On the Structure and Formation of certain English and American 
Coals, read at a Meeting of the Cotteswold Club, on Tuesday, 
February 3rd, 1885. By E. Weruerep, F.G.8., ere. 
Much has been written on the subject of the structure of 
coal since Dr Luc, in the years 1793—5, contended that it was 
the product of vegetation which grew on the spots where the 
seams are now found. To do justice to the researches of 
Horron, Sir James Hatt, Mc Cuntocs, Goprert, Sir Win11aMm 
Logan, CarrutHEers, Wititiamson, Huxtey, Newton, Dawson, 
Prestwich, Binney, Rernscx, Bronenrart and others, would 
be to compile a volume. I must therefore confine myself to 
brief references to those points which are material to the 
present paper. 
An important addition to our knowledge of the question 
was given by Sir Witt1am Loean in 1840, when he pointed 
out that under every seam of coal there was a stratum of clay, 
called the underclay, in which a fossil vegetable, Stigmaria 
_ ficoides, was always to be found. Later on Mr Bryyney 
_ discovered this vegetable to be the root of the Carboniferous 
genus Sigillaria; and it is now generally regarded as the root of 
the Lepidodendroid plants generally. Accepting then the views 
_ of Dr Luc, in conjunction with the discovery of Stigmaria and 
its relations, it was assumed that seams of coal were formed 
by the submergence of forests of Sigillarie and Lepidodendra, 
with, perhaps, other forms of terrestrial vegetation. Thus 
- Gérrrrr,* after examining the coal-fields of Germany, remarks 
that “many seams are rich in Sigillarie, Lepidodendra and 
* Quart. Jour. Geol. Soc., Vol. V., Mem. p. 17. 
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