20 PROCEEDINGS OF THE GEOLOGICAL. SOCIETY. 



exact parallelism with that of Belgium, as we now see in each country 

 a great series of fossiliferous schistose beds surmounted by, and inti- 

 mately connected with, a calcareous series, viz. the limestones and 

 subjacent schists of South Devon, and the Eifelian limestone and 

 schists of Belgium and the Rhenish provinces ; and the above series 

 is thus disconnected from the Red Sandstone formation. It now 

 becomes quite unnecessary to force the Old Red Sandstone of England 

 into a parallelism with the schists and limestones of South Devon, as 

 was done in 1837 by Mr. Lonsdale, Professor Sedgwick, and Sir R. 

 I. Murchison. And our Old Red Sandstone appears on a parallel 

 with the Belgian formation of red sandstone and conglomerate, the 

 Poudingue, psammite et schiste rouge of M. Dumont, as was suggested 

 in 1829 by M. Rozet. And instead of having, as in 1830, only two 

 formations represented as intervening between the Eifel limestone 

 and the slate-rocks of the Ardennes, M. Dumont now presents five 

 well-established groups of rocks in that interval. 



Our short visit to Belgium did not give us time to verify all the 

 new divisions, but M. Dumont's accuracy as a field- geologist is too 

 well known to render such confirmation necessary. I had, however, 

 the advantage of examining, in company with Mr. Austen, one of the 

 most illustrative lines of section along the valley of the Hoegne and 

 Wayay, from Pepinster by Spy to the Barriere des Marteaux, and we 

 drew up together the annexed section, fig. 1, which we submitted to 

 M. Dumont on our return to Liege. We were glad to find that it 

 coincided with the lines laid down on his map, and with his present 

 views of the relative position of the masses of rock. 



The section thus represented differs materially both from that given 

 by Professor Sedgwick and Sir R, I. Murchison in the sixth volume 

 of our 'Transactions,' second series, pi. 23. fig. 12, and also from 

 the more theoretical section A. B. of M. Dumont's first memoir. At 

 that time M. Dumont endeavoured to explain the complicated struc- 

 ture of the province of Liege by flexures and folds of the rocks without 

 any break in the continuity of the beds. Such flexures undoubtedly 

 exist in that district in a remarkable degree, but there are also many 

 faults accompanied with great upward shifts, by which beds of very 

 different age are brought to the same level : thus, at Pepinster the 

 Eifelian schists meet the red sandstones ; a little south of Pepinster, 

 the red sandstones abut against the Rhenane greywackes ; farther 

 south, near the Hermitage du Sart, the last-named rock meets the 

 Carboniferous series. None of these circumstances can be explained 

 by the mere bending of the rocks, as the beds which are in contact 

 belong in each case to different formations. From Theux to Les 

 Marteaux the beds lie in a regular order, and the correct sequence of 

 superposition may be traced without any difficulty, thus correcting 

 the erroneous impression which might have been formed from the 

 dip of the younger towards the older rocks in the northern parts of 

 the section. 



The northern end of our section shows one of those inversions of 

 the strata wliich attracted so much attention when they were first 

 described by M, Dumont. The Eifel hmestone, dipping S. 15° 



