NEWTON : COXCHOI.OGICAT, FEATURES Ol' I.EXHAM SANDSTONES. 6l 



As a result of an examination of tlie Prestvvich Collection and that 

 of the Geological Survey, Von Koenen^ was of opinion that Lyell was 

 wrong in his estimate of a Miocene age for the iron-sandstones of 

 Kent, he regarding them as Pliocene because he considered they 

 contained characteristic shells of the Upper Crag. 



Mr. Whitaker" next gave his opinion on the age of the L-enham 

 fauna, assisted by Gwyn Jeffreys in connection with the MoUuscan 

 determinations. Their results suggested an Eocene horizon, because 

 among the fossils was identified a PJiorns like P. agginti/ians, Cyrena 

 ciineiformis, and a small Nuciila like N. miiior. 



Bristow^ supported the Eocene age theory for the Paddlesworth 

 ferruginous sands, which are unfossiliferous, and suggested that they 

 belonged to the Woolwich and Reading series. In a post-script to 

 this paper we are informed that the palaeontologist, W. H. Baily, had 

 examined Lenham fossils and pronounced them to be of London 

 Clay origin. 



In a later paper Von Koenen"* regarded the ferruginous sandstones 

 of Kent as corresponding with the Red Crag on account of the pre- 

 sence more particularly of Area lacfea, Sailaria foliacea, Emarginula 

 fissura, and Terebratiiia grandis. 



Writing on the "Box-Stones" of East Anglia, Sir Ray Lankester'""' 

 thought it very probable they were of the same age as the Lenham 

 Sandstones ; the former he considered as belonging to the Diestian 

 series of Belgium, and approximately equivalent to the so-called 

 Black Crag of Antwerp. The Belgian geologist, Mourlon," next recog- 

 nised that the "Sables de Diest" occurred on the North Downs of 

 Kent, between Folkestone and Dorking, Paddlesworth, and Lenham 

 near Maidstone, as first indicated by Prestwich and Lyell. Messrs. 

 Cogels and O. Van Ertborn'^ alluded to Lyell's statement as to the 

 abundant occurrence of Terebraiiila grandis in the ironstones of the 

 North Downs, which was also found in the Diestian beds of Belgium, 

 this horizon being considered of Lower Pliocene age and not Miocene 

 as understood by Lyell. 



A great advance in our knowledge of the Lenham deposits was next 



1 Die Fauna der Unter-oligocanen Tertiarschichten von Helmstadt bei Braunschweig : 

 Zeitsch. Deiitsch. Gcol. Gcs., 1865, vol. 17, p. 461. 



2 Gn the Lower London Tertiaries of Kent : Qziart. Journ. Geol. Soc, 1866, vol. 22, p. 430. 



3 Note on .Supposed Remains of the Crag on the North Downs near Folkestone : Qua?-:. 

 Joitrti. Geol. Soc, 1866, vol. 22, p. 553. 



4 On the Belgian Tertiaries: Ceo/, .^fag., 1S67, p. 502. 



5 Contributions to a Knowledge of the Newer Tertiaries of Suffolk and their Fauna : 

 Quart. Journ. Geol. Soc, 1870, vol. 26, pi. 34, fig.s. 5 — 10, p. 409. 



6 Geologic de la Belgique, 18S0, vol. r, p. 268. 



7 Contribution a I'Etude des Terrains Tertiaires de la Belgique ; Hull. Soc R. Mai. 

 BelgiqtH, 1882, vol. 17, pp. xliii. — xlv. 



