226 LAND MAMMALS IN THE WESTERN HEMISPHERE 



same as that of the Pleistocene and contained a similarly large 

 proportion of migrant elements from the north, but it was evi- 

 dently older and many of the species were different. The two 

 divisions of the Araucanian fauna, contained in the beds of 

 Catamarca and Monte Hermoso respectively, are very much 

 alike and need not be given separate consideration. In one 

 respect these presumably upper Pliocene faunas formed a very 

 strong contrast to the mammalian assemblage of the Pleistocene, 

 and that is in the quite insignificant part taken by the migrants 

 from North America. Of the Carnivora there were but two 

 representatives, one referable to the raccoon family and one 

 to the dogs, while a hare and a small member of the Artio- 

 dactyla, of indeterminate family, complete the Ust of northern 

 forms, though this list will doubtless be extended by future 

 discovery. The peccaries, deer, antelopes, tapirs, horses, 

 fmastodons, cats, weasels, otters, squirrels, mice, etc. had not 

 reached the southern continent, or were still so rare that 

 remains of them have not been found. This rarity and relative 

 insignificance of the northern forms gave a very different aspect 

 to the fauna. 



On the other hand, the indigenous South American groups 

 were very fully represented. Many kinds of opossums and 

 a few large carnivorous types, much like the so-called Tas- 

 manian Wolf (Thylacynus) , were the remnants of a much 

 larger assemblage of marsupials which inhabited South 

 America in the Miocene. Of the Edentata, there were great 

 abundance and variety, many large fglyptodonts and some 

 gigantic armadillos, as well as numerous examples of normal 

 size ; the jground-sloths, though somewhat smaller than those 

 of the Pleistocene, were mostly of gigantic size, and true or 

 arboreal sloths (Tardigrada) have been reported. The very 

 numerous rodents, with the exception of the intrusive hare, 

 all belonged to typically South American families. Some of 

 the rodents were gigantic and one {'\Megamys), a member of 

 the Chinchilla family, was equal to a rhinoceros in size and 



