PITHECANTHROPUS ERECTUS, ETC. 359 



specially prominent, in the Neanderthal and Spy crania. 

 On the anterior part of the Bengawan calvaria the temporal 

 ridges run parallel to the upper and lower borders of the 

 parietal, being 60 m.m. (?) from the upper border, and 50 

 m.m. from the lower. The position of the ridge may be 

 stated as = f#. The position of the Neanderthal temporal 

 ridges is §§ ; of Spy cranium No. 2, f| ; of Cynocephalic 

 Australian, from £§ to £# ; of modern European, from |5 to £&• 

 The denominator of these fractions gives an index to the 

 development of the temporal muscle, by indicating the 

 extent of its origin. Its development was no greater in 

 fossil men than in many Australians of to-day ; but, on the 

 other hand, it exceeded the temporal muscle of most 

 modern Europeans. 



To appreciate the inferential worth of the temporal 

 ridges one must remember that their position depends 

 upon several factors. In simian and human foetuses the 

 temporal muscle covers only the inferior border of the 

 anterior part of the parietal. As the maxillary apparatus 

 grows, the muscle ascends towards the vertex of the skull, 

 preceded by the temporal ridges as osseous waves. The 

 relative height to which they reach depends principally 

 upon the extent of cranial capacity ; to gain a sufficient 

 area of origin they must ascend relatively further on skulls 

 of a low than on those of a high cranial capacity, hence 

 their relatively high position on fossil crania, and their 

 complete ascent to the vertex of the skull in anthropoids. 

 The only other factor that enters largely into the determina- 

 tion of the temporal ridge is the size of the canine teeth. 

 The larger the canine teeth the greater the development 

 and ascent of the temporal ridges ; so that we may safely 

 infer that the canine teeth of the Bengawan individual were 

 incisiform. The size of the molar teeth determines the 

 development of the temporal ridges only to a minor extent. 



7. THE CONFIGURATION OF THE OCCIPITAL REGION 

 OF HUMAN FOSSIL SKULLS. 



In the same way as the temporal ridges indicate the ex- 

 tent of the temporal muscle, the occipital and mastoid ridges 



