AND CLASSIFICATION OF THE FOSSIL REPTILIA. 
239 
the posterior extremity of the united frontals, when compared to that seen in the 
type skull, makes it highly probable that the parietal foramen in this skull was 
similarly situate and conditioned.* 
The palatal aspect shows the union of the palatine bone with the maxillary, the 
extension of the palatine on the internal border of the pterygoid, the median 
approximation of the pterygoids posteriorly against a compressed median plate, 
2 centirns. high, 1‘4 centim. wide on the palate, and 9 millims. wide superiorly, 
which appeal’s to be the pre-sphenoid ; and a flattened bone descends on to the outer 
surface of the pterygoid, diverging outward and forward, which is in the position of 
the columella, but is only seen on the right side. 
The Quadrate Bone. (Plate 10, figs. 4-6). 
Though several Anomodont skulls in the British Museum have lost their quadrate 
bones, the collection contains but one specimen separated from the skull, and that 
bone, hitherto undetermined, is without record of the locality where found, beyond 
being kept with specimens presented by Mr. Bain. 
It is in a pale grey matrix, which has been completely removed, so that the 
external form of the bone is fully shown. It agrees substantially with the bones 
which are attached to the skulls in every character but one, and that is in the 
presence of a very large foramen or notch, which runs through the bone above the 
distal articulation. The bone indicates a larger skull than any which has been 
described, and may eventually be referred to a new genus. 
The bone consists of a trochlear articulation, from which a strong wide wedge- 
shaped process ascends obliquely, and shows, on the middle of what I regard as the 
inner margin, a large vertical pit for the pterygoid bone (fig. 4). 
The trochlear articulation (fig. 6) consists of two well defined condyles, which are 
convex from behind forward, and separated by a deep wide median channel. The inner 
condyle, as preserved, is the narrower, but this is probably due in part to a fracture, 
which has removed its inner margin. The transverse measurement from within out¬ 
ward is 7'5 centirns. ; and the antero-posterior measurement of the outer condyle is 
less than 6 centirns., and of the inner condyle more than 6‘5 centirns. Both condyles 
project forward,'and are well defined by the less development anteriorly of the bone 
which rises from the articulation ; but the inner condyle appears to have worked in a 
well defined excavation, and is defined posteriorly by a transverse emargination or 
groove above the articular surface. The external condyle has the external margin 
convex from front to back; while the margins of the other condyle appear to be 
straight and parallel. 
* In the fossil No. 36,235, the parietal foramen is an ovate perforation 1'3 centim. long and 9 nhllim.s. 
wide, with an elevated rounded rim, the transverse measurement over which is 2'3 centirns., and the 
length about 2'8 centirns. This border is less than half a centim. wide in front, but widens laterally 
and posterioi'ly; and all round it the bone is depressed. 
