379 
Correspondence — Prof. E. Hüll. 
occasion has openly expressed bis impatience of long papers, will 
consign my production to the slielf or waste-paper basket wben it 
reacbes bis bands, as be probably considers be knows enough of tbe 
matter. 
Tbe paper of Mr. Dakyns in the Geol. Mag. for tbis montb (July, 
1877). is another case in point. It contains a critique on my paper 
as contained and represented in tbe “ abstract ” only ; and of tbis I 
complain. If it had been based on a perusal of tbe paper itself, I 
should liave been perfectly satisfied, wbatever tbe eonclusions of my 
reviewer migbt bave been, because I would have been aware that he 
had all the data before bim ; and if tbese did not bring bim to the 
same eonclusions as myself, I should conclude that this was owing 
to tbe fact that his mind and my own are constituted differently ; 
but I deprecate eonclusions drawn from a partial knowledge of tbe 
facts. 
I cannot now go fully into Mr. Dakyns’ objections — time and 
space forbidding. I ask bim, however, to mark the force of the term 
“ essentially ” — as used by me — and to recollect that it does not 
mean exclusvvely. 
Tben as regards tbe difficnlty of believing tbe Gannister beds to 
be marine essentially — notwithstanding tbe large number of marine 
mollusca, etc., they contain — because of tbe occurrence of beds of 
coal in Scotland. Tbis is not so surprising as tbe occurrence of beds 
of coal in Scotland overlaid by marine limestones, whicb sbows that 
Nature accomplisbes results whicb man sometimes cannot conceive. 
As regards tbe term “ Yoredale,” Mr. Dakyns, as an offieer of tbe 
Geological Survey, migbt surely have concluded that I bave adopted 
tbe term as it is used by tbe Survey itself, wbatever its original 
signification may bave been. It may not be strictly correct, but it 
would be hard to find a better for tbe great series of beds above tbe 
Mountain Limestone of Derbysbire. 
As regards tbe latter part of Mr. Dakyns’ paper, does be hold tbe 
opinion under wbich I myself was enthralled tili lately, that tbe 
great limestone series of the north of England and Scotland is 
all of it the representative of the true Carboniferous Limestone of 
Derbysbire and Lancasbire ? If so, I believe tbis to be a populär 
delusion, wbich I bave endeavoured to prove as such in my paper. 
The true Carboniferous Limestone is, I believe, represented in tbe 
north only by the bed (or group of beds) known as “ tbe Scaur 
Limestone” of Phillips, and in Scotland, as tbe Lower (or Roman 
camp) Limestone. Tbe series of beds, limestones, ironstoues, coals, 
shales, etc., wbich overlie tbis, being tbe representatives of tbe 
“ 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 tbe face of 
tbe great fact of tbe predominance of marine limestones in tbe lower 
part, and tbeir entire absence in tbe upper ? So far from tbis being 
tbe general conclusion to whicb a survey of tbe Carboniferous rocks 
of tbe British Islands and tbe West of Europe would lead us, I 
