Notices of Memoirs—Old Red Sandstone. 017 
the conclusions of Prof. Hull, which the author reviewed in order. 
First, that the hiatus and unconformability, it was understood, were 
supported by the observations of Messrs. O’Kelly and McHenry at 
Kenmare and Glengariff Bays; but one of these geologists, how- 
ever, contradicts this, while the second declines to give an opinion. 
The second, referred to well-known unconformabilities outside the 
limits of the typical West Cork rocks; these on account of the 
places in which they occur, the author was of opinion did not favour 
the idea of a hiatus. The third was a statement that the plotting 
on the maps of the Geological Survey proved an unconformability ; 
the lines, however, to which Prof. Hull was supposed to have re- 
ferred are only the conventional lines in common use to indicate 
folds and flexures in contorted areas; and are fully explained in the 
sections of Jukes and his assistants. The fourth is, that there are 
abrupt changes in the rocks forming Prof. Hull’s different groups— 
this, however, was shown to be improbable, as the Carboniferous 
Slate of Griffith graduates so imperceptibly into his Yellow Sand- 
stone, and tbe latter into his Old Red Sandstone (the upper member 
of Prof. Hull’s ‘‘Glengariff Beds”), that the respective boundaries 
adopted on the Government maps are arbitrary, and depend solely 
on the colours of certain beds. 
V.—Tue Oxtp Rep SanpstoneE or tHE NortH oF IRELAND. 
By G. H. Kinanan, M.R.I.A,, 
President Royal Geological Society of Ireland. 
N the Grou. Mac. for August, 1880, page 381, appears the 
abstract of a paper “On the Old Red Sandstone of the North 
of Ireland,” by Mr. F. Nolan (read before the Geological Society of 
London, June 23rd, 1880). In this communication my classification 
is cautiously acknowledged, although when I first published it in 
my preface to the Geology of Ireland, Prof. Hull, in criticising it 
in the Grotocican Magazine, brought forward most ingenious 
evidence to show that I was mistaken. 
According to the published Map of the Pomeroy District (Ireland, 
Sheet 34), the Old Red Sandstone of Shanmaghry, two miles 8.E. 
of Pomeroy, not only rests on the fossiliferous Pomeroy rocks, but 
graduates into them. I, however, would suggest that the position 
of the boundary is inaccurate, and that the Old Red Sandstone 
extends a little farther north into the townland of Aghafad, its base 
being a friable red conglomerate that rests unconformably on the 
fossiliferous beds a little to the north of it. 
I cannot understand on what reasoning it has been assumed that 
the “‘ Kiltorcan beds” of Professor Hull, which are said to be the 
equivalents of Griffith’s “‘ Yellow Sandstone,” can be supposed to be 
absent in the North of Ireland. They were found there years ago 
by Griffith and others; and there are good exposures, in different 
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