MAC CURDY HUMAN SKULLS FROM GAZELLE PENINSULA. 



average 1 06. i for the males and 104.2 for the females. A com- 

 parative study of the published results for other series and 

 races would probably reveal a like relation. This sexual dif- 

 ference of the indices, if indeed it prove to be. a general one, 

 is well illustrated in the proportion which the combined length 

 of the upper premolars and molars in situ bears to the basi- 

 nasal length: 



In the series from Gazelle Peninsula, the combined length 

 in situ of the premolars and molars of the lower jaw averages 

 from 2 mm. to 6 mm. greater than that of the upper jaw. It 

 was, therefore, thought desirable not to calculate indices from 

 measurements on the lower teeth where these were present 

 and the upper teeth were missing. 



