212 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jan. 21, 



January 21, 1857. 



C. Greaves, Esq., C.E., G. A. Ibbetson, Esq., M.R.C.S., and C. 

 F. A. Courtney, Esq., M.R.C.S., were elected Fellows ; and M. E. 

 Lartet was elected a Foreign Member. 



The following communications were read : — 



I. On some Fossiliferous Ironstone occurring on the North 

 Downs. By Joseph Prestwich, Esq., F.R.S., F.G.S. 



(The publication of this paper is postponed.) 



[Abstract.] 



Besides a drift of red loam with flints, and the few local outliers of 

 lower tertiary sands and pebble-beds, there are scattered on the sum- 

 mit 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 acquainted with these 

 ferruginous sands near Vigo Hill, where they are about 20 feet thick ; 

 and at Paddlesworth and other places near Folkestone, where they 

 are even better developed ; but though the ironstone fragments de- 

 rived 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, near 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 speci- 

 mens in some sandpipes 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 Lurmlites, Biadema, &c. The pre- 

 sence of a Terebratula very like T. grandis, with several species of 

 Astarte, and afterwards his finding a large Lutraria-like 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 be referred to the Upper Tertiaries, and in all probability to the 

 Lower Crag period ; the occurrence of a Pyrula and an Emarginula 

 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 arrangement 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 



* Vol. xi. p. G4. 



