IV 



PREFACE TO THE NINTH EDITION. 



The gradual increase in the number of species of each 

 class of Animals of which specimens have been exhibited, 

 as recorded in the various editions,, is shown in the following 

 Table : 



As regards the names used in the present Edition, I have 

 endeavoured to make as few changes as possible, not being 

 one of those advocates of priority who seek to carry out that 

 useful principle without reference to grammar or common 

 sense. But in the case of the Marsupials and Monotremes 

 I have followed Mr. Thomas's well-known Catalogue of 

 these groups ; and in the nomenclature of the Reptiles and 

 Batrachians I have thought it best to adopt throughout the 

 revised terms employed by Mr. Boulenger in his excellent 

 series of catalogues of these Classes lately brought to a 

 close. 



In conclusion, I wish, on the part of the Society, to offer 

 to Mr. Boulenger our very best thanks for the great trouble 

 he has taken in the determination of the specimens of 

 Reptiles and Batrachians which have been added to the 



