xii PREFACE. 



my thanks are due for the facilities which have been afforded me of studying the contents of 

 perhaps the finest collection of Birds in the world, and to the gentlemen having charge of that 

 department for their unvarying courtesy and attention — even my application to be allowed to 

 remove the rare Notornis from its hermetically closed case, for the purpose of examination, 

 having been readily complied with. 



In working out the historical synonymy of the species I have found the Library of the 

 Zoological Society of great service ; and in consulting authorities I have received valuable assistance 

 from Mr. E. B. Sharpe, the late librarian, whose long connexion with the Society had made him 

 familiar with the bibliography of the subject. The excellent lists already published by 

 Mr. G. R. Gray and Dr. Otto Finsch had rendered this part of my task a comparatively light 

 one ; but all the references have been carefully verified, and the chronology given for the first 

 time ; while numerous synonyms have been added, and the whole of the nomenclature critically 

 examined and revised. 



To my brethren of the British Ornithologists' Union I hereby tender my acknowledgments 

 for the readiness with which they have at all times given me the benefit of their opinions and 

 judgment on doubtful points, or lent me specimens for comparison. 



In conclusion, I have only to state that, in consideration of the generous assistance accorded 

 to me by the New-Zealand Government, I have presented the whole of my collection of Birds, on 

 which the descriptive letterpress is chiefly founded, to the Colonial Museum at Wellington, 

 where it will in future be accessible for purposes of reference. 



W. L. B. 



London, March 1873. 



