1824.] 



Dr. Fitton's Additional Remarks. 



459 



to Mr. Lyell and to myself, to acknowledge unequivocally the 

 priority of his observations and deductions. 



I take this opportunity also of correcting an omission of 

 importance, and some errata in that part of the table at the end 

 of my paper, which refers to Prof. Sedgwick's valuable memoir 

 in the Annals of Philosophy for May, 1822.* The first three 

 divisions of the column under Mr 

 stand tin is : — 



Sedgwick's name should 



Beds as they exist in the Isle of Wight. 



1. Chalk, with flints. 



without flints, 

 grey (marly), 

 bluish. 



2. Greenish sand and sand- 

 stone, with chert. {Firestone.) 



Clay of 

 (Gault.) 



the under cliff. 



Sedgwick. 



| Chalk. 



" Indurated chalk marl." 



In the Isle of Wight, " green- 

 sand." 



In Cambridgeshire, " a very 

 thin bed of tenacious blue 

 clay, which is mixed with 

 greensand, and contains a 

 great many fossils." 



In the Isle of Wight, consi- 

 dered as the same with the 

 weald-clay , No. 5. 



In Cambridgeshire, " tena- 

 cious blue clay. (Gautl.)" 



I have intimated in the concluding paragraph of my paper 

 (p. 383), the probability that the order of the strata now recog- 

 nised in the Isle of Wight would serve to clear up the obscurity, 

 in which some other districts, consisting of the beds below the 

 chalk, have been hitherto involved ; and it is obvious, that as the 

 firestone has been frequently confounded with the lower beds, 

 and the Hastings sands with the upper ferruginous portion of 

 the greensand, — and the gault with the weald clay, it will be ne- 

 cessary again to examine the strata to which any of these 

 names have been applied, for the purpose of deciding upon 

 their true relations. — It seems to be highly probable, from Mr. 

 Smith's geological maps of Berkshire, Oxfordshire, Bucking- 

 hamshire, and Bedfordshire, that a part at least of what has 



* Mr. Sedgwick has himself been so obliging as to point out these inaccuracies in the 

 Table, which were, in part, occasioned by an oversight of the person who transcribed the 

 paper for the press. The order of the beds in the vicinity of Cambridge, correspond* 

 precisely with that of the Isle of Wight and of Sussex. 



