WHALES, PORPOISES, AND DOLPHINS. 



173 



the neck are thicker than in the right-whales, and mostly free from one 

 another. In length the female varies from 40 to 44ft., but the male is rather 

 smaller. 



The other members of the family are the humpback (Megaptera) and the 

 rorquals or finners (Balcenoptera), in both of which the skin of the throat is 

 marked by a number of longitudinal flutings or grooves, while the back carries 

 a fin ; the whalebone being short and coarse, and usually of a yellowish colour. 

 The vertebrae of the neck are of considerable thickness, and totally separate 



Fig. 93. A FIN WHALE (Balcenoptera)- 



from one another ; and the tympanic bone of the internal ear is much more 

 rounded and globular than in the right- whales, its shape somewhat recalling 

 that of a large cowri shell. In the skeleton of the flippers the number of 

 digits is reduced to four ; and the head is comparatively small in proportion to 

 the body, with the palate bub slightly arched, and the branches of the lower 

 jaw little bowed outwards. Another character of the group, as compared with 

 the right- whales, is the smaller degree of expansion of the tail-fin or flukes. 

 From the finners, the single species of humpback (Megaptera boops) is dis- 

 tinguished by the relative shortness a.nd depth of the body, which rises above 

 the level of the back-fin behind the shoulders, and likewise by the extra- 

 ordinary length of the flippers, which is nearly one-fourth that of the entire 

 animal. In length the female is about the same as the Greenland-whale. 

 As a rule humpbacks have the flippers of a pure glistening white ; and when 

 one of these animals is gambolling, as they often do, it will frequently lie on its 

 side just below the surface of the water, so that the whole body is concealed. 

 In this position one white flipper will be seen sticking straight up some 9 or 

 10 ft. above the water, and when first viewed from the deck of a passing 

 vessel appears a most extraordinary object, which may well puzzle the 

 beholder. 



The rorquals, or finners, on the other hand, are characterised by the 

 elongation and slenderness of the body and the comparative shortness of 

 tne flippers, which are pointed at their extremities. The largest member of 

 the group, as indeed it is of all whales, is the blue, or Sibbald's rorqual 

 (Baloenoptera sibbaldi), commonly known to the American whalers by the 



