THE FACE OF FOSSIL MAN 489 
the zygoma, and the root of the nasal bones occupies 
nearly the level of the plane A-B, on which the skull 
is poised. 
In the skull shown in fig. 182 it will be seen that the 
tip of the coronoid process of the mandible just reaches 
the zygomatic arch. That is the usual relationship in 
anthropoid skulls and in human skulls of a primitive 
type. We therefore, in estimating the length of the face 
of Eoanthropus, flex the mandible until the coronoid 
process reaches the zygomatic arch. At that angle the 
chin reaches its normal position and marks approximately 
the lower limit of the face. Having thus estimated the 
length of the face, it is an easy matter to reproduce the 
palate and upper teeth, for they hold definite relations to 
the lower. The lower border of the zygomatic process 
ends above the first molar tooth in both men and 
anthropoids. 
As the Piltdown mandible shows many simian traits, 
it will be well to see how far the method just employed 
for the reconstruction of the profile of a human skull can 
be applied to that of an anthropoid. For this purpose 
the skull of an orang has been selected, because, as already 
mentioned, there are some features in the Piltdown 
forehead reminiscent of the conformation seen in the 
orang. The problem and its solution are presented in 
fig. 183. The plane of orientation, A-B, has been used 
for orientation as in fig. 182. In the human skull the 
forehead extends forward on that plane to a point which 
is 100 mm. in front of the ear (fig. 182) ; in the orang 
the forehead is rather less than 80 mm. in front of the 
same point. When, however, we look at the lower line 
(C— D, figs. 182, 183), which is drawn 50 mm. below and 
parallel to A-B, we see the conditions are reversed. The 
snout or jaws in the anthropoid face project 135 mm. in 
front of the ear-passage, while in the primitive Tasmanian 
the projection is less than iio mm. In man the forehead 
projects, the jaws recede ; in the anthropoid the opposite 
is the case. There is another striking difference : the 
zygomatic arch is lower on the base of the skull — lies 
