74 Geological Society : — 



a subzone; that the " Upper Kimmeridge " and the Hartwell clay, 

 with the " Portland sand," should make a new subdivision to be 

 called Bolonian, the northern and southern types being both repre- 

 sented at Boulogne, which may be divided into Upper and Lower ; 

 and that the true Portland limestone and the Purbeck be united 

 into one group, as Lower and Upper Portlandian, the fact of the 

 latter being freshwater being paralleled by parts of the true Portland 

 having that character. 



3. " On fossil Chilostomatous Bryozoa from the Tarra-Tarra, 

 Yictoria, Australia" By Arthur William Waters, Esq., F.G.S. 



June 8. — Eobert Etheridge, Esq., E.E.S., President, 

 in the Chair. 

 The following communications were read: — 



1. " The Beptile-Fauna of the Gosau Pormation, preserved in the 

 Geological Museum of the University of Vienna." By Prof. H. G. 

 Seeley, P.E.S., P.L.S., E.G.S. ; with a Note on the Geological 

 Horizon of the Fossils, by Edward Suess, F.1LG.S. 



2. " On the Basement-beds of the Cambrian in Anglesey." By 

 Prof. T. McKenny Hughes, M.A., P.G.S. 



In this paper the author first pointed out that there was in 

 Anglesey (1) an upper slaty group, in which he had fixed two 

 life zones, which snowed that the series belonged to the Silurian 

 (Sedgwick's classification), and (2) a lower group of slates and sand- 

 stones in which Arenig fossils had been found in several localities, 

 and Tremadoc had been less clearly recognized, while by the cor- 

 rection of the determination of a species of Orthis there was now a 

 suspicion of even ]y!enevian forms. These all rested upon the base- 

 ment-beds of the Cambrian, of which the paper chiefly treated. 

 They were made up of conglomerates, grits, and sandstones, with 

 Annelids and Pucoids. 



The Basement-beds varied in thickness and character according 

 to the drift of currents along the Pre-cambrian shore and the ma- 

 terial of the underlying rocks. Near Penlon, where they rested on 

 a quartz-felspar rock, they consisted chiefly of a quartz-grit and con- 

 glomerate, almost exactly like that of Twt Hill. Near Llanerchy- 

 medd, where there was a mass of greenish schistose rock succeeding 

 the Dimetian, the Cambrian basement-bed contained a large number 

 of fragments of that rock, certain bands being chiefly composed of it. 

 Near Bryngwallen, where the underlying Archaean consisted of 

 gneissic rocks, the Cambrian basement-beds were made up of quartz 

 conglomerate. Tracing it still further to the S.W. he found bosses 

 of conglomerate among the sand dunes of Cymmeran Bay, full of 

 fragments of green schistose rock, like that of Bangor, and telling of 

 the further development of Pebidian at the S.W. end of the Anglesey 

 axis. In several localities these conglomerates were associated with 

 and passed into fossiliferous grits and sandstones. He exhibited 

 slices of the more important rocks, which, he showed, confirmed the 

 results arrived at from other evidence. He pointed out that the 



