SOS CONCLUDING OBSERVATIONS. 



continuous bed*, but was originally imbedded in sand, like the masses of 

 " AVhin stone" in western Sussex (vide p. 73 ). It is destitute of organic 

 remains. 



The Plastic clay (p. 256), consists of various beds of marl, sand, clay, 

 and gravel ; the lowermost constituting a ferruginous breccia, which lies 

 immediately on the chalk. Castle hill, near Newhaven, and Chimting 

 Castle east of Seaford, are the principal locahties of these deposits in 

 Sussex. This formation contains aluminite, crystallized sulphate of lime, 

 surturbrand, wood, the impression of the fohage of a species of Platanus, 

 fruit of the Palm ? shells of the genera Cerithium, Helix, Mactra, Unio, 

 Cytherea, Cyclas, and Ostrea ; a shell which is supposed to be a fresh 

 water bivalve (p. 264), and the teeth of a species of Shark. 



The analogues of these beds appear on the opposite coast near Dieppe, 

 where strata of sand, sandstone, and Plastic clay, are seen lying upon the 

 chalk (p. 266)-f. 



The London clay ( p. 267), is confined to the south-western part of 

 the county. At Bracklesham it abounds in fossil shells, which exactly 

 correspond with those of Hordwell in Hampshire, and Grignon near 

 Paris; nearly forty species have been discovered. 



The Limestone constitutes several groups of rocks, near Bognor and 

 Selsea, (p. 271), and appears to be decidedly analogous to the calcaire 

 grassier of Paris. It contains nearly twenty shells, pecuhar to that 

 deposit. 



These Tertiary formations closely correspond with the lower beds of 

 the Paris basin, and are without doubt detached portions of a series of 

 strata, deposited under similar circumstances in that excavation of the 

 English chalk, which geologists distinguish by the name of the Isle of 

 Wight basin. 



* Phillips^ Outlines, p. 14. 



t That Great Britain was formerly united to the continent can scarcely be questioned; 

 indeed, as Mr. Phillips observes, "the many remarkable points of agreement between the 

 opposite coasts of France and England, render the supposition too reasonable to be ranked 

 among mere hypotheses ; their separation was, in all probability, occasioned by an iiTuption of 

 the sea, which washed away the connecting mass." Vide Geological Transactions, Vol. v. p. 51. 



