136 Reviews — Geology of Paihtow and Camelford. 



4. The Geo logs: of the Country around Padstow and Camelford. 

 By Clement B,ErD, G. Baruow, and Henbt Dewey; with con- 

 tributions by J. S. Flett and D. A. MacAlister. London : printed 

 for H.M. Stationery Office, and sold by E. Stanford, Long Acre, 

 and T. Fisher Unwin, 1 Adelphi Terrace. 8vo ; pp. vi, 120, with 

 4 plates and 7 text-illustrations. 1910. Price 2s. 3d. 

 rPHIS memoir has been written in explanation of Sheets 335 and 336 

 L of the jNVw Series Geological Survey map of England. The area 

 thus takes in portions of the north Cornish coast, from the famous 

 Bedruthan Steps to Trevose Head and Harlyn Pay, Padstow, Pentire 

 Point, and Port Isaac ; it includes also the little towns of Wadebridgo 

 and Camelford, and a large part of Bodmin Moor. The maps show, 

 for the first time, the divisions of Lower, Middle, and Upper Devonian, 

 but it must be confessed tbat the colouring of the Upper Devonian slate 

 is so nearly like that of the Middle Devonian that the distinction is 

 not apparent without a close inspection. The physical features of 

 Bodmin Moor are made manifest by the mapping of the Alluvium and 

 Peat, which are separately coloured in the Index tablets but not on 

 the map. An important addition is the indication of the petrological 

 characters of the metamorphic aureole surrounding the Bodmin granite. 

 There the altered Devonian rocks include sundry schists, and also calc- 

 flintas " whei-e the calcareous rocks have been converted into insoluble 

 lime-silicates ". 



The Lower Devonian rocks have yielded but few fossils, including 

 Homalonotus ; in the Middle Devonian slates, thanks to the pains- 

 taking labours of Mr. Howard Fox, many fossils have been found, 

 and notably species of Pteraspis and Scaphaspis ; while to Mr. Fox 

 again, who discovered the Biidesheira fauna in Trevone Bay, our 

 knowledge of the Upper Devonian fossils is chiefly due. The specimen 

 of Homalonotus Barratti, which Avas found by Mr. Walter Barratt and 

 described by Dr. Henry Woodward, is referred to the Upper Devonian 

 of Mother Prey's Bay (not Porthcothan). Important additions to the 

 lists of fossils have been made during the progress of the Geological 

 Survey, especially from the Upper Devonian of Port Quin, where 

 many specimens were collected and developed by Mrs. Clement Ileid. 



The contemporaneous volcanic rocks, spilites, schalsteins, and tuffs 

 have been separated from the ' greenstones ' or diabases The pillow- 

 lavas, grouped as spilites, were described by Messrs. Ileid and Dewey 

 in a paper published by the Geological Society, and although particulars 

 are given in the memoir, it is to be regretted that the illustrations of 

 these remarkable and interesting features have not been reproduced. 

 In connexion with the subject Dr. Tempest Anderson's account of the 

 formation of pillow-lava in Savii, one of the Samoa Islands (Q.J.G.S., 

 lxvi, p. 632, 1910), may be read with advantage. 



Particulars are given of the granites, elvans, and minettes, and of 

 the thermometamorphism surrounding the granite. An excellent view r 

 of lloughtor illustrates the characters of tors that "are built up of 

 lenticular blocks or sheets of granite ". 



Attention is drawn to the features of Pliocene and earlier age, to 

 the liaised Beaches and Itiver Terraces, and to the connexion between 

 the amount of superficial deposits and the history of the valleys. 



