MAMMALS 263 



of more or less fish-like aquatic mammals, among which 

 are the largest of living animals. In all the posterior 

 limbs are wanting, and the fore limbs are developed as 

 broad flattened paddles without distinct fingers or nails. 

 The tail ends in a broad horizontal fin or paddle. The 

 Cete are all predaceous — fish, pelagic crustaceans, and 

 especially squids and cuttlefishes forming their principal 

 food. Most of the species are gregarious, the individuals 

 swimming together in "schools." The dolphins and 

 porpoises compose a family (Delphinidas) including the 

 smaller and many of the most active and voracious of the 

 Cete. The whales compose two families — the sperm- 

 whales (Physeteridae), with numerous teeth (in the lower 

 jaw only) and the whalebone whales (Balajnidx) without 

 teeth, their place being taken in the upper jaw by an 

 array of parallel plates with fringed edges known as 

 "whalebone." The great sperm whales or cachalots 

 [Phjseter macroccplialus), found in southern oceans, reach 

 a length (males) of eighty feet, of which the head forms 

 nearly one-third. Of the whalebone whales the sulphur- 

 bottom {^Balanoptei-a sidfitrca) of the Pacific Ocean, 

 attaining a length of nearly one hundred feet, is the 

 largest, and hence the largest of all living animals. The 

 common large whale of the Eastern coast and North 

 Atlantic is the right whale {Balcena glacialis) ; a near 

 relative is the great bowhead [B. injsiicetiis) of the Arctic 

 seas, the most valuable of all whales to man. Whales 

 are hunted for their whalebone and the oil yielded by 

 their fat or blubber. The story of whale-fishing is an 

 extremely interesting one, the great size and strength of 

 the "game" making the "fishing " a hazardous business- 

 The hoofed mammals (Ungulata). — The order Ungu- 

 lata includes some of the most familiar mammal forms. 

 Most of the domestic animals, as the horse, cow, hog, 

 sheep, and goat, belong to this order, as well as the fa- 



