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Black Rhinoceros (R. africanus) extends from the Cape all up the Eastern side of Africa into the plains of the Atbara and Upper Nile.

The Oriental Rhinoceroses are three in number. Two of these have only one horn on the nose, while the third is provided with two of these appendages. Of the former the large Indian Rhinoceros (R. unicornis) appears to be confined to the North-eastern provinces of the Indian Peninsula, whilst the smaller one-horned form (R. sondaicus) ranges from the Sunderbunds of Bengal through the Malay Peninsula down to Java, Sumatra, and perhaps Borneo. The third Oriental species, the Sumatran Rhinoceros (R. sumatrensis), has nearly the same range as the last-named species, but appears to extend rather farther north. Thus we may consider the existing Rhinoceroses as typical forms of the Ethiopian and Oriental Regions, but not to be met with in any other part of the world's surface.

Section V.—Distribution Of Tapirs

The second family of Perissodactyle Ungulates, the Tapirs, has a still more remarkable distribution. Out of the five known species four belong to the Neotropical Region, while the fifth, which in some respects is more closely allied to one of the American Tapirs than the American Tapirs are to one another, is an inhabitant of the Oriental Region, being met with only in the Malay Peninsula and Sumatra. This is a good instance of the rare phenomenon of "discontinuous distribution" which, however, may be explained by the fact known from geology

that the Tapirs were formerly a prevalent group over a large portion of the earth's surface, so that in these days we have only to deal with a few scattered remnants of a former considerable series.

Of the American Tapirs two (Tapirus bairdi and T. dowi) are found in Central America, a third (T. roulini) occurs in the Andes of Colombia and Peru, and a fourth {T. a/mericanus) is widely distributed over the South American continent from Venezuela to Paraguay.

The Tapirs may be therefore considered as a characteristic form of the Neotropical and Oriental Regions, and a "lipomorph" or absent form in all other parts of the world's surface.

Section VI.—Distribution Of Horses

The third family of Perissodactyle Ungulates comprises the Horses (Equidm)} now a very isolated group, although allied to the Tapirs by many extinct intermediate forms. The Horses at present known to exist in a state of nature belong to about nine species, of which three may be attributed to the Palsearctic Region and six to the Ethiopian. Among the Palsearctic species the recently discovered Equus prjevalskii of the deserts of Central Asia is the sole living representative of the typical section of the genus Equus with callosities on both the fore and hind limbs. The other eight species all belong to the Asinine section, with callosities upon the hind limbs only. Unless it shall turn out to have been Equus prjevalskii, the exact

1 On the species of Horse, consult Sir William Flower's "The Horse" (London, 1891, Kegan Paul 4; Co.).

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progenitor of our domestic Horse is extinct, but it was in all probability of Pahearctic origin.

The two Asses of Asia are the Kiang of High Tibet (Equus kiang), which is a larger animal clad with a thick coat of fur in winter, and the smaller, more sandy-coloured and thin-coated Onager (Equus onager), which occurs in many parts of the deserts of Western Asia and intrudes into the Oriental Region in Cutch. Passing on to Africa we find two members of the Asinine section still wild in the North-eastern part of that continent. These are Equus tmniopus of the deserts of Nubia and E. somalicus of Somaliland. The former of these was probably the origin of our domestic Ass (Equus asinus). Going farther southwards into Africa we meet with four distinct species of the beautifully striped Asses commonly called Zebras, viz. (1) the Quagga (E. quagga) of the Cape Colony, now nearly, if not quite, extinct; (2) the Mountain Zebra (E. zebra) also confined to Africa south of the Zambesi, and now becoming extremely rare; (3) Burchell's Zebra (E. burchelli) distributed under slightly varying characters from the Transvaal to British East Africa along the eastern portion of the continent; and (4) GreVy's Zebra (E. grevii) of southern Abyssinia and Somaliland.

The Horses (Equidm) of the present epoch may, therefore, be regarded as characteristic of the Palaearctic and Ethiopian Regions.

Section VII.—Distribution Of Bovine Mammals

At the head of the great Arctiodactyle section of the Ungulates, which we now enter upon, we meet with the numerous and important family Bovidm, to the variety and extent of which in the present day we have already alluded. The Bovidm in fact contain nearly two-thirds of the species of Ungulate animals now existing on the world's surface, and embrace at least 200 species belonging to forty-five distinct genera, amongst which are the Sheep, Ox, and Goat, the animals of which the flesh is mostly used for food by civilized man.

According to the arrangement of Flower and Lydekker, the Bovidm are divisible into about ten sub-families, the seven first of which embrace the mammals commonly known as Antelopes. These are mostly met with in the more open districts of the Ethiopian Region, where in former days they roamed about in exuberant multitudes, but have been sadly diminished at the present time by the persecutions of the sportsman and the hunter. We have not space here to go into the numerous and varied forms of Antelopes, but must refer our readers who wish for special information on that subject to "The Book of Antelopes" now in process of publication. It must suffice to say that the roll of Antelopes numbers some 150 species, of which 9 are attributable to the Palaearctic Region, 4 to the Oriental, and 135 to the Ethiopian Region. Three of the Oriental species belong to peculiar genera restricted to that Region, and the fourth is a Gazelle, a member of a genus which is also well represented in the Palsearctic and Ethiopian Regions. It is therefore evident that the Antelopes, although slightly represented elsewhere, form one of the most predominant and characteristic features of the Ethiopian Region.

The Rupicaprinm, forming the eighth sub-family of Bovidm, and containing what are commonly called the Mountain-Antelopes, have a very different distribution They are absolutely unknown in the Ethiopian Region, and are found mostly in the Palaearctic Region with stray species in the Oriental and Nearctic Regions. The wellknown Chamois (Rupicapra) is the typical form of this group. It is confined to the western portion of the Palsearctic Region, and is the single species of the genus. In Eastern Palsearctica it is represented by the genera Cemas and Nemorluedus, some species of which occur also on the higher mountain-ranges of the Oriental Region. In the Nearctic Region the Rocky Mountain Goat (Haplocerus montanus) is the sole representative of the Mountain-Antelopes.

The Goats and Sheep (Caprinm), which follow next, have nearly the same sort of distribution. It should be mentioned that the distinctive differences between the Goats and Sheep, from a structural point of view, are very difficult to define; and that the two forms are so nearly allied that it has been proposed by some naturalists to unite them into one genus. The Caprinm altogether, although by no means satisfactorily worked out at present, may be held to embrace some twenty-six species, of which nineteen are Palaearctic, two are Nearctic, five are Oriental, and one species only (Capra walie of the high ranges of Abyssinia) occurs within the confines of the Ethiopian Region. The Caprinm are represented in the Nearctic Region by two, or possibly three, species of Sheep, which extend from Alaska, along the main range, nearly down to Northern Mexico.

Finally closing the long list of the family Bovidm we have the oxen, or typical Bovinm, embracing about twelve or thirteen species, and thinly distributed over the

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