1824.] below the Chalk, fa. 375 



which I have had an opportunity of seeing : — its occurrence 

 indeed in that of Petworth has been long since mentioned by 

 Mr. Sowerby, in the description of his plate of the Vivipara 

 (Min. Conch. PI. 31, vol. i. p. 78), though it seems to have 

 escaped attention, as a fossil of this formation. 



Subordinate to the clays, especially in the lower part of the 

 formation, are also several beds of clay iron stone, some of 

 which contain, disseminated, the same species of cypris as 

 that of the shale, and also in considerable abundance, the 

 casts of a species of Paludina (elongata), which seem to have 

 been filled with pyrites ; one of these beds at Sandown Bay was 

 remarkable in having attached to it irregular concretional masses 

 of a hard calcareous grit, containing numerous casts of a Palu- 

 dina, filled with lamellar sulphate of barytes.* Towards the 

 bottom of the formation, very thin courses of a hard calcareous 

 grit alternates with greyish clay ; and below them is a bed, from 

 ten to twenty feet in thickness, of sand rock or slightly coherent 

 sand, of alight greenish grey colour, but in some places ferrugi- 

 nous, containing concretions of grey calcareous grit; this bed, 

 the forerunner, as it were, of the iron sand, is insulated in the 

 clay,f and is followed by thin beds of mottled greenish sand, 

 containing a small proportion of clay, and of blue clay; the 

 whole about forty feet in thickness. And these are finally 

 succeeded by sand rock, containing a large proportion of con- 

 cretional calcareous grit of a greenish hue, — the commencement 

 of what may be considered as the proper Hastings sands ; after 

 which no more blue clay appears. 



The succession of the beds, near Atherfield Point, where they 

 are best displayed, seemed to me to resemble that above de- 

 scribed ; and the fossils there were the same with those of 

 Sandown. In Compton Bay, the section is perplexed by a con- 

 siderable subsidence, or perhaps a fault ; which after the first 

 rise of the iron sands, brings down the weald clay again to 

 the shore, so as to produce the appearance of an alternation : — 

 but the order of the beds, and the fossils they afford, are still 

 the same. 



The following are the fossils which I have found in this forma- 

 tion in different places : — The concurrence of the vivipara and 

 cypris, in such great abundance, with several other shells in no 



tation to the Curl (or " Cone i.i Cone") of Staffordshire, &c. is mentioned by Prof. 

 8 edge wick {Annals of Philosophy, vol. iii. p. 839) ; and there appears to be a grada- 

 tion, from the indistinctly fibrous incrustations of this place, to the highly crystalline 

 fibrous carbonate of I'urbeck. 



* My attention was directed to this fact, and to the occurrence of the crystals of sul- 

 phate of barytes in the fuller's earth of the Nutfield green-sand, by Mr. Sowerby. — I have 

 myself a specimen of crystalline sulphate of barytes, with carbonate of lime, from the 

 tirestone beds of Worbarrow Hay ; so that, this mineral appears to be generally, 

 though sparingly, diffused throughout these formations. 



-}- It is not impossible that the occurrence of this or similar detached beds of sand 

 rock, within the lower part of the weald clay, may have occasioned obscurity, where the 

 state of the surface prevents their relations from being perceived. 



