older Deposits of the North of Germany and Belgium. 223 



overlaid by many thousand feet of slate rocks almost devoid of fossils, was of the 

 date of the old red sandstone, and that the greater part of the slates of Cornwall 

 (heretofore regarded, from their crystalline structure, as primary formations of 

 great antiquity) also belonged to the same epoch, required no common confidence 

 in the weight of evidence offered by groups of fossils. With good hopes, but not 

 without considerable anxiety, we therefore resolved to examine some of the conti- 

 nental localities which seemed likely to throw light on our proposed classification ; 

 conscious that it could never meet with general acceptance unless confirmed by 

 some analogous development of the upper transition rocks of France and Germany. 

 We at first intended to commence our observations in Brittany, which, from 

 its geographical position, might be expected to offer some analogies of structure 

 with Devonshire and Cornwall. We however abandoned that intention on learn- 

 ing, from the geologists of France, that the connexion between the carboniferous 

 system and the inferior strata was obscurely exhibited in that region, and that the 

 evidence offered by the fossils of the lower groups was meagre and unsatisfactory- 

 We therefore resolved to begin with the transition rocks of the Rhenish provinces, 

 knowing that on both banks of the Rhine we should be conducted through a true 

 carboniferous series, based on mountain limestone, into still lower groups of strata. 

 If, therefore, in the examination of these regions, we could discover a series of beds 

 mineralogically and zoologically intermediate between the carboniferous and Silu- 

 rian systems, then would our proposed classification be confirmed by evidence of a 

 higher nature than any offered by our English sections, none of which were perfect. 

 But if, on the other hand, no such intermediate series were exhibited, then would 

 our Devonian system be urfsupported by that direct evidence of superposition 

 which seems essential to its permanent acceptance as an European Deposit. 



Of the Belgian groups we had some knowledge, chiefly from the descriptions of 

 M. D'Omalius d'Halloy and Professor Dumont ; and it appeared to us quite certain 

 that the three lower members of the systems anthraxifere (notwithstanding the 

 more recent comparison of them with the Silurian system) must be exactly, or very 

 nearly, the equivalents of a higher group of rocks, to which we had given the name 

 Devonian. For the systems anthraxifere was, as its name implied, anthraxiferous ; 

 its upper division was, from its fossils, the representative of our mountain lime- 

 stone ; and even in its lowest division there appeared (from the published lists) to 

 be a few mountain limestone fossils : at the same time, we were unwilling, in the 

 commencement of our labours, to encounter the peculiar difficulties of the Belgian 

 sections. 



The coal-field of Dortmund and the great chain of the supposed mountain lime- 

 stone, extending (as represented in the maps of Von Buch and Hoffmann) from the 

 right bank of the Rhine to the confines of Hessia, seemed to offer a more inviting 



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