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far as has been dug down ; at the lowest depth, however, trunks or roots are found 

 so close together as to justify my former supposition as to the thickness of 

 the forest; for whilst clearing out the dyke, the whole road was lined with 

 the fragments of the trees thrown up. Oak is the prevailing kind of timber, but 

 there are also other sorts whose species I cannot ascertain, though birch and alder 

 are, I think, among them. With the trees, at even the lowest depth, are found, 

 here and there, very many species of shells, not fossilized, but in a recent state ; 

 and it is from many of these being land species that we must infer, as I have before 

 observed, the inundation of the plain by some river ; Helices, and a great variety 

 of other land shells, being found among them. If left on the bank as they are 

 thrown up, the atmospheric influence soon destroys them ; but I have several pre- 

 served in my collection which are unlike any I have ever seen, and relative to 

 which I should be glad to have the opinion of some more able conchologist. In 

 other places nuts and acorns are dug up, from various depths, in a perfect state, 

 though apt to crumble to pieces after two or three days exposure to the air. The 

 present extremely level state of the surface has evidently been brought about by 

 the action of water (probably when receding), filling up or smoothing down the 

 inequalities which I have before shewn to have existed. The tide is still kept 

 from floating the present surface of the country by embankments on the Trent, 

 and even at low water it is still above the level where these sea-shells and nuts 

 and acorns are found in deepening the dykes, which might probably be discovered 

 even still lower, if the soil were cleared away to a sufficient depth. 



It would appear, then, that the question must be asked, whether the sea has 

 risen on the eastern coast, since the washing in of these shells ; and also whether it 

 must not have ^r^ fallen to allow of the present surface (so much above the for- 

 mer deposit left by the sea) becoming high and dry ? It also requires some ex- 

 planation to account for the great accumulation of soil, to the depth, as I have 

 shewn, of at least eight feet, over every part of the plain ; although this is partly 

 accounted for by the upper inequalities of surface filling up the hollows, when sub- 

 jected to the washing of so great a body of water. 



With regard to the former of these two suppositions, the sea has certainly, 

 even of late years, made great inroads on this eastern coast, and some suppose that 

 this is partially accounted for by its gradual rising above its accustomed level, inde- 

 pendent of the crumbling nature of some of the cliffs, which leaves them an easy 

 prey to the ceaseless dashing of the mighty ocean. With respect to these lands 

 having been also formerly covered by the sea, this is abundantly evidenced by 

 the numerous species of sea-shells, muscles, and other shells, with which they 

 abound. Whether the anomaly of sea-shells being found by the excavators in 

 some parts of the Levels at a similar depth to that at which, in other parts, they 

 discover acorns and nuts, may be explained by supposing a slight inaccuracy of 

 measurement, and that one or the other may lie in a stratum an inch or two more 



