INTRODUCTORY AND EXPLANATORY xlx 



The connection between the two is explained on 

 page 76. However, the reader may rest as- 

 sured that these restorations are infinitely more 

 nearly correct than many figures of living 

 animals that have appeared within the last 

 twenty-five years, and are even now doing 

 duty. 



The endeavor has been made to indicate, at the 

 end of each chapter, the museums in which the 

 best examples of the animals described may be 

 seen, and also some book or article in which fur- 

 ther information may be obtained. As this book 

 is intended for the general reader, references to 

 purely technical articles have, so far as possible, 

 been avoided, and none in foreign languages 

 mentioned. 



For important ww^ks of reference on the 

 subject of paleontology, the reader may consult 

 '■'A Manual of Paleontology^' by Alleyne Nich- 

 olson and R. Lydekker, a work in two volumes 

 dealing with inveiiebrates, vertebrates, and 

 plants, or "-A Text-Book of Paleontology," by 

 Karl von Zittel, English edition, only the first 

 volume of which has so far been published. An 

 admirable book on the vertebrates is '"'Outlines 



