S6 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



west of A; but I have no doubt that the fossiliferous gravels, 

 A B, will be found to lie in a similar concavity to those at Grays and 

 Crayford, where the Thanet sands and chalk have been exposed. 



The material for the beds e and d seems to have descended from 

 A, and to have been brought by land-floods, and contains bones, but 

 no shells except derived ones. On the contrary, h is full of shells 

 deposited quietly. Many of the species are extremely delicate, and 

 are found quite as perfect as recent specimens ; the two series of 

 deposits are interstratified together at D, the eastern bed (h) being 

 of fluviatile origin, and the western (d) being apparently of pluvial 

 origin, and more due to land-floods. 



The chalk below A in fig. 19, Erith, along the line A B, Plate VI., 

 is 50 feet from the surface. The bottom-bed (6) shown in the sec- 

 tion is false-bedded sand with a few veins of gravel. The Cyreaa 

 is very abundant between D and B in this sand (6). The mammalian 

 remains are most abundant in the brick-earth beds (d). 



These beds {d, d) dip near A at 25° E, then fall to 9°, 5°, and even- 

 tually dip 5° W. near B, forming a gentle curve. The covering bed 

 (e) is 4 feet thick, and full of the Woolwich pebbles between B and 

 D. It then changes its character, and contains only a few flints, 

 but masses of the Woolwich shell-bed when it reaches A. The 

 remains of this shell-bed occur through h, c, d, and e. The angles 

 of deposition were observed both by Mr. y. Skertchly and myself in 

 1868, and the heights were measured by the former. Great removals 

 of brick-earth have recently been made near A, so that the original 

 section cannot be seen. 



Fig. 18. — Section in Erith Pit. 



E. 



(Natural scale.) 



G 



Between B and C, Plate YIII., a long face of the C?/re?irt-sand-bed 



