BEACHES, ETC., OE THE SOUTH OF EK^GLAND. 271 



5 feet, but of 15 feet according to the label on the specimen in the 

 Brighton Museum, a well-shaped pointed flint implement, weathered 

 white and slightly patinated, had been found shortly before my 

 visit. The brown clay, 5, may have been derived from adjacent 

 Tertiary strata, * 



(9) The Sussex Coast Plain. — This plain is covered by a thin bed 

 of drift-clay and flint-gravel, which it is not possible to connect 

 with the action of the two small rivers (Adur and Arun) that 

 traverse the eastern half of the plain, while the western half is not 

 traversed by any river. Nor can it be ascribed to marine action, 

 although it overlies a marine bed — the equivalent of the liaised 

 Eeach of Brighton.^ But it may be, and I believe is, an extension 

 at a lower level of the llubble-drift or Head swept down from the 

 slopes of the neighbouring Chalk hills, which in transit has lost 

 (except in a few places near the Chalk hills) its calcareous matter, 

 together with the bulk of the heavier load of flints, so that on the 

 coast it is represented merely by a thin bed of gravelly clay and brick- 

 earth. This also was the opinion of Murchison and of God win- Austen. 



At Waterbeach and Lavant, a few miles to the north of Chichester, 

 we find thick beds of mixed chalk-and-flint rubble or of flint-rubble 

 with enclosed masses of chalk-rubble. At Broil Common, nearer to 

 Chichester, this has passed into a mass of unstratifled, coarse flint- 

 gravel 8 feet thick. At the Portfield the rubble-gravel is inter- 

 calated with thin lenticular seams of sand and loam, in which the 

 late Mr. Hill, Curator of the Chichester j^fuseum, found : — 



Helix nemoralis. 



concinna. 



pulchella (?). 



Piqoa marginata. 

 Succinea j^utris. 

 Zua hc'irica. 



Nearer the coast the bed becomes thinner and consists merely of 

 brick-earth with a bed of flints at its base, but without stratification. 



Occasionally the deposit shows disturbance and distortion, the 

 flints {a') being pushed up into the brick-earth (a), as in tig, 5, 

 below. 



Fig. 5. — Section in the cliff near Paf/Jiam. 





a 



a. Brick-earth 





a'. Irregular seams of fliut-gravel j 4 to 6 feet. 



Sometimes the base-line is level, at other times it rests on an irre- 

 gular and eroded surface. 



Mammalian remains, similar to those of the Elephant Bed of 

 Brighton, are occasionally found in this drift. The fine lower jaw 



1 The inland range of this beach I hare before described, Quart. Journ. 

 Geol. Soc. Aol. XV. (1859) p. 215. 



