ANNIVERSARY ADDRESS OF THE PRESIDENT. XXXV 



a valuable record of carefully observed facts and be consulted by the 

 scientific miner as a useful guide. 



There is also a brief notice of the fossils of the district ; but this 

 great subject had not as yet been fully developed or become a di- 

 stinct science, nor had Siluria been explored, so that this part of the 

 paper is not in importance equal to the rest. At the present moment, 

 indeed, we can hardly estimate the true value of such elaborate papers, 

 or the vast labour of collecting the data for compiling them ; enter- 

 ing, as we now do, upon our inquiries, after these early pioneers of 

 science have shaped out a course for us, and enabled us to pass easily 

 over ground which to them was full of difficulties. 



February 20, 1824. — In the paper read on this day, Dr. Buck- 

 land, then President of the Society, announced the discovery, at 

 Stonesfield near Woodstock, of parts of the skeleton of an enormous 

 fossil animal, which had been then deposited in the Museum of Ox- 

 ford. This animal Dr. Buckland identified, though the fragments 

 were few, as belonging to the order of Saurians or Lizards, and from 

 the length of the largest thigh bone he deduced a length of 40 feet, 

 and a bulk equal to that of an elephant ; although, as he rightly 

 observed, the same proportions cannot be always ascribed with safety 

 to fossil and recent species. He named this animal, relics of which 

 had also been obtained by Mr. Mantell from the Wealden, generi- 

 cally Megalosaurus, and it would appear that in his examinations he 

 availed himself of the assistance of Mr.Conybeare and the greatCuvier. 

 Dr. Buckland also noted the existence of the elytra of Beetles in the 

 now so well-known deposit of Stonesfield, as well as the bones of 

 what he then considered birds, but which he afterwards ascertained 

 to belong to a Pterodactyle. 



In this year Dr. Buckland contributed two other papers to the 

 * Transactions,' the first on the " Occurrence of Agates in Dolomitic 

 Strata of the New Red Sandstone Formation in the village of Sandford, 

 two miles east of Banwell." He describes them as exteriorly rugged, 

 but internally as made up of alternating bands of chalcedony, jasper, 

 and hornstone, disposed in irregular and concentric curves, the outer- 

 most being conformable to the irregularities of the external surface, 

 whilst the interior is occupied by an amorphous mass of chalcedony 

 and hornstone, through which are dispersed a number of smaller and 

 nearly spherical agates. These agates resemble the Bird's-eye Agate, 

 and are distinguished by Dr. Buckland from the imperfect agates 

 called potatoe-stones, so common in these strata. Dr. Buckland 

 ascribes the formation generally, but not always, to the infiltration of 

 siliceous matter into geodes or cavities of the rocks, as in the case 

 of the agates of trap-rocks ; and he observes, that " wherever silex 

 is present in a state of sufficiently minute division to be filtrated into 

 any small cavity, there the formation of agates may proceed." 



Dr. Daubeny is quoted by Dr. Buckland as having found entire 

 beds of jasper and jasper-agate in the dolomite hills near Palermo ; 

 and in that region the formation of such bodies might be more readily 

 assimilated to that of the geodes of trap-rocks ; as it may be sug- 

 gested that the infiltration of silica in an undissolved condition, 



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