128 



THE WHALEBONE WHALES OF THE WESTERN NORTH ATLANTIC. 



Some individuals, however, have a few white plates on the left side, in addition to 

 the large series on the right side. 



In a whale 55 ft. 2 in. long (No. 1), the length of the white portion of the right 

 whalebone series was 4 ft. 1 in., and comprised 166 plates. In No. 2, which was 

 64 ft. 8 in. long, the white area had a length of about 6 ft., and comprised about 

 200 plates. In No. 4, ?, 61 ft. 10 in., the white whalebone area was 4 ft. 2 in. 

 long. No. 7, 9 , 50 ft. 7 in. long, had 270 anterior white plates on the right side. 

 No. 10, $ , 53 ft. 9 in. long, had about one half the right whalebone, or about 210 

 plates, white. Only a small number of the most anterior plates in this individual 

 were entirely white, the other anterior ones being white externally, but gray 

 internally. 



From the foregoing figures it will be evident that the extent of the white 

 portion of the whalebone is not always the same, nor is it proportional to the 

 length of the individual. (See also pi. 12, fig. 6.) 



The streaked whalebone shows the most extraordinary variety as regards the 

 width and number of light and dark streaks. As a rule, however, the dark streaks 

 prevail more and more toward the posterior end of the series, and the plates here 

 are commonly quite uniform dark gray. The darkest color is on the exterior edge. 

 The matted surface of bristles appears whitish when looked at in the direction of 

 the roof of the mouth, with a rather broad margin of dull brown where the whale- 

 bone plates are dark externally. The width of the throat is about 7 inches. The 

 plates of whalebone are reduced to nothing posteriorly, the short, matted bristles 

 being attached directly to the integuments of the mouth, the curly masses of the 

 two sides approaching each other posteriorly within 5 inches. (See pi. 11, fig. 6; 

 pi. 12, figs. 3 and 4.) 



The length of the longest whalebone in various European and American speci- 

 mens is given in the following table : 



BALJ4NOPTERA PHYSALUS(L). AMERICAN AND EUROPEAN. LENGTH OF WHALEBONE. 



1 Straight. " Whether includes bristles not stated. $ Including the hairy ends. 



* Exclusive of bristles. * From the surface of the gums and exclusive of the bristles. 



