1034 
longer in mesio-distal direction, though the whole of the jaw must 
have been less large than that of Wadjak II. All these differences 
between Homo wadjakensis and Homo heidelbergensis are certainly 
significant of a difference in function of the molars. 
A five-cusped m, have on an average three of the four Australians 
and one of the four representatives of the Malay race; in both races 
m, is five-cusped in two out of three individuals on an average. 
In this respect Papuans agree more closely with Malays than 
with Australians. In Homo neandertalensis nine of the twelve 
m, were found to be five-cusped, and m, nearly always four-cusped 
(in ten out of eleven of these teeth); probably the crown of m, is 
no less reduced. The two individuals of Homo wadjakensis, 
therefore, in this respect, closely resemble Homo neandertalensis, 
and are certainly less on the primitive side than the average Australian 
native. As has been said, the lower molars of Homo heidelbergensis 
on the other hand, are all three five-cusped, hence they present the 
more primitive condition. From what is observed in the living races 
it seems, however, that both the number of cusps and the size of 
the dental crowns are in connection with the function. 
Some of the most important characters of the maxilla and the 
mandible of Homo wadjakensis I have already briefly described. 
The following remarks may now be added. 
The protuberantia mentalis, a low trigonal pyramid with rounded 
edges and vertex, with its base put, as it were, on the uniformly 
bent outer side of the corpus mandibulae, and rising 3 mm. above 
this surface (ideal of the “e@minence triangulaire, plus au moins: 
bombée a son centre, qui se superpose a la face anterieure de la 
mandibule” of the European lower jaw, in the description of Topinard), 
may be clearly recognised as a formation that has arisen independently 
of the growth of the basal part of the corpus mandibulae. According 
to KuaatscH’) such a “trigonal prominence” is also what is found, 
as a rule, in Australian mandibles. The basal part is by no means 
bent outward as in many modern lower jaws, but the external surface 
of the corpus mandibulae is straight to the inferior border. The 
internal surface at the chin, apart from the spina mentalis 
placed on it, is only slightly convex, and inclines almost uniformly 
from above downward. The spina is of a type frequently occurring 
in Home sapiens, which | will designate as scissor-shaped of outline, 
as it really presents a close resemblance with the outline of a 
) H. KLAATSCH, The Skull of the Australian Aboriginal. Reports from the 
Pathological Laboratory of the Lunacy Department. New South Wales Government. 
Vol. I. Part Ul, p. 155. Sydney 1908. 
