46 



SEALS AND WHALES OE TLJE BRLTLSLL SEAS. 



which go to build up the giant form of the Right- Whale. Some possess 

 numerous formidable teeth in both jaws ; others have teeth in the lower jaw 

 only ; and in one section the teeth are only present in the embryo, but in 

 their stead, from the upper jaw depend curious plates, arranged side by side, 

 to which the name of baleen has been given. The animal is encased in a 

 layer of fat called " blubber," which lies beneath the skin, and serves to 



Fig. II. Median .Section, showing outside Left Half of Skull of Whalebone 

 Whale, with Baleen in position (modified aficr Eschrulit). 



Br., Ijmin cavity; J.J"*, upper ,ind lower jaw-bones ; bo, bo, Ijeing roughened parts of the bone s.awn 

 througli ; arrows indicate tlie narial passages, wliich open at s, spout-hole ; w, whalebone ; 

 t, tongue, in dotted outline ; n, nerve aperture, lower jaw. 



retain the heat of the body, and the skin is smooth, polished, and quite devoid 

 of hair or scales. On the back of most species is found a fleshy dorsal fin, 

 and the fore limbs are represented by flippers externally undivided ; the hind 

 limbs, so far as external appearance is concerned, are altogether absent, but a 

 rudimentary pelvis is found embedded in the flesh. The tail-fin forms the 



