1824.] below the Chalk, &,x. 381 



istic fossils completely identify the limestones of that tract with 

 those of the Isle of Wight; and there can be no doubt as to the 

 place where the formation commences, the Cyprisf'ababeingfound 

 in the clay immediately beneath the green sandstone, above the 

 town of Hythe. 



In pursuing the boundaries of the chalk around the great 

 denudation of Kent and Sussex, the same succession of beds 

 can be recognized in several other places. — Thus the description 

 given by Mr. Mantell, from Mr. J. Hawkins, of the ' Malm rock' 

 of Western Sussex, accords with the succession represented in 

 Sections 1 and 2. A similar section has been communicated 

 to me by Mr. Lyell, from the village of Shiere, between Dorking 

 and Guilford, on the north western side of the weald district : 

 the following being the order of the beds, — chalk, green sand 

 with calcareous chert (firestone) ; blue marl (gault) of dark 

 colour, with a few fragments of shells ; and ferruginous sand 

 (the upper beds of the green sand). — The section (fig. 1), it will 

 be seen, corresponds essentially with that given by Mr. Web- 

 ster,* and by Mr. Phillips (" Outlines," p. 150, &c.) of the 

 tract between Merstham and Nutfield, in Surry. — And Mr. War- 

 burton informs me that he has traced the upper ferruginous por- 

 tion of the green-sand eastward, — from Guildford through Red- 

 Hill (Ryegate), River-Head, Seal, Ightham, and Wrotham 

 Heath, to Aylesford, in the neighbourhood of Maidstone. 



On the east of Godstone however, the structure of the county 

 must still be considered as, in some degree, uncertain, for the 

 following reasons : 1 . That the firestone beds have not been 

 traced to the west of the point above-mentioned ; though their 

 equivalent will probably be found among the harder beds at the 

 bottom of the grey marly chalk. 2. Notwithstanding the many 

 evidences of correspondence, — the great abundance of fossils in 

 the Folkestone marl, and their comparative scarcity throughout 

 the Isle of Wight, is a variation of such amount as to demand 

 the strongest evidence of geological identity r[ 3. The ferrugin- 

 ous beds at the top of the green-sand formation, have not yet 

 been observed in the vicinity of Folkestone ; while on the other 

 hand, calcareous matter exists there in much greater propor- 

 tion than in any part of the lower beds in the Isle of Wight : — 

 The fossils, however, are the same. But I have observed some 

 appearances on the shore between Sandgate and Folkestone, 



* Geol. Trans, vol. v. p. 35.1. 



+ On the opposite coast of France, the Folkestone marl occurs beneath the chalk 

 without the intervention of the fire stone, at least in a prominent form. I have traced 

 it with most of the characteristic shells of Folkestone, all round the denudation of the 

 lower Boulonnois, from the foot of Blancnez, through Boursin, Colembenj, Lottin- 

 ghen, &c. to the vicinity of Samer ; and have found in several places beneath it tracts of 

 green sand — In j\lr. Smith's maps of Kent and Surry, the gault is continued, without 

 interruption, from the west of Dorking to the coast. 



