GIO CTNOPTEIiUS BKACHYOTIS. 



larger of the t^vo. There remains one form, angidatus, ranging 

 from Assam and Siam in the north to Sumatra in the south, and 

 characterized, as compared with typical brachj/otis, by its consider- 

 ably larger average size ; in the Malay Peninsula and Sumatra, as 

 mentioned above, this large race meets and occurs together with 

 typical braclitjotis ; and in the island of Nias it has developed into a 

 distinct species (C major). 



It may be considered, and probably is, rather premature to 

 venture any general conclusions from the above facts. But so far 

 as these facts go, they seem to point to the effect that the existence 

 of C. bracht/otis dates back to an epoch when Ceylon was much 

 more closely approximated to Malaya. This assumption appears 

 necessary to explain the occurrence in Ceylon of a form which 

 has its closest relative not in the Indian Peninsula nor in Indo- 

 China but in Borneo, Sumatra, and the Malay Peninsula (the other 

 alternative being that a form essentially similar to typical brachyotis 

 once was distributed over the whole of the Oriental Region, but 

 subsequently disappeared from the Indian Peninsula and Indo- 

 China, while remaining in Ceylon). Already at that period the 

 species was probably differentiated into two distinct races, the one 

 and larger (now represented by C. b. angulatus) continental (Indo- 

 Chinese), the other and smaller inhabiting ancient Malaya includ- 

 ing Ceylon (now represented by all the other races together). This 

 would explain the remarkable fact that while typical braclnjotis 

 is the only form occurring in Borneo, the Philippines, and Celebes, 

 it in the Malay Peninsula and Sumatra occurs together with 

 angulatus. That angulatus, if originally an Indo-Chinese race, 

 has at a more recent period, under altered physical conditions, 

 spread southward over the Malay Peninsula and Sumatra, is only 

 what might be expected ; and it is equally easy to understand that, 

 in similarly favourable circumstances, typical braclnjotis, coming 

 from east, has invaded the Malay Peninsula and Sumatra. That 

 this spreading of angulatus and typical bracliyotis, respectively 

 southward and westward, has taken place in a quite recent period, 

 seems further proved by the facts that angulatus from the Malay 

 Peninsula and Sumatra is absolutely indistinguishable from angu- 

 latus from North Siam, Burma, and Assam, as are individuals of 

 brarjiyotis from the Malay Peninsula and Sumatra from Bornean 

 individuals of brachyotis. 



Sijnopsis of the Subspecies of Cynopterus brachyotis. 



n. Averaging larger : skull (lambda to gnathiou) 



30-O-33-2, forearm 65-72 mm. (Assam to [p. 611. 



Sumatra, inch Natuna and Mentawei Is.). . 2a, C. h. atifficlatus, 

 b. Averaging smaller : skull 25-8-31 -2, forearm 

 54-5-70-5 mm. 

 a'. Ears relatively larger : length (from ovitice) 

 15-17 mm. 

 «^ Cranial rostrum (orbit to nares) usually 

 distinctly less than one-fourth of skull 

 (lambda to gnithion). , ; ,'t; 



