164 DESCRIPTION OP FIGURES OF SKULLS. 



angles to this vertical line will pass at a slightly variable distance 

 above the floor of the nostrils, and will be found ordinarily, though 

 not invariably, to be parallel with the horizontal plane which would 

 be obtained from a consideration of the visual axis, or from the 

 direction of the fronto-ethmoidal suture as proposed by Professor 

 Goodsir 1 , or from a horizontal surface touching the skull at its 

 occipital condyles and at the posterior border of its occipital 

 foramen, as proposed by Professor Cleland 2 . 



The principal measurements taken have been : — 



I. Measurements of Calvaria. 



Cubical capacity. 

 Frontal arc. 

 Parietal arc. 



Extreme length. 

 Fronto-inial length. 

 Extreme breadth. 

 Vertical height. 

 Absolute height. 

 Basi-cranial axis. 

 Circumference. 



Occipital arc. 

 Minimum frontal width. 

 Maximum frontal width. 

 Maximum occipital width. 



II. Measurements of Face. 

 Length of face : ' naso-alveolar ' line. 

 Breadth of face : interzygomatic line. 

 1 Basio-subnasal ' line 3 . 

 ' Basio-alveolar ' line. 

 Height of orbit. 

 Width of orbit. 

 Length of nose. 

 Width of nose. 



Lower jaw, interangular diameter. 

 Lower jaw, depth at symphysis. 

 Lower jaw, width of ramus. 



III. Indices. 

 Length -breadth index: 'cephalic index.' 

 Antero-posterior index. 



Where any of these measurements have been omitted, it will be 

 understood that the damaged condition of the skull prevented them 

 from being taken. 



It will be well, as some differences exist in the practice of cranio- 

 graphers as to the exact points whence their measurements are 

 taken, to specify, in cases where such differences have existed, what 

 the points are whence and to which the measurements given in 

 the subjoined descriptions have been taken. 



1 'Anatomical Memoirs,' 1868, vol. i. p. 247, Edinburgh. 



2 See 'Phil. Trans.' vol. clx. p. 121, 1870. 



3 For explanation of the words ' Basio-subnasal' and 'Basio-alveolar' see p. 168 ivfra. 



