1905.] OF THE GENUS RHINOLOPHUS. 119 



trying to answer this question, the following facts must be borne 

 in mind : — Firstly, that all palaeontological evidence is wanting, 

 which detracts from what we know about the affinities and 

 distribution of the now existing representatives of these Bats. 

 Secondly, that the ferrimi-equinum type is unknown in Egypt, 

 as well as in the Avhole region of the continent north of British 

 East Africa, and that we have no reason, of any kind, to believe 

 that it ever existed there. Thirdly, that we have to account not 

 only for the distribution of Rh. augur and deckeni as compared 

 with the other members of the sarae section of the genus, but 

 also for the presence in Tropical Africa of representatives of the 

 borneensis and rouxi types, and, be it noticed, representatives 

 which, without exception, are more highly differentiated than 

 their Oriental allies. These facts, so far as they go, seem to 

 allow of no other satisfactoiy explanation than this : the im- 

 migration of these Bats, as of so many other Oriental types in the 

 Ethiopian fauna, has taken place by way of the broad tract of 

 land which, as commonly supposed, in a geologically late period 

 connected Southern Asia with the African continent. In the 

 case of the ferruTn-equinum type this explanation would make 

 it evident, why it, though vastly distributed in South and 

 Equatorial Africa, is absent from the whole north of the con- 

 tinent with the exception of the extreme north-western (Medi- 

 terranean) coast-region, which it, no doubt, has reached from 

 South-western Europe, since the Algerian race is subspecifically 

 indistinguishable fi'om the Spanish form {Rh. f. ohscurus). 

 In the case of the borneensis and rouxi types it would account 

 for the fact that they are common to the Oriental and Ethiopian 

 Regions, but absent from the whole of the Pala^arctic Region. 

 And it would also account for the presence of the genus Rhino- 

 lophus in the Ethiopian Region, for, as I shall have to show later 

 on in this paper, all the Ethiopian representatives of the genus 

 are tindoubtedly of Oriental origin. 



Such being the case, I am able to draw up the following 

 rough sketch of the history of Rh. augur, deckeni, and their 

 Oriental and Palaearctic relatives : — 



Th.Q ferrum-eqimium type has originated somewhere in South 

 Asia ; we find there the long series of more primitive forms 

 which lead up to that type, whereas in the whole of the Ethiopian 

 Region there is not any species with which it can be brought in 

 genetic connection. The ancestral ^'' ferrum-equinum " broke up 

 into three branches : a south-western, a western, and an eastern. 

 The south-western branch, which had spread directly from South 

 Asia into the Ethio^Dian Region, was cut off from the main stem 

 by the submergence of the connecting ti-act of land, and is now 

 differentiated into two species — the southern Rh. augur and the 

 northern Rh. deckeni. Both of them have retained at least two 

 '• ancient " characters : a slightly more piimitive dentition (the 

 upper canine and p* often more or less separated ; p^ sometimes 

 half in row *) and a short tail. To the external difference 



* 35 skulls oi Rh. augur (all races) have been examined: — In 17 the upper canine 

 and p'* are more or less separated, in 7 in contact, in 11 more or less overlapping 



