﻿Vol. 6 1.] CONTIGUOUS DEPOSITS OF GLAMOR 3AITSHIRE. 421 



(ii) Descriptions are given of sections, the most important of 

 which are at Lavernock (near Cardiff), Barry, Tregyff (near 

 Cowbridge), Quarella (Bridgend), and Stormy Down. 



(iii) Earth-pressures affected the rocks during the formation of 

 the Sally Beds. The Pteria (Avicula)-contorta Black Shales rest 

 with perfect parallelism, but, nevertheless, non-sequentially, upon 

 the Sully Beds. 



(iv) Owing to a local upheaval of the Lavernock district, early 

 in the age during which the Upper Rhsetic Stage was deposited, 

 only a portion of the lowest bed of that stage is found, and this 

 deposit was subjected to subaerial denudation during the accumu- 

 lation of the remaining Upper Rhsetic beds elsewhere. 

 4 (v) Subsidence in the Lavernock district allowed of the deposition 

 of the White Lias. As a result, the White Lias rests non-sequentially 

 upon a portion of the lowest Upper Bhsetic deposit. 



(vi) The White Lias at certain localities in Glamorganshire 

 contains in abundance Plicatula intus-striata, PI. hettangiensis, and 

 Lima valoniensis. The deposit intervening between the Sun-Bed 

 and the Upper Rhaetic near Bath (Newbridge Hill) is over 11 feet 

 thick : at Lavernock the equivalent deposit measures but 2 feet 

 2 J inches. At the last-named locality, above the probable equi- 

 valent of the Sun-Bed, are marls 6 feet 4 inches thick, which are 

 grouped with the White Lias. Abovo come the Lower Liassic 

 Paper-Shales, succeeded by the Ostrea-Beds. 



(vii) The Upper Rhaetic of North- West Gloucestershire and 

 Worcestershire is not the equivalent of the White Lias of the Bath 

 district: the White Lias comes above the Cotham Marble (the 

 topmost bed of the Upper Rhaetic) and below the Paper-Shales, 

 which occur immediately below the Ostrea-Beds. 



1 am much indebted to a number of geologists and others 

 for kind assistance. For the trouble which he took in procuring 

 photographs of the Lavernock sections I have to record a debt of 

 gratitude to Mr. John Storrie (son of the late John Storrie), of Cardiff; 

 while, in obtaining the literature on the Rhaetic of the county I 

 have received much help from Mr. H. B. Woodward, F.R.S., Mr. F. T. 

 Howard, F.G.S., Mr. J. Storrie, and Mr. G. H. Dut'ton, F.G.S. 

 Valuable assistance with regard to some of the fossils has been most 

 courteously accorded to me by the Rev. J. F. Blake, F.G.S. , Mr. S. S. 

 Buckman, F.G.S., Mr. E. T. Newton, F.R.S., Mr. A. C. Seward, F.R.S., 

 and Dr. A. Vaughan, F.G.S. ; while to Mr. E. B. Wethered, F.G.S., 

 and Dr. C. G. Cullis, F.G.S., I acknowledge my indebtedness for 

 help in certain penological matters. For assistance in the field- 

 work I tender my best thanks to Mr. E. Talbot Paris ; while I feel 

 that any expression of thanks inadequately conveys my gratitude 

 to Mr. J. W. Tutcher for preparing the excellent photographs of 

 fossils from which the figures in PI. XXXIII were reproduced. 



