NO. 1621. 



MEASUREMENTS OF CRANIAL FOSSM—HRDLICKA. 



213 



EXTERNAL LENGTH OF SKULL COMPARED WITH THE INTERNAL. 



There are several items of interest which were inciuired into \\\ con- 

 nection with the preceding study. 



One of these is the relation in the several series between the greatest 

 external and the greatest mean internal length of the skull. The com- 

 parison given in the succeeding table siiows a slight excess in the 

 thickness of the skull in the white brach^^cephals over that in the white 

 dolichocephals; a slight excess in the Indians over whites; and an 

 appreciable excess in the negroes over the Indians. These differences 

 explain better than has been done heretofore the discrepancies noticed 

 between the comparisons of the cranial fossa; with the dorsal and ven- 

 tral lengths, and demonstrate the greater suitability of the latter for 

 such a function. 



Diaiiietev antero-posterior maximum of the skull dorsally compared 'wHli mean diameter 

 antero-posterior maximum ventrally. 



"Difference from dorsal length. 



In order to see how other lengths of the anterior fossaj, and espe- 

 ciall}^ their relation to the ventral length of the skull, agree with the 

 measurement chosen and its relations, the writer secured also in most 

 of the specimens utilized the distance from the foramen coecum to the 

 anterior boundary of the pituitary fossa. The table beneath gives 

 the results and these, it will be seen, express much the same condi- 

 tions as were found with the regular measurement of the frontal cav- 

 ity. There is (except in the white females where the small number of 

 specimens is evidently at fault) again a predominance of the length in 

 the brachycephals over that in the dolichocephals, and there are seen 



