PREFACE TO NEW EDITION XX1 
most grateful. Dr. C. W. Andrews and Mr. W. P. Pycraft have 
also given much help of a similar nature. The kind advice of 
such learned gentlemen is greatly valued by their friend the 
Author, for they know practically all that goes on in the world 
of Paleontology. 
H. N. HUTCHINSON. 
Lonpon, March, 1910. 
