vi PREFACE 



The writing of this book was begun in 1913, and 

 interrupted for nearly four years by pressure of war- 

 work. It was at first intended that it should be 

 illustrated by original drawings of fossils, and a certain 

 number of such drawings were made before the war 

 from specimens in the collection of the Imperial College. 

 I have to record my grateful thanks to the Governors 

 of the Imperial College and Professor Watts, F.R.S., 

 for permission for the use of these specimens, and to 

 Mr. F. G. Percival, B.Sc., the artist. Subsequently it 

 became evident that to continue this method of illustra- 

 tion would delay the work too much, and that for the 

 purposes of the book diagrammatic copies of figures in 

 standard monographs would be equally useful. I have 

 to thank Miss L. Lyle, F.L.S., and my wife for these 

 later figures, about four-fifths of the. total. 



Mr. S. S. Buckman has been so kind as to read the 

 manuscript of the chapters on Brachiopoda and Cepha- 

 lopoda, and I have profited by his criticisms and 

 suggestions, and incorporated additional information 

 to a much greater extent than it was practicable to 

 acknowledge in the text. I cannot sufficiently express 

 my gratitude to him for this help, as well as for the 

 generous loan of the block which forms the frontis- 

 piece a beautiful example of Mr. Tutcher's photographic 

 skill, from the latest part of Mr. Buckman's " Type 

 Ammonites." 



A. MORLEY DAVIES. 



February 2, 1920. 



