192 THE WHALEBONE WHALES OF THE WESTERN NORTH ATLANTIC. 
symphysis, the boundary of the dark gray of the left mandible runs obliquely to 
the left and goes into the fourth left furrow, leaving the first three left ridges white. 
Below the center of length of left mandible, we first find blackish, or dark gray, 
ridges, and furrows of the same color, then ridges mottled gray and white, gradually 
changing toward the median line to all white; then the dark gray of the furrows 
breaks up into detached blotches; finally both ridges and furrows are white. 
Opposite the anus the inferior border of the gray of the sides is 16} in. above the 
inferior median line of the body. A little behind the anus the gray comes forward 
and downward in a line. (See pl. 9, fig. 4.) 
On the left breast the gray of the sides extends down in broad arms or prolonga- 
tions. Opposite the middle of the left pectoral, when laid back, the gray extends 
down so far as to leave only four white ridges above the median line. 
The right mandible is all white externally, except that the superior margin is 
streaked transversely with gray, which is continuous with the dark color of the 
interior. This dark color runs out at the corner of the mouth and passes back 
below the eye toward the inferior insertion of the pectoral. From the ear to the 
head of the humerus is an area of gray lighter than the surrounding color. Under 
the right pectoral the upper twenty furrows are dark entirely or partly ; they are 
all dark at their anterior ends. 
No. 3. Female. Length, 63 ft.7 in. General color dark. Left mandible dark 
gray externally, right mandible white. Under the left pectoral the gray comes down 
over 27 abdominal ridges. The median ridge is streaked with gray about midway 
between the navel and the line of the extremity of the pectoral, as are also four or 
five ridges above it on the left side. All furrows at this point from the median line 
upward are entirely gray, or gray and white blotched. On the flanks the gray 
comes down to within 27 in. of the navel, to within 18 in. of the vagina, and to 
within 13 in. of the anus. On the caudal peduncle the gray comes downward and 
forward in a line toward the anus, and there is also a feather-like inferior median 
gray band extending backward from the anus. This is followed by gray streaks, 
so that there is no unmarked white on the inferior median line of the peduncle. 
The sides and anterior end of the sexual orifice and the inside of the mammary slit 
are also gray. 
No. 4. Female. Lenyth, 61 ft. 10 in. General color light. Eighteen furrows 
below the root of the pectoral are gray. Opposite the extremity of the pectoral, 
when laid back, the furrows are all dark, except the three nearest the median line. 
The white of the exterior of the right mandible occupies also the superior margin 
in the anterior half, and is continued backward as a narrow light-gray line, which 
broadens out to a foot in width in front of the eye, and passes over and under it. 
Underneath the eye and at the corner of the mouth the color is very light. 
The inferior border of the gray of the sides is 18 in. above the anus and is without 
linear prolongations. The inferior surface of the caudal peduncle is, therefore, all 
white nearly to the flukes, where it is slightly streaked with gray. The anterior 
boundary of the dark color of the outside of the left mandible runs into the fourth left 
furrow. (See pl. 9, fig. 2.) 
