410 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Apr. 4, 



eruptive rocks. It was then that the EngUsh geologists compared 

 the southern limb of the chain with the masses of older rocks in the 

 Rhenish provinces and those with of the Harz, and also endeavoured 

 to indicate the German districts to which the terminology used to di- 

 stinguish the ancient British sedimentary formations might be applied. 

 As that survey, the result of which was embodied in the ' Transac- 

 tions of the Geological Society,' was made in one long summer only, 

 and as at that time there were few local collectors of palaeozoic 

 fossils, it was not to be expected that the authors could offer more 

 than a broad and suggestive outline. 



In the sixteen years which have elapsed since that memoir was 

 published, the Rhenish provinces have been sedulously examined by 

 various able geologists and palaeontologists, who have accurately 

 defined the limits of the sub-formations of each group, and have 

 shown that, if the distribution of animal life be the guide, there are 

 no true Silurian rocks in the Rhenish provinces — provided the adja- 

 cent slaty masses of the Ardennes should not prove to be such. 

 The great mass of the Rhenish fossils pertain unquestionably to the 

 Devonian rocks, and constitute, as we have lately stated, a triple 

 group, of which the Spirifers and stones and slates form the base, the 

 Eifel limestones the centre, and the Cypridina and Clymenia schists 

 and limestones the upper band *. 



This group is clearly followed by the Lower Carboniferous rocks 

 properly so called, because they contain true mountain limestone 

 fossils, and also certain plants ; the order of succession being ad- 

 mirably exposed on the northern edges of the hills which flank the 

 lower country of \Vestphalia. Much of this lower carboniferous 

 group is mineralogically identical with the culm series of Devonshire, 

 whilst the uppermost band of it, the * floetz-leerer sandstone,' is the 

 equivalent of the British millstone grit, as first shown in the memoir 

 above cited f . We may here refer to the original General Section 

 (fig. 1, pi. 23, Geol. Trans. 2 ser. vol. vi.) made by us when we first 

 examined the Rhenish rocks in 1839 — which shows how truly the 

 physical order is what it was then represented to be. 



Such is the succession in the Rhenish provinces, and of this we 

 have elsewhere given a condensed description and synopsis % as pre- 

 pared from our own observation and that of competent authorities, 

 who have corrected the details and amplified the original comparison 

 of the rocks with British types. 



When the first comparative survey of the older rocks of Germany 

 was made, no one had developed in any part of that vast region a 

 true Silurian series ; but in the interval M. Barrande has had the 

 high merit of showing the existence in Bohemia of a perfect basin of 

 all those rocks which he terms Silurian, i.e. from an unfossiliferous 

 base through great masses of sediment representing the Lower and 

 Upper Silurian divisions. 



Now, each of the two tracts which are brought under considera- 



* ' Siluria ' (1854), p. 367, &c. 



t Trans. Geol. Soc. 2 ser. vol. vi. p. 228, 229. 



: * Siluria,' p. 382. 



