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PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



of fossils, published many years before* ; and though my present col- 

 lection, from the time and labour employed upon it, is probably the 

 most complete that has yet been made, there still are several unex- 

 plored chasms, from which new additions may be expected. 



The drawing which accompanies this paper represents a vertical 

 surface parallel to the face of the cliffs and following their inflections. 

 It has no pretension to metrical exactness ; my principal object 

 having been to illustrate the distribution of the fossils. The horizontal 

 distances in the sketch are, from the construction, often erroneous ; 

 and for the thickness of the beds, I contented myself with such an 

 approximation as could be obtained without the use of the level f. 



^ Chines^ and ^TJndercliffs.^ — The strata upon this part of the 

 coast rise uniformly, at an angle of about 2° to the horizon. The 

 only irregularities by which the cliffs are varied, are called in the Isle 

 of Wight, " Chines and Undercliffs," which are well described in 

 the excellent work of Sir Henry Englefield and Mr. Webster :[;; 

 the word " Chine" signifying those great fissures on the shore, which 

 are produced by the action of water in the beds of sand and clay, 

 here unsupported by solid strata ; so that when a spring or torrent 

 has once formed a channel, it soon cuts down to the shore, as in 

 Walpen and Whale Chines. In Black-Gang Chine, the process has 

 been interrupted by a firm group of ferruginous beds, which crosses 

 the streamlet, and has given origin to a cascade ; and the continuation 

 of these same bands has stopped the progress of other chasms (fig. 1) 

 between Black-Gang and Walpen Chines, in one of which the clay 

 has been entirely carried away, and a large surface of the ferruginous 

 beds exposed in a solid floor. In Ladder Chine the lower part of 

 the chasm is reduced to a narrow fissure, and finally closed before it 

 reaches the shore, by the firmness of a group including nodules in great 

 numbers, above which the sand is swept out in the form of a great 

 bowl. The subjoined figures illustrate these modifications of the 

 chine : — 



Fig.l. 



Fig. 2. 



Remote Cliff near Walpen High. 



Ladder Chine. 



* A collection, including some very fine specimens from the south coast of the 

 Isle of Wight, has been some years exhibited at the Polytechnic Institution, 

 placed there very liberally by Captain Ibbetson, to whom I am indebted for the 

 freest access to its contents ; but no description has been pubhshed. 



t The distances were measured with an ordinary rope of 300 feet, subdivided 

 and checked by frequent comparison with a fixed standard in a level field. For 

 the heights and thicknesses I used a light measuring-rod of 20 feet in four divi- 

 sions, which I found verv convenient in practice. 



% * A Description, &c.'of the Isle of Wight,' 4to, 1816. 



