512 Mr. M. A. C. Ilinton 0^1 



panied by most valuable notes. His labours will clear up 

 many difficult problems left unsolved by pioneers like 

 Kelaart, or by the more recent work of the Bombay Natural 

 History Society^s Mammal Survey. I have, therefore, great 

 pleasure in associating Mr. Phillips's name with this fine 

 monkey. 



It is a remarkable fact that in a small island like Ceylon 

 the mammalian fauna should be broken up into so many 

 subspecies. Of course_, the high relief in which part of the 

 island is carved may account in some measure for this, al- 

 though usually the differences between the highland and low- 

 land forms of the island are specific rather than subspecific. 

 But in the case now before us, as in several others which I 

 think could be cited, relief has nothing to do with the 

 matter, for all three subspecies occur on the low ground 

 vrithin quite a small area, although not in association with 

 each other. Some admirable maps of the rainfall of Ceylon, 

 published in the Report of the Colombo Observatory for 

 1920, seem to throw a good deal of light upon the matter, 

 suggesting that different subspecies have arisen in response 

 to difi'erences of humidity. In the south-west there is an 

 ovate area, extending between latitudes 6° 3' N. and 7° 23' N., 

 and through about 45' of longitude, in which the annual 

 rainfall is not less than 100'^, and in places more than 200''. 

 This tract forms what is termed above the " wet area"" ; it 

 is inhabited by the typical black subspecies v. vetulus, and 

 in the north probably by the slightly less saturate v. nestor. 

 This humid area is in contact with the coast only between 

 the latitudes 6° 5' and 6° 40' N. Elsewhere it is surrounded 

 by a narrow belt in which the annual rainfall varies between 

 75" and 100" ; to the east this belt stretches across the 

 island as a tongue, which almost reaches the eastern coast. 

 The narrow coastal strip to the south of Colombo belonging 

 to this less humid belt is the country inhabited by the pallid 

 P. V. phillipsi. The northern half of the island has for the 

 most part an annual rainfall of between 50" and 75"; and a 

 narrow belt of similar slight humidity occurs in the south- 

 east. In the extreme north-west and in the extreme 

 south-east are still drier narrow coastal strips in which 

 the annual rainfall varies between 25'^ and 50". Unless 

 P. ther sites proves to be a subspecies of vetulus^ these drier 

 parts of Ceylon (25"-75") are inhabited by P. priamus 

 alone ; the latter species, in turn, although the most-widely 

 distributed Langur of the island, is quite unknown from the 

 humid area in the south-west. There is, of course, nothing 

 novel in the idea that humidity may play a part in con- 

 trolling either subspecific variation or the distribution of 



