CLASS MAMMALIA. 



201 



puncture, through which it sucks the blood of its victim 

 till gorged. The bite, however, is rarely serious.* 



ORDER CETACEA (se ta'shi a). 



The Cetaceans are swimming carnivorous mammals, 

 and destitute of hair. They have blow-holes on the top 

 of the head, sometimes called nostrils, though it is prob- 

 able that the sense of smell is but poorly developed, and 

 in some forms it is entirely wanting. The fore limbs 

 consist of a shoulder-blade, humerus, radius, ulna, wrist- 

 bones, and five fingers. There is no external evidence of 

 hind limbs. The tail is horizontally flattened and fluked. 

 They progress mainly by vertical movements of the 

 horizontal tail, in marked contrast with the lateral 

 movements of the vertical tail of fishes. They may be 

 classified according to the disposition of the teeth : 



Teeth in both jaws, 

 Teeth in lower jaw, 

 Teeth wanting, 



Dolphin. 



Sperm-whale. 



Right-whale. 



FIG. 348. 



Belu'ga can a den' sis. White Whale. ( T A 3 .) Del phi' nits del' phis. 



The Beluga (be lu'ga), of the Arctic Seas, is remark- 

 able when mature for the clear white hue of its skin, 

 though when young it is black. 



* Most exaggerated stories have been reported by travelers, as that the Vam- 

 pire, winging its silent flight in the darkness, poises itself over the exposed toe 

 of an incautious sleeper, and painlessly extracts his life-blood, all the while by 

 gentle fanning inducing a deeper slumber, until its victim expires. 



