558 CHORDATA. 
extra articular processes. The sub-order is entirely re- 
stricted to the Neogeean realm (South America). 
Family I.—Bradypodidz or Sloths.—Purely arboreal, leaf-eating 
animals ; Bradypus has been described. We may recall (1) the adapta- 
tion to arboreal habit ; (2) the low eutherian characters shown in a bi- 
partite uterus, occasional presence of a complete coracoid and varying 
number of cervical vertebrae. They are found only in forests of South 
America. 
Family II.—Megatheriidee or ground sloths.—Extinct terrestial 
forms, occurring backwards from the Pleistocene. They are closely allied 
to the sloths, but show certain resemblances to the anteaters. They 
'Fig. 382, —TAMANDUA ANTEATER (Tamandua tetradactyla. ) 
(From Proc. Soc., 1871., PL, xxti1.) 
were apparently huge hairy monsters, that fed upon leaves of trees. 
Megatherium walked upon the outer side of the feet, on pads covering 
the fifth digit of the front-limb and the fourth and fifth of the hind-limb. 
The second, third and fourth digits of the front-limb and the third of the 
hind-limb were armed with huge claws. JZylodon was another well- 
known form which may possibly still survive in parts of South America. 
Family III. —Myrmecophagidz or Anteaters. — These show a 
similar adaptation to anteating to that already noticed in Echidna. 
There are no teeth, the mandible is rudimentary, facial region tapering 
and terminating in a small round mouth. The tongue is very long 
and copiously supplied with saliva from the large submaxillary glands. 
The tail is usually long and in the tree-anteaters is prehensile. The 
