Reference will be found in the text to the sources of informa- 
tion made use of in the preparation of this volume. No geologist 
who follows in their footsteps can withhold his tribute of admiration 
for the labours of Strickland, Thomas Wright, Charles Moore , 
E. B. Tawney, and Professor R. Tate. Besides the work of these 
writers, assistance has been obtained from the published papers 
of Messrs. W. D. Carr, W. D. Crick, and E. Wilson. In the 
field, while working on the Liassic part of his subject, Mr. Wood- 
ward has been further personally aided by Mr. Alfred Gillett of 
Street, the Rev. H. H. Winwood of Bath, Mr. T. Beesley and 
Mr. E. A. Walford of Banbury, the Rev. P. B. Brodie of Row- 
ington, Mr. T. J. Slatter of Evesham, Mr. R. F. Tomes of South 
Littleton, and Mr. Beeby Thompson of Northampton, to all of 
whom the thanka of the Geological Survey are due. 
With regard to the illustrations in the present volume, Dr. 
Henry Woodward has been good enough to supply a number of 
engravings of fossils from the official guides to the Department of 
Geology in the British Museum, and other cliches have been 
taken from the wood-cuts of Liassic fossils in my Text-book and 
Class-book of Geology. The sources of the several figures are 
acknowledged in the List of Illustrations. 
AKCH. GEIKIE, 
Director-General. 
Geological Survey Office, 
28, Jermyn Street, S.W. 
12th June 1893. 
