34 Meyer— On the Cretaceous Rocks. 



sub-divisions, I propose to trace eacli group separately in its course 

 from East to West, briefly noticing such, of the principal variations 

 in its component rocks as have resulted from changes of mineral 

 character or from the thinning out or intercalation of particular beds : 

 omitting, however, any mention of the Wealdon strata on account of 

 their being so little exposed along the line of section. 



1. The lovs^est sub-division of the Grreensand — the Atherfield clay 

 of Fitton, and Lovrer Neocomian (in part) of foreign authors, is 

 knovPTL to occur beneath the Kentish-rag series at Folkestone^ although 

 unexposed in the coast-section, and its continuity has been traced 

 inland past Maidstone,^ Sevenoaks,^ Eedhill, and Guildford.* It is 

 visible on the shore beneath Eedcliffe and still more conspicuously 

 at Atherfield, in the Isle of Wight ; westward of which it scarcely 

 appears to have extended. The thickness and mineral composition 

 of this group is very uniform throughout its course, consisting in its 

 lowest layers of sandy-clay which, where the fossils are most abun- 

 dant, has become consolidated into hard, nodular concretions of shell- 

 rock. A stiff brown or bluish clay (the " Lobster-clay" of Ather- 

 field) 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 Maid- 

 stone ; and may also be observed at Sevenoaks, and at Bletchingley, 

 near Nuffield. To the westward of Nuffield these beds alter their 

 character so considerably as to be no longer clearly recognizable ; 

 the regular beds of limestone and hassock so conspicuous at Hythe 

 and Maidstone being replaced by sandrock 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 repre- 

 sent 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 a,nd helow 

 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 " Sandgate-beds," and repre- 

 senting the " Middle or Argillaceous division" of Fitton. The out-crop 

 of this bed is very conspicuous on the shore between Folkestone and 

 Sandgate, where it forms a low and iigly cliff of a blackish-green color, 

 and its presence may be traced westward for a considerable distance. 

 I cannot, however, agree with Dr. Fitton in tracing his " Argillaceous 

 division," as a day-bed, so far inland as Nuffield, and (as will pre- 



^ Simms, Quart. Journ. Geol. Soc. vol. iv., p. 206. 

 ^ Fitton, Quart. Journ. Geol. Soc. vol. iv., p. 209. 

 3 Evans, Proc. Geol. Association, vol. i., p. 395. 

 * Austen, Quart. Journ. Geol. Soc. vol. iv., p. 172. 

 " Fitton, Quart. Journ. Geol. Soc. vol. iv., p. 398. 

 « Simms, Quart. Journ. Geol. Soc. vol. iv., p. 206. 



