194 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.83 



of these parts in still earlier mandibles. Remnants of this convexity 

 are still met with occasionally in modern skulls. 



The inner aspect of the lower jaw anterior to the second molars 

 gives a sense of spaciousness, with the inner symphyseal line more 

 vertical than in most modern jaws ; and the axes of the canines 

 and incisors are somewhat evergent, rather than vertical or invergent 

 as they are in most modern jaws. 



The mylohyoid ridge on each side is markedly developed and runs 

 far forward (to beneath the posterior premolars) ; beneath it is a 

 marked, long triangular fossa which is indicated more or less but 

 never developed to such a degree in modern mandibles. This fossa 

 is especially deep on the left side of the Spy jaw. 



The molars on the right are all of very nearly the same size ; on 

 the left the M3 is slightly broader than Mi and M2. The following 

 additional measurements will show the moderate proportions of the 

 bone and the teeth : 



MEASUREMENTS OF THE LOWER JAWS 

 (By Hrdlicka) 



UPPER JAW OF SKULL NO. 2 



Two fragments, stronger than in No. i. 



LOWER JAW OF SKULL NO. 2 



Present, two pieces, chin portion wanting. Both the jaw and the 

 teeth are stronger and larger than those of No. i. The body of the 



