vi PREFACE 



Albert Boulenger has been generally adopted. Dr. 

 Boulenger's monumental series, The Catalogue of the 

 Chelonians, Lizards and Snakes of the British Museum, 

 stands as the only complete technical work on the rep- 

 tiles of the world. From its pages the author has de- 

 rived valuable assistance in treating the Old World rep- 

 tiles and in the lists showing classification. 



R. L. D. 

 New York Zoological Park, 1910. 



