Vol. 6^.~\ CARBONIFEROUS ROCKS OF DEVON AND CORNWALL. 9 



on De la Beche's map of this part of Devon. They have been 

 repeatedly described, notably by Sedgwick & Murchison, 1 De la 

 Beche, 2 Townshend Hall, 3 and others ; and I have nothing material 

 to add to what has already been said on this subject. An account 

 of the fossil flora associated with the Bideford culm-bands has 

 already appeared elsewhere. 4 



Attention may, however, be called to the fact that there is no 

 indication that such culm-bands exist on the southern side of the 

 basin. One would rather expect to find them near Bude in Cornwall, 

 or to the south of that place, occupying a similar position on this 

 side of the main syncline to those of the Bideford district in the north. 

 A close examination of the coast-lino has not led to the discovery of 

 any such deposits, and there is no reason to believe that carbonaceous 

 beds, whether of sufficient thickness to be of economic importance 

 or not, are to be found in West Devon or North Cornwall, other 

 than in the Bideford district. In this conclusion, the provisional 

 statement made by De la Beche, 5 in 1839, to the same effect, is 

 confirmed. 



It would appear, however, that some of the dark splintery shale- 

 deposits, especially when weathered, may have been mistaken for beds 

 of culm. No doubt this error is at the base of the local tradition 

 that culm occurs, and has been worked, in the neighbourhood, of 

 Hartland, at a spot near a road still known locally as Coalpit 

 Lane. The results of a special enquiry into the matter, however, 

 have tended to show that no culm exists, nor any trace of culm- 

 workings, similar to those still to be found along the strike of the 

 culm-bands in the Bideford district. Nor can an}^ culm be found in 

 the coast-section, not far distant from this spot. Possibly these rocks 

 may once have been worked, to some small extent, under the belief 

 that they were of a nature similar to those near Bideford, whereas, 

 in reality, they consist of weathered black shales. I am especially 

 indebted to Mr. Rogers for investigating the facts of the matter, 

 to which my attention had been repeatedly called by residents in 

 Devon. 



As I have already pointed out elsewhere, 6 it is in the general 

 absence of carbonaceous deposits that the greatest contrast is to 

 be found between the Upper Carboniferous Series of Devon and 

 the Coal Measures of other British areas. So far as the sand- 

 stones and shales are concerned, there is a general lithological 

 resemblance, which is confirmed by the discovery of numerous 

 marine beds, to be discussed at a later stage in this paper. 



A study of the state of preservation of the plant-remains found 

 in the higher beds of the trough may perhaps throw some light on 

 the question why this district is so generally barren of carbonaceous 

 deposits. This barrenness is probably not due to any lack of 



1 Sedgwick & Murchison (40). 



3 De la Beche (39) pp. 124 & 513. 



3 Hall (75). 4 Arber (04). 



5 De la Beche (39) pp. 102 & 515. 



6 Arber (04). 



