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ness, and that the remaining Sub-regions all resemble one another more or less closely, and are difficult of separation.
This Sub-region, which is so distinct from the others, consists of the large island of Madagascar, together with the island-groups in its immediate vicinity, viz., the Comoros, the Seychelles, and Amirantes to the north, and the Mascarene islands (Reunion, Mauritius, and Rodriguez) to the east. Whatever other conclusions may be arrived at regarding the best mode of dividing the Ethiopian Region, every authority is, we believe, agreed on this matter, the only doubtful point being whether the Malagasy Sub-region is not well entitled to the full rank of a Region.
On the African continent itself a fairly distinct Subregion can be recognized, extending all over the forest country of Western Africa from the Senegal River over the whole Congo basin, or perhaps rather further south. The best inland boundary of this Sub-region would probably be the water-parting between the West African rivers on the one side, and the Nile on the other. There can, at any rate, be now little doubt that the West African fauna extends nearly as far eastwards as the western bank of Lake Tanganyika. Even on the shores of Victoria Nyanza, according to Herr Neumann's (5) recent researches, some typical West African forms are met with; but for the present it will be safer to restrict the West African Subregion to the western watershed. The Southern or Cape Sub-region, as denned by Wallace, includes only the country south of a line drawn from Walfisch Bay, just to the north of the tropic of Capricorn, to Mozambique. Since the publication of Mr. Wallace's book, however, much additional information has been obtained regarding the distri
bution of the mammals of Eastern Africa. Many of the animals formerly supposed to be confined to the southern end of the continent, have been shown to extend all through Nyasaland, at least as far north as British East Africa. It will, therefore, be advisable to extend the boundaries of this Sub-region further north. The boundary adopted in this paper, as will be seen by consulting the map (Plate IV., p. 122), runs from Angola in the west, along the southern water-parting of the Congo as far as Lake Tanganyika, passing thence to Kilimanjaro, and so on to the Indian Ocean along the Tana River.
The rest of Africa, including the Sahara, the southern portion of Arabia, and North-East Africa, will form a fourth Sub-region, which, however, does not contain nearly so high a percentage of endemic genera as the other three.
The Ethiopian Region may therefore be divided into four Sub-regions as follows:—
1. The Malagasy Sub-region, including Madagascar and its adjacent islands.
2. The West African Sub-region, including the great equatorial forest of Central Africa contained in the basins of the western rivers, from the Senegal to the Congo inclusive.
3. The Cape Sub-region, including all Africa south of the watershed of the Congo on the West and of the Tana on the East coast.
4. The Saharan Sub-region, consisting (if we exclude the Abyssinian plateau) chiefly of desert, or at any rate of a comparatively dry country, including the Sahara, Eastern Africa as far south as the Tana River, and Southern Arabia.
Section IV.—The Malagasy Sub-region
The island of Madagascar is separated from the mainland of Africa by the Mozambique Channel, which, though only about 250 miles across at its narrowest point, is more than 100 fathoms deep throughout its extent.
For our recent knowledge of the fauna of Madagascar we are chiefly indebted to the great work of Grandidier1 (3). Unfortunately, up to the present time only the plates and a small portion of the letterpress of that part which deals with the mammals have been published.
Out of a total number of forty-seven genera of mammals found in this Sub-region, no less than thirty-three are exclusively confined to it. Of the others, two or three occur also on the mainland of Africa, and the remaining twelve—most of which are bats—are cosmopolitan, or at any rate extend beyond the limits of the Ethiopian Region.
The Ungulates are represented in Madagascar by only one form—a peculiar River-hog (Potamochcerus) closely allied to the South African species, but still sufficiently distinct to have earned a title to a separate appellation. With this exception, the Ungulates, so numerous and so conspicuous a feature on the African continent, are entirely absent from Madagascar.
The Rodents are represented in this Sub-region by seven genera of Mice, containing thirteen species, all confined to it.
The Malagasy Sub-region possesses six peculiar forms of
1 Dr. Forsyth Major's recent explorations in Madagascar have added considerably to our knowledge of its smaller mammals, particularly of Rodents and Insectirores.
Carnivores, of which the most remarkable is the Fossa or Cryptoprocta—a large cat-like animal allied to the Civets, but sufficiently distinct to form a separate family (see Fig. 19, p. 102) according to some authorities. Of the Civets, besides a Viverricrda closely allied to the Indian Civet, there are six genera with eight species of Mongooses, all confined to the island. Of these the most remarkable is Eupleres—a form the jaws and teeth of which are so weak and small, that it was at one time thought to belong to the Insectivora. On the whole, out of the seven genera of Carnivora found in the island, six are absolutely peculiar.
Among the Insectivora of this Sub-region even greater specialisation prevails. Besides two species of ubiquitous shrews (Sorex) said to occur there, there are eight genera of this Order found in Madagascar, all of which are confined to the island. Geogale, a small mouse-like animal about which little is known, is said to be allied to Potamogale, an aquatic otter-like animal found only in Western Africa. The remaining seven genera make up the family Centetidm, the affinities of which are somewhat doubtful, but seem on the whole to approach the Solenodonts, a group confined to the Greater Antilles. The best known of the CenteticUe is the Tenrec—the largest member of the order, between twelve and sixteen inches long, and devoid of a tail (see Fig. 20, p. 104). The young of this creature are covered with spines like a hedgehog, but these are lost in the adult state.
The Bats of Madagascar, as would naturally be expected, do not exhibit the great peculiarities found among the other orders of mammals. Out of about twelve genera only one is confined to the island. The distribution of Pterapus, the genus of large tropical fruit-eating bats, often