Turning to _South America_, we find in the pampas of Argentina a wonderful museum of Pleistocene mammals, such as occurs nowhere else in the known world, and this is supplemented by the very rich collections gathered from the caverns of Brazil and from deposits of Ecuador and Bolivia, and thus all the important regions of the continent, save the far south, are well represented. These faunas are far stranger than the corresponding ones of North America and differ more radically from those of modern times, since they include a much larger proportion of extinct types, and the extinctions have swept away not only species and genera, but families and orders as well. The South American Pleistocene assemblage of mammals is very clearly divisible into two elements: (1) the immigrants from the north, which reached the southern continent in successive waves of migration, that have left records of themselves as early as the older Pliocene, perhaps even the upper Miocene, and (2) the indigenous element, which had a very long history of development in South America. To the immigrant class belonged all of the Carnivora, which therefore resembled their North American relatives, but were less varied in character. Of the bears, only the huge, †short-faced kind (_†Arctotherium_, Fig. 275, p. 549) are known, and it is not likely that true bears existed except in the Andes, as is also the case to-day. Of the cat family, the †sabre-tooth tigers (_†Smilodon_) were as common in South America as in North, and, while there were no lions, there were large cats nearly allied to the Jaguar and Puma, and smaller ones, like the Ocelot. The dogs were quite numerously represented by species resembling closely the existing South American fox-like wolves and the Bush-Dog (_Icticyon_) and, strange to say, by one which seems referable to the same genus (_Cyon_) as the Dhole of India. The weasel family (Mustelidæ) were less numerous and varied than in the northern continent, as they still are; coatis (_Nasua_) and raccoons (_Procyon_) were abundant and one species of the latter was much larger than any existing one; extinct species of skunk (_Conepatus_), tayra (_Tayra_) and otter (_Lutra_) were also present, but the badgers, minks, martens and wolverenes were not. [Illustration: FIG. 118.—Some of the commoner Pampean mammals, reduced to a uniform scale, with a pointer dog (in the frame) to show the relative sizes. 1. _†Dœdicurus clavicaudatus._ 2. _†Glyptodon clavipes_, †glyptodonts. 3. _†Macrauchenia patachonica_, one of the †Litopterna. 4. †Pampas Horse (_†Hippidion neogæum_). 5. _†Toxodon burmeisteri_, a †toxodont. 6. _†Megatherium americanum_. 7. _†Mylodon robustus_, †ground-sloths.]