Northumberland and Durham. 19 



Galena is found together with pyrites in the nodules of clay-iron- 

 stone, that are imbedded in the shale : as at Montagu main, at the 

 depth of 40 fathoms. 



Iron pyrites is found in great abundance crystallized and dis- 

 seminated in the beds both of coal and of shale : it is sold to the 

 manufacturers of green vitriol. 



Azure iron ore is not uncommon in the potters' clay at Elswick, 

 and in other brick fields. 



Calcareous spar is common, either blended with the coal or in 

 the form of stalagmites. 



The Organic remains found in the coal measures are, 



Impressions of plants resembling those of the genera fontinalis 

 and equisetum, except that the latter are destitute of the jointed 

 stem of the true equiseta. In shale. 



A fern, like polypodium filix mas, (Parkinson, vol. i. tab. 4. 

 fig. 7.) Impressions of plants, (vide Parkinson, vol. i. tab. 3. fig. 

 6, 7.) In shale. 



A fern, like blechnum boreale, (Parkinson, tab. 4. fig. 1, 2. and 

 Sowerby, tab. 296.) and another like osmunda regalis j from Kenton 

 colliery, and from the shale contiguous to the Coley hill dyke. 

 In nodules of clay iron-stone. 



Impressions of cones, (Parkinson, vol. i. tab. 9. fig. 1.) from 

 Urpeth Dean, Durham. In nodules of clay ironstone. 



Obscure impressions of a fern, from Murton colliery. In nodules 

 of clay ironstone. 



Large flattened lumps of iron pyrites, bearing the form of the 

 Stem and the impression of the bark of a plant resembling an 

 euphorbia ; called by the miners petrified salmon. From the floor 

 of several collieries. 



c2 



