182 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



Wealden is about 59 feet, according to Mr. Simms ; nearly the same 

 thickness as of the corresponding portion of the section at Hythe. 



§. The aspect of the shore from the Crackers eastward is diversified 

 only by the presence of an undercliff, which varies in extent from 

 the rapid destruction to which every part of this coast is subject. 

 At Atherjield-high-cliff, between 500 and 600 paces from the 

 Crackers, is a fossiliferous group, the top of which descends thence 

 to the shore at a distance of more than 250 paces ; and includes 

 several remarkable ranges of Gryphcea sinuata, among which are 

 very fine specimens with large Ostreas ; the lowest bed of this 

 group also consists of a similar range, and immediately beneath 

 are masses composed for the greater part of agglutinated shells of 

 Terebratula sella, with another (plicated) species. 



To compare the two sections at this point, let us suppose a lime- 

 stone as thick as that of Hythe (about 130 feet), to be introduced in 

 the place of the Crackers. This, from the inclination of the strata, 

 would extend along the coast to a point about 300 paces east of 

 Whale's Chine ; and would include the fossiliferous nodules of the 

 Crackers at the bottom, and also, near the top, another nodular mass 

 of strata which rises to the summit of Atherfield-high-cliff. The 

 contents of this latter group are, as yet, imperfectly known ; but 

 the fossils hitherto found on this part of the coast are nearly the 

 same with those of the quarries at Hythe. 



The strata from hence to Whale's Chine consist, generally, of a 

 greenish sandy mud, including several ranges of Exogyra, with 

 other fossils, one of which crosses the mouth of that chine, and is 

 visible within the chasm itself, descending to the shore at a point 

 very near the mouth of the next chasm on the east called Ladder 

 Chine. 



Another group, containing nodular concretions, is visible on the 

 east of Walpen Chine, beneath what is called Walpen high-cliff ' : 

 it first rises on the east about 350 paces from the chine, and ex- 

 tends to a distance answering to about 200 paces eastward. A second 

 remarkable group containing Gryphaea rises between Walpen high- 

 cliff and Cliff-end. 



The beds above Cliff-end to the top of Black-Gang-Chine have 

 hitherto afforded few fossils ; but in the corresponding part of the 

 section, from Bonchurch to Shanklin, the upper beds are much 

 better displayed, and deserve a new examination. They contain 

 numerous casts, chiefly those of Gervillia aviculoides, Natica, 

 Rostellaria, Thetis minor, Terebratula, Trigonia alceformis, Turbo, 

 and Venus ; and the shore immediately on the east of Shanklin- 

 Chine exhibits, at low water, an extensive surface of a lower bed, 

 almost entirely composed of large Gryphasa sinuata. 



§. The distinction between the first and second subdivisions of 

 the Lower Green Sand, pointed out in my description of the coast 

 near Folkstone, is much less prominent near Atherfield than in 

 Kent : but a group corresponding to the upper or ferruginous 

 division (which Mr. Austen mentions as conspicuous also in Sur- 

 rey) is clearly distinguishable at the farm of Walpen, where a 

 continuous ridge of sand impends over the lower ground between 



