KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 58 NO 2. 27 



but two other skins from Debundscha belong also to the cahus group, and it is therefore 

 most probable t hat all tliree skulls represent the same race. 



Old female from Debundscha 385 ccm. 



j » » 460 » 



male » » 323 » 



These cubic measiirements are very striking, because the brain-cavity of the male 1 

 is much smaller than that of the females, and its capacity is even below the minimum - 

 350 ccm. - - for male Ohimpanzee skulls according to »Selenka. On the other hand the 

 largest female has a capacity which is above the maximum - - 450 ccm. for female Chim- 

 panzee skulls according to the same authority, and not far from the maximum even 

 for male skulls (480 ccm.). 2 



The small-brained female Chimpanzees from Rutshuru have a capacity of the 

 brain-case which is not much above the minimum — 320 ccm. - according to »Se- 

 lenka, but the large-brained are above the average - 390 ccm. - - in this respect. 

 The largest of the males is also above the average for males, or 420 ccm. 



The average diffcrence in capacity between male and female Chimpanzee skulls 

 »Selenka puts to 30 ccm. Broadly speaking a similar diffcrence in capacity exists between 

 the largest male and the large-brained females on one hand, and between the smaller 

 male and the small-brained females on the other. 



As quoted from Captain Arrhenius's notes the old male Chimpanzee was ready to 

 attack when shot. The natives also fear the Chimpanzee, which is called »Impundu » in 

 the Kiniaruanda language, and say that he often will attack a man. They say also that 

 the Chimpanzees use sticks or branches for fighting, how true this might be is uncertain. 

 The Chimpanzees of this region make ncsts in the crown of high trees, just as is known 

 about such apes from other places. 



Colobus occidentalis Rochebrune. 



A very fine series partly from Rutshuru, and partly from Beni. Of those from 

 the former place eight are males in different stages of age, four are females, and one quite 

 young (§). All these specimens are signed »la »Shasha riviére — petit forét», and with 

 exception of one male shot 16 / 2 1914, the others have been collected '" — 28 / 2 1914. The 

 three specimens from Beni are all males shot in January 1914. 



The latter are larger than the others, their skulls measuring resp. 119, 122 and 124 

 mm. in total length, while none of the male skulls from Rutshuru attains a greater length 

 than 115 mm. Otherwise no distinct difference is to be seen. Both in specimens from 

 Rutshuru and from Beni there is some variation with regard to theextensionof the white 

 on the sides of the head as in some almost the whole ear is surrounded by white except 

 at the upper margin, while in others the greater part of the ear is implanted in the dark 



1 This Chimpanzee was, however, regarded by the donor Mx. G. Waldau as an unusually small imlividual. 



-' For further comparison may be mentioned that the capacity of a female Chimpanzee skull from Kribi Ca- 



meroon is about 373 ccm. and that of another also female (possibly A. vell er osus) from Ya River, Cameroon, is 360 ccm. 



