24 BINAR LONNBERG, MAMMALS COLLECTED BY THE SWEDISH ZOOLOGICAL EXPEDITION ETC. 



and the others abolished, but the facts mentioned form another of the numerous 

 proofs that many members of the typical fauna of a subregion extend into other 

 subregions as well, if suitable conditions of life in accessible districts are 

 offered to them. On this depends the distribution. 



Since »the Geography of Mammals » appeared also several important discoveries 

 of new mammals characteristic of the West African forest region have been made.^ 

 The one which created most interest was probably the Okapi, but it is also striking 

 that the first specimen of a new genus Hylochoerus- which evidently is a typical 

 forest mammal was obtained at Mau, British East Africa, outside of the West African 

 forest region, although later on it was proved that members of this genus live in 

 the Kongo forest, in Cameroon and so on. 



Before an investigation is made whether any West African mammals have been 

 obtained by this expedition in British East Africa the discussion about the two 

 other subregions of Solatbr's system ought to be continued. The »Cape Subregion* 

 as defined above includes Wallace's South African and the southern half of his 

 East African subregion. It was undoubtedly a step in the right direction to unite 

 these two subregions as they have proved to be more similar with regard to their 

 faunas than was known when Wallace wrote his book on geographical distribution, 

 but it is more uncertain whether the limitation towards the north of Sclatee's 

 »Cape subregion* is successfully chosen. The name is certainly not very characteris- 

 tic. It is true that sCape* or South Africa has a certain number of endemic mam- 

 malian genera as for instance Gynictis, Suricata, Petromys, Bathyergus, Pelea etc. 

 and probably is Vhrysochloris still more typical for South Africa, although some of 

 its species reach much further north. There are also some endemic species like 

 Hycena brunnea, Equus zebra a. o. but they have near relatives further north. Very 

 little of the fauna belonging to Sclateb's »Cape Subregion » can be supposed to 

 have its origin in South Africa, or even to be especially characteristic for that 

 country. Not a few of the genera enumerated by Sclater as typical for this »sub- 

 region» extend according to what we know now beyond its proposed northern boun- 

 daryline for instance JEpyceros, Pachyuromys, Myoscalops, Proteles' Otocyon, Rhyncho- 

 cyon and Myosorex. 



The »Saharan Subregion* according to Sclater's definition appears to be arti- 

 ficial. Its easternmost portion, Somaliland with its borderlands form a zoogeogra- 

 phical centre of its own with several endemic mammals, for instance not less than 

 three genera of antelopes, Ammodorcas, Lithocranius and Dorcatragus to which might 

 be added Str&psiceros imherbis, further the rodents Heterocephalus, Fornarina and Pec- 

 tinator. In Somaliland is the centre for the genus Rhynchotragus as well. There live 

 also the aberrant Grevy's Zebra and the Somali Ass in addition to several other 

 endemic species of genera with a wider distribution. But these characteristic mem- 

 bers of the Somali fauna do not extend their distribution westwards through Sudan 



1 But at that time 1899, there were already several typical West African mammals known which are 

 not mentioned, as f. i. Idiurus, Zenkerella, Limacomys etc., and in addition to these genera a very great num- 

 ber of species. 



