﻿Vol. 6 I.] SEQUENCE IN THE BRISTOL AREA. 211 



Dibunopht/llum-Zone. 



0<£-subzone (D } ). 



Lithological character. — Massive limestones, to a large 

 extent oolitic, containing a band of quartz-conglomerate with 

 ' veinstone-quartz' pebbles. 



Exposures : — 



(1) The end of the Carboniferous-Limestone exposure in 



the cutting. 



(2) The uppermost beds of the second quarry. 



Note. — Only the lowest part of the subzone 9<p is exposed at Sodbury ; 

 the higher part of that subzone and the whole of the Lomdali a- Subzone 

 are entirely unexposed. 



Faunal character: — 

 Corals : 



Alveolites, septosa. 

 Syringopora of. dintans. 

 Lithostrotion Martini (mutations 



towards L. affile). 

 Lithostrotion irregulare. 



Brachiopods : 



Productus l giganteus? 

 Productus hemisphericus & vars. 

 Chonetes aff. comoides. 



Cyathophyllum Murchisoni and va- 

 riants. 



Clisiophyllids, including Clisiophyl- 

 lum 0, Dibunophyllum 9 and 0, 

 Koninckophyllum 9. 



Orthotetes crenistria (raut. D). 

 Seminula ficoidea. 

 Athyris cf. expansa. 



Correlation with the Avon section. — The two sections are 

 palseontologically identical, the same fossils occur in each and in 

 the same relative abundance. 



Campophyllum air. Murchisoni which, in the Avon section, attains 

 its maximum near the top of the 0^-subzone has, however, not been 

 found at Sodbury. 



(c) The Failand Area (including Flax Bourton). 



Failand Inn lies 3 miles west 22° south of the Clifton Suspension- 

 Bridge ; it may be taken as the centre of the area. Just 1200 yards 

 west of the Inn, measured along the Clevedon road, is a branch- 

 road running northward to Portbury. After following this branch- 

 road for 500 yards, exposures in the Carboniferous-Limestone 

 Series begin to occur, and successively-lower beds are here and there 

 exposed until, near Millpond Farm (some 1200 yards from the 

 commencement of the road), the uppermost beds of the Old Red Sand- 

 stone are reached. This somewhat-discontinuous section includes 

 almost the whole of the Tournaisian division of the Carboniferous 

 Limestone, and will be referred to in this paper as the Failand 

 section. 



Turning back at Millpond Farm, we will retrace our steps towards 

 the Clevedon road, so as to examine the beds in ascending order. 



The lowest beds in the section have to be made out from the 

 low roadside-cuttings, in which the rocks are only partly and 

 occasionally exposed ; this portion of the section (some 350 yards 



