﻿Vol. 6 I.] SEQUENCE IN THE BRISTOL AREA. 255 



{b) The Tenby Area. 



From Skrinkle Bay to Lydstep the series is almost complete, from 



the Old Red Sandstone up to (and including) the D 1 subzone ; not 



only is the faunal succession identical, but the relative abundance of 



individual species is almost the same in the Tenby and Bristol areas. 



In ascending order we meet with : — 



M. A basal series exhibiting a strong Modiola-ostra,cod phase. 

 K. The Cleistopora-Zoue has all its characteristic fossils (Productus 

 bassus was found at the base and Gleistopora near the top). 

 Z. The lowest beds of Z x are, in the cliff-section, pinched out by 

 a fault, but they are well shown in a neighbouring quarry. 

 Z 2 is well developed, and abounds in Zaplirentes with their usual 

 associates, Caninia becoming common at the top. 

 y is moderately displayed. 



f The laminosa-subzone is largely dolomitic ; but the upper 



C ] part of the SyringotJiyris-Zone is splendidly displayed, 



and d. 1 and bears a remarkable resemblance to the same level 



[ in the Mendip area. 



S 1 is apparently poor in fossils ; a block, probably derived from 



this level, contained Productus afT. semiretiadatus and 



Athyris cf. eocpansa. 



S 2 1 are splendidly displayed and contain all the characteristic 

 and D x J fossils. 

 D was not, at the time of my visit, definitely made out. 



(c) West Gower (Glamorgan). 



In the Proceedings of the Bristol Naturalists' Society, Dr. W. 

 B. Gubbin gives an account of the development of the Carboniferous 

 Limestone in the west of the Gower Peninsula. The large col- 

 lection of brachiopods and corals which he had made was submitted 

 to me for determination, and the results of my examination are 

 embodied in a supplementary note to his paper. In this note 

 I point out how striking is the resemblance between the faunal 

 sequence in West Gower and that in the Avon section.] 



V. CoMPAEISON WITH THE BELGIAN SEQUENCE. 



As I have no personal knowledge of the Belgian rocks, and have 

 only read the general accounts given in the Belgian text-books, the 

 following comparison pretends to no great value ; the great amount 

 of valuable work, however, which has been done by Belgian geologists 

 in zoning the Carboniferous Limestone, forbids the entire omission 

 of such a comparison. 



Since a large number of divisions are characterized solely by 

 lithological characters, it is impossible to refer them to their correct 

 place in my zonal system. It is, however, interesting to observe 

 that the main horizon of dolomitization is the same in Belgium as 

 in the Bristol area. 



