180 
A First Stud}/ of the Burmese Skull 
alone were missing have settled the Frankfort plane by means of this apex. All 
measurements dependent on this approximation are of course queried. 
O^R and O^L. Of the two methods — the "curvature" method and the "geo- 
desic* " — of completing the orbital margin where it becomes indefinite on the nasal 
side, I have used the curvature method, which Fawcett herself used and which 
was followed by Thomson, although Macdonnell and Benington used the geodesic. 
G^i'. This was a measurement first made by Macdonnell, and has continued to 
be used by his successors in this Laboratory. 
NH. In all the papers of this school until Thomson's this measurement was 
defined as taken to the lowest point of the margin of the pyriform aperture, 
whether this may be to the light or to the left. Thomson says she has taken it to 
the left, unless this is damaged, and has also measured the right if this be sensibly 
different; but from the fact that she gives no separate measurement of the right 
side in her data we infer that her interpretation of the term " sensible difference " 
applied only to marked nasal asymmetry and that this feature in the Moriori 
Series was much more regular than among the Burmese, whose maximum difference 
between nasal height R and L is 2-7 mms. I have measured both sides in all cases. 
Si, S2, S^, S^', Oc. I fnib, fml, fmhj fml are all measurements added to the series 
by Macdonnell|, and have continued to be made by his successors here. 
Oc. I. was called by him the Cerebellar Index, but the more accurate title of 
Occipital Index was adopted later. 
DA and DC were first measured by Benington J, and DS was obtained from 
them by calculation. 
SA, SS, I'^.C were also measured by him§ later, when he had the use of the in- 
strument invented by Merejkowsky, by which I also have obtained DS as well 
as SS. 
Sex. The sex of the skulls was determined by Professor Pearson, when classify- , 
ing them into the three types to be described later (p. 217). 
Mandibles. There were no skulls with mandibles in my series. 
3. On the Difficulties attached to the Definition of certain 
Cranial "Points." 
Basion. In Thomson's paper it was suggested that the basion and opisthion 
should be marked off as points before any measurements are made from them||, 
it having been noticed that slightly different points may be selected on the different 
occasions on which use is made of them, e.g. in measuring the basio-bregmatic 
height, and the foraminal length, and in drawing the sagittal contour. I have 
adopted the suggestion and find it very advantageous. In selecting basion and 
opisthion on the foraminal border it is very desirable to bear in mind that the 
foraminal length will be determined probably by the dividers and the basio- 
* Biomeirika, Vol. I. p. 431. 
§ H id. Vol. VIII p. 317. 
t Ihid. Vol. V. p. 91. 
il Ihid. Vol. XI. p. 129. 
X Ibid. Vol. vm. p. 297. 
