132 Geological Society:-^ 



turbcd, and offers great difficulties. The following classification of 

 its deposits is proposed, in descending order : — (3) The Plynlimmon 

 Grits ; (2) The Metalliferous Slates ; (1) The Aberystwith Grits. 

 (1) consists of dark grey grits and imperfectly cleaved slates ; they 

 are not very fossiliferous, Graptolites being most abundant. (2) A 

 more argillaceous series of pale blue and grey colour, much folded. 

 This series, near the Devil's Bridge, appears of extraordinary thick- 

 ness ; but the author believes that this is due to a great inversion 

 or, rather, to a series of inversion- folds. Above this is (3) the Plyn- 

 limmon group. The area occupied by, and general characteristics 

 of, these groups were described in detail. Fossil evidence enables the 

 author to correlate beds and constitute an order of succession in a 

 considerable number of the sections. All three divisions, however, 

 may be regarded as composing one great group, forming a great 

 primary synclinal, with subordinate anticlinal folds along IS", and S. 

 lines. The relation of these beds to the Denbighshire Grits and 

 Tarannon Shales has been investigated in neighbouring districts. 

 The author regards the Plynlimmon Grits as representing a special 

 gritty development in the Tarannon Shales, and so above the 

 Llandovery Grits. The Metalliferous Slates and the Aberystwith 

 Grits, an arenaceous development of their lower parts, represent the 

 Llandovery group of the Survey, probably the Upper and a part of 

 the Lower Llandovery. There does not appear to be any evidence of 

 a break in this district between the Upper and Lower Silurian. This 

 is confirmed by palaeontological evidence; and in the study of the 

 Graptolites the author has been assisted by Mr. Lapworth. These 

 show that the Mid- Wales beds are on the horizon of the Upper Birk- 

 hill group of Scotland, and of the Coniston Mud-stones of the Lake- 

 district. A table of fossils was appended to the paper, with a de- 

 scription of some new forms. The Appendix, by C. Lapworth, Esq., 

 described a new species of Cladophora. 



5. " On new Erian (Devonian) Plants." By J. W. Dawson, 

 LL.D., E.E.S., E.G.S. 



6. " On the Terminations of some Ammonites from the Inferior 

 Oolite of Dorset and Somerset." By James Buckman, Esq., E.G.S., 

 F.L.S. 



7. "Faroe Islands. Notes upon the Coal found at Siideroe." 

 By Arthur H. Stokes, Esq., E.G.S. 



The coal in this district is associated with shales ; and these are 

 interbedded with sheets of basalt and dolerite. It is worked after a 

 primitive fashion by the natives. Some of the seams are more than 

 half a yard thick. There are two varieties of the coal or, rather, 

 lignite, containing respectively 51-7 and 68*2 per cent, of carbon. 

 The author gave details of sections and other matters connected 

 with the coal-bearing area, and various notes upon the geology of 

 the district. 



8. " On some new Cretaceous Comatulce." By P. Herbert 

 Carpenter, Esq., M.A. Communicated by Prof. P. Martin Duncan, 

 M.B., E.R.S., E.G.S. 



