MACACUS. 71 



There is still another monkey from the Himalayas {Dalamcote, Blmtan), which, 

 although not quite so rufous as M. rheso-similis and the youngish monkey referred 

 by Hodgson to M. pelops, seems to me to differ from M. rhesus in the same direction 

 that these do, and to he an immature female of M. assamensis. I refer to the M. 

 problematicus, Gray. This opinion has been first expressed by Dr. Sclater.^ It is 

 a dark-brown monkey, all the upper parts being of a nearly uniform tint. The in- 

 dividual hairs pale into reddish yellow towards their extremities, which are tipped with 

 dark brown, but not truly annulated, their lighter-coloured subterminal areas pro- 

 ducing a very faintly speckled appearance, giving it at the same time a warm rufous 

 tint. The hair on the inside of the limbs and on the ventral aspect is a some- 

 what sullied white, without the golden tinge of the previous specimens, than which, 

 however, it is older, and, unlike them, belongs to the female sex. The hair behind 

 and below the ears is not much longer than that of the neighbouring parts, but 

 paler, and without any rufous tinge. The hair on the vertex radiates from a point, that 

 on the forehead being directed forwards and on the sides of the head outwards and 

 backwards. There are long black hairs on the internal angle of the frontal and 

 eyebrows, and on the moustache and beard. The feet, especially those of the hind 

 extremities, are dusky. The hair, as in the female of 31. assamensis from the Irawady, 

 approaches close to the sides of the callosities, and, as in that specimen, the bare area 

 is confined to a restricted region immediately around and below the vaginal orifice. 

 In the stuffed specimen now in the British Museum (69. 3. 5. 15) the body measures 

 22 inches and the tail 11 inches. With regard to the proportion of the tail to the 

 body, it is self-evident that the measurements of dried skins do not give any 

 correct idea of the relative proportions of these parts in life, and moreover the 

 examination of a large series of specimens of 31. rhesus conclusively proves that the 

 length of the tail in that species is the subject of variation. 



The skull of 3f. problematicus, Gray, belongs to one of those unsatisfactory 

 instances of an animal that had lived the greater part of its life in confinement. 

 It is immature, as the last molar is only just appearing. The basi-cranial axis is 

 somewhat thrown forwards, so that the posterior nares are very narroAv both verti- 

 cally and transversely. The pterygoid fossse are shallow and rather more laterally 

 compressed than in 3£. rhesus. The skull of 31. rheso-similis, Sclater, belongs to the 

 same unreliable category as the former and is very young ; the occipital and 

 sphenoid being intact, and the first bicuspid and second molar only just issuing 

 through the jaw. Unlike the skull of 31. problemaMcus, it belongs to a male, and 

 is somewhat larger than the generality of examples of the same sex in 3£. rhesus, 

 than which it is also rather more elongated and narrower ; in these characters and 

 in that of its basi-cranial surface it resembles M. problematicus. 



Some years ago I drew attention to a monkey from the Bengal Sunderbunds 

 which seemed to be distinct from 31. rhesus. After a careful comparison of it with 

 the type of 3£. assamensis in conjunction with the foregoing monkeys, it appears 



1 Proc. Zooi. Soc, 1868, p. 566. 



