A LAND OF SKELETONS 75 



The rich black alluvial mud of the Pampas, which, as 

 we have seen, is entirely of fresh-water origin, is, how- 

 ever, the'; tomb of thousands, if not millions, of the 

 skeletons and bones of a host of extinct animals, which 

 tell us that the country was once inhabited by a fauna 

 stranger than that found in any other part of the world at 

 any epoch of its history. While many of these extinct 

 creatures were allied to the existing South American 

 mammals, although of vastly greater bodily size, others, of 

 equally gigantic dimensions, were quite unlike all known 

 animals, either living or extinct. As some of these extinct 

 mammals are noticed in the next article, I make but brief 

 mention of them here. It may be observed, however, that, 

 while the gigantic glyptodons were the representatives of 

 the diminutive armadillos of to-day (although some of the 

 latter flourished side by side with their huge cousins), 

 the megalothere, which rivalled an elephant in bulk, together 

 with its allies the mylodons, were akin both to the sloths 

 and the ant-eaters of Brazil, and as they were certainly 

 terrestrial in habits, they are called ground-sloths. From 

 the structure of these animals, which were evidently adapted 

 to sit up on their massive haunches and tear down the 

 branches of trees with their powerful front claws, it may 

 be inferred that the physical features of this part of 

 Argentina were once very different from what they 

 are at present, and that in place of continuous tracts of 

 unbroken grassy plain there were probably large areas 

 of forest-land, as in Brazil at the present day. In these 

 forest tracts probably wandered the two species of mas- 

 todons which were the contemporaries of the ground- 

 sloths ; but the existence at the same time of several 

 species of horses (some closely akin to living species, 

 while others were markedly distinct) seems to point to 



