III.] SLOTHS AND ANTEATERS. IOI 



not be taken as an indication that they did not exist during the 

 Pampean epoch, since their remains are not likely to occur in 

 the Argentine, although they might with more probability be 

 looked for in Brazil. On the other hand, their specialised struc- 

 ture makes it highly probable that they had not come into being 

 at the date of deposition of the Santa Cruz beds. Of the dimen- 

 sions of medium-sized monkeys, sloths are characterised by their 

 short, rounded heads, and extremely long limbs, armed with very 

 elongated curved claws ; in the genus Bradypus the latter being 

 three in number on each foot, but in Cholcepus reduced to two 

 in the fore feet. Their bodies are coated with very coarse ragged 

 hair, and the tail is wanting. The teeth are oval prisms, some- 

 what cupped in the middle of their grinding surfaces ; but in 

 the last-named of the two genera the first pair in each jaw are 

 larger than the rest, from which they are separated by an interval, 

 and form tusks wearing against one another to oblique facets. 

 Usually there are five upper, and four lower teeth on a side. 

 The range of sloths extends from Mexico throughout the greater 

 part of the forest-districts, although they do not appear to reach 

 as far south as Paraguay. 



Likewise unknown in a fossil condition, the true anteaters, or 

 Myrmecophagidce, constitute another exclusively Neo- 



.. ' . . i , Anteaters. 



gseic family, with nearly the same geographical range 

 as the sloths, but represented in Paraguay. So unlike are these ani- 

 mals to sloths, that it is at first difficult to believe that there is any 

 close relationship between the two, and it is largely due to the evi- 

 dence of the ground-sloths referred to below that it has been possible 

 to discover how close the connection really is. In place of being 

 rounded and shortened, the skull in the present family is more or 

 less elongated and slender, with the jaws entirely devoid of all 

 vestiges of teeth, and the tongue long, cylindrical, and extensile. 

 An equally striking difference obtains in regard to the structure of 

 the limbs, the fore foot of the great anteater having five toes, of 

 which the middle one is much more powerful than the others, 

 while all except the fifth are furnished with strong claws. In 

 walking, the outer side and part of the upper surface of the fore 

 foot is applied to the ground ; but in the hind limbs the sole 

 forms the support in the ordinary manner. Whereas sloths are 



