Geological Society of London. 327 



They are supposed by the author to have overlapped each other, so 

 as to show little more than the surfaces of the oblique ridges. The 

 author stated that this Amphibian aj)pears to be most nearly related 

 to his genus Pliolidogaster, but that it differs therefrom in the form 

 of the vertebral centre, and in the nature of the ventral armour. He 

 proposed to give it the new generic name of Plioliderpeton. 



Mr. Miall stated that the fossil described by Professor Huxley 

 was obtained from the Black Bed or Eoyd's Coal at Toftshaw, near 

 Bradford, and remarked that the Amphibians of the Coal-measures 

 appear to have been not only specifically numerous, but individually 

 abundant. He also noticed the difficulty of defining exact horizons 

 within the Coal-measures. 



Discussion. — ^Mr. Salter observed that, with both plants and moUusks, it appeared 

 to him that there were some which were eminently characteristic of different horizons 

 in the Coal-measures, which were to be traced over large areas. It was possible that 

 the same might prove to be true with regard to vertebrate animals. 



Dr. Duncan called attention to the conditions of life necessary for such an animal, 

 which could not have been in accordance with the commonly received views of the 

 character of the Carboniferous period. 



6. " On the Maxilla of Megalosatirus." By T. H. Huxley, LL.D., 

 F.E.S,, President. 



The author stated that the specimen which he was about to de- 

 scribe, belonging to Mr. Abbay, of King's College, was the first ex- 

 ample of the upper jaw of Megalosaurus that had ever been seen. It 

 showed the left side of the jaw, measured nearly 18 inches in length, 

 and 4J inches in depth anteriorly ; the posterior part was produced 

 into a thin and probably free process. The author described the 

 general form of the nasal and orbital opening, as indicated by the 

 characters of the specimen, and stated that the anterior part of the 

 jaw exhibits no suture indicating the separation of the premaxilla 

 from the maxilla. The teeth were stated to be few in number, but 

 very large, the part concealed by the jaw being exceedingly long. 

 One tooth, exposed in its whole length by the breaking away of the 

 bone, measured 6*4: inches, of which the crown formed 2*6 inches. 



Discussion. — Mr. Boyd Dawkins made some remarks as to the stratigraphical 

 range of Megalosaurus. The oldest example with which he was acquainted was a 

 tooth from the Lias of Lyme. It occurred also in the Lower Oolite of Dorset. 

 Higher up it was found in the Kimmeridge Clay, and again in the Tilgate Beds of 

 the Wealden. He had, however, himself found it in the Wadhxu-st Clay, above the 

 Ashdown Sands, near Battle. He had also seen remains in still higher beds, possibly 

 of Lower Greensand age, at Potton, but in this case the bones were probably deriva- 

 tive. An animal with almost identical teeth, the Tcratosauncs Suevicus of You Meyer, 

 occurred in the Lower Keuper, and possibly might belong to the same generic form. 



The President agreed that the Dinosaurians had occm-red in the Trias, and that he 

 was quite prepared for an extension of the family into earlier beds. 



II. June 9th, 1869.— Papers read : 1. " Notes on the Sutherland 

 Gold-fields." By the Eev. J. M. Joass. With an Introduction by 

 Sir E. I. Murchison. 



Sir E. I. Murchison, in introducing the Eev. J. M. Joass to the 

 meeting, called attention to the general geological structure of the 

 counties of Sutherland and Eoss, and especially to the circumstance 

 that the summits of the moimtains of that region are situated 



