112 THE GEOGRAPHY OF MAMMALS 



Cercocebws, contains four species, all confined to this Sub- 

 region. 



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 Simiidse, 

 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 

 Tragulidse of the Ungulata. 



2. Two genera (Malacomys and Deomys) of the family 

 Muridaz, and Atherura (Brush-tailed porcupine), found 

 elsewhere only in the Oriental Region, among the rodents. 



3. Two genera (Poiana and Nandinia) of the family 

 Viverridee, 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 : Orycteropodid& (Aard-vark), 

 Giraffidse (Giraffes), Equidse (Zebras and Wild Asses), 

 Khinocerotidee (Rhinoceroses), and Leporidx (Hares). 



