312 J. 1\. Dabjns — Prof. Hull’s Carboniferous Classification. 
some instances, too hastily arrived at in the earlier days of their 
worb, before time and experience bad shown the necessity of that 
liabit of caution and hesitation whicli is forced upon a field -geologist 
more and more as he pursues his worb, and wliich might have pre- 
vented such inconsistencies as are illustrated by the case of the 
“ Rotherham Roch,” as it is mappe'd in two different editions of the 
One-inch Survey Map ; or by such a Statement as that of Mr. Aveline 
himself that “ a peculiarity of the [Lower Bunter] sandstone is, that 
it is quite free from the pebbles that characterize the formation over- 
lying it,” when a little closer observation might have shown him 
some half-a-dozen sections within easy reach of Nottingham, in whicli 
the pebbles of quartz, quartzite, slate, and grit, are scattered sparsely 
through the sandy matrix. But these are of course petty matters of 
detail, worthy only of the attention of that inferior Order labelled by 
Mr. Aveline “ local geologists,” one of whom has observed a good 
many of the pebbles in question even in the typical section of Lower 
Bunter south of Mansfield, which Mr. Aveline refers to in his 
“ Memoir ” (p. 12). 
I will not intrude further upon your space and your courtesy, 
except to disclaim, on my own part and that of my co-worbers in 
the same field, any wish to mabe an attaclc upon Mr. Aveline or any 
of his colleagues (several of whom I have the honour and the pleasure 
to bnow personally) ; while, on the other hand, he, no doubt, would 
be the last to repudiate the notion, that, with all their exceptional 
advantages, tliey possess a raonopoly of geological bnowledge. We 
have on both sides a strong desire to arrive at the actual truth ; and, 
even if further investigation should prove our position to be alto- 
gether untenable, I shall, for my part, be glad, if I have in any way 
lielped to bring this question into the full light of criticism. 
YI. — On Professor Hull’s Carboniferous Classification. 
By J. R. Dakyns, M.A. ; 
of Iler Majesty’s Geological Survey. 
I N a paper read before the Geological Society of London, Prof. 
Hüll proposes, as generally applicable to the whole of Great 
Britain and Ireland, a new Classification of the Carboniferous rocbs, 
as follows : 
Upper Carboniferous Group. 
Stage G. Upper Coal-measures ) 
,, F. Middle Coal-measures ... ) 
Middle Carboniferous Group. 
Stage E. Lower Coal-measures or Ganister Beds j 
,, D. Millstone-grit Series 
„ C. Yoredale Series ... J 
Lower Carboniferous Group. 
Essentially 
freshwater. 
Essentially marine 
Stage B. Carboniferous Limestone Series 
„ A. Lower Shales, Slates, Carboniferous, Cal- 
cif'erous and Sandstone Series 
Essentially marine 
(except in Scot- 
land). 
There are two points in this Classification : one is the division of 
the whole Carboniferous Series into two portions, distinguished as 
