48 BRITISH MAMMALS 



fused. The eye is proportionately rather large, and is situated 

 well above the angle of the jaw. There is absolutely no trace 

 of a neck, and the body is even more fish-like in shape than 

 that of any other whale. There is a back fin. A row of bony 

 tubercles, referred to in connection with other whales, often 

 grows along the edge of the lips. The skin under the lower 

 jaw, and along the throat and a portion of the belly, is streaked 

 with folds, which are so marked a characteristic of the Rorquals 

 and of the Ziphioid whales. 1 There is a slight hump in the 

 middle of the back. The head is often studded with large 

 scaly tubercles about the size of an orange, which may also be 

 the remains of the original bony plates that covered the bodies of 

 the primeval whales. In colour the hump-backed whale is black 

 above, with entirely white or black-speckled flippers, and with 

 under parts marbled in black and white. The hump-backed whale 

 is of almost universal distribution. As regards its connection 

 with the British Islands, it is commonly seen during the summer 

 off" the east coast of Scotland and the north-east and north-west 

 of England, occasionally appearing in large numbers off the 

 north of Ireland. This whale frequently produces two young at 

 a birth. The hump-backed whale eats much larger molluscs 

 and crustaceans than the right whales, and it will also swallow 

 small fish. 



Baltenoptera musculus. THE COMMON RORQUAL 



This genus in the species next to be mentioned probably 

 includes the largest of living whales. The Common Rorqual 

 may be taken as a type of the genus. Curiously enough, in the 

 rorquals, as also in the hump-backed whales, the female is 

 generally bigger than the male. The length of the common 



1 These plica, or longitudinal folds, are thought by some whalers and 

 zoologists to serve almost the purpose of gill openings in fishes, and to 

 oxygenate the blood from the oxygen of the water by dermal respiration. 

 The Balaenopterids are certainly able to remain for very lengthened periods 

 twelve hours, it is said beneath the surface of the water without coming up 

 to breathe atmospheric air. 



