M. L. TiLDESLEY 
227 
Type contours based on 100 English skulls: 
Transverse Contour. Range of variation from 1-4 inms. at apex tapering down 
to 0-8 ram. by the auricular points. 
Horizontal Contour. Range about 1-2 mms. all round. 
Sagittal Contour. About 1-6 mms. from glabella to lambda, tapering to 0-7 mm. 
at gamma and 0-9 mm. at nasion (below gamma not given). 
Extent to which this range should be increased for Burmese groups : 
Group 
No. 
Multiplying 
coefficient 
Group 
No. 
Multiplying 
coefficient 
44 
1-5 
39 
1-6 
8 
35 
18 
2-4 
7 
3-8 
(c 
17 
2-4 
Type Contours of Groujis A and C {Burmese) com^pared. 
One rather noticeable characteristic of the Group which we take to be Burman 
— Group A — is an impression of flatness -at the back of the skull. Our photograph 
of skull No. 110 (Plate I, Fig. 1) in profile shows an extreme example of this 
flattening; it will also, however, be remarked in No. 4 (Plate III, Fig. 8) which has 
been photographed as a type (with all the characteristics rather marked) of our 
Group A males, and here we can see it also as looked at from above. The effect 
is helped by the fact that the parietal eminences are further back in proportion 
than are those of the Chinese for example (Plate VI, Fig. 19), or the Hindu (Plate V, 
Fig. 16), or to go outside the various series we have specially used for comparison 
in this paper, further back than in the Moriori skull (Plate XI, Biometribt, Vol. xi. 
after p. 135). This is a feature which is not brought out in our direct measure- 
ments, nor indeed very clearly in our contours, since the vertical contours are taken 
in a plane well in front of these eminences while in the horizontal contours the 
pointer of the contour tracer passes well below them. We shall, however, expect to 
find some confirmatory indication in the horizontal contour even though this is not 
drawn at the height where it would most clearly illustrate our point. 
In so far as the effect is due to the actual flattening of the upper part of the 
occipital bone, that is, to its steeper fall from the lambda to the inion, the sagittal 
contours should serve quite well to demonstrate it. 
Let us first take up the transparent-paper tracings of the c? and ? Horizontal Type 
contours for Group A (Burmans) and place them upon the corresponding contours 
for Group C, F to F, and FO falhng along FO. We notice at once the shmmer pro- 
portions of Group C, and the more flattened occipital region in Group A. It will, 
however, also be noticed that the frontal curve of the C's is more concave, and it 
may be this that has thrust the occipital point 0 of Group C type contour too far 
out when we made our mid-frontal points F to coincide. We will therefore make 
the points where the contours indicate our temporal ridges lie in the same straight 
