1844.] 407 



Maidstone junction of the Soutli-Eastern Railway), seem to be 

 identical with the marine clays found at Hythe and at Atherfield 

 in the Isle of Wight. He adds, " There is also a bed of stone, 

 not a continuous bed, but in concretionary masses, just above the 

 junction, from which I obtained fossils, and which, I consider, re- 

 presents the Atherfield rocks. This bed is also similar to the blocks 

 taken from the cutting in the vicinity of Red Hill, near Reigate." 

 He states also, that the same junction can be traced from the Teston 

 Cutting in the direction of Maidstone, to near the Farley Cutting 

 through the Kentish Rag. The junction of the "Wealden and 

 greensand clays is at the bottom of the valley, near the banks of 

 the river Medway. 



4. On the Section between Blackgang-Chine and Ather- 

 field Point. By Capt. L. L. B. Ibbetson and Prof. Edw. 

 Forbes, F.R.S. 



The accompanying Table exhibits the succession of strata, pre- 

 sented in ascending order, from the Wealden to the top of the 

 Upper Green-sand, in the Isle of Wight, between Atherfield Point 

 and St. Catherine's Down. The measurements of the upper portion 

 were ascertained by trigonometrical survey, by Capt. Ibbetson, 

 during the years 1833 — 38, those of the lower portion during the 

 winter of 1842-3. 



The following observations refer to that portion of the section 

 which includes the Lower Green-sand strata, visited by Capt. 

 Ibbetson and Prof. Forbes in March, 1844. 



Between the Gault, as seen near Blackgang-Chine, and the 

 Wealden at Atherfield Point, there are sixty-three distinct strata, 

 the total thickness of which is 843 feet. 



§ 1. Description of the Strata. 



The lowest of these is a brown clay 3 feet thick, the base of 

 which, at the junction with the Wealden, abounds in remains of 

 fish. Through this clay are scattered many fossils, none of which 

 are peculiar to this lowest bed, but mostly such as run on through 

 the fossiliferous clays of the Lower Green-sand. This is suc- 

 ceeded by a harder bed or rock of a sandy texture, 2 feet thick, 

 characterised by the presence of numerous fossils, among which 

 the most remarkable is the Perna Mulleti, peculiar to this bed. 



The clays which succeed are fossiliferous at the lower part, but 

 very slightly so in the middle, where they contain numerous crys- 

 tals of sulphate of lime. The uppermost of these clay strata, called 

 the Loiver Lobster-bed, is an impure fullers' earth, abounding with 

 fossils, the most characteristic of which are numerous remains of 

 Astacus scattered here and there, and found in so perfect a state 

 that no time could have elapsed between the death of the animal 

 and its entombment in the strata, sufficient to permit decomposi- 

 tion to take place. These clays present a thickness of 99 feet. 



The hard noduliferous bed which succeeds, termed the Lower 



H H 3 



