286 Reports and Proceedings — 



Ann's Hill (230 ft.), was given, and the possible existence of a trough 

 or synclinal towards the centre of the section discussed. It was shown 

 from the position of the Hatch brick-earth that if the Lower Bag- 

 shots retain anything like the mean thickness of, say, 120 ft., which 

 prevails in this district, the London Clay surface must here be 60 ft. 

 helow O.D., on the supposition that these beds represent the basal 

 clays of the Middle Bagshots ; whereas, at Chertsey, in the valley of 

 the Thames itself, the London clay surface coincides with 0. D. 



In conclusion, it was held (1) that the more we study the Bagshot 

 beds of this area, the less likely are we to see a passage between the 

 curiously diversified Lower Bagshots and the much more uniform 

 and homogeneous London Clay ; (2) that, until we realize the 

 considerable though sporadic development of clays in the Lower 

 Bagshots, we shall be in danger of referring beds to the Middle 

 Bagshots which do not belong to them, and thereby give encourage- 

 ment to a speculative stratigraphy which can only mislead. 



III.— May 11, 1887.— Prof J. W. Judd, F.E.S., President, in the 

 Chair. — The following communications were read : — 



1. " Further Observations on Syperodapedon Gordoni." By Prof. 

 T. H. Huxley, LL.D., F.E.S., F.G.S. 



The author briefly noticed the circumstances under which he 

 first described the occurrence of Lacertilian and Crocodilian fossils 

 in the Elgin Sandstones, and the confirmation which his views as to 

 the Mesozoic age of these remains had received from the discovery 

 of Syperodapedon in English Triassic rocks and in India. The 

 original type of Jlyperodapedon Gordoni from Elgin was, however, 

 in bad condition, and the receipt at the British Museum of a second 

 much better preserved skeleton, found in the Lossiemouth quarries 

 of the same neighbourhood, had enabled him to add considerably to 

 the known characters of the genus, and to compare it more thoroughly 

 both with the recent Sphenodon (or Hatteria) of New Zealand and 

 with the Triassic Bliynchosaurus articeps, several specimens of which 

 are in the British Museum palgeontological collection. 



The recentljf-discovered Jlyperodapedon-skeleton was of nearly 

 the same size as that formerly described, and must have belonged 

 to an individual about 6 or 7 feet in length. The specimen was 

 exposed by the splitting of a large block of sandstone, and comprised 

 the skull, the vetebral column as far as the root of the tail, all the 

 bones of the left and of part of the right fore limb, and those of the 

 right hind limb, the whole almost in their original relations. 



The bones were described in order and compared with those of 

 SpJienodon, the most important differences in Syperodapedon being 

 the following : — 



1 . The centra of the presacral vertebrae are ossified throughout and more or less 



opisthocoelous, especially in the cervical reojion. 



2. The anterior cervical vertebrae have long and strong ribs. 



3. The external nares are not separated by bone. 



4. Conjoined premaxillary bones form a long, conical, curved, pointed rostrum, 



which is received between the rostral processes of the mandible. All these 

 were devoid of teeth and probably sheathed in horn. 



