PALAEOZOIC CLASSIFICATION OF THE BRITISH ISLES. 
realized by a train of inquiries which proved, that the group of fossils which occur 
in the calcareous slaty rocks of Devonshire were of the same age as the Old Red 
Sandstone. A new survey of Devonshire established, in short, the fact, that 
though they had previously been considered to belong to the older grauwacke 
rocks, large masses of schistose deposits overlying certain limestones and slates 
of that country and of a small part of the adjacent county of Cornwall, were 
nothing more than equivalents of the carboniferous series ; and subsequent in- 
quiries showed that the subjacent strata, into which the carboniferous formations 
appeared to pass conformably downwards, occupied the place of the Old Red 
Sandstone 1 . 
It being thus shown that these lower rocks, though black and slaty, contained 
shells, which, when the formation was developed in its sandy and red characters, had 
never been found in it, the term “ Devonian System” was proposed as a synonym, 
if not as a substitute, for that of “ Old Red Sandstone,” the lithological import of 
which had led to much confusion, and had prevented the comparison of various grey, 
black and slaty deposits of Europe with the Old Red Sandstone of the British Isles. 
As, however, it might have been possible, that the distinctions pointed out in the 
British Isles were local, the authors, who had suggested this change of nomencla- 
ture, next undertook an extensive survey of the Rhenish Provinces, including the 
Hartz district and Franconia on the one side, and Belgium and the Boulonnais on 
the other, in the latter part of which they were accompanied by M. de Verneuil. 
This inquiry may be said to have verified and established in that part of the conti- 
nent of Europe, a portion of the palaeozoic classifications first worked out in England. 
It proved that rocks immediately beneath those having a true carboniferous type, 
assumed the same characters and contained many of the same shells as the rocks 
pounded by Mr. Murchison (after four years of previous labour) in July 1835, and the system was then 
divided into Upper and Lower Silurian rocks, each containing subordinate formations. (See Lond. and 
Edinb. Phil. Mag., vol. vii. p. 46, with a section explaining the relations.) The term Devonian was first 
applied in 1839, or immediately after the publication of the Silurian System. 
1 See the memoirs of Professor Sedgwick and Mr. Murchison, Trans. Brit. Assoc, for the Advancement 
of Science, 1836, Sect. Trans, p. 95 ; Trans. Geol. Soc., 2nd series, vol. v. p. 633 ; and Lond. and Edinb. 
Phil. Mag., April 1839, pp. 241, 354, where the term Devonian was first proposed. From an examination 
of certain organic remains collected in South Devon by Mr. Austen, Mr. Lonsdale had previously sug- 
gested that these forms were of characters intermediate between those of the Carboniferous and Silurian 
systems, and consequently of the age of the Old Red Sandstone. (See Trans. Geol. Soc., 2nd series, vol. v. 
PP- 690, 696, and 721. See also the work of Sir H. T. De la Beche, ‘ Geological Report of Devon and 
Cornwall,’ and the Palaeozoic Fossils of Devon and Cornwall, by Professor Phillips.) 
B 2 
