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(2) Land where Euther-^

ians and Marsupials
occur; no Insecti-
vores; many Eden-
tates; no Mono-
tremes

(3) Land where Euther

ians only occur; few
Edentates, no Mar-
supials1 nor Mono-
tremes

America south of the Isth- \
mus of Tehuantepec. J

Europe, Asia, Africa, Asia-
tic Islands down to Wal-
lace's line, and North
America down to the
Isthmusof Tehuantepec. J

Arctogoea.

The fault of this division is that it leaves the great mass of land in the Northern Hemisphere undivided and rather unmanageable. But this northern land is easily separable into four sections, although it should be understood that these four sections are not of equivalent value to the two other primary divisions. Thus we obtain a division of the land-area of the globe for mammals into six areas, which are called Regions (see Plate I., p. 16), and which may be shortly defined and named as follows:—

it

Australia, New Guinea, and adjacent| islands up to Wallace's line .

j- I. Australian Region.

i fCentral America south of the Isthmus-!

g -J of Tehuantepec, the West Indies, and J- II. Neotropical Region.

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South America

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Africa south of the Atlas, and Madagascar III. Ethiopian Region.

South Asia, the Philippines and Islands of-j the Indian Archipelago down to Wal- J- IV. Oriental Region. lace's line, and Celebes J

1 As will be shown later on, this statement is not absolutely correct as regards North America, as at least one species of marsupial occurs within its limits.

«, _ [ North America down to the Isthmus) TT .. „ . || ofTehuantepec . . . ) ^-Nearctu Region.

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S ■5

a 5 Europe, Africa north of the Atlas, and) TrT „ , .. „ . <S -Tr' \ VI. Palaarctic Hegum.

^ ~ v Northern Asia . . . . ) J

We will now take a brief survey of the principal features of these six regions—as shown in the accompanying chart (Plate I., p. 16) and their most characteristic mammal-forms.

1.—Australian Region Extent.—Australia, New Guinea, and Moluccas up to Wallace's line, New Zealand, and the numerous islands of the Pacific.

Characteristics.—Absence of nearly all Eutherian Mammals, except a few Rodents and Bats; presence of six distinct families of Marsupials with one hundred species, and the only two known forms of Monotremes.

2.—Neotropical Region

Name.—i/e6?, new, and Tpcm-ucos, i.e., tropical land of the New World.

Extent.—America, south of the Isthmus of Tehuantepec, and the West Indies.

Characteristics.—Monkeys of the peculiar families Cebidm and Hapalidm; absence of Frugivorous Bats, and presence of Vampires (Phyllostomatidm); abundance of the Porcupine family; absence of Insectivores and Civets, also of Elephants; presence of Tapirs; no Ruminants except Deer and Lamas; presence of Sloths, Ant-eaters, and Armadilloes; one family of Marsupials— Opossums.

3. —Ethiopian Region

Name.'AWUnres, ancient name for negroes.

Extent.—Africa, south of the Atlas; Arabia up to the Persian Gulf, and Madagascar.

Characteristics. — Chimpanzee and other Monkeys; absence of Bears and Deer; presence of Lion, African Elephant, Hyrax, Rhinoceros, Hippopotamus, Wart-hog, numerous Antelopes, Giraffe, Pangolin, Ant-bear—general richness in large and highly-organised Ungulates.

4. —Oriental Region

Extent.—Southern Asia, south of the Pakearctic Region, and islands of Indian Archipelago down to Wallace's line, including Celebes.

Characteristics.—Orangs, Gibbons, and other peculiar Monkeys. Flying Lemur, Tiger, and other cats, Indian Elephant, Rhinoceros, Malayan Tapir, Manis.

Generally, it may be said that the peculiar forms of the Oriental Region are fewer than in the Ethiopian Region, and that the Oriental Region has Bears, Deer, and Tapirs, which are wanting in the latter.

5. —Nearctic Region

Name.—veo?, new, and ap/cros, north, i.e., northern district of the New World.

Extent.—North America, down to the Isthmus of Tehuan tepee.

Characteristics.—General mammal-fauna, very like that of the Palsearctic Region, but mixed up with endemic forms and intruders from the south. Bears, Beavers, Sheep, and Deer similar; Prong-buck, Pouched Mice, and Musquash peculiar; Raccoon and Opossum, probably derived from the south.

6.—Palsarctic Region

Name.irakaibs, ancient, and ap/ero?, north, as embracing the whole northern area of the Old World.

Extent.—Whole of the Eastern Hemisphere north of a line on the south of the Atlas, and running eastward through the south of Palestine and Persia, along the Himalayas, through Central Asia and the centre of China to the Pacific.

Characteristics.—Absence of Monkeys, Lemurs, and Frugivorous Bats; abundance of Carnivores—Ounce, Lynxes, Wolves, Foxes, Bears, and Weasels; Rodents— Marmots, Beavers, Pikas; Ungulates — Sheep, Deer, Chamois, and Musk-deer; no Elephants nor Hyrax.

This division of the Earth's surface into six regions was first proposed by one of the authors of the present work in an essay on the distribution of the Class of birds read before the Linnsean Society in 1857 (9). It was further elaborated and upheld in an address given to Section D. of the British Association at the Bristol Meeting in 1875 (10), and in a Paper published in The Ibis in 1891 (11). The same system was adopted by Mr. Wallace in his standard work on "Geographical Distribution" (13), and was there shown to be applicable to the other principal groups of terrestrial animals. Moreover, the names then bestowed on the six great primary Regions are now in general use among naturalists in all countries. Mr. Wallace, who has devoted many pages to the discussion of this subject,1 has come to the conclusion that, admitting that these six regions are not precisely equal in rank, and that some of them are more isolated than the others, they are in geographical equality, compactness of area, and facility of definition beyond all comparison better than any others which have been suggested for the purpose of facilitating the study of geographical distribution.

Notwithstanding Mr. Wallace's strong support, however, it is right to say that this system has not been universally accepted. Professor Huxley (6) in 1868 proposed to separate the world into two divisions—Arctogsea and Notogsea, the former containing the Nearctic, Palsearctic, Ethiopian, and Oriental Regions, and the latter the Neotropical and Australian Regions. He adopted the Nearctic, Palsearctic, Ethiopian, and Oriental Regions as subdivisions of Arctogsea, and only stipulated for the formation of a Circum-polar province independent of the Nearctic and Palsearctic Regions. Notogsea Professor Huxley divided into three provinces (a) the Austro-Columbian ( = the Neotropical), (6) the Australian (= the Australian Region minus New Zealand), and (c) the New Zealand province.

From this it will be seen that Professor Huxley's scheme does not really diverge materially from the system here employed; the chief points of difference being (a) the uniting together of the Australian and Neotropical Regions into Notogsea; (b) the formation of independent Circumpolar and New Zealand provinces. With regard to the first point, almost the only bond of union between the Australian and Neotropical Regions, so far as mammals, at any rate, are concerned, is the presence of Marsupials 1 "Geographical Distribution of Animals," vol. i., chap. iv.

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