922 C. MOORE ON THE PALEONTOLOGY 



Discussion. 



Prof. Ramsay said that as the South Wales coal-field, the Bristol 

 coal-field, and the Forest of Dean coal-field were basins originally 

 continuous, and only separated by denudation, Mr. Prestwich and 

 himself had agreed before the Royal Coal Commission that coal- 

 fields might exist below the Secondary strata to the eastward. The 

 correctness of this opinion was proved by the boring put down by 

 Mr. Pox at Burford, in Oxfordshire, which reached undoubted Coal- 

 measures. Prof. Ramsay thought that one of these coal-fields 

 might yet be found near London by penetrating the overlying 

 Secondary rocks. 



Prof. Seeley stated that in the supposed Triassic deposits of the 

 Kentish-Town well he found a portion of a Belemnite of a form 

 peculiar to the Neocomian. He referred to the numerous derived 

 specimens of Carboniferous rocks and fossils found in the local Neo- 

 comian deposits of Cambridge, and to the absence of all traces of 

 Devonian. He regarded the evidence of the Devonian age of the 

 beds at the bottom of Meux's we]l as not perfectly satisfactory, 

 owing to the imperfection of the specimens. 



Mr. Whitaker remarked on the difference between the Lower 

 Greensand at the outcrops north and south of London, and 

 the peculiar oolitic limestone found in Meux's well. He regarded 

 the beds at the bottom of the Crossness boring as by no means 

 proved to be Devonian, but thought some of the specimens more 

 closely resembled New Red Marl. He referred to the Loughton 

 section, in which water was got at the base of the Gault, probably 

 indicating the existence of Lower Greensand. He thought that, con- 

 sidering the inverted condition of corresponding strata in Prance 

 and Belgium, the determination of the direction of the dip of the 

 beds in Meux's well was by no means of great importance. He did 

 not think that the depth of Gault at Shoreham was exceptional, as 

 at Caterham and other points along the outcrop an even greater 

 thickness of Gault had been found. He stated that the Cambridge 

 phosphate-bed, a few inches thick, was found immediately above the 

 Upper Greensand in Meux's well, and pointed out that some doubt 

 existed as to the thickness of the several beds passed through in the 

 boring. 



Mr. Blake suggested that the bed above the Devonian might be 

 derived from the denudation of Jurassic as well as of Neocomian 

 deposits. He alluded to the evidence from Thecidium and Carpenteria 

 as bearing on this subject, and stated that evidence of the presence 

 of the latter had been obtained from Corallian deposits. 



Mr. Champernowne suggested the possibility of the existence of 

 Old Red Sandstone beds at the bottom of some of these deep wells. 



Prof. Jtjdd stated that the fossils of the oolitic beds at Meux's were 

 shown by Mr. Etheridge and Mr. C. Moore to be undoubtedly Neo- 

 comian. He supported Mr. Whitaker's view as to the great thick- 

 ness of the Gault at some points round the London basin. 



