1882.] PROF. FLOWER ON THE SKULL OF A CHIMPANZEE. 635 



i8 formed mainly by two lines, a short anterior and a longer poste- 

 rior one, which meet at an open rounded angle at the highest point, 

 which is considerably in front of the middle of the cranium. 



In addition to, and probably connected with, this peculiar form of 

 cranium, is to be noted the absence of all trace of a fronto-parietal 

 or coronal suture, and the partial obliteration of the sagittal suture, 

 both of which in all other Chimpanzees examined are open long after 

 the age to which this individual had attained. The sutures between 

 the exoccipitals and supraoccipital are also consolidated to a greater 

 extent than is usual at this age ; but the temporo-parietal and the 

 occipito-parietal or lambdoidal sutures are perfectly distinct. 



The following comparative measurements are taken from some of 

 the principal points now usually adopted in craniometry : — 



Soudan West-African 

 Chimpanzee. Chimpanzee. 



Basion to alveolar point 76 72 



„ narion 66 64 



,, ophryon 73 70 



„ middle of frontal bone 84 74 



„ bregma 87' 74 



Length of cranium (ophryo-occipital) .. 103 107 



Ma.ximum parietal width 88 89 



Maximum frontal width 77 86 



It will be seen from these and from the figure, that the skull is 



Skull of a young Chimpanzee. 



actually shorter than that of a slightly younger specimen from the 

 west coast, although so greatly higher as well as wider in the frontal 

 region. It presents in fact a true case of the deformity recognized 



^ Owing to the absence of the coronal suture, the exact position of the bregma 

 can only be guessed. 



