Chap. XVI.] 
DEVONIAN EOCKS OF THE RHINE. 
393 
we meet with those older slaty rocks, rising from beneath all the other 
deposits, to which allusion will presently be made. 
Although this view of the age of the Ehenish strata has for some years 
prevailed among scientific men, it is right to explain how it has hap- 
pened that the English geologists * who, in the year 1839, applied to these 
Ehenish rocks the classification they had worked out in their own country, 
and thus changed the views of their precursors, should in their turn have 
seen reason to admit the value of certain important corrections made by 
their successors. 
The clear general views of the Nestor of continental geologists, d'Omalius d'Hal- 
loy t , the remarkable work and map of Dumont, as well as the previous labours 
of Prussian geologists, including the maps of Leopold von Buch, Hoffmann, 
von Dechen, and von Oeynhausen, unquestionably led the way in the succes- 
sion of efforts through which our present knowledge has been obtained. After 
the publication of the above works, Professor Sedgwick and myself endeavoured 
to show that, like Devonshire and Cornwall, the Ehenish Provinces contained a 
great mass of those strata, intermediate between the Silurian and Carboniferous 
deposits, which we had called Devonian — the equivalent of the Old Eed Sand- 
stone of Scotland and Herefordshire. Our cotemporaries have admitted that in 
our excursion of one long summer in Germany Sedgwick and myself succeeded in 
proving the existence of such an intermediate series in Belgium, Prussia, Fran- 
conia, and the Harz, and also in showing how on the right bank of the Ehine 
the ' Uppermost Grauwacke ' was divisible into Lower Carboniferous and Upper 
Devonian rocks. Misled, however, by our interpretation of some of the lowest 
fossils (for at that time the Lower-Devonian forms were only partially known, and 
those which had been obtained were not rigidly examined), we adopted the belief 
that the ' lower fossiliferous grauwacke,' or that which has since been called the 
' Spiriferen-Sandstein ' of the Ehine, might be an equivalent of the uppermost 
Silurian. I have, however, for a very long time been convinced, through the palse- 
ontological labours of Ferdinand Eomer and the brothers Sandberger, that the 
types of the lower Ehenish subdivision are quite distinct from those of the Lud- 
low rock, and even of the Tilestones, and are in perfect harmony with the lowest 
Devonian group of other countries. In admitting this amount of former misap- 
prehension, let me say, however, that the sections by Sedgwick and myself, re- 
presenting the succession of the mineral masses, have all proved to be correct. In 
the superior portions of the group, however, now recognized as Devonian, the 
geologists and palaeontologists of Prussia, Nassau, and Belgium have made sub- 
divisions, both mineralogical and zoological, which it is essential to notice. 
In two recent visits to my old ground, it is satisfactory to have ascertained 
that all the knowledge acquired since 1839, when our first survey was made, has 
but confirmed and completed that identification of the rocks of the Ehenish 
Provinces with those of Devonshire which was then proposed by my colleague 
and myself ; for it now appears that not some only, as we thought, but all the 
Palaeozoic strata of Devon have their equivalents on the banks of the Ehine and 
in Belgium ; so that, starting from the North Foreland of the Bristol Chan- 
nel, and ascending into the heart of the culm- or coal-fields of Devon, as de- 
* See Sedgwick and Murchison, Trans. Geol gium prepared by M. d'Omalius d'Halloy in the 
Soc. Lond. ser. 2. vol. vi. p. 211. time of the first Napoleon, 
t See the Geological Map of France and Bel- 
