4 
T1':KT1AEY VRliTEHllATA OF THE FAYlJM. 
I'orni of the skull is woll shown, other notable points being the highly arched palate 
and the large median anterior palatine foramen. 
'I'lie cxoccipitals {exo.) seem to form the whole of the great occipital condyles, 
though the sutures between them and the basioccipital are obscure. The condyles 
(text-fig. 1, cwid.) themselves are somewhat peduncxdate and project entirely beyond 
any other })ortiou of the skull. 'I'heir inner faces are tlatteued, with a deep depression 
near their Ixasc. The articular surface is much less convex from side to side than 
from above downwards, in which direction the curvature of the surface is nearly 
a semicircle. In fact, the articulation may almost be described as a slightly oblique 
section of a cylinder, and nnxst have allowed great freedom of movement to the 
head in an up-and-down direction. There is no condylar foramen, or at least 
none has yet been observed. The foramen marjnnm (text-tig. 1, f.m.) is large and 
oval in outline. Its concave upper border is formed entirely by the exoccipitals, 
which meet in a median suture, thus excluding the supraoccipital entirely from 
the opening (PL III. fig. 2) ; while its ventral border, which is nearly straight 
and somewhat posterior to the upper border, is probably formed mainly by the 
basioccipital. The suture between the exoccipitals and the supraoccipital runs 
outwards and somewhat upwards from the middle line (PI. III. fig. 2), and crosses 
the lower end of the massive lambdoidal crest, of which the thickened and prominent 
ventral end is therefore formed by the exoccipital. Laterally the exoccipitals are 
applied by a broad surface to the posterior face of the post-tympanic process 
(PI. I., PI. II. fig. 1, PL III. figs. 1, 2 k, pty.) of the squamosal, the suture between the 
two being nearly vertical. Between this squamosal process of the exoccipital and the 
condyle, below the level of which it projects considerably, there is a blunt ju’ominence, 
which seems to represent the paroccipital process (PL I., PL III. fig. 
The hasioGcipital {hoc.), which, as already mentioned, forms the nearly straight 
ventral border of the foramen magnum (text-fig. I, f.m.), is broad and flat posteriorly, 
but its outer boundaries are not clear. Antero-laterally it seems to be notched 
on either side by the posterior angles of a pair of large fossje, which open into 
the cranial cavity, arc separated by the narrow anterior portion of the bone, and 
must in life have lodged the tympanic bones. The anterior portion just mentioned 
deepens considerably from before backwards, so that near its junction witli the 
basisphenoid the vertical diameter is much greater than the transverse extent. In 
this anterior region the ventral surfitce bears a median keel, while a transverse 
ridge marks its junction with the hasisplumoid (PL II. fig. 1, hsp.), the ventral 
surface of which is likewise keeled in the middle line. The axis of this bone is 
not quite in the same straight line as that of the basioccipital, but turns slightly 
upwards in front, its anterior portion being embraced by the up{)er edges of the 
pterygoids posteriorly and of the palatines anteriorly. The vomer has not been 
observed in any s[)ccimen. 
