238 



FltfST LESSONS IN ZOOLOGY. 



4. Fore-limbs long, webbed, and 



adapted for flying C/ttroptera. Bats. 



5. Cetaceans; body fish-like in shape; 



no hind limbs Cetacea. Whales. 



6. Body fish-like in shape; teeth like 



those of ruminants Sirenia. Manatee. 



7. Snout prolonged into a proboscis . . Proboscidea. Elephants. 



8. Long curved incisor teeth; feet with 



pads; toes hoofed. Hyracoidea. Hyrax. * 



9. Toes hoofed Ungulata. Horse, Ox. 



10. Teeih pointed for tearing flesh ; 



claws large . . Carnivora. Dog, Cat. 



11. Nails usually present; walking on 



all-fours; or using fore legs as 

 hands, or erect and walking on 

 the hind legs Primates. Monkey, Ape, Man. 



The Toothless Brutes. The most remarkable examples of 

 adaptation to very different modes of life occur in this 

 group. Look at the sloth (Fig. 237). On the ground it 



is the most helpless of brutes. Its 

 great claws and small feet render it 

 absolutely helpless, but in the tops of 

 trees it is an excellent climber. Its 

 front teeth are wanting, and the back 

 teeth become sharp with use, like chis- 

 els, with which to crush boughs and 

 leaves of trees. In disposition the 

 sloth is very sluggish, since its food 

 is near at hand, while it is protected 

 from its enemies by living in the tops 

 of tall forest trees in Brazil. Its fur 

 is so near in hue to the moss which 

 grows on the branches that it is diffi- 

 cult for the hunter, whether a man or 

 a panther, to perceive it. 

 Quite different in all respects are the ant-eaters. Though 

 they live on animal food, yet they have no teeth; but as a 

 compensation, the jaws are remarkably long, while the 

 tongue is of great length, slender, and extensible. Thus 



FIG. 237 Ai, or Three- 

 toed Sloth, in its natural 

 attitude. 



