270 Reviews — Geological Survey of England and Wales. 



Monmouthshire, and the precise position of the boundary between 

 the Upper and Lower Old Eed Sandstone still remains doubtful. 



The Carboniferous Limestone is concealed for the most part by 

 later rocks, but is evidently far thicker on the southern than on the 

 northern side of the coalfield, as is the case with all the subdivisions 

 of the Carboniferous system. 



Among the most interesting features of the geology is the partial 

 uncovering of a pre-Triassic landscape by the denudation of the 

 Trias and Lias from parts of the platform of Palaeozoic rocks upon 

 which they were deposited. Not a few old headlands and islands 

 have thus been brought to light, and some are even playing the same 

 part in the present seascape which they played in Triassic times. 

 All these facts received full recognition from De la Beche. 



In the examination of the Rhgetic and Liassic beds the surveyors 

 have availed themselves of the detailed work of H. W. Bristow, 

 E. Etheridge, and H. B. Woodward, and of the additions made to it 

 by Mr. John Storrie and Mr. F. T. Howard. 



Superficial geology is well illustrated in the neighbourhood 

 described in this memoir. The raised beach so well known round 

 the shores of the Bristol Channel exists near Weston-super-Mare, 

 and the suggestive observation of Mr. E. C. H. Day as to the age of 

 the bones contained in it have received confirmation from recent 

 observations in Gower, where the beach and its associated ' head ' 

 are seen to be of earlier date than the local glacial drift. Recent 

 work on the glacial deposits confirms Professor Edgeworth David's 

 conclusions made in 1883. 



Post-glacial deposits were admirably displayed in the excavations 

 at the Barry Docks, where conclusive evidence was obtained of 

 a subsidence of the land of upwards of 50 feet during and since 

 Neolithic times. In this investigation also Mr. Storrie gave valuable 

 assistance. 



The Map is issued in two editions. On the edition for Solid 

 Greology the Glacial Drift is omitted, while on the Drift edition the 

 areas occupied by Drift are coloured, as well as those portions of solid 

 geology which are not concealed by the Drift. Manuscript six-inch 

 maps, geologically coloured, are deposited in the Office, where they 

 can be consulted. Copies of these maps can be obtained at cost price. 

 It is much to be regretted that a geologically coloured map is not, 

 as a rule, issued with every Survey Memoir. 



The figures given in the text leave much to be desired (see p. 58). 

 Surely clearer figures and better printing ought to be insisted upon 

 from the King's Printers at the present day. 



The memoir is accompanied by an excellent index. 

 2. — Index to Report on the Geology of Cornwall, Devon, and 

 Somerset, by Sir Henry T. De la Beche, C.B., F.R.S. Index 

 compiled by Clement Reid, F.R.S. pp. 34. Printed for 

 H.M. Stationery Office. (London : E. Stanford (or of Messrs. 

 Dulau & Co., 37, Soho Square, W.), 1903. Price Is.) 



The Geological Survey have done good service to science in 

 printing this Index to De la Beche's " Report " on the Geology of 



