21^ Geological Society : — 



the summit of the North Downs from Folkestone to Dorking a 

 few masses of sand, gravel, and ironstone, which present a certain 

 regularity of structure and uniformity among themselves, and are 

 clearly different from and of a later age than the outliers of eocene 

 tertiaries on the same hills. Mr. Prestwich had long been ac- 

 quainted with these ferruginous sands at Vigo Hill, where they are 

 about 30 feet thick ; and at Paddlesworth near Folkestone, where 

 they are even better developed ; but though the ironstone fragments 

 derived from these beds are frequently found dispersed about the 

 Downs, it was long before he met with any fossils in these beds, 

 with the exception of a piece of fossil wood pierced by Teredo, and 

 an obscure cast of a bivalve shell, at Paddlesworth. In December 

 1854, however, some blocks of gritty ferruginous sandstone full of 

 casts of shells were communicated to the author by Messrs. W. 

 Harris and Rupert Jones, who had met with the specimens in some 

 sandpipcs in the Chalk at Lenham, eight miles east of Maidstone, and 

 regarded them as belonging to the Basement Bed of the London 

 Clay. This fossiliferous ironsand on close examination yielded casts 

 of bivalve and univalve shells belonging to nearly thirty genera, 

 besides indications of LvnuUtes, Diadema, &c. The presence of a 

 Terehratula very like T. grandis, with several species of Astarte, and 

 afterwards his finding a large Mya-shaped shell, led Mr. Prestwich 

 to conclude that these sandy beds belonged to the Lower Crag. 

 Mr. Searles Wood, to whom the fossils have been submitted, states 

 that, as far as the evidence goes, he thinks they may with some pro- 

 bability be referred to the Lower Crag period ; the occurrence of a 

 Pyrula more especially strengthening this view. Mr. Prestwich 

 assigns without any doubt this shelly ironstone to the ferruginous 

 sands above referred to, and points to the peculiar concentric arrange- 

 ment of the contents of the sandpipes of the locality in question as 

 definitely indicating (in accordance with the observations he formerly 

 published in the Society's Journal) the former existence of horizontal 

 strata of — 1. (lowermost) loam with flints, — 2. greenish sands with 

 ironstone nodules, — 3. yellow and reddish sands, — superposed on the 

 bare chalk, after the eocene beds were for the most part denuded, and 

 before the sandpipes were formed, into which these overlying beds 

 were here and there let down and thereby preserved when further 

 denuding agencies removed the later tertiary beds. 



Regarding then the outliers of ferruginous sands and sandstones 

 above referred to as of the age of the Lower Crag, Mr. Prestwich 

 points out the relative position of beds of similar age and of not dis- 

 similar structure, on the Downs between Calais and Boulogne, also 

 on the top of Cassel Hill near Dunkirk, at Lessines, at Louvain, and 

 at Diest in Belgium. This extensive range of Crag-beds to the south 

 of the typical Suffolk area, and their considerable elevation above the 

 sea, are of course matters of great interest, not only as pointing out 

 the relative age of some of the drifts, but especially as giving us a still 

 nearer date to limit the denudation of the Weald, and indicating 

 marginal sea-beds now stretching far inland and ranging once 

 probably over the Wealden area, — possibly connected too with the 



