200 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXXlI 



The actual differencos in the combined fossal length ra,nged thus: 



Aiiterior, middle, and podcro-xiqierior J'oa^^tv longer tlidii the same uf the ujiposile .s/(/f. 



« 1 = G.5 mm.; 1 = 7 mm. 



''1 = 6.5 mm.; 1 = 8 mm.; 1 =12 mm. 



The g-reatest of the diiierences among the human adults are on the 

 left side; also the proportion of cases with large differences is greater 

 where the left combined fossal length is greater. In the human 3^oung 

 the differences are smaller, showing that the peculiarity is to quite a 

 large degree of later development, which agrees with what was 

 observed with all the individual cavities. Jn anthropoid apes and 

 monkeys the differences are relatively small, exceeding in no case 2 

 millimeters. 



It remains to show how the combined fossal length agrees with the 

 greatest ventral length of the skull of the same side. The succeeding 

 table gives the averages of the right and left ventral antero-posterior 

 diameters in human adults. It will be seen that here also, as with the 

 a + 7/1 + j'As length the left diameter preponderates in the mass of the 

 .specimens, and it will also be noticed that in the white brachycephals 

 there is .scarcely any difference, while in the white dolichocephals, 

 both male and female, the inequalit}^ is pronounced. 



^''entral antero-posterior maxirnum diameter of the skull. 



"Difference from the length on the right side. 



