480 Geological Society : — 



and of the Sandgate Beds and Kentish Rag." By T. M c Kenny 

 Hughes, Esq., B.A., F.G.S. 



At the bottom of the Thanet Sand there is always a bed of green- 

 coated flints in a green and rust-brown clayey sand, which the 

 author is of opinion was derived from the decomposition of the 

 chalk by the percolation of carbonated water after the deposition 

 of the Thanet Sand, as none of the flints are water- worn, and only 

 chalk-fossils have been found in the bed. 



At the base of the Sandgate Beds, and resting on rubbly Kentish 

 rag, there is generally a bed of green sand; it may be seen in the 

 quarries near Maidstone, where it occupies furrows of the nature of 

 pipes. Mr. Hughes endeavoured to show that this bed has been 

 derived from the decomposition of the Rag after the deposition 

 of the brick-earth, and that the rubbly limestone below it is the 

 same, in process of decomposition. He remarked in conclusion that 

 conformabilities or uncomformabilities of beds must not be inferred 

 from an examination of the line of junction only, as that may have 

 been very much modified after the deposition of the newer formation. 



4. "On the Lower London Tertiaries of Kent." By W. Whit- 

 aker, Esq., B.A., F.G.S. 



This paper gave the general results of the Geological Survey 

 work in the Tertiary district of Kent, chiefly by the author, who 

 expressed his agreement with Mr. Prestwich's paper, except in a few 

 matters of mere detail. 



Five different members of the Thanet Beds were distinguished, 

 the only constant one being the " base-bed," the possible formation 

 of which, after the deposition of the sands, &c. above, worked out 

 in detail by Mr. Hughes, had occurred also to the author. It was 

 shown that the fine Thanet Sand of West Kent was replaced east- 

 ward by beds of fossiliferous sandy marl and sand, which come on in 

 succession above it. 



Of the overlying Woolwich Beds, only the lower part is present 

 in the eastern part of the county, the middle (the estuarine shell- 

 beds) and upper parts being limited to the western and central 

 districts. 



The sands of East Kent which Mr. Prestwich had somewhat 

 doubtfully classed with the basement bed of the London Clay and 

 the pebble-beds of West Kent, part of which had been classed 

 with the Woolwich series and part with the basement bed, the 

 author had been led to look upon as a distinct division, to which he 

 gave the name " Oldhaven Beds," and which are separable alike 

 from the London Clay above and from the Woolwich Beds below. 



The basement bed of the London Clay, in the limited sense in 

 which it is understood by the author, changes its structure accord- 

 ing to that of the underlying beds. 



The author corrected some mistakes that had been made in a 

 paper printed in the Society's Journal, in which an undoubted 

 Eocene-bed near Chislet was classed with the Crag, on the strength 

 of its fossils, many of which he believed to have been wrongly 

 named. 



It was then pointed out that the Woolwich and Reading series 



