SECTION V.-THE WEST AFRICAN SUB-REGION

The West African Sub-region, as defined above, does not contain nearly so large a proportion of peculiar genera as the Malagasy Sub-region. At the same time, twelve out of a total of eighty genera of mammals that are found within its limits are not met with elsewhere. Moreover, we notice that, as a general rule, the genera inhabiting other parts of Africa are here replaced by distinct species.

The Edentata are represented by one genus, Manis, the Scaly Ant-eater. Of the four known African species three are confined to this Sub-region.

Of the Ungulates only one genus is endemic. This is Hyomoschus, a very curious aquatic form, which, together with an allied genus found only in the Oriental Region, forms a peculiar Family (Tragulida) distantly allied to the deer (Cervida). Many of the genera of Ungulates, however, are here represented by peculiar species. Instances of this are the Liberian Hippopotamus (Hippopotamus liberiensis), the Red River-hog (Potamochoerus penicillatus), the West African Eland (Oreas derbianus), a peculiar species of wild ox (Bos pumilus), and several species of Rockconey (Hyrax).

The Rodents do not present any features of special interest, the only peculiar genera being Deomys (allied to Mus), recently obtained from the Congo district; and the Brush-tailed Porcupine (Atherura), of which one species is found only in this Sub-region, and the other two are confined to South-East Asia. Four out of the five known species of the peculiar Rodent-genus Anomalurus,

already referred to, are also confined to the West African Sub-region.

Turning now to the Carnivores, there are found in the West African Sub-region only, two remarkable genera, Poiana and Nandinia. Of these the former is closely allied to the genus Prionodon, a beautifully marked civetlike little animal of the Oriental Region, and the latter is akin to the Palm-civets (Paradoxurus), also found in the Oriental Region, but not in Africa.

There is only one genus of the Insectivora confined to this Region (Potamogale), already alluded to as being probably allied to the Madagascan Geogale. This much modified form is one of the few members of the Insectivora that has adopted aquatic habits. It is, for a member of the order, of considerable size.

The Bats of West Africa, as is usually the case in every land, belong mostly to widespread forms. Out of sixteen genera only two, each containing a single species, are confined to this Sub-region, while a third (Epomophorus) has not been found outside Africa. These three genera all belong to the family Pteropodidae, which contains the large fruit-eating bats. A few species of Lemurs still survive in the forests of the West African Sub-region. They belong to two genera, neither of which is represented in Madagascar. Of these, one (Galago) is also found in the other parts of Africa; the other (Perodicticus), containing two species, is met with only in the West African Subregion.

The forests of West Africa are plentifully supplied with Monkeys. Most of these belong to the genus Cercopithecus, of which, out of about forty species, thirty are met with in West Africa. Another enus,

Cercocebus, contains four species, all confined to this Subregion.

Finally, it is only in these pathless and luxuriant jungles that two man-like apes, the Chimpanzee and the Gorilla, are to be met with. The Gorilla seems to be confined to the Gaboon district, but the Chimpanzee extends all over the Congo basin nearly up to the shores of Tanganyika.

These two, together with the Orangs and the Gibbons of the Oriental Region, make up the family Simiidæ, which in structure is the most closely allied to Man of all the Monkeys.

On comparing the West African Fauna with that of the rest of Africa, it will be seen that it is characterized by the exclusive presence of the following forms :

1. Hyomoschus (the Water-chevrotain), which, together with Tragulus of the Oriental Region, forms the family of Tragulida of the Ungulata.

2. Two genera (Malacomys and Deomys) of the family Muridæ, and Atherura (Brush-tailed porcupine), found elsewhere only in the Oriental Region, among the rodents.

3. Two genera (Poiana and Nandinia) of the family Viverride, among the Carnivora.

4. Potamogale, among the Insectivora.

5. Two genera of fruit-eating bats (Liponyx and Trygonycteris).

6. Perodicticus, a genus of Lemurs, and Cercocebus, and Anthropopithecus, among the higher Monkeys.

The West African Region is further characterized by the absence of the following families, well represented in other parts of Africa: Orycteropodidæ (Aard-vark), Giraffida (Giraffes), Equidæ (Zebras and Wild Asses), Rhinocerotida (Rhinoceroses), and Leporida (Hares).

The following table shows the approximate number of genera of the West African Sub-region in each order and their distribution:

SECTION VI.-THE CAPE SUB-REGION

This Sub-region, when extended so as to include the whole country as far north as Angola on the west, and up to the Tana river on the east, is on the whole, after the Malagasy, the most distinct of the four Sub-regions, since it possesses nineteen endemic genera out of a total of ninetyone. Furthermore, its area exhibits a greater range of temperature and humidity than the other Sub-regions, for, while in Natal and Mozambique tropical forest-conditions prevail, giving the fauna a certain resemblance to that of West Africa, in Cape Colony itself a temperate and fairly dry climate is found. Again, in Namaqua-land, to the north-west of Cape Colony, we meet with an open, dry, hot, desert country, the conditions of which closely approximate to those of the Saharan Sub-region. The distinctness of this Sub-region, apart from the mammals, is strongly marked by a very remarkable Flora, as well as by the exclusive possession of many forms among the other orders and classes of the animal kingdom. Among the Edentata,

H

besides the Scaly Ant-eater (Manis), of which one species extends as far south-east as the Transvaal, there is also found the Aardvark (Orycteropus), an animal characteristic of South Africa, though also occurring in East Africa as far north as the upper Nile basin. The relationships of this creature are very obscure, but the recent discovery of remains of a closely allied fossil form in beds of lower Pliocene age in the island of Samos, in the Ægean Sea, shows that the Aardvark, like so many other African animals, has migrated southwards from the Palearctic Region.

The greater number of the genera to which the numerous Antelopes of the Cape Sub-region belong, extend northwards into the Saharan and even into the West African Sub-region, although the species of the Cape Sub-region are in many cases distinct.

Among the distinct species may be mentioned the Hartebeest (Bubalis caama), the Spring-bok (Antidorcas euchore), and the Sable Antelope (Hippotragus niger). The two Gnus (Connochates) and the Pallah (Epyceros) are confined to this Sub-region. To the portion of this Sub-region south of the Zambesi are restricted two of the African horses, the Quagga (Equus quagga), now said to be extinct, and the Mountain Zebra (Equus zebra), which is fast approaching the same condition. But Burchell's Zebra (Equus burchelli), under various slight modifications, occurs in suitable localities throughout the whole Sub-region.

The White or Square-lipped Rhinoceros (Rhinoceros simus), which now only exists in two small districts of Mashonaland and Zululand, was formerly abundant in the Cape Colony and the Transvaal, but has never been met with north of the Zambesi.