CLASS MAMMALIA 



673 



FIG. 540. The African elephant, Loxodonta aj'ricanus. (From Beddard, 

 after Baker.) 



Order Sirenia. SEA-COWS. This order contains four species 

 of manatees (genus Manatus) , one on the Atlantic coast of Africa, 

 and three on the Atlantic coast of America; and three species 

 of dugongs (genus Dugong) on the shores of the Red Sea, Indian 

 Ocean, and Australia. 



Steller's sea-cow (Rhytina) formerly inhabited the north 

 Pacific, but became extinct about 1768 because its fearlessness 

 enabled hunters to kill it 

 easily. Sea-cows differ con- 

 siderably in structure from 

 whales. Their bones are 

 heavy, enabling them to 



remain on the bottom; the FIG. 541. The American manatee, 



teeth are broad and crush- ^^ r l } atlrostris - (From Flower and 

 .ing; the lips ate large and 



movable and are used to seize seaweeds and other water-plants 

 upon which they feed ; the fore limbs are flexible flippers ; 



2 X 



