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The cases are very few in which [ have ever seen fossil trees, or 
any smaller vegetables erect and petrified in their native place. 
The Cycadites and stumps of large Coniferous trees on the surface 
of the oolite in Portland, and the stems of Equisetaceous plants 
described by Mr. Murchison in the inferior oolite formation near 
Whitby, and erect plants which I have found in sandy strata of the 
latter formation near Alencon, are examples of stems and roots over- 
laid by sediment and subsequently petrified without removal from 
the spots in which they grew. At Balgray, three miles north of 
Glasgow, I saw in the year 1824, as there still may be seen, an un- 
equivocal example of the stumps of several stems of large trees stand- 
ing close together in their native place in a quarry of sandstone of 
the coal formation. 
In a paper on the sinking of the surface over coal mines, Mr. Bud- 
dle has shown that the depressions produced on the surface by the 
excavation of beds of coal near Newcastle-on-Tyne are regulated by 
the depth and thickness of the coal, the nature of the strata above 
it, and also the partial or total extraction of the beds of coal. The 
accumulation of water forming ponds in these superficial depressions, 
and the sinkings of a railway, have afforded accurate measures of the 
amount of the subsidences in question. 
WEALDEN AND PORTLAND FORMATIONS. 
In the north of Germany Mr. Roémer, of Hildesheim, has identified 
beneath the Cretaceous system, the Purbeck stone and beds of the 
Wealden formation, with nearly all its characteristic shells, and three 
minute species of Cypris. He has also found the Portland sand 
and the upper and lower Green sand and the Gault clay, in the 
north of Germany. He has, moreover, found the Wealden forma- 
tion near Bottingen in the High Alps. 
CHALK FORMATION. 
In extension of our knowledge of the Chalk formation, the Rev. 
J.Gunn has sent us a short communication, accompanied by a litho- 
graph representing the columnar disposition of some Paramoudras 
to the height of many feet one above another in the chalk of Norfolk. 
The history of these enormous urn-shaped flints, which were first 
noticed by Professor Buckland in an early volume of our Transactions, 
