378 Dr. Fitlon on the Strata [Nov. 



superior solidity of these beds, — the bony skeleton as it 

 ■were of the formation, that its resistance to the denuding 

 forces which have swept away such large portions of the adja- 

 cent clay, must be ascribed, in the wealds of Kent and Sussex, 

 and on a smaller scale in the Isle of Wight. — Thus the bed, 

 called the " upper sand rock," which rises very gradually near 

 Cowleaze Chine, may probably have contributed to the support 

 of Atherfield Point ; and the successive ledges of Barnes's sand 

 rock, Ship ledge, the Bull rock (about 20 feet in thickness), and 

 the very remarkable ranges at Brook Point, all owe their promi- 

 nence and solidity to a concreted calcareous grit, precisely 

 resembling that of Hastings ; at which place also reefs of the 

 same description occur upon the shore. In Swanage Bay four 

 or five reefs, consisting of the same kind of rock, run out from 

 the sands into the sea ; and even at Sandown Bay, a few such 

 ledges can be seen at very low tides. 



The grit is, in all these cases, of the same general character, 

 and is evidently nothing more than sand agglutiuated by a cal- 

 careous cement which has crystallized within it ; so that in a 

 certain stage of decomposition, a double structure is discern- 

 ible, the masses of stone becoming fissile so as to disclose 

 the original stratification of the sand, while the fresher pieces 

 show the crystalline fracture of carbonate of lime; and in some 

 cases the parallel faces of the crystals distributed through 

 the mass give by reflection the lustre of carbonate of lime, from 

 a surface which, in other positions, appears to be composed of 

 grains of sand. In the Isle of Wight, the varieties of grit are 

 numerous, and of various shades of grey inclining to blue and 

 green. They all effervesce with acids: but differ considerably 

 in hardness, probably from variation in the proportion of sili- 

 ceous matter. 



The only fossils that I have found in the Hastings' sands 

 and limestones, belonging also to the weald clav. I have 

 added to the following list a few others, from the beds of 

 clay and limestone below the Hastings sands, in Sussex. 



Cypris faba ~\ 



Paludina lenta ? — smaller and 



more 



viorum | 



Cyrena media J 



f In calcareous grit ; between 



Cyrena media I Battle and Bristling, Sus- 



Cyrena, a larger species \ sex ;— and Brook Bay, Isle 



I. of Wight. 

 Remains of fishes. 

 Remains of plants. 



* ut * I 



i lenta? — smaller and I T , , TT ... 



pointed than P. flu . U» calcareous grit ; at Holhng- 

 1 ( ton, near Hastings. 



