THE DOLPHINS. 95 
SECTION IV -THE BAY PORPOISE. 
Phooena vomekina, Gill. (Plate xviii, fig. 2, 3, 4.) 
This peculiar species of Dolphin is the least in size of the entire whale tribe 
inhabiting the Pacific North American Coast. When fully matured it may attain 
the length of six feet, but those we have had opportunity to measure fell con- 
siderably short of these dimensions. Usually the adults are not more than four 
and one -half feet between linear extremes. The body of the male is jet black 
above, a little lighter below ; and while the female is of the same color above, it 
is lighter on the sides, with a narrow black streak running from the corner of the 
mouth to the pectorals, and the lower portion of the animal is of a milky white- 
ness, yet the pectoral and caudal fins are black underneath, or of a dark gray. 
Occasionally, however, both males and females are found with the larger portion, 
or the whole, of their dorsal and caudal fins white. The former are of triangular 
shape, and placed very nearly midway between the animal's extremities. The 
caudal fin varies much in its contour, sometimes being quite broad and straight 
on its posterior edge, which is slightly notched in the centre ; in other specimens 
the caudal lobes are lunate, and united present a forked appearance. Its pectorals 
are extremely small and placed low. Its head is somewhat pointed, but destitute 
of the slender, elongated beak of the Delphinus Baird'd, and the Right Whale 
Porpoise. The anterior portion of the animal resembles that of both the Orca and 
the White - headed Grampus-. Its eyes are placed about two inches behind the 
corner of the mouth, and nearly in a line with it. Its ears are two inches 
from the eyes, and these minute orifices would not be noticed by the casual 
observer, as they are less than a sixteenth of an inch in diameter. The spiracles 
are placed a little forward of the eyes, and unite in one where they pass through 
the fleshy part of the cranium. The valve which covers them is convex on its 
posterior side. When the animal respires this valve is turned downward. Both 
upper and lower jaws are furnished with teeth, which in the adults are thin, flat, 
and broadest near their summits. In one example, a female four feet long, taken 
at San Francisco, California, the number was f£, and in another, %$. In a male, 
four feet eight inches in length, taken in Port Townsend Bay, Washington Terri- 
tory, the number was the same as last mentioned. 
The following measurements and memoranda were carefully taken from a male 
specimen obtained at Port Townsend, Washington Territory, April 28th, 1869 : 
