570 THE CARBONIFEROUS SUCCESSION IN GOATEE. [Nov. I9II, 



bottom which they believed had taken place ; and also whether 

 their suggestion that a considerable deepening occurred at the close 

 of the S 2 lagoon-stage was compatible with the presence, in the 

 succeeding deposit, of a ' thin coaly layer.' As this, in one portion of 

 the district, was accompanied by an under clay, it seemed to present 

 a difficulty. 



Mr. A. Wade compared these beds with some which had been 

 forming quite recently at the northern end of the Red Sea. Here, 

 there was a very shallow platform fringing the Eastern Coast, and 

 running out to sea for upwards of 20 miles. A series of limestones 

 could be traced on the islands from the edge of the platform to 

 the mainland. The changes which took place in the physical 

 characters of these limestones might clear up the difficulty that 

 the Authors had with the limestones of the Seminula Zone, 

 which were dolomitic in the south-west of Gower but were not so 

 in the north-west. They were, however, entirely oolitic in this 

 direction. The limestones referred to in the Red Sea area 

 changed from massive limestones (not oolitic, but to some extent 

 dolomitic) on Jubal Island at the edge of the reef, to oolitic 

 limestones interbanded with beds of very fine sediment on Gaysum 

 Island, half-way between Jubal and the coast ; while on the 

 mainland, they consisted of oolitic limestones with many gasteropod- 

 remains, interbedded with sands and coarse grits — very like the 

 material of the Millstone Grit. The later oolites were evidently 

 laid down in the estuary of some river. 



He was interested to hear that Mr. Tiddeman had long con- 

 sidered that some of the oolites of Gower might have been laid down 

 under seolian conditions, because some of the oolites in these 

 recent Red-Sea beds were probably affected by similar conditions. 

 It seemed, therefore, that the conditions which the Authors 

 considered to have existed during the deposition of these beds in 

 Gower, might find a close parallel in the conditions which recently 

 existed, and probably still exist, in the northern part of the 

 Red Sea. 



Mr. Dixon, after thanking the Fellows for their kind reception 

 of the paper, remarked, with reference to an observation by the 

 President, on the usefulness of a classification of the Lower Car- 

 boniferous in facilitating comparison of developments in different 

 districts ; and added, in reply to Mr. Tiddeman, that the occasional 

 occurrence of large marine fossils in even the most unfossiliferous 

 oolite militated against the view that any of these rocks were of 

 Eeolian origin. 



Regarding the name to be applied to the shales above the 

 Limestone Series in Gower, the Pendleside Series had good claims, in 

 that it represented rocks to which a distinctive fauna had been 

 ascribed ; and further, in answer to an objection raised by 

 Dr. Strahan, he remarked that the correlation depended not solely 

 on the occurrence of Posidonomya becheri Bronn, but rather on that 

 of Glyphioceras spirale Phill. In agreement with Mr. Tiddeman. 

 he did not think that any of the Gower limestones possessed 

 features characteristic of true coral-reefs. 



