﻿Vol. 6 1.] SEQUENCE IN THE BRISTOL AREA. 219 



Fauna :— 

 Alveolites se])tosa. 

 Syringop>ora cf. geniculates. 

 Lithosirotion Martini (cf . L. affine). 

 Cyatliophyllum Murchisoni and 



variants. 

 Koninckophyl lid Cyatliophyllum . 

 Campophyllum aff. Murchisoni. 

 Campophylhim sp. 



f Dibunophyllun 

 Clisiophyllids •! and D. (p. 



I Clisiophyllum 

 Proeluctus ' giganteus? 

 Procluctus hemispkericus. 

 Chonetes aff. comoides. 

 Cyrtina carbonaria (mut.). 



Comparison with other areas. — The general resemblance, 

 as indicated by the above list of fossils and their relative abundance, 

 amounts almost to identity ; in fact, the Flax-Bourton quarries 

 afford the best collecting-ground in the whole district for fossils of 

 this subzone. 



ii. Lonsdalia-Snbzone (D 2 ) is unexposed. 



(d) The Tytherington Section. 



Introduction. — Tytherington lies about 11 miles north 30° east 

 of the Clifton Suspension-Bridge, and about -1| miles north 35° west 

 of Chipping Sodbury. 



The Carboniferous Limestone (Lower or Tournaisian Division 

 only) is now imperfectly exposed, in the cutting on the branch-line 

 from Yate to Thornbury, between Grovesend and Tytherington ; and 

 a slightty-higher portion of the series (bottom-beds of the Upper 

 or Visean Division) can be examined in the limestone-quarries at 

 Tytherington. 



Prof. Lloyd Morgan l has given so excellent an account of the 

 general geology of the district, and has illustrated his description by 

 so good a map, that I can proceed without further introduction to 

 the detailed paleontology of the section. 



Details of the Grovesenci-Tytherington Section. 

 Tournaisian. 

 Modiola-Zone (M). 



Lithological character. — Shales and thin calcareous bands, 

 capped by red limestone (Horizon a). 



Exposure. — Entirely unexposed at the time of my visit,- and so 

 the beds could only be examined by uuearthing them here and 

 there. Prof. Lloyd Morgan estimates the shales and calcareous 

 beds, below Horizon a and above the Old Eed Sandstone, at a 

 little over 200 feet horizontal (which is equivalent to about 

 100 feet normal thickness). He records no fossils. 



1 'The Geology of Tytherington & Grovesend' Proc. Bristol Nat. Soc. n. s. 

 vol. y\ (1888-91) p. 1. The Eev. H. H. Winwood has also contributed a paper 

 on this cutting to the Cotteswold Naturalists' Field-Club, vol. ix (1888) p. 325, 

 which is accompanied by a good section and explanatory diagrams. 



