118 THE GEOGRAPHY OF MAMMALS 



and Somaliland, 0. beatrix from Arabia, and 0. leucoryx 

 extending from Senegal to Nubia), and a distinct species 

 of Kudu (Strepsiceros imberbis), which inhabits the Sub- 

 region from Somaliland as far south as the Tana. This 

 Sub-region is also the headquarters of the Gazelles 

 (Gazella), at least twelve species out of a total of twenty- 

 five being found there. 



Three genera of antelopes are endemic ; these are the 

 Dibatag (Ammodorcas), and the Gerenuk (Lithocranius), 

 both found in Somaliland, and remarkable for their very 

 long necks, by means of which they are enabled to reach 

 down branches of trees from a considerable height. The 

 third is the Addax (Addax), which is found throughout 

 the Sahara, and extends into Arabia. 



The Rodents are well represented in this Sub-region, 

 but there are only three peculiar genera — Lophiomys, 

 Heterocephalus, and Pectinator. 



Lophiomys, a curious crested Rodent, forms a distinct 

 family. The remarkable little animal Heterocephalus is 

 almost entirely hairless, and apparently lives underneath 

 the ground, burrowing in the soft sandy soil of the desert. 

 It was originally obtained by the celebrated traveller 

 Riippell in Abyssinia, and has since been brought from 

 the interior of Somaliland by Mr. Lort Phillips. 



The third endemic genus, Pectinator, is also from the 

 coast of Somaliland and Abyssinia. It was first obtained 

 by Captain Speke, and named by Blyth (P. spekei) after 

 its discoverer. 



The Saharan representatives of the Carnivora, In- 

 sectivora, and Bats are almost all widespread forms, and 

 present no features of special interest. Among the 

 Monkeys, however, we find one peculiar genus — this is 



