PREFACE. 
In the Preface to the first volume of this memoir on the 
Cretaceous Rocks it was stated that the description of the Upper 
Cretaceous strata would be published in two volumes, but it has 
since been found more convenient to divide the work into three 
volumes. That now issued is the second of this series, and deals 
with the Lower and Middle Chalk; the third will include the 
description of the Upper Chalk, with chapters on Economics, the 
Water-supply, and the Physical Features of Chalk areas, together 
with a complete catalogue of the fossils found in all three 
divisions of the Chalk. 
The delay in the publication of this volume is due partly to 
circumstances connected with the author’s retirement from the 
Service, and partly to other causes, but the third volume is 
already in type, and will, it is hoped, be also published within 
the current year. 
In the present volume the Lower and Middle Chalk are 
described as separate stages in the Upper Cretaceous Series; 
and the account of each includes not only the stratigraphical 
details of the beds, but also chapters on their microscopic 
structure and mineral contents, their chemical composition, and 
on the physical conditions under which they were respectively 
accumulated. In arranging the stratigraphical particulars the 
chapters have been made to coincide as far as possible with 
county-divisions, each chapter dealing either with one county or 
with parts of two or three counties. 
The first chapter contains a brief history of the subdivision of 
the English Chalk into stages and zones, and for remarks on the 
nature and value of zones the reader is referred to Chapter III. 
of the first volume. Among the earlier geologists who contributed 
to our knowledge of the formation, the most notable are Mantell, 
W. Phillips, S. Woodward, and C. B. Rose; among the later are 
W. AVhitaker, Caleb Evans, F. G. H. Price, and more especially, 
Dr. Charles Barrois, whose “ Recherches sur le Terrain Cretace 
Superieur de I’Angleterre et de l’lrlande ” has long been a mine 
of information on the subject. 
In the preparation of this volume the author has had the 
valuable co-operation of Mr. W. Hill, who has not only contributed 
largely to the chapters on both the Lower and Middle Chalk of 
Kent, Surrey, Hampshire, Sussex, Dorset, Norfolk and Yorkshire, 
but has carried on elaborate investigations into the mineralogical 
and microscopic structure of the beds which compose this portion 
of the Chalk formation, the results of his researches being em¬ 
bodied in Chapters XXII, XXIII and XLIII. 
4219. 750.—Wt. 18296. 5/03. Wy. & S. a 2 
