lO PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



tltes, such as characterize the upper part of the Carboniferous Lime- 

 stone elsewhere. 



Kev. H. H. AVixAvooD believed the Author's stratigraphical and 

 pala:ontological evidence was weak. The Author mentioned that the 

 Hangman Grits were comparatively unfossiliferous, but there are at 

 least 10 species, including 2Y«^m;«, none of which have been found by 

 Dr. Hicks in the Pickwell-Down Beds, a difficulty to be explained 

 if he correlates them with the Hangman Grits. 



Rev. G. F. Whidborne remarked that Phacops latifrons had a wide 

 range in South Devon. The uumberof Carboniferous forms went to 

 prove that the beds in the north were very much higher than the 

 Great Devon Limestone. 



Mr. HuDLEsroisr wished to know how the beds were got into the 

 position represented in the diagram. 



Prof. Blake asked whether the Pilton Beds did not pass up into 

 the Carboniferous. 



The President remarked that, in altering the recognized order of 

 succession of these rocks, the Author would have to reckon also 

 with Continental stratigraphers and palaeontologists. Dr. Hicks 

 had not made as clear as might be the evidence for such thrust-planes 

 and faults as his views of the structure of the ground required. 

 The plications and dislocations in South Devon and Cornwall, 

 although abundant and often ver}" complicated, appeared to the 

 speaker to be on a comparatively small scale ; and although he did 

 not wish to insist that this must be : he case in North Devon, he felt 

 that it might be so. 



The Author, in reply, stated that he had gone carefully into 

 Continental questions, and he maintained they were strongly in his 

 favour. He declared that there was ample evidence to show that 

 there was any amount of thrusting in North Devon. The Hang- 

 man Grits in Combe-Martin Bay have three sharp folds against the 

 fault, indicating that beds are missing, and he maintained that 

 even in the Hangman Beds the palseontological evidence was in 

 favour of his views. Mr. Yalpy had found Cucullcea in these beds, 

 and two species are given in Mr. Roberts's list of the Hangman 

 fauna. Along the Tors he found that every one was a broken fold, 

 though there was no great thrusting there, and these beds abutted 

 against the Morte Slates. He had no means of calculating the 

 amount of the equivalents of the Baggy-Pilton Beds lost at the 

 Combe-Martin fault. He had carefully considered all the evidence 

 placed on record, therefore Mr. Ussher's remarks seemed unwar- 

 ranted. The thickness claimed by the supporters of a continuous 

 upward succession was about 15,000 feet, indicating, of course, a 

 gradual depression to that extent. This, he maintained, was im- 

 possible in the face of the lithological evidence, and of facts obtained 

 from neighbouring areas ; moreover, it would necessitate that such 

 a characteristic zonal fossil as Stringoceplia.lv s Burtini should be 

 placed at the base of the Ilfracombe Beds (shore of Combe-Martin 

 Bay), and therefore separated from its closely associated fossils 

 (Baggy and Pilton fauna) by about 10,000 feet of strata. He 



