Subspecies of the Genus Rhiuoloplius. 655 



dentition, it has apparently remained on a slightly lower level 

 than any other species of" the genus. JRk. arcuatus and suh- 

 rufus are the most primitive members of the arcuatus group ; 

 Rh. inops a representative of the same group, cliietly charac- 

 terized by its peculiarly modified sella. Rh. hirsutus is a 

 very primitive species of the macrotis group, closely related 

 to the Himalayan Rh. macrotis. — Rh. philippinensis and 

 Rh. arcuatus cannot be brought into close genetic connexion 

 with any other known bat; in the absence of paUeontological 

 evidence to the contrary, we may therefore regard them as 

 autochthonous Philippine types — i. e. as the least modified 

 survivors of types which have originated in the Philippines, 

 or, more likely, in a tract of land of which the Philippines 

 are the relicts. We can still trace their radiation out from 

 that centre: i\\Q philippinensis type has spread both south- 

 wards, to the Key Islands {Rh. achilles), and westwards, 

 through India {Rh. mitratus) as far as the Ethiopian Region 

 (Rh. Maclaudi), while a third oflfslioot has given rise to 

 the slightly more aberrant Indo-Malayan sedulus-trifoliatus 

 branch ; the arcuatus type has spread southwards and become 

 differentiated into the comparatively rather higiily developed 

 Anstro- Malayan Rh. euryotis. Tiie presence of the simplex 

 type {Rh. virgo) in the Philippines is evidence of an immi- 

 gration into the islands from the south ; the close relationshi-p 

 between the Himalayan Rh. macrotis and the Philippine 

 Rh. hirsutus points to a former connexion with the continent. 

 N. Borneo: — Rh. homeensis {typicus) ; Rh. sedulus, Rh. 

 trifuUatus, Rh. luctus ; Rh. Creaghi. — Rh. borneensis is a bat 

 of the simplex type, slightly more advanced than Rh. cele- 

 bensis. Rh. sedulus, tri/oliatus, and luctus are members of 

 the p)hilippinensis group ; the former species in its cranial 

 characters rather primitive, in its essential external characters 

 close to trifoliatus ; Rh. trifoliatus and luctus are more hio-lily 

 developed species of the group. Rh. Creaghi is a peculiar 

 modification of the arcuatus type. — The fauna points partly 

 {Rh. borneensis) eastwards, to Celebes and the Austro- 

 Malayan islands, partly and most decidedly north-eastwards, 

 to the Philippines (all the other species). It is very closely 

 connected witli the Rhinolophus fauna of the Malay Peninsula 

 no less than three species {sedulus, trifoliatus^ luctus) bein-*- 

 common to both countries. 



S. Natunas and Karimata Archipelago : — Rh. borne- 

 ensis spadioC, extremely closely related to (or identical with) 

 the Bornean form of the si)ecies. 



Malay Peninsula, Lower ISiam, South Tenasserim :— 

 Rh. malayauus, Rh. stheno, Rh. affinis superans ; Rh. rejul- 



