532 DR. J. ANDERSON ON A NEW INDIAN MONKEY. [Apr. 16, 



I. rhesus the superciliary ridge depends over them, and they are 

 broader than high. In 1. rhesus the palate partakes more or less of 

 an elongated oval, whilst in the Sunderhunds Monkey it is much 

 more oblong ; in the latter it may also be pointed out that the 

 posterior nares are narrower and more elongated than in the former, 

 in which they are broader and more triangular than oval. The 

 nasal orifice of the Sunderbunds skull is proportionally much more 

 capacious than in I. rhesus, longer and directed more upwards. Its 

 frontal shelves at once backwards and downwards from the super- 

 ciliary margin, behind which there is a very faint convexity suc- 

 ceeded by a depression on either side of the frontal crest in the posi- 

 tion of the same suture. The crest begins in the middle of (he upper 

 surface of the frontal, and is continued backwards as a sagittal crest. 

 The temporal ridges proceed from the posterior sharp malar angle 

 of the frontal, and abruptly arch inwards to join the anterior extre- 

 mity of the median frontal ridge, defining a triangular surface, the 

 base of which is formed by the superciliary margin of the frontal. 

 In I. rhesus the frontal is well arched, and there is a considerable de- 

 pression behind the superciliary crest, the temporal ridges not uniting 

 in the median line, but being continued widely apart and passing 

 directly backward parallel to each other as far as the lambdoidal 

 suture. There is no frontal or sagittal ridge or crest in any adult 

 I. rhesus I have examined. The parietal region in the Sunderbund 

 Monkey wants the full rounded character that that area of the skull 

 has in /. rhesus ; and the occipital surface in the latter is much more 

 convex than in the former, in which it is nearly quite flat, and 

 directed much more downwards than backwards, while it looks 

 backwards and only slightly downwards in /. rhesus. The mastoid 

 region of the Sunderbunds skull is much more developed than in 

 J. rhesus. 



When the two skulls are viewed from the under surface, the most 

 striking difference between them in that aspect is the contracted zygo- 

 matic arch of the Sunderbunds Monkey compared with the full and 

 much arched zygomata of I. rhesus, which confers on the skull a 

 shorter and more rounded character which does not belong to the 

 former. 



I have examined numerous living adult males of I. rhesus, but I 

 never yet observed a specimen with the hair devoid of annula- 

 tions ; and in all, the thighs below the callosities were seminude, — 

 characters which are the very opposite of those that prevail in the 

 supposed new form. As I have not seen the living animal, and only 

 know of it through two skins, I hesitate to do more than to 

 state that it appears probable that two Monkeys occur in the Sun- 

 derbunds, and that they have hitherto been both included under J. 

 rhesus*. 



The accompanying table contains the measurements of the skull 



* The Monkey recently purchased of Mr. Jamrach, and named /. rheso- 

 svnilis in my report (antea, p. 495), is, I have little doubt, a young example of 

 the present species. Mr. Blyth suggests it may be the Macacus assamen'sis, 

 M'Clell. (P. Z. S. 1839, p. 148). which is very probable.— P. L. S. 



