166 DESCRIPTION OF FIGURES OF SKULLS. 



and that, except in those rare cases in which the ' fronto-inial ' 

 diameter can be taken to a ' tuberculum linearum' as distinguished 

 from a ' protuberantia occipitalis externa/ it is always necessary to 

 compare the internal with the external surface of the skull. 



The extreme breadth has in these skulls been taken upon the 

 parietal bones, either in ' well-filled ' skulls at some point abutting 

 upon the posterior edge of the squamous portion of the temporal 

 bone, or in ' ill-filled' skulls at the tuberosities. The squamous por- 

 tion of the temporal has very frequently in old skulls become 

 separated a little from the parietal, and it is rendered consequently 

 unfit to be taken as a surface to measure from. The extreme 

 breadth therefore being always the extreme parietal breadth, it 

 has been unnecessary to have a separate entry for this as for the 

 corresponding frontal and occipital diameters. 



The anterior margin of the occipital foramen has been frequently 

 so much injured in these ancient skulls as to render it impossible 

 to take their actual or *. absolute ' height from the plane of the fora- 

 men magnum. In these cases the so-called 'upright' height of 

 Professors von Baer 1 , His 2 , and Ecker 3 , taken by placing one arm 

 of the beam-compasses upon the posterior border of the occipital 

 foramen and at right angles to a vertical line passing from the 

 middle of the auditory foramen to the junction of the coronal and 

 sagittal sutures, and the other upon the most distant part of the 

 cranial vault, becomes of especial importance. This measurement 

 is, of course, somewhat greater than that of the 'actual' or 'abso- 

 lute' height as usually taken from the plane of the foramen magnum 

 — a point to be borne in mind when we compare the height and 

 breadth of these skulls with those dimensions in other series. 



The imperfect state of the skulls has similarly rendered it im- 

 possible in many cases to take the measurements of the basi- 

 cranial axis, or of the cubical capacity. 



The minimum frontal width has been taken from a spot imme- 

 diately behind the external angular process of the frontal bone, and 

 below the temporal ridge on one side, to the corresponding spot 

 on the other. The maximum has been taken between two points 

 below the temporal ridge at the coronal suture. 



1 ' Zusammenkunft einiger Anthropologen,' p. 50, Leipzig, 1861. 



a 'Crania Helvetica,' p. 7, 1864. 



3 'Crania Germaniae Meridional. Occident.' p. 3, 1865. 



