NEOTROPICAL REGION 103 



most distinctive are the Pouched Rats {Geomyidce), and the Beaver-like 

 rodents known as the Hajolodontidce. True Rats and Mice (Mus), 

 which are represented throughout the Old World, are totally wanting 

 in the New, where they are replaced by the Vesper-mice, which may 

 be included in the European genus Oricettis, although often separated 

 as Hesperomys. This feature alone would seem to justify the dis- 

 tinction of the Nearctic from the Palsearctic region. The Musquash 

 (Fiber) is a genus of Nearctic rodents unknown in the Old World. 

 Among other characteristic genera we may mention, in the Carnivora, 

 the Skunk (Mephitis) and the American Badger (Tazidea). Primates 

 are absent from the entire region. 



Neotropical Region. — The last of the six main regions is the 

 Neotropical, including Mexico, South America, and the West Indies. 

 A very large extent of this area is occupied by forests, which are 

 described as being denser and more luxuriant than those of any 

 other part of the globe. Alternating with these forest areas are 

 the vast grassy plains known in different regions as llanos, savannas, 

 and pampas. The back-bone of the region is formed by the great 

 chain of the Andes. Next to the Australasian, this region is 

 perhaps better characterised by its mammalian fauna than any of 

 the others. Commencing with the Ungulates, we find a total 

 absence of Antelopes, Sheep, and Oxen, and also of all Perissodac- 

 tyles except Tapirs. Deer are, however, represented, although by 

 peculiar forms (Cariacus) unknown beyond the New World. The 

 Peccaries (Dicotyles), Avhich are often made the type of a distinct 

 family, take the place of the Old World Pigs, while the Llamas and 

 Alpacas (Auchenia) are the substitutes for the Palsearctic Camels. 

 The Carnivora include several Cats (Felis), among which the Puma 

 and the Jaguar are the most noticeable ; and there are also Racoons, 

 Coatis, Foxes, and one species of Bear. Insectivora are totally 

 wanting ; but the Bats are characterised by the presence of the 

 Vampyres (Phyllostomatidce), which are almost restricted to this 

 region. The Rodents likewise include three families unknown 

 elsewhere, namely the Chinchillas and Viscacha (Chinchillidce), the 

 Agouties (Dasyproctidce), and the Cavies (Caviidce) ; while a large 

 number of the Octodontidce are Neotropical, all the other forms 

 being Ethiopian. In the Primates, again, we have all the forms 

 quite peculiar to this region, and constituting two families, viz. the 

 Cebidce or Prehensile -tailed Monkeys, and the Hapalidce, or Mar- 

 mosets, both of which differ decidedly in their dentition, as well 

 as in other features, from the Old World Monkeys. Lemuroids 

 are unknown. Perhaps, however, the mammals which may be 

 considered as most characteristic of the Nearctic region are the 

 numerous Edentates, which form three families, mostly confined to 

 it. These comprise the Bradypodidce or Sloths, which solely 

 inhabit the forest region ; the Myrmecopliagidce or Anteaters ; and 



