1 822.] Geology of the Me of Wight, S^c. 353 



Second Section , commencing 198 Feet South of the preceding, and 

 Eight Feet above the High Water Mark» 



Feet. 



(1 .) Soil 4 



(2.) Sand containing salt springs 12 



(3.) Blue clay, containing selenite, &c 74 



(4.) Gravel, with vegetable matter Unknown 



In the neighbourhood of Harwich, the crag is associated with 

 No. 2. No. 3 is probably the representative of the London clay, 

 Nos. 4, 5, 6, 1 J 8, 9, will then represent the sand and plastic clay 

 formation. 



If these views be correct, Mr. Smith*s arrangement of the crag 

 must be considered quite untenable. 



3. Uj)per Freshvater Formation. We have now arrived at the 

 last of th.e formations discovered by Mr. Webster — a system of 

 calcareous beds more than 100 feet thick, which appear to have 

 been deposited in a freshwater basin to which the sea had no 

 longer any access ; for we find in it no marine shells, and very 

 few of those species for the living analogues of which we have 

 to look among the river shells of distant climates. On the 

 contrary, there are diffused almost through every part of it 

 innumerable specimens of genera which abound in the stagnant 

 waters of England. To the details published by Mr. Webster 

 (Geol. Trans, ii. 226, &.C.), we have very little to add. In the 

 higher part of the hill above Totland Bay, we found among the 

 beds of compact limestone the casts of one or two species of 

 land-shells, and of a large turbinated shell which we have not 

 seen described. Immediately above the hmestone, there is a 

 thin bed of clay containing; laminaB of coaly matter, and many 

 shells, of the genus cyclas, in a state of perfect preservation, and 

 Avith their valves united. As the same species is very abundant 

 m some parts of the upper marine formation, we im^gmedLdming 

 our first visit to the island, that we had discovered the trace of 

 a marine deposit over the highest freshwater beds. The facts 

 already stated prove that the supposition was devoid of foun- 

 dation. Indeed we may hope that difficulties which 'at first 

 appeared insurmountable in classing the tertiary rocks will gra- 

 dually disappear as inquiries respecting the genera of freshwater 

 shells are more widely extended. The formation may be traced 

 on the north side of the road between tlie villages of Freshwater 

 and Calbourne ; but it does not extend very far to the north, 

 nor has its eastern termination been well ascertained. It may 

 be expected on the north side of the chalk range between New- 

 port and Whitecliff* Bay : its existence, however, in that region 

 has not been yet ascertained. All the blocks we have seen near 

 Bembridge and Whitechff" Bay are decidedly derived from the 

 hirer freshwater formation. Of the blocks which are scattered 



New Series, vol. in. 2 a 



