41 G DR MATTHEW YOUNG. 



the heights of the corresponding arcs, and a consideration of these later will bring 

 out more fully the greater similarity between the frontal and parietal arcs in the 

 Scottish series, as evidenced by the close approximation to equality in the size of 

 the two angles, than in the Tasmanian and Australian as shown by a comparison of 

 Berry's values, and than in the Australian as figured by Klaatsch. In the European 

 skull described by the latter the frontal angle is 141° and the parietal 129°. 



As regards the inion angle, i.e. the angle at the vertex of the chief occipital 

 triangle, in the Scottish series the angle varies from 97° to 114°, with a mean of 

 10477°. In the Australian as figured by Klaatsch the angle is 101°, well within 

 the range of variation found in the Scottish series ; in another Australian it is 105° ; 

 in the European (according to Klaatsch) it is 99°; in a Negro it is 113°; in a 

 Chinese skull 104°, and in a brachycephalic German 101°. In the series of 90 skulls 

 shown in Berry's atlas, I have measured the angle and find that it shows in these 

 a mean value of 104'84° and a range of variation from 95° to 114° (S.D. 4'12), values 

 which are practically identical with those given by the above-mentioned Scottish 

 series. The angle thus shows much variation in the Scottish skulls, but the values 

 of the corresponding angle in those different types of skull all fall within its range. 



Figures are given by Buchner"(60) for the Tasmanian series in a study of the 

 prognathism of the Tasmanian aboriginal for the first of the two angles which 

 Klaatsch makes use of in his median diagrams as evidence of prognathism, i.e. the 

 angle at the prosthion (at the vertex of the upper facial triangle) and the angle 

 included by the glabella-prosthion line and the continuation forwards of the lambda- 

 glabella line ; but, as I intend to confine my attention for the present largely to the 

 brain-box, I need not refer to this at greater length than to mention that in the 

 Australian, as evidence of the prognathism present, these angles show a distinct 

 diminution in value from the mean values of the Scottish series. 



With regard to the chords, and considering first of all the glabella-lambda length, 

 we find, in the Tasmanian series, that this varies from 167 to 189 mm. in the male 

 skulls, with a mean length for the series of 178*7 mm., S.D. 5'43, V. 3'03. In the 

 Scottish series the range of variation is from 172 to 198 mm., with a mean value of 

 18475 mm., S.D. 5'85, V. 3'87. 



By a comparison of these measurements the greater absolute length of this chord 

 in the Scottish series is brought out, associated with the greater length of the skull, 

 while in the two series the coefficients of variability show a fairly close correspondence 

 with one another, that of the Scottish series being slightly greater than the other. 

 In the Australian figured by Klaatsch the length is 182 mm., which is not greatly 

 different from the Scottish mean value, but in the 90 Australian skulls previously 

 mentioned the length varies from 160 to 192 mm., with a mean value of 177'12 mm., 

 S.D. 6'83, V. 4*42, bringing the mean length of the line in the Australian below that 

 in the Tasmanian. 



The basi-bregmatic height in the Tasmanian series varies from 118 to 139 mm., 



