XXXVl INIEODtrCTION. 



To Dr. AHman and to Prof. St. George Mivart, who obtained for 

 me from the Council of the Linnean Society the privilege of retain- 

 ing books from the Library of the Society for a longer time than 

 usually permitted, and to Dr. P. L Sclater, who lent me his valuable 

 collection of scientific papers, my most particular thanks are due, 

 for without this assistance the completion of the work must have 

 been greatly delayed. 



Finally, my very grateful acknowldgments are due to Sir 

 William Mure Muir, K.C.B., M.D., for the opportunities he has so 

 kindly afforded me during the past seven years for continuing my 

 zoological work, of which this volume is the principal outcome, 



G. E. D. 



