98 MARINE MAMMALS OF THE NORTH-WESTERN COAST. 
SECTION V.- THE STRIPED OR COMMON PORPOISE. 
Lagenorhystchcs obliquidens, Gill. (Plate xix,-fig. 2.) 
This species of the smaller dolphins varies but little in its general proportions 
from Baird's Dolphin, except in its back fin, which is more falcated and slender, 
and its snout, which is more blunt. In point of color it is greenish black on the 
upper surface, lightened on the sides with broad longitudinal stripes of white, gray, 
and dull black, which in most examples run into each other, but below it is of a 
pearly or snowy white. The posterior edge of the dorsal fin is tipped with dull 
white or gray, and sometimes the flukes are marked in the same manner. 
We have observed that this species has a wider range, congregates in larger 
numbers, and exhibits more activity, than any other of the Dolphin family. They 
are seen, in numbers varying from a dozen up to many hundreds, tumbling over 
the surface of the sea, or making arching leaps, plunging again on the same curve, 
or darting high and falling diagonally sidewise upon the water, with a spiteful 
splash, accompanied by a report that may be heard at some distance. When a 
brisk breeze is blowing they frequently play about the bow of a ship going at her 
utmost speed, darting across the cutwater and shooting ahead, or circling around 
the vessel, apparently sj^orting at ease. In calm weather they are sometimes seen 
in immense shoals, leaping, plunging, lobtailing, and finning — in fact, exhibiting an 
endless variety of attitudes — and at the same time the whole assemblage moves 
swiftly in various directions, as if enjoying a general frolic. 
While on a cruise in the U. S. Revenue cutter Wayanda, during the month of 
October, 1872, we had an opportunity of witnessing, at midnight, the gambols of an 
immense herd of these active and rapacious animals. The sea was quite smooth, 
and not a breath of wind was stirring. At first we could hear a harsh rustling 
sound, as if a heavy squall of wind, accompanied with hail, was sweeping over the 
otherwise tranquil sea ; and, as the moon burst through the clouded sky, we could 
see a sheet of foam and spray surging toward us. In a few moments the vessel 
was surrounded by myriads of these Common Porpoises, which, in their playful 
movements, for the space of one hour, whitened the sea all around as far as the 
eye could discern, when they almost instantly disappeared. 
The Striped Porpoises are often seen in considerable numbers about the large 
bays and lagoons along this coast, that have no fresh water running into them. 
They abound more along the coasts where small fish are found than in mid -ocean. 
