Liberia + 



relations, and one reason why they thrive so badly in con- 

 finement (away from Africa) is that their leaf dietary has been 

 overlooked or has proved difficult of supply ; so that most 

 Colohus monkeys reaching England alive die in a short time 

 from diseases of the digestive organs due to unsuitable food. 



Their distribution across the continent of Africa has been 

 horizontal rather than longitudinal. A peculiar species of 

 reddish brown colobus is found in the island of Zanzibar. 

 Another reddish coloured monkey of this genus is met with 

 on the LJpper Tana River, and reappears again in Western 

 nda, and no doubt in the Congo Forest. In Liberia, as 

 in other parts of West Africa, there is a red colobus, Colobus 

 ferntgineus, the range of which stretches as far westwards as 

 the Gambia Colony. Very probably the original colours of 

 this genus were chestnut-brown and grey, but it is best known 

 by its most recent developments, which are black, with more 

 or less distinct patches of grey or white. 



The most splendid development of the Colobus genus is 

 probably to be found in Southern Abyssinia (C. guereza\ in 

 which the long tail is heavily plumed with very long white 

 hairs while the sides of the body develop a long and thick 

 silky white mane. On Kilimanjaro Mountain this form of 

 Colnbus has evolved a peculiar variety in which the tail is 

 more or less thickly plumed with white from its base to its 

 extremity. 



In 1 ,iberia this black-and-white type of Colobus is apparently 

 represented (according to Biittikofer) by C. polycomus, which is 

 much more commonly met with in Sierra Leone. In this 

 monkey the forehead, sides of the face, throat and short beard 

 are dazzling white. So also is the long mane on either side 

 of the body. The long tail is white throughout its whole 

 length, and has a small white tuft at the end. The rest of 



682 



