Geological Society. 375 



May 1st, 1907.— Sir Archibald Geikie, D.C.L., Sc.D., Sec.R.S., 

 President, in the Chair. 



The following communication was read : — 



' On the Xerophytic Character of Coal-Plants, and a Suggested 

 Origin of Coal-Eeds.' By the Kev. Prof. George Henslow, M.A,, 

 F.L.S., r.G.s. 



Of the Palaeozoic flora, the Equisetites, now represented by the 

 sole genus Equisetum, are decidedly hygrophytic, if not hydrophytic. 

 The Perns, which appear to have much resemblance to certain 

 modern types, especially the Maratfiece, seem to have lived under 

 more or less similar conditions to the present; that is, varying from 

 the hygrophytic habit of Hymenopliyllum to the xerophytic Ceteracli. 

 The Cycadofilices, Cordaites, etc. are decidedly xerophytic; and 

 the same is the character of the Lycopodiahs, represented now by 

 Lycopodium and iSelar/ineUa, and of Psilotum, Scdishuria, and 

 others. In fact, the characteristic feature of the great coal-forests 

 was xerophytic, and the vegetation appears to be of an upland 

 type. Illustrations are given from recent and Carboniferous plants, 

 to show the characters of leaf, root, and stem which separate these 

 classes of plants. The position of coal-seams is accounted for by 

 the action of earth-movements in late Carboniferous times : these 

 threw the forest-bearing surface into shallow waves and troughs, 

 which became gradually accentuated, the latter being gradually 

 filled with sediment, upon which, during intervals of rest, new 

 forest-growth took place. 



June 5th, 1907.— Sir Archibald Geikie, D.C.L., Sc.D., Sec.R.S., 

 President, in the Chair. 



The following communications were read : — 



1. ' A Marine Pauna in the Basement-Beds of the Bristol Coal- 

 field.' By Herbert Bolton, P.R.S.E., P.G.S. 



Isolated and rare fossils have been occasionally discovered in the 

 Bristol Coalfield, but the list of genera and species hitherto recorded 

 is a short one. During the progress of an exploration-branch at 

 the Ashton-Yale Colliery, fossiliferous shales were traversed in tho 

 lowest Coal-Measures resting upon the Millstone Grit. A section 

 of the Coal-Measures in this part of the Coalfield is given, the Gays 

 Seam being the lowest workable seam, and the chief fossiliferous 

 shale is localized at a depth of 84 feet below it. The moat striking 

 feature of the fossils is their dwarfed condition, especially among 

 the fish-remains. Fossils found in the spoil-banks of other pits 

 indicate that other marine horizons occur in the Coalfield. The 

 thickness of the Millstone Grit appears to be about 9S0 feet. The 

 palseontological description embodies a tabular list of fossils from 

 the marine horizon, which shows a close correspondence with the 

 list drawn up from the marine beds associated with the Gin Coal of 



