Fig. 4. Lower jaw bones of the Piltdown man, of a female orang-utan and of a 

 modern negro, viewed from the inner side. Abbreviations as in Fig. 3; also, ah. c. i., 

 alveolus for central incisor; ch., bony chin; g. t., genial tubercle; m. L, mental ledge; 

 t. r.. ridge in area of temporal muscle; s, section through symphysis 



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