104 MOSTLY MAMMALS 
during life with huge claws, while the outermost was small 
and clawless. That during life the creature rested on the 
outer side of this fifth claw and the backs of the three 
large toes, in ant-eater fashion, may, from the structure 
and arrangement of their bones, be considered certain. 
Unlike the ant-eater, in which it rests upon the sole, the 
hind-foot of the Pleistocene ground-sloths is even more 
strangely modified than the front one, these creatures 
walking only on its outer edge, while the enormous 
middle toe, with its gigantic claw, does not appear to 
have touched the ground in walking, and was thus 
always kept sharp. The first toe is wanting, and the 
second rudimentary, while the two outer ones were rela- 
tively small and unprovided with claws. Some idea of 
the gigantic proportions of the megalothere may be 
gathered from the circumstance that its hind-foot measures 
nearly a yard in length. Of the pigmy ground-sloths of 
Patagonia the complete skeleton has not yet been de- 
scribed; but so far as my recollection of a specimen in 
the La Plata museum goes, I believe that it was not of 
the extremely specialised type characterising. the later 
gigantic forms. Moreover, while in the latter the terminal 
joints of the feet were neither grooved nor split at the 
extremities, in the small Patagonian species these were 
deeply cleft at the end, as in the scaly ant-eaters or 
pangolins of India and Africa. As regards the structure 
of the vertebral column, the ground-sloths exhibit certain 
peculiarities distinctive of the ant-eaters, which are only 
rudimentary in the sloths. 
When to this brief survey of the chief structural 
peculiarities of the skeleton of the creatures under considera- 
tion is added the circumstance that, from their enormous 
size, they must necessarily have been terrestrial in their 
