46 Proceedings of the Royal Irish Academy. 
therefore, a good specimen of a brachycephalic skull, and it corre- 
sponds in its measurements with the skulls belonging to the Croat, 
different German tribes, and the Finlander. I believe its original 
possessor was one of the mixed people who originally came from the 
shores of the Baltic, and whom we know in Irish history as Pirate or 
Black Danes. 
So far as the general facies is concerned, I think we may safely 
recognise two different and distinct types. One of these is straight- 
faced or orthognathous; the other possesses a projecting upper jaw, 
which produces a prognathous appearance. There is no difficulty in 
distinguishing well-marked specimens of both forms, but some appear 
with intermediate features. 
The skull marked 19 is an example of the orthognathous face, 22 
is intermediate, 21 is prognathous. 
The little microcephalic skull, as I have already stated, is hkewise 
prognathous. The degree of forward projection of the upper jaw in 
any skull is ascertained by obtaining the alveolar index, the formula 
basivalveolar length x 100 
basilar nasal measure. 
ranges below 980, the face must be classed as orthognathous. An 
index ranging from 980 to 1030 is mesognathous, and all above 1030 
fall into the class of prognathous individuals. 
When these typical skulls are arranged beside each other, it is easy 
to see the great and striking differences they present in form, and in 
the aspect of their faces. 
I think we can amongst these skulls recognise some which fall 
under the Scandinavian type of Thurnam and Davis, and that, there- 
fore, will correspond with numerous examples of people still existing 
in our land, in Scotland, and in the maritime districts of the east of 
England, where Danish settlers planted their numerous colonies. To 
quote the words of these accurate ovservers: ‘‘ The skull is small and 
regular, has a long slender elevated aquiline nose, closely correspond- 
ing with such as prevails in the northern counties of England where 
Scandinavian blood predominates. A narrow, long, orthognathous 
face, an upright square forehead, yet neither decidedly broad nor high, 
having a frontal suture, a long oval outline in the vertical aspect, with 
distinct parietal tubers, a globose tumidness in the supra-occipital 
region, and a large foramen magnum.” 
The lower jaw belonging to this class of skull is distinguished by 
its massive structure, square outline, and strong everted angles. The 
lines for muscular attachment are always prominently developed; the 
chin square-shaped, projecting, and forming a predominating feature, 
whilst the glossal tubercles are unusually developed, becoming in some 
even long bony growths. 
The second variety of skull is smaller, of mesaticephalic form, and 
of neat outline, but it presents a prominent prognathous upper jaw, 
which gives it a very peculiar and distinctive appearance. The nose 
for which is Whenever the ascertained index 
