KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 58. N:0 2. 21 



The male n:o 163 is very dark. Its head, arms, breast, and upper back are almost 

 black, grizzled with light brownish tips to a number of the hairs (least on the arms). On 

 the lower back tliese light tips dominate so that it is quite overlaid with brownish grey. 

 The same is also the case with the hind legs, although not quite in the same degree. 



The old male (n:o 70) has the remaining hairs on the upper side of the head partly 

 grey, partly blackish. The whiskers are in their upper portion blackish, in their lower 

 brownish grey. The arms and upper back are blackish, but mixed with whitish grey 

 hairs. The colour of the back becomes gradually paler towards the pelvic region and is 

 there very påle brownish grey, in some lights it might be termed isabellinc grey. The 

 upper parts of the tighs are like the middle back, but the greater portion of the hind legs 

 is just as påle as the lower back. In the old specimens where the påle brownish grey colour 

 dominates on some parts of the body the hairs themselves are to great extent påle horn- 

 coloured, unlike the condition in other specimens which only are more or less grizzled wit h 

 brownish. In the latter as already has been mentioned the brownish tint is produced af 

 least partly by the faded broken and often split ends of the hairs. Whether the påle ends 

 of the hairs are intact or broken they are somewhat shiny by which the effect produced 

 by them is greater t han it other wise should ha ve been. 



The description thus given proves that the fur and its colour is rather variable in 

 tliese Chimpanzees. Partly this variation is explaincd by the difference in age, the old 

 ones gradually becoming more bald-headed and more palc brownish grey on the lower 

 back and the hind legs. The almost completé blaekness of the rather old female n:o 224, 

 and the shortness of the fur of the male n:o 163 appear, however, without accordance 

 with other facts and indicate a stränge variability which is also displayed by the skulls 

 as will be set forth below. 



All the adult specimens are providcd with very well developed ischiadie cal- 

 losities. These are largest in the old ones, f. i. 7 X 4 cm. in the old male, 6,0 ;< 3,5 cm. in 

 the oldest female. In the least old female (11:0 181) the dimensions of these callo- 

 sities are about 4,5 X 2,3 cm. The callosities are so thoroughly developed that they 

 can be scen very plainly from the inner side of the skin as well. In the young animal with 

 milk-dentition the callosities can hardly be more than traced 011 the skin. 



The length of the skin of the old male (70) measures from upper lip to opening about 

 1)3 cm. The same measurement of the other male is about 91; that of the largest female 

 (181) about 89. The other female skins havc this dimension about 83 — 84 cm. 



The ears are small, basally at the insertion measuring from about 35 to 40 mm. 011 

 the skins and probably the longest diameter from one free lobc to another does not much, 

 if at all, exceed 50 mm. 



These skin measurements pro ve that this Chimpanzee is smaller than Anthropo- 

 pithecus purschei Matschie from the forest between LakeKivu andLakeLuhondo, German 

 East Africa. The same fact is corroborated by the cranial measurements below. A. pur- 

 schei has a cranial length to gnathion of 205 mm. A. purschei is also said to be »ohne 

 Stirnglatze ». 



A. cottoni Matschie has been described from specimens which had not reached 

 maturity and is thus insufficiently known. As the description of cottoni, as far as it is 



