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Remarks on a Deposit of Shell- Mar I. By Mr JAMES MITCHELL, Sur- 

 geon, Royal Navy. 



ABOUT a mile and a half from Wooler, Northumberland, on the estate of 

 Colonel Hughes, called Middleton Hall, there is a very extensive deposit 

 of shell-marl, about three or four acres in length, and one in breadth. The 

 Colonel remembers it as a lake, with its margin and banks adorned with 

 trees and shrubs ; it seems to have been fed by numerous springs, some 

 of which exist even in the present day ; but it has been so well drained 

 that now it may be crossed anywhere in safety, and is indeed so dry as 

 annually to yield a fine crop of natural hay. Only a very small part of 

 this agricultural treasure has been dug into, no more being taken out 

 than suffices for the use of the estate, and it has produced very luxuriant 

 crops. Yet, small as is the part which has been opened, there is suffi- 

 cient to interest the observer of nature. Previous to its being drained, 

 the peat was so spongy "as to measure about four feet deep ; it is now re- 

 duced to between two and three. In this peat, which covers the marl, were 

 found oak and willow trees, with acorns, hazel-nuts, &c. ; but no re- 

 mains of animals have yet occurred in it. The marl, so far as they have 

 yet dug, is, in the best places, about ten feet, but it varies in thickness, 

 and it is very likely that it will be thicker in the centre. It is white, 

 with rather a yellow tint. In its upper strata the shells are very perfect, 

 but below, from the greater pressure, they are broken or comminuted, 

 and in general obliterated. They are the same species which are found 

 in fresh-water ponds at the present day ; and, through the kindness of 

 Mr Nichol of Edinburgh, I am enabled to give their names, viz. Cyclas 

 cornea, C. pusilla, Succinea amphibia, Planorbis contortus, PI. fontanus, 

 Limneus pereger, Valvata obtusa, and V. spirorbis. There was found 

 also in the marl two complete skeletons of the red deer(Cervns elephas), 

 with very large branching antlers. They were standing in an upright 

 position, which seems to corroborate the statement of Mr Lyell, who 

 says " Deer, and such species as take readily to the water, may often 

 have been mired in trying to land where the bottom was soft and quaggy, 

 and, in their efforts to escape, may have plunged deeper into the marly 

 bottom. Some individuals, we suspect, of different species, have fallen 

 in when crossing the frozen surface in winter, for nothing can be more 

 treacherous than the ice when covered with snow, in consequence of the 

 springs which are numerous, and which, always retaining an equal tem- 

 perature, cause the ice, in certain spots, to be extremely thin, while, in 

 every other part of the lake, it is strong enough to bear the heaviest 

 weights." Prin. of Geol. vol. ii. p. 251. 



