606 
Proceedings of Royal Society of Edinburgh. [sess. 
the frontal, parietal, and occipital bones, and thus provide a series 
of facts which are complementary to those ascertained by measur- 
ing the frontal, parietal, and supra-inial sections of the great 
longitudinal arch. 
At the same time, the lambda is occasionally so close to the 
occipital end of the glabello-occipital diameter that the post- 
lambdoidal segment can only he stated approximately. 
I have also segmented the glabello-occipital length in terms of 
the anterior margins of the occipital condyles, and it will he found 
that the anterior margin of the foramen magnum closely corre- 
sponds to a line drawn transversely between the anterior margins 
of the two condyles. This measurement is of much value in con- 
nection with the degree of erect attitude assumed by the various 
races of men as well as by anthropoid apes and other mammals. 
These segments are defined by the terms prse-condyloid and post- 
condyloid. 
Lastly, by using the external auditory meatus, I have represented 
prse-auditory and post-auditory segments for contrast with those 
derived from the position of the condyles. Approximately, these 
segments are calculated from the centre of the external meatus by 
inserting the Y-shaped end of the middle limb of the callipers. 
The details of the measurements of the various skulls, taken in 
the manner above indicated, are given in the accompanying Tables. 
Analysis op the Measurements. 
Minimum Frontal Diameter . — (a) Brachy cephalic skulls — Sand- 
wich Islanders. — In three cases the right and left segments were 
alike ; in one case, there was a preponderance of 2 mm. in favour of 
the left segment ; while in seven cases the excess lay to the right 
side of the mesial plane. This excess varied from 2-5 mm., the 
average being 3*2 in favour of the right side, (b) Dolichocephalic 
skulls — Aboriginal Australians. — In one case there was equality 
between the right and left segments. In eight cases the right 
segment predominated, the variation being from 2-6 mm., with an 
average of 3*2 mm. In three cases the left segment was in excess, 
giving an average of 2*3 mm. 
(c) Anthropoid Apes,-=-The skulls of the orang and of a young 
