﻿243 DR. A. VAUGHAN ON THE PALiEONTOLOGICAL [May I905, 



IV. Comparison op the Bristol Sequence with that 

 in Neighbouring Areas. 



My only object in this section is to demonstrate that the pro- 

 gression of zonal faunas, which has been established for the Bristol 

 area alone, holds true throughout the South -West of England and 

 South Wales. 



Since each area to which I shall refer is now undergoing detailed 

 examination, it would be premature, as well as out of place, to 

 attempt here anything beyond a statement of the broad outlines of 

 the faunal succession. The lithological development will be entirely 

 passed over, except in so far as the occurrence of dolomites or grits 

 may interrupt the faunal sequence. 



(i) The Mendip Area. 



The brief account which follows is mainly compiled from an 

 examination of the following localities : — 



(a) Burrington Combe. 1 



Zonal extent: All the zones and subzones are here excellently 

 exposed and typically developed, from M up to and including D x - 



(b) Traverse from Cheddar to Charterhouse. 



Zonal extent: Same as at Barrington, but the sequence is not 

 completely exposed. The Cheddar Gorge displays the Seminula- 

 Zone ending in D x ; there are numerous exposures in the Zaphrentis- 

 Zone (both Z x and Z 2 ) between the Gorge and Charterhouse. 



(c) Emborough. 



Specimens collected by Prof. S. H, Reynolds and Mr. T. F. Sibly 

 point clearly to the presence of a normal D 2 facies in the Mendip 

 development. 2 



Interruptions of faunal sequence by dolomites or grits : practically 

 none. Hence the prolific fauna of the Syringoihyris- and lowest 

 Seminula-Beds is in striking contrast to its rarity in the Bristol area. 



Correlation of the Mendip and Bristol Areas. 



So closely does the faunal sequence in the two areas agree, that it 

 is only by dint of detailed study that the small differences become 

 apparent. 



The following points of resemblance, selected from a very long 

 list, will serve to give an idea of the practical identity of the 



1 This section has been more recently examined in great detail by Mr. T. F. 

 Sibly, and his results are published in the Proceedings of the Bristol Naturalists' 

 Society, ser. 4, vol. i, pt. i, p. 14. 



2 The detailed examination of the Carboniferous Limestone throughout 

 the Mendip area is being undertaken by Mr. T. ¥. Sibly, and to him I am 

 indebted for several of the facts stated below. 



