CHAP. Ill] 



THE MAMMALIAN ORDER PRIMATES 



57 



Fronto-squamous 

 articulation 



Lacrymal 

 bone 



Long audirory 

 passage 



Permanent - teeth 



Fig. 32. Cranium, with mandible, of a young Gorilla (Simiidae) ; the first tooth 

 of the permanent set has appeared (permanent molar tooth). Note, in contrast to 

 Fig. 33, the comparatively large brain-case. There is no auditory bulla: the 

 auditory passage is long, but not so long as in adults: there are fronto-squamous 

 and fronto-maxillary articulations. Osseous ridges and crests are still undeveloped. 



Fronto-squamous 

 articulation , 



Fronto-maxillary 

 articulation 



Lacrymal bone 



Fig. 33. Cranium, with mandible, of an adult Gorilla (Simiidae) : note the absence 

 of an auditory bulla, the presence of great bony crests ; and of fronto-squamous 

 and fronto-maxillary articulations (the latter within the orbit in place of a lachrymo- 

 ethmoidal junction). The canine teeth are enormously developed in the male sex. 



