BRANCH CHORD AT A : CLASS MAMMALIA 393 



are the largest of living animals. In all the posterior limbs 

 are wanting, and the fore limbs are developed ^s 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 (Delphinidae) 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 (Balaenidae) without 

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

 of parallel plates with fringed edges known as "whale- 

 bone. ' ' The great sperm-whales or cachalots (Pkyseier 

 inacrocephalus) 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 

 (Balcenoptera sulfured) of the Pacific Ocean, reaching 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 (Bal&na glacialis] ; a near relative is the great 

 bowhead (B. mysticetus) 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 

 familiar deer, antelope, and buffalo of our own land and 



