738 • EDENTATA. 



them, they leave on our mind a very different impression. They em- 

 brace the branches with their strong arms, and bury in the bark the 

 enormous claws which terminate their four limbs. As the last joint of 

 their toes is movable, they can bend them to a certain extent, and thus 

 convert their claws into powerful hooks, which enable them to hang on 

 trees. Hidden in the densest foliage, they browse at their ease on all 

 that surrounds them ; or, firmly fixed by three of their legs, they avail 

 themselves of the fourth to gather the fruit and convey it to their mouths. 

 They appear sleepy during the day, their eyes not being fitted for sun- 

 light. Their stomach, like that of the ruminants, is divided into four 

 compartments, but it is not known whether they chew the cud. They 

 have no tail, or visible ear. Their fur is harsh, long, and abundant. 



GENUS CHOLOEPUS. 



The two species are sloths with two toes on the fore-limbs, and the 

 sexes are alike in appearance. They are found in the virgin-forests from 

 Costa Rica to Brazil. 



The Two-toed Sloth or Unan, Choloepus didactylus (Plate LX1), 

 measures about thirty inches in length. The hair on the forehead and 

 neck is of an olive-green gray color ; on the body, olive-gray ; on the 

 breast, olive-brown. The muzzle is hairless and flesh-colored ; the soles 

 of the feet are also flesh-colored, while the nails are bluish-gray. They 

 pass their whole lives suspended with their backs downward from the 

 branches of trees, hooking their curved talons over it. Their food con- 

 sists of leaves, buds, and young shoots. 



GENUS BRADYPUS. 



The Sloths forming the two species of this genus possess three toes 

 on the fore-limbs, and extend from the Amazon River to Rio de Janeiro. 



The Ai or Three-toed Sloth, Bradypus tridactylus (Plate LXI). 

 is rather smaller than the Unan. The color of this animal is rather 

 variable, but is generally of a brownish-gray, slightly variegated by 

 differently tinted hairs, and the head and face being darker than the 

 body and limbs. The hair has a curious hay-like aspect, being coarse, 

 flat, and harsh toward the extremity, although it is very fine toward the 



