372 Dr. Fitton on the Strata [Nov. 



Surry and Hampshire : — so that Mr. Conybeare's description of 

 the green-sand between Leith Hill and Dorking, — where the 

 more ferruginous beds are stated to appear ' like a second 

 formation of iron sand resting upon the green sand,' * is most 

 correctly applicable also in the Isle of Wight. 



One of the most remarkable of the lower beds of this forma- 

 tion seems to occur at the very bottom of it, and is indeed 

 detached from the superior strata, by a group which forms, as 

 it were, a transition to the weald clay ; consisting of greenish 

 grey sand in very thin beds, intimately mixed with a small 

 proportion of clay, and of bluish slaty clay. This detached bed 

 is itself composed of large irregular concretions of greenish 

 sand, with much calcareous matter, and contains numerous 

 petrifactions. It rises about 1000 paces from the chalk in 

 Sandown Bay, and may be traced upwards in the face of the 

 ruined cliffs on the west of Red cliff. The same fossils abound 

 also on the shore to the east of Shanklin Chine, and in a bed 

 which rises on the west of the central chalk, and may be 

 traced from Walpen Chine to Atherfield Point. It is, proba- 

 bly, from the corresponding part of the series in Surry and 

 Sussex, that a great many of the green sand fossils of those 

 counties will be found to have come : several of the shells found 

 near Ashford, in Kent, and at Parham Park, in Sussex,*)- being 

 the same with those of the vicinity of Shanklin, £kc. 



One feature of this formation, which is very conspicuous on 

 the coast of the Isle of Wight, and might lead into error in 

 situations less favourable for examination, consists in the great 

 variation of aspect and solidity in different portions of the 

 same continuous beds ; one part not unfrequently appearing as 

 a very dark greenish, or almost black, sandy clay ; while the 

 very same bed has in other places, where the fracture is recent, 

 a bright reddish and yellowish hue. This appearance has been 

 noticed by Sir H. Englefield and by Mr. Webster, and is 

 ascribed by them, I believe correctly, to the effects of moisture 

 and exposure, on the variable proportion of clay and ferruginous 

 matter which the beds every where seem to contain. 



The greater part of the fossils assigned to the Iron sand, in 

 Prof. Sedgwick's valuable paper on the Isle of Wight, belong- 

 to the lower part of the green-sand formation. J I have 



Outlines, p. 154. -j- See Mantcll, p. Tl, &c. 



Annals of Philosophy, May, 1822, p. 329, &c. They are as follows: — 



Cylindrical concretions, probably 



from organized bodies, 

 Stems of the tulip alcyonium, 

 A compound madrepore, 

 An obscure coralline body, 

 Veimicularia, 

 Ammonites, 

 Jtostellaria, 

 Casts of three or four other univalves, 



A palmated cockscomb oyster, 

 Trigonia daedalea, 

 T. alaformis, 

 Astarte excavata? 

 Sphara corrugata, 

 Terebratula pectita ? 

 Perna aviculoides ? 

 Gryphaea sinuata. 



The other fossils of Prof, Sedgwick's enumeration belong to the Weald clay. The 



