THE WHALEBONE WHALES OF THE WESTERN NORTH ATLANTIC. 



125 



general color of the surrounding parts. A light line began at the ear and curving 

 in a semicircle was lost in the region above the root of the pectoral. 



In adults the side and top of the head below and in front of the dark oblique 

 eye-line is usually lighter than the back. 



There is commonly a light gray, or whitish, mark under the eye, especially on 

 the right side, and sometimes a similar mark around the right ear. 



HAIRS. 



In the Newfoundland Finbacks, at the tip of the mandible and following the 

 line of the symphysis on each side, are two rows of thick but soft whitish bristle-like 

 hairs, about ^ in. long. There are about fifteen hairs in each row. In a male foetus 

 6 ft. 5 in. long there were nine hairs on the right side of the lower jaw, in a row 

 running obliquely downward and backward and terminating above the tenth right 

 furrow. On the light upper jaw were twelve hairs, beginning about six inches from 

 the top of the jaw and irregularly disposed. Around the root of each hair was a 

 light-colored ring. 



DORSAL FIN. 







The dorsal fin in the Newfoundland Finbacks showed a considerable variation 

 in size, as in European specimens. The following are the actual vertical heights 

 in various Newfoundland specimens : 



BAL-'ENOPTERA PHYSALUS (L.). SNOOK'S ARM, NEWFOUNDLAND. DORSAL FIN. 



The dorsal fin in these Finbacks is subject to a considerable variation in form, 

 being normally falcate, but with the tip sometimes longer and more acute, and 

 sometimes shorter and more rounded ; the posterior margin in some individuals 

 moderately concave, in others strongly concave. (See text figs. 1-7 and pi. 11, fig. 

 5.) The variation is, however, less marked and striking than is found in the 

 Sulphurbottorns. The normal shape of the dorsal in European specimens of B. 

 physolus is well shown in Sars's figure of his Lofoten Ids. specimen (77, pi. 2, fig. 

 5). In color the dorsal fin agrees with the dark gray of the adjacent part of the 

 back. In one instance (No. 2, Snook's Arm) there was an irregular, pure-white 

 blotch close to the tip of the fin, on the right side. 



