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ghost-like middle finger, with which they have been supposed to extract wood-boring insects from their burrows, although their chief food in captivity certainly consists of succulent juices.
Of the extinct mammal-fauna of Madagascar we know as yet too little. Dr. Forsyth-Major (4) has lately described a large lemur (Megaladapis) differing considerably from those now inhabiting the island; while remains of two small Lemurs and of two small species of Hippopotamus have been also met with. These remains, together with the bones of a large flightless bird (JSpyomis), apparently allied to other Ratite birds, are of a comparatively recent period.
On the whole, however, we cannot but presume that Madagascar originally obtained its animal life from the mainland of Africa. The striking differences between the present faunas of Africa proper and Madagascar are doubtless due to the fact that the great bulk of the existing African fauna is of comparatively modern origin, and came from the Northern continent at the end of the Miocene or the beginning of the Pliocene times, whereas Madagascar was cut off from Africa before this eruption of Northern forms took place. Madagascar, therefore, appears to contain a sample of the ancient Ethiopian fauna, which has been almost exterminated on the mainland, but has survived here under the protection afforded by its separation from the adjacent continent. The fauna of the Malagasy Sub-region may be summarized by the exclusive possession of—
(1) Seven genera of the family MuricUe, among the Rodents.
(2) Six genera of the family Viverridm, among the Carnivores.
(3) One genus (Geogale) of the family Potamogalidm (shared with the West African Sub-region) and six genera making the whole of the family Centetidm, among the Insectivores.
(4) One genus (Chiromys), alone forming the family Chiromyidm, and ten genera of the family LemuricUe, out of a total of fifteen generally recognized.
Almost equally important is the absence of the following groups:—
(1) The orders Edentata and Ungidata (except Potamochoerus).
(2) The families Sciuridm (Squirrels), Spalacidm (Blind Moles), OctodonticUe, HystricidM (Porcupines), and Leporidm (Hares), among the rodents.
(3) The families Felidm (Cats), Canidm (Dogs), and Mustelidm (Weasels), among the Carnivora.
(4) The Primates, other than the lemurs.
The following table shows the number of genera of each order represented in the Malagasy Sub-region and their distribution:—
[N.B.—The "Endemic" genera are those confined to the Malagasy Sub-region; the "African" genera are those common to Madagascar and the mainland of Africa; and the "Cosmopolitan" genera are those which range beyond the limits of the Ethiopian Region.]
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 (Tragulidm) distantly allied to the deer (Cervidm). 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 (Potamoch&rus 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 (Paradoxv/ms), 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 Pteropodidm, 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 Simiidm, 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 Tragididm of the Ungulata.
2. Two genera (Malacomys and Deomys) of the family Mvmdm, and Atherura (Brush-tailed porcupine), found elsewhere only in the Oriental Region, among the rodents.
3. Two genera (Poiana and Nandinia) of the family Viverridm, 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: Orycteropodidm (Aard-vark), Grirafftdm (Giraffes), Equidm (Zebras and Wild Asses), Rhinocerotidm (Rhinoceroses), and Leporidm (Hares).