About loo feet 



E 



ViSEAN. 





Dihunophyllum 



D 2^ 



>> 



D 1/ 



Seminula 



S 2) 



>> 



TOURNAISIAN. 



S i/ 





Syringothysis 





Zaphrentis 



Z 2) 



_ >> 



Z ij 



Cleistopova 



K 



Modiola 



M 



Hind: Carboniferous Geology. 151 



life zones exist in Belgium, and that it will be a comparatively 

 easy matter to correlate with some approach to exactness, 

 the Carboniferous Limestone Series of the Meuse and Bristol, 

 a view expressed by I.ohest, many years ago, and previous 

 to the publication of Dr. Vaughan's work. 



Dr. Vaughan shews the Bristol sequence to be about 2300 

 feet thick, and thus he sub-divides it as follows :— 



400 feet 

 850 „ 



250 „ 



360 ., 



100 



Speaking generally, the fauna of the Bristol area is not 

 rich in genera or species, except in Corals and Brachiopoda ; 

 Lamellibranchs, Gasteropoda, and Cephalopoda are exceedingly 

 rare. Fish remains occur abundantly at certain horizons, but 

 are rare in the Dibunofhyllum beds. There are no shellbeds, 

 such as are not uncommon in the Upper Limestones of the 

 Midlands, indeed there is a very great difference in the faunas 

 of the Dibunophyllum beds in these two areas, both in numbers 

 of species, gene a, and individuals. 



In the Bristol district the Dibunophyllum beds pass up into 

 a series attaining about 100 feet of limestone, which Dr. 

 Vaughan has classed as (E.), which are characterised by 

 brachiopods of a late Dibunophyllum type, which are common 

 also in the Midland area. And on these limestones repose the 

 so-called Millstone Grits of the British district, said to be about 

 980 feet thick, on which lie the Coal Measures, which, from 

 the flora, would seem to represent only the upper moiety of 

 the Coal Measures of the Midlands. Mr. Bolton has published 

 the description of marine bands and their fauna passed through 

 in an exploration heading at the Ashton Vale Colliery.* 



Unfortunately we know nothing more of the fauna or 

 flora of this 900 feet of beds. The fauna of the marine band 

 described by Mr. Bolton, has some resemblance to that asso- 

 ciated with the Gin Mine of the North Staffordshire Coalfield, 



* Q. J. Geol. Soc, Vol. LXII., pp. 445-469. 



1909 April I. 



