142 Reports and Proceedings — Geological Society of London. 



A correlation with the Bristol area brings out the following more 

 important points. The faunal succession is essentially similar in 

 the two areas ; and in both there is good ground for a twofold 

 division into Clevedonian and Kidwellian stages, the line of separation 

 being drawn at the top of the S])ringothjris Zone. The Mendip 

 area exhibits, however: (1) a great expansion in the thickness of 

 the Zaphrentis and Syringoihjris Zones ; (2) a continuously 

 fossiliferous sequence from the top of the Zaphrentis Zone to 

 the base of the Seminula Zone, possessing a characteristic coral 

 and brachiopod fauna ; and (3) a relative acceleration of the coral 

 fauna on the brachiopod fauna, exhibited in the Zaphrentis Zone. 



The paper contains a detailed account of the Ebbor Eocks 

 District, near Wells, and concludes with notes on certain corals and 

 brachiopods included in the faunal lists, together with descriptions 

 of some new species and mutations. 



2. " The Igneous Eocks of the Eastern Mendips." By Professor 

 Sidney Hugh Eeynolds, M.A., F.G.S. 



The igneous rocks associated with the Old Eed Sandstone of the 

 Mendips are exposed along the crest of the range from Beacon Hill 

 on the west to near Downhead on the east, a distance of rather 

 more than 2 miles. Hitherto they have always been regarded 

 as intrusive, but the opening of some new excavations has shown 

 that they are associated with a considerable thickness of tuffs, and 

 are in all probability contemporaneous lava-flows. 



The exposures show a division into three sections — those of 

 Beacon Hill, Moon's Hill, and Downhead ; and a large quarry has 

 been opened in the trap in each section. The trap, which can be 

 traced fairly continuously from one end of the area to the other, is 

 very uniform in character, consisting (as already noted by Dr. Teall) 

 of a non-amygdaloidal pyroxene-andesite, which usually contains 

 augite in addition to enstatite. A fine section of tuff some 100 feet 

 thick is seen lying with perfect conformity below the trap in the 

 New Quai'ry near Stoke Lane ; and an interesting little exposure of 

 tuff, remarkable for the numerous rounded blocks of trap present, 

 is seen in the excavation for the rifle-butts on Beacon Hill. The 

 tuff here dips under the Old Eed Sandstone to the north. Although 

 the tuff is seen in situ only at the above two points, loose pieces 

 have been met Avith at a number of other spots all along the 

 southern outcrop of the trap, and point clearly to the occurrence 

 of a continuous band underlying it. 



Thougb no sedimentary rocks are seen in direct contact with 

 those of the igneous series, outcrops of Old Eed Sandstone com- 

 pletely surround the exposures of trap and tuff, and occur in such 

 close relation to them as to leave little room for doubt that the 

 igneous series is of Old Eed Sandstone age. On the other hand, 

 Silurian fossils were met with below the igneous series at a point 

 to the west of Downhead, and render it possible that the igneous 

 rocks may be of Silurian age, and the equivalents of those which 

 are exposed at Tortworth. 



