Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/240

 surface of the bone, while of the inner series the four hindmost teeth are but little affected by wear. The teeth of the outer series are larger than those of the inner, the base of the largest being 0.15 in. in diameter ; the middle teeth in each series are the largest, the anterior and posterior diminishing in size.

The inner two series of teeth cannot be traced as far forward as the outer, the inner wall of the anterior half-inch of this valley being so thoroughly ground down that it is converted nearly into a plain. It is a curious circumstance that at the posterior part of the inner surface the apices of four teeth appear, as if they were about to protrude on this face. It is quite clear that this remarkable wearing down of the palato-maxillary teeth can only be explained by their attrition against the teeth of the mandible ; and the sharpness of the groove in the posterior half of the palatal surface clearly shows that these mandibular teeth were themselves sharpened to a sort of knife-edge.

Dr. Lloyd's second specimen is a fragment of a larger palato- maxillary bone of the same (left) side. It is, however, smaller relatively to the original size of the bone, as some of the anterior portion is broken away, and the posterior edge, though nearly preserved, is somewhat imperfect. The transverse diameter of the nearly entire posterior end is 0*8 in. ; so that this bone is about half as large again as the foregoing, and belonged to an animal probably not more than half as large as the Elgin specimen.

In this specimen the outer series of teeth is double posteriorly, two large conical teeth making their appearance on the outer side of the four which remain tolerably unworn. As before, there are two rows on the inner side of the groove ; and anteriorly all the series of teeth are worn down to one flat surface with the bone which holds them.

Mr. Whitaker's specimen*, from Devonshire, is a right palato- maxillary bone of a Hyperodapedon of small size, probably less than that to which Dr. Lloyd's smaller specimen belonged. It is in an imperfect condition, but shows part of a single outer series of teeth, and of two inner series, both completely worn down. The apices of four or five teeth project in two rows upon the posterior half of the inner face of this specimen.

I propose to give a full account of the Indian specimens elsewhere. At present I merely wish to observe that, for the most part, they belong to animals of a larger size than the Elgin specimen, but that I have not yet discovered any grounds for regarding them as specifically distinct. In the series sent by Dr. Oldham, there is a fragment of a ramus of a mandible which shows the scissor-edge character of the dentary margin extremely well.

drawing my attention to some additional examples of the Warwickshire Hyperodapedon. Two of them are fragmentary palato-maxillary bones. The third has very much the appearance of two crushed palato-maxillary bones, with one ramus of the mandible of a small specimen ; but I have not been able to work it out fully.
 * I am indebted to my friends the Rev. P. B. Brodie and Mr. Kershaw for