142 MOSTLY MAMMALS 



Congo and the Nile in the neighbourhood of Wadelai. As 

 a large number of the peculiar animals of this district are 

 more or less exclusively confined to the west coast, extend- 

 ing from Sierra Leone to the Congo, the area is appropriately 

 termed the West African sub-region. It is here alone that 

 we find the gorilla and the chimpanzee, the former being 

 restricted to the neighbourhood of the coast, whereas the 

 latter ranges far into the heart of the continent. And this 

 district is likewise the exclusive home of the pretty little 

 mangabeys, or monkeys with white eyelids (Cercocebus). 

 The galagos, which are near relatives of some of the 

 lemurs of Madagascar, extend throughout the forest region ; 

 but the even more curious pottos, or thumbless lemurs, are 

 confined to the west coast. Huge and forbidding fox-bats, 

 some of them with remarkable tufts of long white hairs on 

 the shoulders, are likewise restricted to this portion of the 

 tract, as is the insectivorous otter, or Potamogak, first 

 discovered during the travels of Du Chaillu. The equatorial 

 forest-tract is also the sole habitat of the African fl^^ing- 

 squirrels, to which further reference is made in the sequel ; 

 all these being distinguished from the flying-squirrels of Asia 

 by the presence of a number of scales on the under-surface 

 of the tail. Most of them belong to the genus Anomalunis, 

 but the smallest of all forms a genus {Idiurus) by itself, 

 while a flightless type {Zenkerclld) also belongs to the 

 group. Dormice of peculiar types and tree-mice are also 

 very characteristic of this tract. But far more generally 

 interesting are the pigmy hippopotamus of Liberia and the 

 water-chevrotain {Dorcatherium) of the west coast, the latter 

 an ally of the chevrotains of India and the Malay countries. 

 So far, indeed, as the equatorial forest tract fauna has any 

 representative in other parts of the world, it is to the 

 Malay Peninsula and its islands that the resemblance is 



