312 
Tllli GEOLOGIST. 
for instaucc, wc have the coiTcct separation iu the language used of the Bryozoa 
from the Corals, the word " coraliae " being ignored in respect to one division of 
the Crag, ■which 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 DiatomaccM, distinct from animalcules, 
and better definitions of the BrachiopoJa and of t)ie Foi-aminifera 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 Rodfern, 
Queckett, and other investigators. 
In the preface to the second volume, Mr. Rupert Jones has pointed out very 
modestly, but very propgrly, some of the additions he has made in it. Among 
other subjects there included, are the highly interesting rescai'chcs of Mr. 11. C. 
Sorby in the microscopical structure of rocks, by which considerable light h.as been 
thrown not only on the methods and conditions of formation of various stratified 
rook-masses, but oven 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 Ilampstead and Harwich Iiave led to the knowledge of 
the existence of a subterraneous ridge, continuous, probably, from the Ardennes 
to the West 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 bo grateful for Sir Roderick Murchison's generous per- 
mission to the Editor to anticipate iu the corrected classification of the Permian 
and Silurian beds, as elaborated by that eminent geologist, the forthcoming 
edition of " Siluria." 
The discovery, by Mr. 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 t!ie north-west 
Highlands of Scotland, and enabled bim to place them in their true relations with 
the equivalent formations in Scandinavia, Canada, and elsewhere. These arc also 
inserted by the same favour. 
Last, not least, wc would notice the copious index Avith 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, affording 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 wc arc surprised it should bo 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 favouriti.^m. 
