132 J. H. LEES 
This curve is formed by the quadratojugal, and immediately above 
this the squamosal enters the margin and continues its outline to 
the upper border. 
Supratem poral fossa.—Lying above the lateral temporal is the 
supratemporal fossa, much smaller than the lower opening and, 
unlike the other openings of the skull, facing inwardly, and that in a 
plane which has a very high inclination. In order to adapt itself 
to this condition the parietal is in this region deflected downward 
and forms the floor of the fossa with an outward slope of about 30°. 
The result is the irregular, suboval depression of triangular section 
described above. 
The anterior margin of the fossa is formed by the parietal, with 
the exception of the outer angle. The parietal also forms a little 
more than one-half of the inner border, and the squamosal forms 
the remainder. On the outer border the squamosal forms the margin 
for at least two-thirds of the length of the fossa. The boundary is 
completed by the postorbital, which extends to the anterior margin 
to meet the parietal. 
The fossa measures two and one-half inches in length by three- 
fourths inch in extreme width, in its anterior portion, though in the 
posterior region it narrows to a width of one-fourth inch. In shape 
it is a narrow, irregular ovoid, almost gourdlike in outline, as the 
narrow posterior part curves slightly upward in characteristic fashion. 
The plane in which the opening lies is not parallel with the median 
line, but diverges posteriorly at an angle of about 20° along the anterior 
two-thirds of its length; thence the divergence suddenly increases, 
approaching 55°.. 
Ouadrate foramen.—One of the smallest apertures of the skull is 
the quadrate foramen, situated, as previously described, between the 
quadrate and the quadrato-jugal, about midway in the height of 
the former bone. It is subcircular in outline and has a diameter of 
about three-fourths inch. In the natural condition of the skull the 
opening must have faced almost directly upward. 
Another opening of the skull, but one which is imperfectly closed, 
is the small notch in the posterior margin already mentioned. It is 
hollowed out of the quadrate in large part, although the squamosal 
forms part of its posterior margin. It lies in the upper portion of 
