232 Eeviews — Jukes-BroK-nes Students' Geology. 



Breconshire, so spelt (as we are told) by a decision of the County 

 Council in 1910, is for the most part a mountainous county of Old 

 Red Sandstone with Silurian and Ordovician rocks on the north, and 

 a fringe of Carboniferous rocks with Coal-measures on the south. 

 A somewhat brief account is given of the local geology, with a few 

 geological views and others of river scenery. Agriculture is the main 

 industry, and small fruit is now cultivated in some of the valleys. 

 The physical and geological maps are given as of Brecknock. 



VI. — The Students' Handbook of Stratigraphical Geology. Second 

 edition. By A. J. Jukes-Brownk, F.R.S. 8vo ; pp. xiv, 668. 

 London : Edward Stanford, 1912. Price 125. net (post free 12s. 4(^.). 



WE welcome a second edition of this comprehensive and well- 

 arranged manual, of which the former edition was noticed in 

 the Geological Magazine for 1902, p. 279. The book has naturally 

 grown in size and in number of illustrations, and it is noteworthy that 

 the author has not introduced any photographic plates. These render 

 some modern works more attractive as picture-books ; they are useful 

 in the matter of scenery and rock-structure, but not usually so clear 

 and instructive as regards the stratigraphical arrangement. The 

 author has brought his work well up to date in giving the leading 

 subdivisions of the geological formations in the British Isles, and in 

 various parts of Europe, so that, apart from its essentially British 

 interest, it forms a work of reference on European stratigraphical 

 geology that will be of the greatest service to students and teachers. 

 In the vexatious task of revising the names of fossils according to the 

 latest changes, the author acknowledges the special help of Mr. Henry 

 Woods. We fear, however, that both in palseontological names and 

 in the use of certain chronological terms (such as Valentian, Salopian, 

 and Downtonian) there never will be entire uniformity among 

 geological writers. 



The term Charmouthian for part of the Lias (pp. 383, 387) is used 

 for the Middle Lias zones of the Ammonite genera Paltopleuroceras 

 spinatum and Amaltheus margaritatus, whereas on p. 405 the term is 

 taken to include also the Lower Lias zones of capricornus and armatus. 

 This is unfortunate and no improvement. As a matter of fact the 

 term is inappropriate as no Middle Lias (as above defined) occurs 

 in the cliffs at Charmouth. If used at all the term should be applied 

 to the Lower Lias clays (zones ohtimis to capricornus). Mr. Jukes- 

 Browne reintroduces his terms of Glevanian, Clavinian, and Vectian, 

 but like new names of fossils they add but a burden to the student 

 who is bound also to learn the older and more widely known names. 

 The Bovey Beds are now placed in the Miocene. The Pleistocene 

 Series is taken to include all deposits (subsequent to Pliocene) 

 " which are older than those containing metal implements of human 

 manufacture". This again is not the usual grouping; the term 

 Holocene is now largely applied to deposits from Neolithic times to 

 the present day, and should at any rate have been so noted. 



The extended bibliographical references have been carefully selected, 

 and form an important feature in the volume. 



