120 THE WHALEBONE WHALES OF THE WESTERN NORTH ATLANTIC. 



fifteen minutes tills again becomes conspicuously darker tban the surrounding parts 

 which are still protected by the superficial layer, as may be seen in a sti'iking 

 manner by peeling off an additional piece of the upper layer, or removing a part of 

 the second layer so as to expose the third. 



This deepening of tlie color goes on gradually in B. j^^iysalus, and other gray 

 species, until the whole of the pigmented areas are black, and the rejected fragments 

 of blubber from the dorsal region with the skin attached, which are fou?id around 

 a whaling station, ai'e always of this coloi'. 



It is obvious that any specimen of JB. physalus which has been stranded and 

 has lain in the sun for several days before coming to the attention of a naturalist 

 will be described by him as black above. Specimens which liave fioated dead on 

 the waves, with the back down, for some days, but are observed as soon as brought 

 to land, are moi'e likely to have retained a semblance of their natural color. Such 

 a specimen was described in his usual accurate manner by Sars in 1866 {77, 15-16, 

 Sep.). With due allowance for the deepening of the tints, this is one of the best 

 descriptions of the coloration of European B . physalus. The following is a transla- 

 tion from the Norwegian original : 



" The color above in the median line is dai'k slate, or almost black, but passes on 

 the sides of the body into a veiy light Isabelliue gray, which grades almost imper- 

 ceptibly into the white of the belly. On the back part of the body (tail) the dark 

 color reaches so deep down on the sides that thei'e remains in the middle (below) 

 a very small white stripe. Directly under the doi'sal fin this stripe is smaller and 

 is limited hei'e on both sides by a small, pointed, dark projection, which reaches 

 forward to the anus, where it almost touches the corresponding one of the other 

 side. The white color occupies the whole ventral surface on the most anterior 

 part of the body, and stretches up to the pectorals, back of whose root, however, 

 the dark color of the back sends down a small oval prolongation. Between the 

 root of the pectoral and the corner of the mouth on each side a whitish (not pure 

 white) mark shows itself, which sends out a number of small stri[)es, of which the 

 most conspicuous are one passing forward in the direction of the eye, and another 

 backward in the direction of the dorsal fin. 



"The pectorals are white on the inner surface, but with the ti[) and along the 

 upper border somewhat dark streaked ; on the outer surface they are dark, but 

 here also the white color is seen along the lower border, forming here a small pui'e 

 white border, which widens out forwards [proximally] not so veiy insignificantly, 

 until it is suddenly interrupted by a dark tongue-shaped mark passing over the lOot 

 of the pectoral. The dorsal fin retains the dark color of the back throughout. The 

 flukes are rather dai'k color on the upper surface, but on the under surface white, 

 surrounded along the edges by a narrow dark border. Of the pectoi'al furi-ows, 

 the upper are blue-black within, but the lower, pale flesh-color. The above- 

 desciibed coloration is entirely alike on both sides of the body. 



"The most anteiior part of the head, or the facial part, however, is very notice- 

 ably unequally colored on the two sides. On the left side, the upper jaw, as well 

 as the whole of the upper part of the lower jaw, is dark, but on the right side, not 

 alone the under jaw but the most anterior part of the upper jaw along the border 

 is pure white ; but at the root of the lower jaw is an indistinctly defined grayish 

 ahade. The dissimilarity in color reaches also to the whalebone. On the left side 



