DESCRIPTIVE REMARKS. liii 
These rocks of Devon and Cornwall have, like the true Old Red 
Sandstone, been classified into three groups, and an attempt has been 
made to correlate them with the typical Old Red; so much difference 
of opinion, however, prevails as to their exact relations, that it will be 
preferable to consider them as a distinct series, some of the lower 
elements of which (as pointed out by Mr. Jukes), may probably have 
been contemporaneous with the Old Red Sandstone and other strata 
of the upper division with the Carboniferous Limestone. 
The order of succession has been ascertained to be as follows :— 
Pilton and Marwood beds, N. Devon, Petherwin 
and Tintagel, Cornwall. 
: Torquay, Plymouth, Newton, Bushel, and Ilfra- 
Middle do. combe, 8. Devon. 
Lynton, N. Devon; Meadsfoot, S. Devon; Looe 
and Fowey, Cornwall. 
The fossils of the typical Old Red Sandstone of Herefordshire, 
Wales, Scotland, and the south of Ireland, are in their general character 
quite distinct from those of Devon and Cornwall. Whilst in the 
former series of strata fishes, peculiar crustacea, a single Molluscan 
shell, and plants, all indicating a fresh water habitat, are the predomi- 
nant fossils; in the latter, which consists, for the most part of lime- 
stone and slaty rocks, Corals, Crinoids, and Mollusca, undoubtedly of 
marine origin, are the prevailing organisms. 
Our knowledge of the vegetation of the Old Red Sandstone is still 
very imperfect, and has only been derived from collections made at 
a few localities. It bears a considerable resemblance to that of the 
succeeding Carboniferous formation, all being clearly of terrestrial 
origin. In the lowest division fragments of land plants only have been 
discovered. Ferns, Lycopodiaceous plants, Lepidodendra with roots, 
described as resembling Stigmaria of the coal, also stems and roots of 
Coniferous trees have been found at Wick, in the central portion of 
the Caithness Flags, in the Orkneys, and at Thurso. In higher strata 
fossil plants of large size, belonging either to Calamites or an allied 
genus, have been discovered in the Orkney and Shetland Isles. Whilst 
in the uppermost division in Ireland, at Kiltorcan in the county Kil- 
kenny, and other places in the county Cork, numerous plant remains 
have been found in the Upper Old Red Sandstone, accompanied at some 
of the localities by a large freshwater bivalve Molluse:in shell, and fish 
remains, corresponding with those found in the Old Red Sandstone of 
Scotland. 
The Upper Old Red Sandstone occurs extensively in the south-eastern 
parts of Scotland, the highest beds of the series are of yellow sand- 
stone, upon which rests the Coal strata of Fife; this is well shown at 
Dura Den, near Coupar. The beautiful fossil fern, so abundant in the 
south of Ireland, Paleopteris ( Cyclopteris) Hibernicus, is also found in 
the Upper Old Red Sandstone of Berwickshire, at Jedburgh, associated 
with the Fossil Fish, Holopfychius, Coccosteus, and Pterichthys. On 
h 2 
Upper Devonian, 
Lower do. 
