674 



COLLEGE ZOOLOGY 



and the tail is rounded and not notched as in whales. The 

 Florida manatee, Manatus latirostris (Fig. 541), is about nine 

 feet in length. It is now nearly extinct. 



Order Odontoceti (Denticeti). — Toothed Whales. — Four 

 families belong to this order: (1) the Platanistid.e, or river 



Fig. 542. — The dolphin, Dclphinus delphis. (From Sedgwick's Zoology, 



after regne animal.) 



dolphins; (2) the Delphinid^:, or dolphins, porpoises, gram- 

 puses, and killer whales; (3) the Delphinapterid^e, or belugas 

 and narwhales; and (4) the Physeterid^e, or sperm whales and 

 beaked whales. 



Whales are adapted to life in the water. They possess a very 

 large head with elongated face and jaw bones; the fore limbs are 



Fig. 543. — Skull of Greenland whale, Balcena mysticetus, with the whale- 

 bone. (From Sedgwick's Zoology, after regne animal.) 



modified as paddles ; the tail is flattened horizontally and forms 

 two lobes, the " flukes " ; the eyes are small, and there is no exter- 

 nal ear. The nostrils form a single semilunar opening, and the 



