312 



THE GEOLOGIST. 



for instance, we have the correct separation in the language used of the Bryozoa 

 from the Corals, the word " coraliue " l3eing ignored in respect to one division of 

 the Crag, Yrhich is really bryozoiferous, and contains neither corals nor 

 coralines. 



In regard to the absolute classification, we have here, too, great improvements. 

 There is a proper classification of corals, of Diatomacere, distinct from animalcules, 

 and better definitions of the Brachiopoda and of the Foraminifera than heretofore, 

 and better botanical tables and order of grouping ; and especially we may refer to 

 the new exposition of coal-structure, derived from the observations of Hedfern, 

 Queclsett, and other investigators. 



In the preface to the second volume, Mr. Rupert Jones has pointed out very 

 modestly, but very properly, some of the additions he has made in it. Among 

 other subjects there included, are the highly interesting researches of Mr. H. C. 

 Sorby in the microscopical structure of roclis, by which considerable light has been 

 thrown not only on the methods and conditions of formation of various stratified 

 rock-masses, but even more remarkably on those of the hypogene or igneous rocks, 

 and their included and component crystals. Another topic is Mr. Prestwich's 

 hypothetical extension over the south-east of England of the Upper Tertiary 

 deposits, based on the discovery of casts of crag mollusca in ironstone of the 

 " drift " on the North Downs, near Lenham. 



The borings for water at Hampstead and Harwich have led to the knowledge of 

 the existence of a subterraneous ridge, continuous, probably, from the Ardennes 

 to the AVest of England ; and connecting, by an upheaval of the coal-measures 

 along its flanks, the great coal-fields of Belgium and Somersetshire. Hence the 

 possibility of obtaining coal by deep borings along this line of disturbance, as 

 pointed out by Mr. Godwin Austen. 



Notices of the new Crustacea from the Permian and Carboniferous deposits, and 

 new forms of fish from the Upper Silurians of the Ludlow district, and of the 

 luminous expositions by Dr. Falconer, of the zoological and geological relations of 

 the true species of Mastodon and Elephant, ought also to be mentioned. While 

 the public cannot but be grateful for Sir Roderick Murchison's generous per- 

 mission to the Editor to anticipate in the corrected classification of the Permian 

 and Silm^ian beds, as elaborated by that eminent geologist, the forthcoming 

 edition of " Siluria." 



The discovery, by ]\Ir. Peach, of important characteristic fossils in altered or 

 metamorphosed limestone, has served as the clue by which Sir Roderick has un- 

 ravelled the obscurity which invested the vast rock-masses of the north-west 

 Highlands of Scotland, and enabled him to place them in their true relations with 

 the equivalent formations in Scandinavia, Canada, and elsewhere. These are also 

 inserted by the same favour. 



Last, not least, we would notice the copious index with which this edition is 

 supplied. No part of a book is usually more neglected, and no one part is really 

 of more essential service to the student, than a good index, alfording a ready 

 means of reference to any particular subject, which more than anything else, 

 perhaps, tends to keep the owner in good humour with a book. So much effect 

 has it in this way, that we are surprised it should be so commonly slurred over, 

 and often nearly, if not entirely, omitted. 



We recommend this edition to every student, and to our readers, as a work of 

 the highest merit, and one which we sincerely desire to see, under the same 

 accomplished direction, long maintain its popular favouritism. 



