﻿Vol. 64.] ON THE CARBONIFEROFS ROCKS AT LOUGHSHINNY. 473 



have far-reaching consequences, as it was here, if anywhere, that 

 the structure of the Carboniferous basin of this part of Ireland could 

 be unravelled. He enquired what method had been employed in 

 measuring the thickness of the Rush and Lane Conglomerates, as 

 the amount stated was greater than he should have anticipated in 

 intra- formational conglomerates of this type. While acknowledging 

 his inability to criticize the palaeontological data, he remarked on 

 the change now proposed in the Authors' previous classification of 

 the lower beds of the Rush sequence, and he asked whether the 

 new results were in any way dependent upon stratigraphical 

 considerations. He enquired also in what respect the fauna of the 

 Lane Limestone differed from that of the Holmpatrick Limestone, 

 as this might be a case in which the stratigrapher would have to 

 rely entirely upon the palaeontologist. 



Mr. Cosmo Johns remarked that he had noticed recently a 

 tendency to regard the Avon section as something not exactly 

 normal. This was because in other areas that had been described 

 the rocks were laid down under rather different conditions. For 

 that reason, he regretted the unavoidable delay in communicating 

 the results of his investigations in North-West Yorkshire, where he 

 had found a Yisean facies identical with that of the South- Western 

 Province. For example, on Ingleborough he had mapped faunal 

 lines which could be matched assemblage for assemblage with those 

 of the Visean of the South-West. The normal S^ was followed by 

 S„ with its scanty fauna ; D^ came in with its characteristic assem- 

 blage at the base, and was succeeded by D^. The base of D,^ lay 

 below the top of the Great Scar Limestone, and thus the whole of 

 the Yoredale Series of Phillips was included in the upper part of 

 D.„ while the Main or Upper Scar Limestone had a fauna that 

 corresponded with the top of D^ in the South- Western Province. 

 In both areas, the Millstone Grit immediately succeeded. If, now, 

 two such well-known areas, so far apart and so extensive, were 

 identical, he would urge that they should be regarded as the 

 normal Yisean sequence. If that were granted, then he would ask 

 the Authors which of their stratigraphical zones they would cor- 

 relate with the top of D.^ in, say, the Avon section. There could 

 be no question as to the great value of the results achieved by the 

 Authors, in having worked out in such detail the faunal sequence 

 and stratigraphy of so very difficult an area. 



Mr. J. A. Douglas gave a very brief comparison of the Upper 

 Limestone succession on the western coast of Ireland with that of the 

 Rush-Skerries sequence. The district of Burren in North Clare 

 was perhaps the finest example of a limestone-country in the 

 British Isles. The country was practically devoid of vegetation 

 and drift, and was built up of huge jointed limestone-terraces 

 which had often almost an artificial appearance. The beds dipped 

 very slightly at an angle of 1° or 2° southwards. The thickness of 

 the Upper Limestone from sea-level to the overlying shales was 

 about 1500 feet, and the succession varied but slightly in lithological 

 characters. The bulk of the limestone was of a pale-grey colour 



