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what one would expect, as members of these two Orders are essentially forest-loving in their habits, and this Subregion consists chiefly of sparsely wooded and arid districts.
On the whole, therefore, the Cape Sub-region will be found to be characterized, as compared with other parts of Africa, by the exclusive possession of the following forms:
1. Connochætes (the Gnu), Pelea (the Rhébok) and Æpyceros (the Pallah) among the Antelopes.
2. Pachyuromys and Mystromys, genera of Muridæ ; Bathyergus and Myoscalops, genera of the burrowing Spalacidæ ; Petromys of the Octodontidæ, among the Rodents.
3. Five genera of Mongooses, belonging to the family of Viverride ; Proteles, the only representative of the family Protelidæ ; Otocyon (the Cape Hunting-dog); and Poecilogale (a small weasel), among the Carnivora.
4. Rhynchocyon, of the Macroscelidæ ; Myosorex (a Shrew); and the Chrysochloride (Golden Moles), among the Insectivora.
The following table, showing the distribution of the genera, is constructed on the same plan as that of the other Sub-regions.
SECTION VII.—THE SAHARAN SUB-REGION
The Saharan Sub-region, as its name implies, is essentially a dry and desert district. As here regarded, in addition to the Sahara proper, it includes the southern part of Arabia and Somaliland, both of which are distinctly arid countries. The only part of the Sub-region where there is much rainfall is in the Abyssinian highlands and the country surrounding such isolated mountains as Kenia. In consequence of these facts, and also in accordance with the fact that the Sub-region is conterminous for so long a distance with the Palæarctic Region, the number of endemic genera of the Saharan Sub-region is extremely small, being only seven out of a total of eighty-five—that is, 8 per cent, as compared with 21 per cent. in the Cape, and 15 per cent. in the West African Sub-region.
Of recent years a considerable number of new forms, especially of Antelopes, have been obtained from Somaliland, a country which, up to a few years ago, was quite unknown, and it is quite possible that eventually the "unknown Horn of Africa” will be found to possess a Fauna sufficiently distinct from the rest of the continent to be separated as another Sub-region. But for the present, until our knowledge is widened a little more, it will be best to keep Somaliland in the Saharan Sub-region.
The most characteristic feature of the Sub-region is, perhaps, the large numbers of Antelopes. : These, as a rule, are specifically distinct from those of the Cape Subregion. Among them may be mentioned Swayne's Hartebeeste (Bubalis swaynei), Hunter's Bontebok (Damaliscus hunteri), three species of Oryx (0. beisa from Abyssinia
and Somaliland, 0. beatrix from Arabia, and 0. leucory. extending from Senegal to Nubia), and a distinct species of Kudu (Strepsiceros imberbis), which inhabits the Subregion from Somaliland as far south as the Tana. This Sub-region is also the headquarters of the Gazelles (Gazella), at least twelve species out of a total of twentyfive being found there.
Three genera of antelopes are endemic; these are the Dibatag (Ammodorcas), and the Gerénuk (Lithocranius), both found in Somaliland, and remarkable for their very long necks, by means of which they are enabled to reach down branches of trees from a considerable height. The third is the Addax (Addax), which is found throughout the Sahara, and extends into Arabia.
The Rodents are well represented in this Sub-region, but there are only three peculiar genera-Lophiomys, Heterocephalus, and Pectinator.
Lophiomys, a curious crested Rodent, forms a distinct family. The remarkable little animal Heterocephalus is almost entirely hairless, and apparently lives underneath the ground, burrowing in the soft sandy soil of the desert. It was originally obtained by the celebrated traveller Rüppell in Abyssinia, and has since been brought from the interior of Somaliland by Mr. Lort Phillips.
The third endemic genus, Pectinator, is also from the coast of Somaliland and Abyssinia. It was first obtained by Captain Speke, and named by Blyth (P. spekei) after its discoverer.
The Saharan representatives of the Carnivora, Insectivora, and Bats are almost all widespread forms, and present no features of special interest. Among the Monkeys, however, we find one peculiar genus-this is Theropithecus, containing two species of terrestrial baboons, which inhabit Abyssinia and the Galla country.
The other genera of African monkeys are fairly represented here, though by no means so abundantly as in the West African Sub-region.
The Saharan Sub-region, therefore, is characterized by the exclusive possession of the following genera :
(1) Ammodorcus, Lithocranius, and Addax among the antelopes.
(2) Lophiomys (forming a distinct family), Heterocephalus, and Pectinator among the rodents.
(3) Theropithecus among the Monkeys.
The following families, found in other parts of Africa, are absent from this Sub-region: Tragulidæ (chevrotains), Protelidæ (aard-wolf), Potamogalidæ (river-shrews), Chrysochloridæ (golden moles), and Simiidæ (the anthropoid apes).
The following is the summary of the mammals inhabiting the Saharan Sub-region:
SECTION VIII.—THE PAST HISTORY OF THE ETHIOPIAN
Up to the present time palæontology has afforded us little assistance in tracing out the past history of the African Mammal-fauna. With the exception of a few still
surviving species found in a semi-fossil condition in caves, the only fossil mammal hitherto obtained from the Ethiopian Region is a form named by Owen Tritylodon, the remains of which were discovered in the Karoo beds of Basutoland, in South Africa. This formation is of Mesozoic age, and seems to correspond to the Trias of Europe. Near Stuttgart, also, in beds of the Trias age, another specimen closely resembling that of South Africa has been obtained. Tritylodon belongs to a group which was apparently allied to the modern Marsupials, and many somewhat similar forms have been found in other Mesozoic beds in Europe and North America.
The only conclusion to be drawn from this is, that before the commencement of the Tertiary epoch the whole world was, so far as is at present known, inhabited by small insignificant mammals distantly allied to the Marsupials, which are at present restricted to Australia and South America. Besides Tritylodon, the only fossil mammals hitherto known, from the Ethiopian Region, are those which have been described by Grandidier (3) and Forsyth-Major (4) from Madagascar, as mentioned above.
The resemblances between the Faunas of the Oriental and Ethiopian Regions have been noted and commented on by many writers ; Mr. Allen is even disposed to join the two Regions into one realm. The number of prevailing genera, however, common to these two Regions, and not found in the Palæarctic Region, is very small, the total being, as was pointed out in the first article of this series, only eight, and of these one (Mellivora) has since then been recorded by Büchner (2) as occurring in the TransCaspian district, and is therefore also Palæarctic. Of the other seven, four have been found, in a fossil state, in