﻿20 



SUPPLEMENT TO THE BRITISH 



* Lobster-clay ' of Atherfield) prevails throughout its middle portion, becoming gradually 

 more arenaceous in its passage upwards. 



"2. The Hythe beds (the Kentish-rag series of Fitton) are well exposed in the 

 vicinity of Hythe, and in the famous quarries at Maidstone ; and may also be observed at 

 Sevenoaks, and at Bletchingley, near Nutfield. To the westward of Nutfield these beds 

 alter their character so considerably as to be no longer recognizable ; the regular beds of 

 limestone and hassock so conspicuous at Hythe and Maidstone being replaced by sand- 

 rock and chert, as at Leith Hill, or almost entirely by sand, as at Guildford and 

 Godalming. The argillo-arenaceous deposits, which in the Isle of Wight represent the 

 Hythe beds, are also devoid of stone ; unless we include in this division the ' Crackers- 

 rock ' of the Atherfield section, which appears, however, to belong more properly to the 

 lower division, and is so placed in my section. It is worthy of remark that the numerous 

 fossil Mollusca of the Crackers-rock occur at East Shalford (in Surrey) on nearly the 

 same level as the Perna-bed and below the principal clay bed, instead of above it as at 

 Atherfield. 



" 3. The Hythe Beds are succeeded in the vicinity of Folkestone by a deposit of 

 dark-coloured argillaceous sand, from 140 to 150 feet in thickness, geologically known as 

 the c Sandgate beds,' and representing the ' Middle or argillaceous division ' of Fitton. 

 The outcrop of this bed is very conspicuous on the shore between Folkestone and Sand- 

 gate, where it forms a low and ugly cliff of a blackish-green colour, and its presence may 



be traced westward for a considerable distance The Sandgate, like the Hythe 



beds, appear, in fact, to lose their distinctive features in passing westward, the two series 

 gradually coalescing, and becoming thereby almost indistinguishable. 



" In the Isle of Wight the Sandgate and Hythe beds may be best observed in the coast- 

 section between Dunnose Point and the middle of Sandown Bay. The former appearing 

 to be represented by blackish-green strata which rise on the shore beneath Knock Cliff, and 

 which, traversing the lower part of Shanklin and the upper part of Small Hope Chines, 

 continue visible in the cliffs as far as Little Stairs Point ; the cliffs thence to Sandown 

 being almost entirely occupied by the representative of the Kentish-rag series. 



" 4. The Folkestone beds, the series next in order of succession, and which constitute 

 the ' ferruginous or Upper division ' of Fitton, although including in their inland course a 

 somewhat complicated series of deposits, exhibit in the Folkestone section but little 

 variation in mineral character, the strata consisting almost entirely of light-coloured sands 

 with irregular concretions of siliceous sandstone 



It is therefore evident that, although we may not possess in this country either the 

 highest or very lowest beds of the Cretaceous System, and though several important 

 Continental intervening divisions are wanting, still, our Cretaceous series is very 

 important, as far as it goes. It is represented both in Ireland and in Scotland ; but 

 does not in either of the last two portions of the United Kingdom assume the importance 

 it does in the south and middle of England. 



