.330 



ME. P. W. HARMEE ON THE LENHAM BEDS [Aug. 189B, 



Table showing, according to Prestwich, the features 

 characteristic of the various zones into which he 

 proposed to divide the Coralline Crag. 







Remarks. 



A. 



B. 



C. 



Bed, 1 to 1 J foot thict, containing 

 phosphatic nodules, mamma- 

 lian remains, and derivative 

 fossils and boulders. 



Apparently confined to one district 

 in which a similar bed occurs at 

 the base of the Red Crag. A few 

 phosphatic nodules only, but no 

 boulders, were found at the base 

 of the Coralline Crag in borings 

 at Gedgrave and Sudbourne. 



Comminuted shells, with Turri- 

 tella, and single valves of 

 Cyprina, Pecten, Mactra, etc. 



This bed, 4 feet only in tliickness, was 

 observed by Prestwich at one spot 

 only at Sutton. The features 

 mentioned are equally api)licable 

 to other parts of the formation. 



Light - coloured marly Crag, 

 abounding in large shells, Mya 

 and Cyprina (sometimes double), 

 Anomia, Biplodonta, Astarte, 

 and Venus. 



Foraminifera abundant. Uni- 

 valves scarce. 



At one spot only at Sutton. The 

 species of mollusca named are 

 among the commonest forms 

 of both the Coralline and Red 

 Crags. 



With the exception of Cyprina, 

 which is common everywhere, the 

 species enumerated by Prestwich 

 {pp. cit. p. 115) as characteristic of 

 zone C at Ramsholt differ en- 

 tirely from those here named 

 from Sutton. 



The authors of ' The Foraminifera of 

 the Crag' state {pp. cit. pp. 374, 

 etc.) that these organisms are 

 more or less abundant in every 

 part of the formation. Univalves 

 are also scarce at localities re- 

 garded by Prestwich as belonging 

 to other zones. 



D. 



Comminuted shells, large entire 



or double shells. 

 Bands of limestone in upper part. 



Features common to other parts of 



the Crag. 

 Found in borings at Gedgrave at 



one spot only. 



E. 



Sand with numerous polyzoa, 

 often in the position of growth, 

 and Echini. 



Common features of the polyzoan 

 rock-bed, regarded by Prestwich as 

 zone G, at Sudbourne, Iken, and 

 Aldeburgh. The spines of echino- 

 dermata occur at all levels. 



