374 Dr. Fitto?i on the Strata [Nov. 



the shore being divided by two considerable ravines, or chines, 

 which greatly favour the examination of it.* 



The uppermost part of this formation, on the confines of the 

 o-reen sand, consists of bluish-grey sand and clay, in very thin 

 alternating courses, frequently not more than a-tenth of an inch 

 in thickness, or of fine greenish grey, mottled with lighter co- 

 loured sand ; the lighter portion sometimes occupying what ap- 

 pear to be the moulds of minute ramified organic bodies, which 

 exist in great numbers, but are indistinct in all the specimens 

 that I could obtain. These upper beds are, altogether, perhaps 

 thirty or forty feet thick. They are succeeded by the bed 

 already mentioned as the last of the green sand series; and this 

 is immediately followed by a considerable thickness of slaty 

 clay, which varies in hue and consistency, but is in general 

 of a dark bluish grey colour, smooth to the touch, scarcely ad- 

 hering to the tongue, yielding very easily to the nail, and 

 effervescing with acids. The laminae of this clay are coated 

 with the remains of a minute bivalved crustaceous animal, the 

 Cypris faba of Desmarest,t in vast profusion ; and it contains 

 also various shells. 



In the clay, there occur subordinate beds of lime stone ; % 

 some of which are from five to nine or ten inches in thickness, 

 consisting principally, of bivalves, probably cyrense, — and con- 

 taining also a small Paludina ; one at least of these beds is 

 coated with a thin, somewhat fibrous crust of impure greyish 

 carbonate of lime, approaching that which in a more distinct 

 form occurs between the beds of the Purbeck limestone; — to 

 which indeed this limestone of the weald bears altogether a 

 very striking resemblance. Another bed of limestone consists 

 almost entirely of a small species of oyster, retaining its shelly 

 lustre. And a third variety must also exist in this formation, 

 either in the form of a bed, or of concretions, though I could 

 obtain only portions of the latter description scattered on the 

 shore ; — but these were numerous, and had evidently come 

 from the immediate neighbourhood : they consist of sparry 

 limestone almost wholly made up of casts of a Paludina, closely 

 resembling the P. vivipara (Sowerby, Min. Conch. PI. 31), 

 and are scarcely to be distinguished from some varieties of the 

 Bethersden stone of Kent. This same stone at Sandown Bay 

 contains also casts of the Cypris faba, so abundant in the slaty 

 clay : and I have had since the satisfaction of finding that 

 remarkable fossil in almost all the specimens of Sussex marble, 



* The state of the weather was so unfavourable, during my visit to this place, that 

 the following characters have been taken principally from the beds at Sandown Bay. 

 •f- Hist. Naturelle des Crustaces Fossiles, p. 140, PL XI. fig. 8. 



X This shelly limestone is known in the neighbourhood of Chale Bay by the 

 name of the " Platnor stone," or " Black lake," or both ; for some of my informants 

 applied the former term to the slaty clay The resemblance of the calcareous incrus- 



