newton : conchological features of lenham sandstones. 59 

 Bibliography (1857-1915). . 



Note. — The conchoiogical determinations mentioned in the following memoirs arc those 

 of the authors themselves, without any attempt at a rectification of the nomen- 

 clature. 



The history of the Lenham deposits and their fauna was commenced 

 by the late Sir Joseph Prestwich in 1S57/ when reporting the discovery 

 by W. Harris and Rupert Jones of certain "blocks of gritty ferrugin- 

 ous sandstone, full of casts of shells," in some sandpipes in the chalk 

 at Lenham, eight miles east of Maidstone, which they regarded as 

 belonging to the basement-bed of the London Clay. Prestwich was 

 familiar with similar sandstones occurring at Paddlesworth near 

 Folkestone, at a height of about 600 feet above sea-level, and at Vigo 

 Hill near Otford in Kent, mentioning likewise that they were to be 

 found in scattered fragments along the summit of the North Downs, 

 extending from near Folkestone to Dorking in Surrey ; but from the 

 fossils he considered that the sandstones were of Lower Crag age, on 

 account of the presence of a Terebratula resembling T. grandis, several 

 species of Astarte, and a large Lutraria-\\k& shell ; this view being 

 also shared by Searles Wood, who had examined the fossil remains, 

 and recognised the importance of the occurrence of a Pyrula and an 

 Emargimda as supporting that horizon. Prestwich also noted that 

 beds of similar structure were present on the hills between Calais 

 and Boulogne, at CasselHUl near Dunkirk, and at Louvain and Diest 

 in Belgium, besides thinking it possible that such sandstones were 

 connected with the Carentan beds of Normandy. 



In the following year Prestwich'-^ again returned to the subject, 

 aided by Searles Wood. He noticed that many of the species found 

 at Lenham were of southern origin, thus confirming his previous 

 ideas that the deposits were of Lower or Coralline Crag age. His 

 determinations of the shells included the following forms : — 



Scaphopoda — 



Dentaliuni costata ? 



Gastropoda— 



Eniarginula reticulata ? 

 Nassa prismatica ? 

 Scalaria subulata ? 

 Pyrula. 

 Trochus. 



Natica. 

 Rissoa ? 



PJwriis related to Trochus 

 cumidaris Brong. 



1 On some Fossiliferous Ironstone occurring on the North Downs : Quart. Jourii. Gcol. 

 Soc, 1857, vol. .\iii. , pp. 212, 213. 



2 On the Age of some Sands and Iron-Sandstones on the North Downs; with a Note on 

 the Fossils, by S. V. Wood ; Quart. Journ. Gtol. Soc, 1858, vol. i.(, pp. 322 — 335. 



