284 
S1LURIA. 
[Chap. XI. 
I therefore range the uppermost beds of the Old Bed Sandstone of Ire- 
land with the upper division of the Old BedJ of Scotland, which in the 
north extends into the Orkney and Shetland Islands, and as being also of 
the same age as the Petherwin beds in Devonshire and the plant-bearing 
Cypridinen-Schiefer or Uppermost Devonian of Germany — a band which 
in the two latter countries is united downwards with the other members 
of the Devonian rocks, and upwards with the Lowest Carboniferous 
strata. 
Becently the maps and sections of the Geological Survey * illustrating 
the South-west of Ireland have appeared ; and in these Mr. Jukes and 
his assistants have laid down all the above-mentioned rocks which 
occupy the lofty mountain of Macgillycuddy's Eeeks, Mangerton, &c, 
extending by Kenmare to Glengariff, as that Old Bed Sandstone whose 
base, as before shown, passes down conformably into true Upper Silurian, 
and is therefore unquestionably Lower Devonian. In truth, these Old 
Eed slaty grits and schists of Ireland have a considerable resemblance 
to some of the Lower Devonian rocks of the Ehine and North Devon. 
Now these sections are quite in accordance with the observations made 
by Professor Phillips and myself (1842), in showing that in their great 
curvatures these rock-masses,, whether consisting of slaty, grey, and purple 
grits and schists, or of red sandstone, all form one system, the upper 
part of which passes conformably under troughs of Carboniferous Slate 
and Limestone, though here and there faults occur at the points of 
junction. Lying between the Lower Carboniferous strata above and 
the uppermost Silurian below, these rocks, which are all termed Old 
Eed Sandstone in the newest maps of the Survey, can, therefore, be 
nothing else than the representatives in time of the Devonian system. 
Consequently I maintain that the natural sections of the South of Ireland 
are proofs of the truthfulness of the Devonian classification. 
In subsequent chapters we shall see that where the Devonian rocks are 
much developed in different parts of Europe, and in the Ehenish Provinces 
especially, they are divisible into three parts as in Scotland and Eng- 
landf. It will further appear how, in other tracts, and particularly in 
Eussia, the Ichthyolites of the Old Eed Sandstone of Scotland and the 
marine Shells of Devonshire, Germany, Erance, and Spain are found united 
in the same strata, thus demonstrating the synchronous accumulation 
of deposits which, although they differ considerably in mineral aspect, 
occupy precisely the same stratigraphical place in the general series of 
deposits. 
In quitting the consideration of the highly diversified and important 
group of the Devonian rocks or Old Eed Sandstone of the British Isles, it 
must not be forgotten that, whilst some of its lowest members have 
* See the Sheets 173, 183, 184, 191, 192, & 199 of t See the triple division of the Devonian rocks 
the Geological Survey Map of Ireland. Also the by Sir C. Lyell, Manual of Elementary Geology, 
large Sections, pi. 21. 5th edit. p. 424. 
