Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/92

6 and I was almost disposed to admit their identity with those of the latter genus, after the rapid examination which was alone possible at the meeting of the British Association at Norwich. A more critical comparison, however, has convinced me that the teeth of this reptile are perfectly distinct from those of the great Wealden Dinosaurian.

A large postfrontal separates the orbit from the temporal fossa, and appears to have united with the jugal, of which only an impression remains. A præfrontal is distinguishable at the upper and anterior part of the orbit. Beneath and behind it, lies a broken but very large and curiously curved lacrymal (La), which is deeply grooved upon its outer surface, the outer and posterior lip of the groove being much shorter than the inner and anterior lip. An ascending process of the maxilla seems to have articulated with the posterior and inferior end of the lacrymal. The anterior margin of this lacrymal process of the maxilla, the superior margin of the body of the maxilla in front of it, and the posterior margin of that broad nasal process of the maxilla which ascends behind the præmaxilla are all smooth, and evidently natural, free edges. Hence there must have been a considerable prælacrymal vacuity (a) in the walls of the face. The postfrontal sends a long process backwards, outside an anterior prolongation of the squamosal, the two combining to form the supratemporal zygoma. An impression on the matrix proves that there was a strong infratemporal zygoma formed by the jugal and quadrato-jugal; and on the left side the under part of this is visible. Remains of large sclerotic plates lie in the orbit. The hinder face of the distal half of the quadrate bone is displayed upon the left side (fig. 4, Qu). It is a very strong bone, the articular surface of the condyle measuring not less than half an inch from side to side.

The occipital face of the skull is much injured, but it was evidently directed almost perpendicularly to the upper face. The left parotic process is well displayed, and is proportionally large, being half an inch long and 0⋅3 inch wide. The base of the skull exhibits the injured basioccipital region, and the more perfect basisphenoid, which possesses two strong, divergent, basipterygoid processes. Against the outer ends of these the strong pterygoid bones abut. These are not at all unlike the corresponding bones in an Iguana. The central part, or body, of the bone is very strong; and it sends backwards and outwards a deep, laterally compressed plate, which abuts against the inner side of the quadrate bone. The body of the pterygoid bone is very strong, and produced vertically. Anteriorly and externally it becomes connected, by a transverse bone, with the maxilla. A small palatine bone is seen on the left side in front of the pterygoid. The pterygoid is, in many respects, like that bone in the existing Iguanæ; and this specimen shows very clearly that the Dinosauria had a Lacertilian and not a Crocodilian arrangement of the pterygoid and palatine bones. Only the right ramus of the mandible can be seen; and the symphysial end of that is broken away. But what remains is nearly in place, and shows that the angular process was relatively small, while the coronoid rises abruptly, in front of the articular surface, to the height of an