106 



earthy contents, large mounds, sometimes of a pure white, hard, 

 siliceous nature, and at others of a substance which, on drying, be- 

 comes pulverulent. In the volcanic district some of the springs are 

 said to be sour; and many sulphureous springs occur both in and 

 west of the mountains. Lastly, pure sulphur has been occasionally 

 seen above the Great Salt Lake, and at the eastern base of the 

 mountains, but none in the volcanic district. 



A letter was then read from H. T. De la Beche, Esq., F.G.S., 

 and addressed to the President, on the Anthracite found near 

 Biddeford in North Devon. 



Mr. De la Beche says, the anthracite occurs along a strip of 

 country about thirteen miles in length from east to west and about 

 three quarters of a mile in breadth from north to south. It com- 

 mences eastward at Hawkridge Woods on the banks of the Taw, 

 and extends westward to Greencliff in Biddeford Bay, where the 

 sea cuts off all further observation of its course in that direction. 

 On the opposite side of the bay, however, a very carbonaceous 

 slate is found in the cliffs among the greatly contorted strata of 

 grauwacke between Clovelly and Hartland Point, There can be 

 little doubt, Mr. De la Beche observes, that this carbonaceous slate 

 belongs to the same system as the Biddeford beds, and thus it would 

 be extended about eleven miles still further westward, where the 

 sea again cuts it off. The anthracite between Hawkridge and 

 Greencliff has been extensively worked at various times, and at 

 the latter place is now vi^orked for the sole supply of a limekiln. 

 The beds of anthracite do not occur precisely in the same line with 

 each other, so that one or two beds are not so far continuous, but 

 swell out in particular places, the maximum thickness not exceed- 

 ing 12 feet. 



The letter was accompanied by a collection of fossil plants, all 

 collected by Mr. De la Beche ; and he says, there can be no question 

 that the shales, slates, sandstones, and anthracite, among which 

 they are found, belong to the grauwacke, the evidence being of the 

 most clear and satisfactory kind*. 



With regard to the position of these beds in the grauwacke of 

 Devon generally, Mr. De la Beche states that, it may be considered 

 at about two thirds of the whole, above that part where the grau- 

 wacke shades away into the mica slate, chlorite slate, and other 

 non-fossiliferous rocks of the most southern part of Devon. It 

 should, however, be observed that the grauwacke of Devon and 

 Somerset is not complete, and that we nowhere can see what can 

 be decidedly termed its upper portions. After very diligent search, 



* The plants have been examined by Prof. Lindley,and he has decided that 

 they are, as far as they can be determined, plants of the coal measures, viz. 

 Pecopteris lonchitica, Spkenopteiis latifolia, Calamites canncefvi-mis, As- 

 terophyllites resembling A. longifolin, another species, which may be A.ga- 

 lioidis, Cyperites bicarinata, and Lepidophyllum intermedium', also fi'ag- 

 ments apparently of Palm leaves, specimens of which Prof Lindley states 

 he has received from Bolton. The most abundant plant is too imperfect 

 for its characters to be determined. 



