. gently towards tail flukes.

[Illustration: Figure 138.--An Atlantic white-sided dolphin off the
eastern Canadian coast. These animals do not usually ride the bow wave,
but when they can be examined at close range, they can be readily
distinguished from their more northerly cousins, the white-beaked
dolphins, by their highly distinctive color pattern. (_Photo by P. B.
Beamish._)]

[Illustration: Figure 137.--Atlantic white-sided dolphins at sea between
Cape Cod, Mass. and Nova Scotia. This species can be positively
identified by the elongated zone of white and the adjacent region of tan
or yellowish tan below and behind the dorsal fin, visible even in the
fast-swimming animal in t