3 56 RORQUALS CHAP. 



symphysis of the jaws to the middle of the belly is, as in other 

 species, marked by furrows, forty to fifty-eight in number. The 

 hairy covering is reduced (in an adult female) to thirteen hairs 

 on each side of tlie lower jaw ; in a foetus tliere were also seven 

 hairs on each side of the upper jaw, as w^ell as rather more on 

 the lower jaw — altogether, forty-eight. This Whale appears to 

 feed cliiefiy upon small Crustacea, especially the Copepod, Calanvs 

 Jimnarchicus. The numljer of lialeen plates is about 330 on each 

 side of the jaw. This Whale sometimes swims singly, but usually 

 in schools of even as many as fifty. 



Eudolphi's liorqual (B. horealis) seems to be a perfectly 

 inoffensive Ijeast ; it is said to be able to stay under water for 

 as long a time as twelve hours. 



A smaller species than the last is B. rostrata — at the outside 

 33 feet in length. Here the hairy covering is reduced^ to "two 

 small hairs on the integument covering the apex of the lower 

 maxilla." Tiie colour is greyish black above, the underside 

 white. On the other hand, B. sihhaldii, the Blue Whale, is the 

 giant of its race, reaching a length of 85 feet. Its colour is a 

 dark l)luish grey, with small whitish spots on the breast. The 

 dorsal fin is small and low with straight margins. 



B. musculus, the Finner, is intermediate in size — not more 

 than 70 feet. It seems doul)tful whether the " sulphur Ijottom," 

 B. ausfralis, of Antarctica and B. 'pataclionica differ specilically 

 from this." 



The genus Megaptera is very near BalaenopUra, but differs 

 from it mainly in the following external and internal cliaracters. 

 The dorsal tin is not very prominent, and its place is taken by a 

 lowish hump, whence, indeed, the common name of this Whale, 

 " Humpback." The pectoral fin is unusually long, and the 

 creature uses it to beat itself, the surrounding water, and, more 

 playfully, its mates. The general outline of this Cetacean is 

 more clumsy than that of Balaeno'ptera. The most important 

 internal difference is in tlie form of the scapula, wliich lias at 

 most a slight acromion and coracoid process. Tliese are ratlier 

 more pronounced, according to Messrs. van Beneden and Gervais,^ 



^ Perrin, "Notes on the Anatomy of ^. rostrata," Proc. Zool. Soc. 1870, p. 805. 

 - von Haast, "Notes ou a Skeleton of Balaenoptera atistralis," Proc. Zool. Soc. 

 1883, p. 592. 



^ Ost£orjra2)hie des Cetacts, Paris, 1880, p. 130. 



