188 EDENTATA 
phalanges, and no claws. The creature probably walked upon the 
outer edge of the sole, so that the great falcate claw of the third 
toe did not come into contact with the ground, and so was kept in 
a state of sharpness ready for use. The foot was therefore formed 
upon quite a different principle from that of the Anteaters or 
Sloths, though somewhat like the latter in having two of the toes 
aborted. 
Taking all the various points of its structure together, they 
clearly indicate affinities both with the existing Sloths and with 
the Anteaters, the skull and teeth more resembling those of the 
former, and the vertebral: column and limbs the latter. It is also 
not difficult to infer the food and habits of this enormous creature. 
That it was a leaf-eater there can be little doubt; but the greater 
size and more complex structure of its teeth might have enabled it 
to crush the smaller branches as well as the leaves and succulent 
shoots which form the food of the existing Sloths. It is, however, 
very improbable that it climbed into the branches of the trees like 
its diminutive congeners, and it is far more likely that it obtained 
its subsistence by tearing them down with the great hook-like claws 
of its powerful prehensile fore limbs, being easily enabled to reach 
them by raising itself up upon the massive tripod formed by the 
two hind feet, firmly fixed to the ground by the one huge falcate 
claw, and the stout, muscular tail. The whole conformation of 
the hinder part of the animal is strongly suggestive of such an 
action. There can also be little doubt but that all its move- 
ments were as slow and deliberate as those of its modern repre- 
sentatives. 
An idea at one time prevailed that the Megatherium was 
covered externally with a coat of bony armour like that of the 
Armadillos ; but this originated in dermal plates belonging to the 
Glyptodon having been accidentally associated with bones of the 
Megatherium. Similar plates, on a smaller scale, have indeed been 
found in connection with the skeleton of the Mylodon, but never 
yet with the Megatherium, which we may therefore imagine with 
a covering of coarse hair like that of its nearest living allies, the 
Sloths and Anteaters. 
Scelidotherium, Mylodon, etc.—Of the more important remaining 
genera of this family a briefer notice will suffice. Scelidotherium (in 
which Platyonyx may be included) comprises several species of 
considerably smaller dimensions than the Megatherium, and is in 
some respects intermediate between that genus and Alylodon. The 
teeth have an oval cross-section, like those of the Sloths, while the 
skull, in which the length of the nasals is subject. to great variation 
in the different species, approximates more or less closely to that 
of the Myrmecophagide. The humerus generally has an ent- 
epicondylar foramen ; and the form and relations of the bones of 
