52 Fossils of Red Crag and Chalk Pits, Suffolk. [Sess. 



which the briony -berries were clustering in scarlet masses, 

 while the tufts of wild clematis-seed {Clematis vitalha) clothed 

 everything in a mantle of snow, we arrived at Foxhall Crag 

 Pit. This pit is leased at present by the farmer on whose 

 ground it is situated, and he accompanied xis to the place 

 where the men had just left off working. 



A few words as to the nature of the crag formation will ex- 

 plain it at once. In the Pliocene period in geology, Britain, 

 after a long time of exposure as a land-surface, when it under- 

 went great denudation by weathering, began gently to subside. 

 Nothing definite can be said as to the extent of this subsidence, 

 but it is well known that that part which forms now the south- 

 east counties of England was gradually submerged, when sand- 

 banks and shelly deposits were laid down in the shallow waters 

 of the North Sea, and it is these accumulations that are termed 

 "crag." Many of the "crag" shells still live in arctic seas. 

 Geikie, in his ' Text-book of Geology,' says : — 



It is evident that in these fragmentary accumulations of the " crag " 

 series we have merely the remnants of some thin sheets of shelly sands 

 and gravels, laid down in the waters of the North Sea, while that great 

 lowering of the European climate was beginning which culminated in the 

 glacial period. 



The " crag " series is subdivided into five groups, of which 

 the " red " is the second oldest, and it is principally in Norfolk 

 and Suffolk that all of these groups are exposed. The cutting 

 which we visited seemed to be about 6 or 8 feet thick. Its 

 natural colour is a deep red, and in some parts it is stained 

 deeper still by a mixture of iron. The section here is very 

 good, and shows the "red crag" resting on the "London clay." 



The crag shells are 230 in number, and there are five dif- 

 ferent species exhibited to-night — viz., Trophon antiquum, 

 Pectunculus glycimeris, Cardita senilis (extinct), Astarte 

 Omallii, and Nucula Cobboldiee. The Foxhall Crag Pit is 

 worked for the purpose of obtaining those valuable phosphatic 

 nodules called " coprolites." These are gathered by the ton, 

 after being extracted from the "crag," and are then conveyed 

 to the crushing and chemical works and converted into manure. 

 As there are various opinions regarding the nature of these 

 nodules, I shall quote an extract from Dr J. E. Taylor's book, 

 'Nature's Bye-Paths,' which gives his verdict on the subject:- — 



