316 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



clay above, which is evidently that of Atherfield, contains nodules of 

 light brown indurated clay in great numbers, with valves of Gryphcea 

 sinuata. 



The cliffs at this place are in general so much obscured by ruin 

 that exact boundaries between the groups cannot easily be found ; 

 but the next mass of brownish clay and sand evidently corresponds 

 to the "lower lobster bed" No. 4. The " Crackers''^ are concealed ; 

 and after a space occupied by ruin comes a great mass of ferruginous 

 sand and sand-rock, in some places of a dull crimson hue, and 

 abounding in brilliant oolitic grains of iron ore, which strongly re- 

 minded me of that which is dug for smelting (the " miniere") near 

 Vassy. The whole of this mass of ferruginous strata may be from 

 100 to 150 feet in thickness; a prominent portion in the lower 

 part representing probably the lower Gryphsea bed. No. 13 of Ather- 

 field. About 70 feet of dark clay succeed, and then again rust- 

 coloured matter, which appears to hold the place of the ferruginous 

 bands at Black-Gang Chine, as it includes masses almost composed of 

 moulds of Thetis, spiral univalves, an Ammonite, &c. Over this is 

 dark clay again, alternating with a series of yellowish sand and sand- 

 rock, answering to those of Black-Gang-Chine ; and finally a series 

 of sands, with a brown stratum at the top, immediately over which 

 the dark blue clay of the Gault is well-exposed and accessible. 

 Nothing in short can be more satisfactory than the general indi- 

 cations of correspondence with the strata described in the foregoing 

 pages, although their precise identification would be difficult or im- 

 practicable, from the intermixture of the various debris. 



Sandown Bay, and Coast near Shanklin. 



The eastern extremity of the undercliff from Bonchurch to Shank- 

 lin northward, corresponds to that which is partially concealed at 

 present beneath the undercliff on the east of Rocken End. Near Bon- 

 church fortunately the strata are fully exposed upon the shore, and can 

 be examined with ease. I shall return to this part of the coast, but 

 shall first mention the section on the north-east of Sandown Bay ; 

 which though obscure at the upper part, affords at the bottom a better 

 view of the junction with the Wealden than any other place that I 

 know of, with the exception of Atherfield : — the section correspond- 

 ing, as to geological site and high inclination of the strata, to that of 

 Compton Bay, from which it is distant in a direct line about fifteen 

 miles. I have long since described the succession in Sandown Bay, 

 and noticed the fossiliferous bed, like the Perna group at Atherfield, 

 which forms the boundary between the lower greensand and the Weald 

 clay. In this place Mr. Warburton found, at low water, some very 

 fine specimens of Perna Mulleti ; and my collector having since, by 

 my direction, examined the shore at low tides, has sent me a large 

 collection which affords a list of nearly forty species, agreeing perfectly 

 with those of the Atherfield Point. 



