﻿430 THE OCCURRENCE OF RUSTIC ROCKS AT BERROW HILL. [Allg. I905, 



There certainly seems to be some overlapping of the ' Tea-Green 

 Marls ' by the Pteria ( Avicula )-contorta Shales here. When my 

 paper on the Ehsetic of Monmouthshire was read, Mr. Strahan was 

 unable to agree with me regarding this matter, 1 but it appears 

 difficult to explain otherwise the phenomena observed here and 

 elsewhere ; and I would also draw attention to remarks by Moore 2 

 and Brodie, 3 geologists who were well acquainted with the deposits 

 under consideration. 



I am indebted to Mr. H. A. Badham, of Tewkesbury, for obtaining 

 the required permission to make the excavations, and to Mr. E. 

 Talbot Paris for much assistance during the investigations. 



Discussion on the two eoregoing papers. 



Mr. Strahan said that much was added by these papers to what 

 had been done by previous authors. The existence of an outlier of 

 Lias about which he had been in doubt was now proved, and Ostrea 

 Bristovi had been obtained in situ. He was unable, however, to 

 see the advisability of introducing the name ' Sully Beds.' It was 

 doubtful what Etheridge had meant by his ' Grey Marls/ and the 

 Author had had to rely upon a biographical notice for an interpre- 

 tation. Neither the downward nor the lateral extension of the 

 ' Sully Beds ' could be defined. The fact that they contained an 

 oyster which did not range up into the Avicula-contorta Zone was 

 hardly evidence that they belonged to that zone. Nevertheless, the 

 oyster indicated one of the first stages in the invasion of the area by 

 the sea, and corroborated the view that, for a time, Keuper and 

 KhoBtic conditions alternated. The facts scarcely supported the 

 theory that the ' Sully Beds ' had been deposited in a lake surviving 

 from Keuper times. The changing of the generic name of Avicula 

 contorta, except under the stress of absolute necessity, was greatly 

 ■to be deprecated. 



1 Quart. Journ. Geol. Soc. vol. ki (1905) p. 384. 



2 Ibid. vol. xxiii (1867) p. 468. 



3 Ibid. vol. xlii (1886) pp. 273, 275. 



