﻿Correspondence — Prof. E. Hull. 379 



occasion has openly expressed his impatience of long papers, will 

 consign my production to the shelf or waste-jDaper basket when it 

 reaches his hands, as he probably considers he knows enough of the 

 matter. 



The paper of Mr, Dakyns in the Geol. Mag. for this month (July, 

 1877), is another case in point. It contains a critique on my paper 

 as contained and represented in the " abstract " only .; and of this I 

 complain. If it had been based on a perusal of the paper itself, I 

 should liave been perfectly satisfied, whatever the conclusions of my 

 reviewer might have been, because I would have been aware that he 

 had all the data before him ; and if these did not bring him to the 

 same conclusions as myself, I should conclude that this was owing 

 to the fact that his mind and my own are constituted differently ; 

 but I deprecate conclusions drawn from a partial knowledge of the 

 facts. 



I cannot now go fully into Mr. Dakyns' objections — time and 

 space forbidding. I ask him, however, to mark the force of the term 

 " essentially " — as used by me — and to recollect that it does not 

 mean exclusively. 



Then as regards the difiSculty of believing the G-annister beds to 

 be marine essentially — notwithstanding the large number of marine 

 mollusca, etc., they contain — because of the occurrence of beds of 

 coal in Scotland. This is not so surprising as the occurrence of beds 

 of coal in Scotland overlaid by marine limestones, which shows that 

 Nature accomplishes results which man sometimes cannot conceive. 



As regards the term " Yoredale," Mr. Dakyns, as an ofSeer of the 

 Geological Survey, might surely have concluded that I have adopted 

 the term as it is used by the Survey itself, whatever its original 

 signification may have been. It may not be strictly coiTect, but it 

 would be hard to find a better for the great series of beds above the 

 Mountain Limestone of Derbyshire. 



As regards the latter part of Mr. Dakyns' paper, does he hold the 

 opinion under which I myself was enthralled till lately, that the 

 great limestone series of the north of England and Scotland is 

 all of it the representative of the true Carboniferous Limestone of 

 Derbyshire and Lancashire ? If so, I believe this to be a popular 

 delusion, which I have endeavoured to prove as such in my paper. 

 The true Carboniferous Limestone is, I believe, represented in the 

 north only by the bed (or group of beds) known as "the Scaur 

 Limestone" of Phillips, and in Scotland, as the Lower (or Eoman 

 camp) Limestone. The series of beds, limestones, ironstones, coals, 

 shales, etc., which overlie this, being the representatives of the 

 " Yoredale " beds only. Lastly, let me ask how is it possible to 

 believe the Carboniferous rocks to be " one indivisible formation," 

 if by that term is meant a heterogeneous collection of beds of various 

 mineral characters, and of various modes of formation, in the face of 

 the great fact of the predominance of marine limestones in the lower 

 part, and their entire absence in the upper ? So far from this being 

 the general conclusion to which a survey of the Carboniferous rocks 

 of the British Islands and the West of Europe would lead us, I 



