PREFACE. 



As was stated l)y Mr. Boulenger in his Introduction 

 to tlie first volume, issued in May, 1920, the second and 

 concluding volume was then ready for printing. He 

 has since retired from the service of the Trustees, but 

 he has corrected the proofs and prepared an index to 

 the whole work. 



C. Tate Rkgan, 

 Keeper of Zoology. 



British Museum (Natural History), 

 London, S.W. 7. 



November, 1921. 



