178 
A First Study of the Burmese Skull 
height from nasion to h)west edge, right and left, of pyriform aperture. NB = nasal 
breadth, greatest breadth of pyriform aperture, wherever it may be. DS = dacryal 
subtense, being the shortest subtense in the sagittal plane from the bridge of the 
nose to the dacryal chord, measured by Merejkowsky's simometer. DC = dacryal 
chord, i.e. length from dacryon to dacryon. DA = dacryal arc, i.e. the shortest arc 
over the bridge of the nose from dacryon to dacryon, measured with the tape. 
SS = simotic subtense, the shortest subtense in the sagittal plane from the nasal 
bridge to the simotic chord, as measured by the simometer. SC = simotic chord, 
i.e. the minimum chord between the two naso-maxillary sutures. 0^ = greatest 
breadth of orbit, R and L, from side to side, using Fawcett's curvature method* to 
determine the margin on the nasal sidef. = greatest height of orbit, R and L, 
taken perpendicular to 0^. = length of palate, from the point of the spina nasalis 
posterior to an imaginary line tangential to the inner rim of the alveoli of the 
middle incisors. Gi — similar measurement to G-^ but taken from base of spine. 
G2 = breadth of palate between inner alveolar walls at second molars %. GL = profile 
length from basion to alveolar point, fml = length of foramen magnum from 
basion to opisthion. fnib = greatest breadth of foramen magnum. G'H = upper 
face height from alveolar point to nasion. PZ. = profile angle, or angle made by 
the line from the nasion to alveolar point with the horizontal, found by means of 
Ranke's goniometer when the skull is in horizontal position on the craniophor, as 
described by Fawcett (Biomefrika, Vol. i. p. 414). From these direct measurements 
there were also calculated the various indices: occipital (Oc. I.), cephalic {BjL', HjL, 
HjL', BjH), facial (G'HjGB), nasal {NBjNH, R and L), orbital (O^R/O^R; O^LjO^L), 
palatal (GolGi), foraminal (fmh/fml), dacryal (DSjDC), simotic (SS/SC). The angles 
(iVZ, A L, B L) of the fundamental triangle whose apices are the nasion, alveolar 
point and basion, were calculated from the measured lengths LB, GL, G'H by the 
aid of Pearson's Trigonometer in the manner described by Fawcett {Biometrilca, 
Vol. I. p. 418). ^1, the basio-nasal horizontal angle, was obtained by the sub- 
traction of N /_ from the supplement of PZ; 6.^, the basio-alveolar horizontal 
angle, was arrived at by the subtraction of A Z from Pzl . 
Of these various measurements, one or two are new; most are similar to those 
made by previous craniometricians. 
C. The measurements, and methods of measurement, described by Fawcett 
{Biometrika, Vol. i. pp. 416-419) have been adopted exactly, with one exception, 
viz. that of C, the capacity. MacdonnelFs labour-saving device of weighing the 
mustard-seed to determine its volume has been adopted wherever possible by all 
later workers in this Laboratory. 
The only available one of the three "cranes etalons" used by Macdonnell 
(BiometriJca, Vol. iii. p. 204) was skull 8. After some preliminary practice in tight 
* See Biometrika, Vol. I. jj. 430. Also Biomelrika, Vol. viii. pp. 311, 312. 
f Another measurement Oj' ( = breadth of orbit measured from dacryon) had to be taken later for 
comparison with the data obtained for other racial series. 
J This may occasionally be the same as the measurement between the inner rims of the alveoli of 
the second molars, but is more frequently rather less than these. 
