•240 
PEOFESSOR H. G. SEELEY ON THE STRUCTURE, ORGANIZATION, 
The channel between the condyles is about 3 centims. wide, and fully 1'5 centim. 
deep, highly inclined towards the inner condyle, and less inclined on the surface 
which contributes to the outer condyle. This channel makes the anterior margin 
concave between tlie condyles, and causes a corresponding concave contour on the 
hinder border. 
The greater length of the inner condyle appears to be correlated with the greater 
antero-posterior extent of the bone which rises above it. Above the outer condyle 
this is a small and comparatively slender vertical process, which is fractured, so that 
its height is not seen. It measures 3'3 centims. from front to back, and less than a 
centimetre and a half transversely where thickest. The convex external surface is 
somewhat irregular, as though it were impressed above the condyle by giving attach¬ 
ment to a bone, which may have been the quadrato-jugal or possibly the squamosal, 
since there is at present no conclusive evidence of the quadrato-jugal as a normal 
element in an Anomodont skull. The height from the base of the articulation to the 
fracture of this process is 5'7 centims. The process is separated from the strong bony 
wedge which rises above the inner condyle by the large notch or channel which is 
situate above the channel between the condyles, from which it is separated by a 
thickness of bone of about 2‘2 centims. in front and 1’5 centim. behind. The base of 
the channel is concave from back to front, as well as from side to side; its external 
border was most produced anteriorly, and its inner border most produced posteriorly. 
The sides appear to have converged upward without meeting. The greatest width of 
the perforation in front is about 2’5 centims. 
The plate or wedge of bone which rises above the inner condyle terminates 
superiorly in a thin compressed edge, convex from front to back, which is inclined 
towards the outer side in front, and towards the inner side behind, so as to obliquely 
cross the direction of the condyle. The lieight to this edge from the condylar surface 
is 10 centims. ; its greatest antero-posterior extent is 9 centims. The wedge is some¬ 
what cut into at the base, in front, by the median supra-condylar perforation, while 
the inner posterior side is excavated for a bony attachment. Otherwise the lateral 
surfaces are convex from front to back and converge from below upward, so as to 
meet in a sharp edge which extends from the back of the condyle to the front. On 
the posterior side the base of this wedge expands to the summit of the outer condyle. 
I have no doubt, from the evidence of the specimens described, that the larger part of 
this wedge was received into the squamosal bone. The large vacuity on the inner 
hinder border of the wedge, which is 4 centims. high and 1'5 centim. wide, is in the 
position in which the pterygoid bone commonly meets the quadrate ; though in 
Ichthyosaurus a similar pit appears to be formed by the malleus. 
On the whole, the bone approaches closely to the quadrate of Ichthyosaurus, not¬ 
withstanding the difference of the supra-condylar perforation ; for, if the external 
ascending process of this South African quadrate were removed, its external surface 
would have the same concavity as the quadrate of Ichthyosaurus where it faces 
