Geological Society of London. 135 



On the west side of the plain there was evidence of a similar axis 

 of upheaval to the south of the Flintshire Coal-field near Hope, 

 where the Lower Carboniferous rocks (Yoredale and Millstone beds) 

 are brought up to the surface at the margin of the New Eed Sand- 

 stone. 



Mr. Hull regarded the uprise on each side of the plain as referable 

 to the same Pre-Permian age, and as belonging to the East and West 

 system of flexures into which the Carboniferous rocks were thrown 

 at the close of the Carboniferous period over the north of England. 

 Such an axis had its antetype in the concealed ridge which once oc- 

 cupied the valley of the Severn, and divided the Devonian rocks of 

 Devonshire from those of South Wales ; and the author suggested 

 that a similar ridge, now concealed beneath the Triassic formation of 

 Cheshire, offered the only satisfactory explanation of the dissimilar- 

 ity in the two types of Permian beds — that of Lancashire, and that 

 of Shropshire and the Midland Counties. 



Discussion. — Prof. Eamsay considered that the lithological differences in the 

 Permian rocks of the two areas referred to were hardly so srreat as was supposed by 

 Mr. Hull. ^ '' 



Mr. Prestwich remarked that the nearly equal thickness of the Permian deposits in 

 the two areas was in favour of their having been deposited in continuity. 



Mr. W. W. Smyth considered that the difference between the Permian beds in 

 question was not so great as the author supposed, but that the undoubted existence 

 south-west of Chester of a breadth of five or six miles of Bunter Sandstone lying 

 immediately upon the MUlstone Grit, although observed only at one point, was 

 strongly in favour of the author's hyi^othesis. 



Mr. Hull stated in reply that the difference between the two groups of Permian 

 rocks to which he had referred was such as to cause their identity to appear at first 

 sight very doubtful. The extent of the anticlinal at Eushton Spencer is so great that 

 it must be inferred to have extended far both to the east and west. 



2. " On the Eed Chalk of Hunstanton." By the Eev. T. Wilt- 

 shire, M.A., E.L.S., E.G.S. 



The author described the section exposed in Hunstanton Cliff as 

 showing : — 1. White Chalk with fragments oi Inocerami. 2. White 

 Chalk with SipJionia paradoxica, having its base undulated and the 

 cavities filled up with a thin bright red, argillaceous layer, resting 

 upon (3) the Eed Chalk, which is divisible into three sections : a, 

 hard, containing Avicula gryphceoides and Siplionia paradoxica, and 

 with fragments of Inocerami at its base ; h, hard, rich in Belemnites ; 

 c, incoherent at its base, rich in Terehratidce. 4. Carstone, a yellow, 

 coarse, sandy deposit, resting on a bed of clay, containing no fossils 

 in its upper part, but with a band of nodules containing Ammonites 

 Deshayesii and other species about thirty feet down, together with 

 ironstone nodules like those of the Lower Greensand of the Isle of 

 Wight, and bearing impressions of fossils which correlate the lower 

 part of the Carstone with the base of the English Lower Greensand. 

 The author gave a list of these fossils, and also of those of the Eed 

 Chalk, the latter amounting to sixty-one, and presenting a mixture 

 of forms belonging to the Lower Chalk, Upper Greensand, and 

 Gault. On comparison with the Gaulc section at Folkestone, the 

 author considered it evident that the Eed Chalk of Hunstanton was 

 equivalent to the upper part of that formation. He mentioned that 



