﻿228 DR. A. VAUGHAN ON THE PALJEONTOLOGICAL [May 1905, 



The most interesting points in the Clevedon develop- 

 ment are as follows: — 



(1) The great abundance of Zaphrentis in the resujrinata-suhzone 

 and the strong demarcation of Horizon y by the abundance of 

 Caninia cylinchnca. 



(2) The dominance of Zaphrentis aff. Phillipsi in the lower part 

 of the resujjinata-siibzone, and of Zaphrentis aff. comucojrice in the 

 upper. 



(3) The occurrence at Horizon y of transitional forms between 

 Zaphrentis, Caninia, and Cyathophyllum (compare Spring Cove). 



(4) The occurrence of a characteristic form of Syringopora in the 

 upper part of the Zaphrentis-Zone. This form is found at the 

 same horizon in the Failand, Sodbury, and Avon sections. 



(5) The light which the accurate determination of the age of the 

 Carboniferous Limestone that surrounds or is included in the 

 Pennant Series, in the Clevedon and Clapton areas, is likely to throw 

 upon the relation of the Coal-Measures to the Carboniferous Lime- 

 stone in the district. So far as I have yet been able to form 

 an opinion, a considerable unconformity seems the only 

 possible solution. 



(/) The Portishead District. 



Portishead Railway-Station lies 4| miles north-east of Clevedon 

 Station, and 6| miles west 20° north of the Clifton Suspension- 

 Bridge. 



The Carboniferous-Limestone ridge stretches continuously along 

 the west side of the road, from Clevedon to near Portishead, where 

 it is abruptly interrupted ; but the Carboniferous Limestone again 

 reappears on the foreshore, in front of the Esplanade, and also 

 extends in a west-and-east ridge, from Battery Point to Portishead 

 Dock. 



The Portishead district has been briefly described by Buckland & 

 Conybeare, 1 and later, in considerable detail, by Prof. Lloyd 

 Morgan. 2 The last-named author dissents from the conclusions of 

 the earlier observers in several important points, only one of which, 

 however, concerns my present object, namely, the interpretation of 

 the beach-sequence near Battery Point. 



The facts, as I read them, are as follows : — Beds identical with 

 the Avon i Bryozoa-Beds ' emerge from beneath the alluvium at the 

 northern end of Woodhill Bay, and form a low cliff; these beds 

 l)end completely over. For a few yards north of this roll, there is 

 a confused jumble in which no arrangement can be detected. Still 

 proceeding northward, we next meet with four or five small, sharp 

 flexures (broken in places) in a series of shales and thin limestones. 

 In these beds Cleistopora is very common. The last of the small 



1 ' Observations on the South- Western Coal-District of Ens-land ' Trans. 

 Geol. Soc. ser. 2, vol. i (1824) p. 210. 



2 Proc. Bristol Nat. Soc. n. s. vol. v (1885-88) p. 17. 



