Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/238

 The pubis and ischium occupy a space equal in length to four vertebrae, which is a proportion very similar to that which obtains in existing Lacertilia.

A distinct impression of the right femur is left almost in its natural position. It is a nearly straight and very strong bone, which is 4-7 in. long, or equal to more than five vertebrae in length. The femur has a similar proportional size in Monitor and Iguana. Impressions of the proximal ends of the tibia and fibula are visible, in such relation to the femur as shows them to have undergone very little disturbance.

No certain indication of the character of the feet is discernible.

The general arrangement of the teeth has been described. The downwardly convex dentigerous edge of the maxilla is 2.75 in. long, and appears to have carried about eighteen (or perhaps more) teeth, of a conical form and very closely set. The outer surface of the maxilla, from the dentigerous edge to the lower boundary of the orbit is fully an inch high, and is excavated and inclined outwards with a very peculiar curvature.

The dentigerous edges of the opposite maxillae converge towards one another at an angle of about 45°, and then become parallel as the snout narrows to its termination.

No suture can be distinguished upon the roof of the mouth, between the maxillae and the palatine bones, though the boundary line between the two is probably indicated by the groove into which the dentigerous edge of the mandible bites. The roof of the palate is therefore formed by a broad plate of bone, which may be called palato-maxillary, as it is constituted by the conjoined maxillary and palatine. Anteriorly this plate has a width of not more than 0.35 in. internal to the groove, but it widens posteriorly to 0.7 in. Its inner edge is convex towards the middle line, roughly following the course of the dentigerous edge. For their anterior halves the two edges of the palato-maxillary bones seem to be separated by only a small interval ; but posteriorly they diverge widely ; whether the interspace was occupied by the pterygoids, or not, cannot be ascertained.

The palato-maxillary plate on the inner side of the groove bears three (or perhaps four) longitudinal series of conical teeth, the largest of which are about 0.1 in. in diameter at the base. The posterior edge of the palato-maxillary is abruptly truncated, smooth, rounded, and slightly concave backwards.

It is upon this part of the organization of Hyperodapedon that Dr. Lloyd's specimens throw such important light. One of them, which is smaller and more perfect than the other (fig. 1, a, b, c, d, e), exhibits nearly the whole of the characteristically convex dentigerous margin, and excavated and outwardly inclined outer face, of the palato-maxillary of Hyperodapedon. Its posterior margin is smooth and rounded below, exhibiting the natural termination of this part of the bone. The inner surface is also quite smooth, and could not have united suturally with any other bone. The anterior end of the bone is broken off transversely ; but probably very little of it is lost. As it