520 Remeics — Horace B. Woochvard — Lower Oolitic Rochs. 



measured angles, which are only apparently anomalous. Their true 

 position can be determined on a crystal of cubic symmetry (such as 

 alum) whose theoretical angles are known. 



A further study of the faces developed during the growth of 

 crystals will, it is hoped, lead to a better understanding of the 

 reasons why a simple face like the octahedron should not be a 

 surface of equilibrium, and of the relation between the vicinal planes 

 and the structure of the crystal. 



K, IB AT" I IE] AAT S. 



T 



-Memoirs of the Geological Survey of the United Kingdom. 

 The Jurassic Rocks of Britain. Vol. lY. The Lower Oolitic 

 Eocks of England (Yorkshire excepted). By Horace B. 

 Woodward, F.G.S. 8vo. pp. xiv. and 628, with 2 Plates and 

 137 Woodcuts. (London : Kegan Paul, Trench, Triibner & Co., 

 Limited, 1894.) Price 10s. 



HIS is, practically, a third instalment of the important work 

 X now in course of publication by the Geological Survey, of 

 which the previous volumes have already been noticed in the 

 Geological Magazine. Yol. iv. contains an account of the Lower 

 Oolites (Inferior Oolite and Great Oolite) throughout their long 

 outcrop from the English Channel to the Humber. 



In his preface Sir A. Geikie observes that much assistance has 

 been derived by Mr. Woodward in the preparation of the present 

 volume from the previous Memoirs of the Survey, especially those 

 dealing with the Oolitic rocks by Professors Hull, Green, and Judd, 

 and more recently by Messrs. Ussher and Jukes-Browne. The 

 Director-General also does justice to the work of other obeei'vers 

 in this field, commencing with William Smith, whose original 

 labours are commemorated in the names given by him to many 

 of the subdivisions of the Oolites. 



The author, in fact, has largely availed himself of the assistance 

 to be derived from previous publications, both official and non- 

 official ; and he likewise acknowledges the help which he has from 

 time to time received from the personal communications of those 

 interested in the Jurassic geology of this country, It is of course 

 obvious that with such a work as Judd's Geology of Eutland in 

 hand, the path of the surveyor in the East Midlands must have 

 been made comparatively easy. 



After some introductory remarks by Mr. Woodward, dealing with, 

 the Oolitic rocks as a whole, we have some petrological notes from 

 Mr. Teall ; nor is the subject of Girvanella-tnhes forgotten in con- 

 nection with the possible origin of Pisolite, Two plates of sections 

 of Oolitic limestones and ironstones illustrate this portion of the 

 work. 



The Inferior Oolite Series (Bajocian). Chapters ii. to vii. 

 inclusive, are devoted to this series, which, in its course throughout 

 England, is justly described as exhibiting almost every variety of 

 stratified rock. The base, Mr. Woodward considers, is not always 



