Geological Society. 539 



GEOLOGICAL SOCIETY. 

 [Continued from p. 395.] 

 April 25th, 1877.— Prof. P. Martin Duncan, M.B., F.E.S., 

 President, in the Chair, 

 The following communications were read : — 

 1. " On the Upper Limit of the essentially Marine Beds of the 

 Carboniferous System, and the necessity for the establishment of a 

 « Middle Carboniferous Group.' " By Prof. E. Hull, F.KS., F.G.S. 

 The author, in this paper, divided the whole of the Carboniferous 

 rocks into successive stages from A to G inclusive, takiug the Car- 

 boniferous beds of Lancashire as a type, and showed that these 

 stages could be identified over the whole of the British Isles. It 

 was only recently that their determination had been made in Ire- 

 land, so that until now the materials had not existed for a complete 

 correlation of the series in the British Islands. The following is an 

 abbreviated statement of the representative stages in descending 

 order : — 



Essentially Freshivater or Estuarine, ivith one or two Marine Bands. 

 Stage G. — Upper Coal-measures of Lancashire (2000 ft.) and 

 other English coal-fields. Eed Sandstones &c, of Bothwell and 

 Ayr, in Scotland. Absent in Ireland. 



Stage F. — Middle Coal-measures of Lancashire &c, with prin- 

 cipal coal-seams (3000 ft.). Flat coal series of Scotland. Present 

 in Ireland (Tyrone, Kilkenny.) 



Essentially Marine. 



Stage E. — & Gannister Beds " (Phillips), with marine shells and 

 thin coals (2000 ft.), in Lancashire. " Pennystone series " of Coal- 

 brook Dale, South Wales, &c. " Slaty black-band " series of Scot- 

 land. Present in Ireland (Kilkenny, Dungannon, Lough-Allen 

 coal-fields) ; also in Belgium, Rhenish Provinces, and Silesia, with 

 numerous marine shells. 



Stage D. — Millstone-Grit series of England and Wales. 3500 ft. 

 in Lancashire ; " Moorstone Bock " of Scotland ; " Flagstone series " 

 of Carlow and Kilkenny ; Millstone Grit of Fermanagh and Leitrim, 

 with coals and marine shells. 



Stage C. — Toredale Beds. 3000 feet in Lancashire ; Upper 

 Limestones and " Lower Coal and Ironstone series " of Scotland ; 

 Shale series of Kilkenny and Carlow ; Ironstone shales of Lough 

 Allen, with marine shells. 



Stage B. — Carboniferous Limestone. Mountain Limestone of 

 Derbyshire ; " Scaur Limestone " in Yorkshire ; " Lower Lime- 

 stone " (Roman camp) of Scotland ; Carboniferous Limestone of 

 Ireland. 



Stage h.—~Lower Limestone Shale of England. Calciferous Sand- 

 stone series (" Tuedian," Tate) of N". of England and Scotland ; Lower 

 Carboniferous Sandstone, N". of Ireland ; Lower Carboniferous slate, 

 with Coomhola grits, with marine shells, S. of Ireland. (In Scot- 

 land, estuarine or lacustrine.) 



