SESSION 1905-1906. xxix 



sands of tlie Reading Beds is shown ; and also in the railway- 

 cutting about the same distance to the west. 



A search for fossils in the basement-bed of the London Clay 

 was unsuccessful, but Mr. Hopkiuson stated that he had found 

 teeth of several species of shark in the bottom layer of sand 

 and pebbles, and had placed them in the County Museum at 

 St. Albans, and also in this layer imperfectly-preserved shells. 

 Mr. E. T. Newton obtained from a workman some teeth which 

 must have come from this bed, and he has determined them to 

 belong to the sharks Odontaspis elegans, 0. cuspidatus, and 

 Lamna Vmcenti, and to the teleostean Phyllodus toliajncus. 

 The base of the Eeading Beds is not exposed ; lower beds have, 

 however, been worked, and a workman stated that he had found 

 oyster-shells in them ; nor is the Chalk exposed, but it cannot 

 be at any considerable depth below the floor of the present 

 workings, and the uneven bedding seen in the Eeading Beds, 

 although partly due to current-bedding, is largely caused by 

 irregular underground dissokition of the underlying Chalk. 



Mr. Monckton gave an account of the geological history of 

 the district. He said that he agreed with Prestwich in thinking 

 the gravel on this and neighbouring high ground to be distinct 

 from the glacial gravel, and he thovight that earth-movements 

 had taken place to a considerable extent since its deposition, 

 this patch and also those on the neighbouring Eocene outliers 

 most probably owing their preservation to the fact that they lay 

 on the line of a slight synclinal flexure. He doubted the marine 

 origin of the gravel, thinking it possible that it might be the 

 earliest gravel of the River Thames. 



Mr. Hopkinson stated that this was one of several outliers 

 which extended from Albury near Bishop's Stortford, on the 

 north-east, to beyond High Wycombe on the south-west, very 

 nearly in a straight line parallel with the line of outcrop of the 

 Eeading Beds, with a few smaller and more distant outliers, and 

 with inliers of these beds within the main mass of the London 

 Clay, as at Pinner and Northaw ; his inference being that the 

 underlying Chalk had undergone a series of slight folds in 

 parallel lines in this direction. He estimated the thickness of 

 the Eeading Beds shown in these sections as 16 feet, their total 

 thickness here as from 25 to 30 feet. The outlier, he said, 

 extended from Ayot Creen, which was chiefly upon it, to Ayot 

 St. Peter's Church on the north-west, and nearly to Digswell 

 Church on the north-east, and covered an area of about two 

 square miles. 



Leaving the brickfields the party walked through Sherrards 

 Park Wood and across the fields, which not long ago were the 

 Woodhall Woods, and are marked as such on the original (1834) 

 Ordnance Survey Map, to a large gravel-pit on the east side of 

 the main line of the Great Northern Eailway, near Woodhall 

 Lodge Farm. The gravel is of glacial origin, and the chief 

 interest of the section lies in the occurrence of two beds of 



