part 3] THE DEVONIAN OP EEKQTTES. 237'' 



warrant any conclusions on the trend of the Devonian coast-line,, 

 and thought that the more northerly occurrence of Devonian oil' 

 the west was more simply explained by one or several dip-faults 

 with a greater throw. 



The Author mentioned the sporadic occurrence of the Les Noces. 

 Dolomites. Undoubted reefs were characteristic of the Frasnian in. 

 the Bassin de Dinant. Was- it not possible that here was a case of 

 small dolomitized reefs ? 



With regard to the plant-remains in the Grres de Gathers, speci- 

 mens collected by the speaker had been identified, as accurately as. 

 their preservation allowed, by Prof. Bertrand, of Lille, as Hos- 

 tinella sp. (Halle) and the sporangial bodies, Dawsonites areuatus- 

 Halle. At Matringhem these were associated with PsilopTiytow 

 princeps (Dawson pais) Halle. It was important that such 

 determinations should be as precise as possible, as a careful stud}" 

 of Devonian plant-fragments might prove them to possess 

 stratigraphical importance. 



The Author replied that there was undoubtedly a system of" 

 dip-faults in the Carboniferous; but, if they were. once continuous, 

 with those in the Devonian rocks, as was probable, they had been, 

 displaced by the thrust-fault. It was possible that there was a 

 later set of faults having the same general direction. The appear- 

 ance of detached masses exhibited by the Les Noces Dolomites was- 

 assignable to the shifting of the otitcrop, otherwise they appeared 

 to be continuous beds : the hummocks seemed to be caused by 

 unecpial weathering due to the varying character of the rock, 

 in places compact, in others loose and cavernous ; corals were rare 

 in these beds. There was no evidence of considerable dip-faults- 

 on the west to account for the facts revealed by borings, but the- 

 sea-floor was undoubtedly lower on the west during the Mesozoic 

 Era ; it seemed, therefore, to be an equally probable explanation 

 that the coast-line receded northwards. 



