CHAP. V] THE CRANIA OF THE SIMIIDAE (PRIMATES) 



219 



Primates. Thus the female cranium in all instances is smaller, and the 

 percentage values in terras of the male capacity (taken as 100) are as follows : 



Cynocephalus 83 



Hylobates 98 



Orang-utan 90 



Gorilla 85 



Chimpanzee 95 



Fig. 146. Cranium of adult female Chimpanzee (Mus. Anat. Cant.) 

 of natural size. 



One-third 



f\-onto-squamousarticulation 



Fronto -squamous 

 arh'culah'on 



Pronto-maxillary 

 articulation 



permanent 

 tooth 



1 st 

 permanent 

 tooth 



Fig. 147. Crania, with mandibles, of (A), young Gorilla, and (B) young Chim- 

 panzee (Simiidae). The first permanent tooth (the first molar) has just been 

 fully acquired in each ease, and comparisons can thus be drawn between examples 

 at corresponding stages in development. Note the greater nasal prominence in the 

 Gorilla; and the fronto-squamous and the fronto-maxillary (orbital) articulations in 

 both specimens. 



Of the cranial sutures, the sagittal may be extremely complicated and 

 tortuous before it becomes closed ; on the other hand, the straight outline 



