Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/234

 teeth bite between the inner and outer series of the palato-maxillary teeth. The surfaces of the teeth, however, are not sufficiently preserved to enable one to make sure of the manner in which the teeth wear.

For a number of years I have been acquainted with two specimens from the quarry opened in a Triassic sandstone at Coton End, near Warwick — the one belonging to the Warwick Museum, and the other to the Rev. P. B. Brodie, F.G.S. Each of these is an elongated jaw- like bone, in which are set parallel rows of conical teeth ; and I have often compared them with the palate of Hyperodapedon, but without being able to satisfy myself that I was entitled to draw any positive conclusions from their resemblance.

In the winter of 1866, however, the Rev. Dr. Gordon sent me several specimens, among which one (belonging to Mr. Grant, of Lossiemouth), though a very much mutilated fragment of a skull, presented part of the characteristic dentigerous bones of the palato- maxillary apparatus of Hyperodapedon ; and my attention was, at once, forcibly drawn to the fact that the opposed faces of two of the rows of the teeth were worn down by attrition against other teeth. These two rows of teeth were placed on opposite sides of a deep longitudinal groove ; and the planes of the worn faces converged to the bottom of this groove.

On looking at the original specimen, it became clear that this groove corresponded with the depression into which the oral edge of the mandible is received when the mouth is shut. The opposed faces of the palato-maxillary teeth had been worn flat by attrition against the opposite sides of the mandibular teeth, which work between them as a knife-blade shuts into its handle; and it followed that the dentary margin of the mandible must be worn to an edge adapted to fit into the groove. So far as I know, no other fossil reptile possesses any such peculiarities ; and thus this interesting fragment presented me with new means of distinguishing the teeth and jaws of Hyperodapedon from those of other Reptilia.

Some time after I had become acquainted with Mr. Grant's new specimen, Mr. Lloyd, F.G.S., was good enough to call upon me for the purpose of showing me some specimens. from the Coton-End quarry before mentioned, which had for many years been in the possession of his father, Dr. Lloyd, long well known for his attention to the geology of Warwickshire. Among these were two bones beset with teeth of the same character as those which I have already mentioned from the same locality, but far more perfect, and presenting rows of teeth not only quite like those of Hyperodapedon in form and arrangement, but worn in a precisely similar way ; in fact, when Mr. Lloyd's specimens were placed side by side with Mr. Grant's, there was no resisting the conclusion that they proceeded from animals of one and the same genus, if not species.

I at once communicated these interesting facts to Sir Roderick Murchison, who refers to them in the following terms : —

"To such fossil evidence as this the field geologist must bow; and instead, therefore, of any longer connecting these reptiliferous