FAUNA OF THE POST-PLIOCENE. 351 



towards the palm of the hand. As in the great majority of 

 the Edentate order, incisor and canine teeth are entirely 

 wanting, the front of the jaws being toothless. The jaws, 

 however, are furnished with five upper and four lower molar 

 teeth on each side. These grinding teeth are from seven to 

 eight inches in length, in the form of four-sided prisms, the 

 crowns of which are provided with well-marked transverse 

 ridges; and they continue to grow during the whole life of 

 the animal. There are indications that the snout was pro- 

 longed, and more or less flexible; and the tongue was proba- 

 bly prehensile. From the characters of the molar teeth it 

 is certain that the Megathere was purely herbivorous in its 

 habits ; and from the enormous size and weight of the body, 

 it is equally certain that it could not have imitated its modern 

 allies, the Sloths, in the feat of climbing, back downwards, 

 amongst the trees. It is clear, therefore, that the Megathere 

 sought its sustenance upon the ground ; and it was originally 

 supposed to have lived upon roots. By a masterly piece of 

 deductive reasoning, however, Professor Owen showed that 

 this great " Ground-Sloth " must have truly lived upon the 

 foliage of trees, like the existing Sloths but with this differ- 

 ence, that instead of climbing amongst the branches, it actually 

 uprooted the tree bodily. In this tour de force, the animal 

 sat upon its huge haunches and mighty tail, as on a tripod, 

 and then grasping the trunk with its powerful arms, either 

 wrenched it up by the roots or broke it short off above the 

 ground. Marvellous as this may seem, it can be shown that 

 every detail in the skeleton of the Megathere accords with the 

 supposition that it obtained its food in this way. Similar 

 habits were followed by the allied Mylodon (fig. 261), another 

 of the great " Ground-Sloths," which inhabited South America 

 during the Post-Pliocene period. In most respects, the Mylo- 

 don is very like the Megathere ; but the crowns of the molar 

 teeth are flat instead of being ridged. The nearly-related 

 genus Megalonyx, unlike the Megathere, but like the Mylodon, 

 extended its range northwards as far as the United States. 



Just as the Sloths of the present day were formerly repre- 

 sented in the same geographical area by the gigantic Megathe- 

 roids, so the little banded and cuirassed Armadillos of South 

 America were formerly represented by gigantic species, con- 

 stituting the genus Glyptodon. The Glyptodons (fig. 262) 

 differed from the living Armadillos in having no bands in 

 their armour, so that they must have been unable to roll 

 themselves up. It is rare at the present day to meet with any 

 Armadillo over two or three feet in length; but the length of 



