DISTRIBUTION 163 



sented by the opossums and Ccrnolestcs, nearly related to the Australian Di- 

 protodonts; among birds the humming-birds, toucans, Cotingidae, Tanagrichc, 

 Tinamous, Palamedidae, Rhea, etc. The almost entire absence of insect! vores 

 and the considerable development of rodents (cavies, agoutis, chinchillas) are 

 noteworthy. 



The four remaining provinces are still closely connected geographically and 

 form a third great division, 'Arctoga-a,' characterized by the entire absence of 

 platyrhine apes, monotremes, and, except the North American opossum, of 

 marsupials. In the secondary and tertiary times the northern parts of these 

 lands were connected and an interchange of faunas occurred, this being the 

 easier on account of the extension of the warm climate to the far north. Hence 

 many unite the palasarctic and nearctic provinces into a 'holarctic' province, but 

 when existing conditions are concerned it is better to retain them as distinct. 



(3) The Nearctic region has three mammalian families, the prong-horned 

 antelope, the opossums, and the Haplodontae, peculiar to it; of the group of 

 Amphibia, the Sirenidae and Amphiumidae. The Nearctic is distinguished 

 from the nearly related palasarctic region through the crowding in of neotropical 

 forms like the raccoon, opossum, humming-birds, etc. The absence of the stag, 

 badger, wild swine and all true mice is noticeable. 



(4) The Pahearctic region covers the greatest area and consequently touches 

 several others; hence climate and great distances have caused important differ- 

 ences between the local faunas, but its contact with other regions explains the 

 fact that it has no peculiar families. Deer, cattle, sheep, and camels have 

 reached a great development; especially conspicuous genera are the chamois, 

 squirrel, badger, and marmot. 



(5) The Ethiopian region has many animals found only there; among li 

 the hippopotamus, giraffe, the recently discovered Oeapia, the aardvark, and, if 

 we include Madagascar, the lemurs are characteristic. To these are added a 

 rich development of antelopes and zebras and the gorilla and chimpanzee. 

 Equally noteworthy is the entire absence of striking families and genera, such 

 as the bears, moles, deer, goats, tapirs, sheep, and the true swine. 



Within the region the island of Madagascar occupies a remarkable position. 

 This is the land of lemurs and Insectivora, the majority of the genera of lemurs 

 living exclusively in Madagascar. On the other hand, the large beasts of prey, 

 all the true apes, antelopes, elephants, and the various species of rhinoccro- arc 

 absent. Consequently, since Madagascar is conspicuously distinguished from 

 Africa, many zoologists separate the island from the Ethiopian region as an 

 independent Malagassy province. 



(6) The Oriental region contains, next to Madagascar, the most lemurs 

 among which the Tarsidae and Galeopithecidae arc exclusively oriental. Re- 

 markable inhabitants are the gibbons and orang-utans, musk-deer, numerous 

 families and genera of birds. 



Arctic and Antarctic Provinces. Of late the view has gained ground 

 that, besides these six, two other, circumpolar, provinces must he distinguished, 

 the Arctic and the Antarctic. Both have a fauna consisting of few specie.- but 

 numerous individuals, of which the auks, polar bear, reindeer, and arctic foxes 

 are characteristic of the northern or arctic region, the penguins and the entire 

 absence of land mammals of the antarctic. 



The Distribution of Aquatic Animals. Since most seas are connected, 

 the faunal regions cannot be distinguished so sharply as in the case oi the land 

 faunas; conspicuous differences are present only when two oceans are separated 

 by continents extending far to the north and south; such, for example, i-xi-t 

 between the Red Sea and the Mediterranean, between the east and west coa 

 of North America, even where they are separated only by the isthmus of Panama. 



