Proceedings. 113 



workman employed in a brick-works at Westerham, near 

 Limpsfield, to save all the fossils he came across, and some 

 weeks after I went there and found he had done as requested ; 

 for he produced about half a pint of fossils, but unfortunately, 

 with one or two exceptions, they were all Belemnites of the 

 small species mininms. These little Cuttlefish must have 

 swarmed in the Gault sea, for in some places they seem to be 

 the commonest fossil. At Limpsfield I have obtained a small 

 Crab, PalcEocort/stes Stokesii, and with this were fragments of 

 Ammonites, with the common Inoceravnis concentricus, and a 

 few doubtful shells. The period occupied in the formation of 

 the Gault must have been very prolonged, judging from the 

 difference in the fossil forms of its different layers. 



It is a characteristic of clay beds, wherever they occur, 

 that they form the flatter parts of the laud's surface, and to 

 this rule our Gault is no exception, for as we proceed north- 

 ward across the marshy clay bottom of Holmesdale we find 

 on coming to an elevation that the nature of the rock has 

 changed — that we have reached the Upper Greensand 

 which overlies the Gault. It appears that after the Gault 

 Clay was deposited a small upheaval occurred, giving rise 

 to shallow water conditions and the prevalence of strong 

 currents. 



Several things seem to indicate this. First, the Upper 

 Greensand occurs only in a limited region ; it is not widely 

 spread ; it is wanting at Folkestone, for instance, where the 

 Gault comes immediately under the Lower Chalk ; and if we 

 go to Norfolk and Lincolnshire we find none there, though it 

 occurs again in the North of Ireland. At Cambridge, which 

 we may regard as intermediate between our district and the 

 counties I have mentioned, we find unmistakable traces of 

 the Gault having suffered denudation, though not very 

 largely, and possibly no great extent of it was raised above 

 the sea. These evidences are the prevalence in the Cam- 

 bridge Greensand of fossils proper to the Gault, which have 

 been worn by rolling as on a beach, and with these are the 

 bones of sea-birds ; though this Greensand of Cambridge is 

 not considered as the exact equivalent of our more southern 



I 



