186 



SKETCH OF THE HISTORY OF MAMMALIA. 



nmtz, from the " thick folded skin on its forehead, which 

 it can draw down over its eyes like a cap to defend 

 them against the storms, waves, stones, and sand." 

 The apparatus consists of a cartilaginous crest which 

 arises from the muzzle and increases rapidly in height as 

 it passes backwards, being about seven inches high at 

 its posterior edge, which is separated into two planes by 

 an intervening depression an inch deep ; this cartilaginous 

 appendage is a development of the septum of the nose, 

 and it runs into the hood or sac-like appendage of the 



126.— Crested Seal. 



head, which is strongly muscular, with circular fibres 

 round its two orifices at the snout like nostrils, the true 

 nostrils opening on each side of the cartilaginous crest 

 beneath the hood, and are of an oblong figure. In the 

 females and young the curious apparatus is undeveloped, 

 being peculiar to the adult male. The eyes, which are 

 capable of being drawn deeply into the socket during re- 

 pose, are eminently formed for discerning distant objects. 

 The fur is soft, long, and woolly beneath ; in old indi- 



