Reports and Proceedings — Geological Society of London. 379 



attention ; elsewhere work has been carried on in the country about 

 Padstow, 'Wadebridge, Callington, Camelford, and Bodmin Moor, and 

 we have notes on the Delabole slates and other Devonian rocks, on the 

 Devonian and Carboniferous rocks near Callington, and on the granite 

 of Bodmin Moor, the rock-platforms and their relation to stream-tin 

 deposits. (2) In the Midland district the Survey has been occupied 

 at Matlock, Alfreton, Mansfield, and Ollerton, including parts of 

 Sherwood Porest and the Trent Yalley. The zones in the Carboni- 

 ferous Limestone, the Coal-measures, Permian, Trias, Lias, and Drift 

 deposits receive due attention. 



In Wales the survey of the western end of the South Wales Coal- 

 field has been continued in a complex area, where igneous rocks 

 possibly of pre-Cambrian age, and Cambrian, Ordovician, Silurian, 

 Old Red Sandstone, and Carboniferous rocks are developed. We note 

 (on p. 39) that the Llandilo Plags are, by mistake, grouped with the 

 Arenig. The disturbances in the Carboniferous rocks are specially 

 mentioned. 



In Scotland field-work has been carried on in the northern and 

 western Highlands, in Caithness, the valley of the Findhorn, near 

 Ben Nevis, and in the islands of Mull and Colonsay. Yarious schistose 

 rocks, Torridon sandstone, Jurassic strata and Drifts, as well as igneous 

 rocks, are dealt with. The Survey has also been occupied in the central 

 portion of the Scottish coalfields. 



The Appendix contains articles on the Mugearites, one of the 

 Tertiary igneoiis rocks of the Inner Hebrides (illustrated by plate) ; on 

 the Marine beds near the base of the Upper Carboniferous in Scotland, 

 on the eastern extension of the Nottinghamshire and Yorkshire Coal- 

 fields, accounts of sections opened up on new branches of the Great 

 Western Railway in Oxfordshire and Somerset, notes on the dates of 

 some of the earlier published Geological Survey Maps, and a list 

 of manuscript maps and sections in the Library of the Museum of 

 Practical Geology. 



I. — Geological Society of London. 



June nth, 1908.— Professor W. J. Sollas, LL.D., Sc.D., P.R.S., 

 President, in the Chair. 



The following communications were read : — 



1. "The Hornblendic Rocks of Glendalough and Grevstones 

 (Co. Wicklow)." By J. Allan Thomson, B.A., B.Sc, F.G.S. ' 



Both these rocks are intrusive into Ordovician strata in the east of 

 County Wicklow : the former occurring as a small boss in the south 

 side of Camaderry, a ridge which separates the Yale of Glendalough 

 from the valley of Glendrosan ; while the latter occur as three dykes 

 traversing the sedimentary rocks on the shore at Greystones. The 

 Glendalough rock is older than the Great Wicklow Granite, and 

 exhibits much heterogeneity in composition. The chief varieties are 

 the following: — (1) A hornblende-peridotite, made up mainly of 



