20 F, A. Bedwell — Ammonites in Thanet Cliffs. 



"be no doubt that they were respectively all at one time continuous 

 and in the same horizontal plane. 



The distance from Margate Harbour to St. Margaret's Bay is about 

 nineteen miles, and from Kingsgate to Westgate is six miles ; and 

 here then we have evidence of lines of flint being formed over an 

 area of at the least about 120 square miles — " by chemical processes 

 identical and simultaneous in their modes of operation." But, at the 

 same time, it would be no unfair deduction to take at least the square 

 of 20 miles as th« probable minimum extent of the field represented 

 by the section thus exhibited to view ; while I cannot help anticipat- 

 ing that these and other bands will hereafter be identified over a very 

 much more extended area even than 400 square miles. 



To return to the Ammonites, many of them are well worth a visit ; 

 one in particular is a magnificent basin, four feet at least in diameter 

 if not more, and out of which the sea has worked the chalk, showing 

 the contour of many of the chambers, and exposing to view a natural 

 internal section of a portion of the sh^U. It lies between the points 

 t and s on the map, and is on a low platform of rock just under the 

 name of Mr. K. Loder, a gentleman who has added lustre to his 

 name by unconsciously associating it, in letters of appropriate pro- 

 portions, with this gigantic natural relic. 



Should any geologist desire to visit the section, I shall be happy at 

 any time to furnish him with exact details, which will enable him 

 more easily to find all the Ammonites. A letter addressed to " Lin- 

 coln's Inn " will be sufficient. 



On reference to the sections, it will be seen that I have figured the 

 Ammonite-bed as appearing in three different places between Kings- 

 gate and Pegwell ; not that I have found any Ammonites in situ 

 in those three places, though I found a fragment on the beach 

 between the points i and h, but the chalk, at the three places 

 which are indicated by the shading, brings, by its undulations, the 

 Ammonite-bed on to the face of the cliff at these points. When we 

 reach Pegwell itself, the Ammonite-bed is clearly represented for 

 nearly half a mile; and four specimens have been found there in 

 situ, by Mr. Leonard Wray, jun., of Eamsgate, who has, I believe, 

 marked their position for me with the letter W- At Pegwell Bay 

 51 feet of the chalk, which is to be seen on the Margate cliffs, is 

 wanting, and has been carried off the upper portion of the cliff. 



The total depth of the chalk in section is obtained by the follow- 

 ing addition : Oo -f Nn + Cc = 32 + 74 -f 74 = 180,— the heights 

 Oo, Nn, and Cc, being the three lines thus figured in the accom- 

 panying sections, and which I measured with a plumb-line and 

 measuring-rod. 



The upper edge of the shaded band represents the " datum line," 

 being the line of flints which guided me to the Ammonites ; the 

 lower edge of the shading gives a line of flints in which the lowest 

 Ammonite appears. 



I have added a table showing the distribution of the specimens, 

 93 in all, along the whole section. 



