South-Western Tart of Somersetshire. 351 



wacke formation prevail ; I shall now point out some of the most 

 extensive quarries where they are worked. 



§ 13. At Allercot, about four miles south of Minehead on the 

 road to Dulverton, the principal bed of limestone is 30 feet thick. 

 It is of a bluish grey colour, variegated with red, of a crystalline 

 structure, and full of small laminae of calcareous spar disseminated 

 in /detached spots through the mass, which are most probably the 

 remains of organized bodies. Besides this great bed, there are 

 several others of less thickness contained in the slate, and the thinner 

 beds are of an iron-grey colour. The slate is one of those fine 

 grained varieties which approach very nearly in appearance to the 

 clay slate of a primary country ; it is very much contorted, and the 

 curvatures are often so small as to be seen in a cabinet specimen. 

 Is is very much traversed by veins of quartz, I was informed by 

 the workmen at Allercot that there are quarries of a similar kind of 

 limestone at Westcot, Treborough and Leigh. At Treborough a 

 very excellent roofing slate is obtained. 



§ 14. At Doddington, Friern farm, and Ely green, on the 

 eastern side of the Quantock hills, the quarries are very extensive. 

 In those of Friern farm I found some of the beds to be a very close 

 grained crystalline limestone without the slightest appearance of any 

 organic remains ; but upon a close examination of the stone when 

 broken in different directions, and particularly at those places where 

 it is bruised by the stroke of the hammer, I found many parts of 

 the bed to be almost entirely composed of a madrepore. Towards 

 the exterior, madrepores are very distinctly seen, and in some of 

 the beds the stone is full of circular bodies composed of large 

 crystalline plates of calcareous spar, which I have little doubt are 

 entrochi, but I did not discover a shell any of description. 



