PEEFACE. 



The present volume, though not numerically the last, has been, 

 owing to various delays in its production, the last to appear. 

 Its publication completes the series, as originally projected by 

 Dr. Giinther more than twenty-five years ago. The whole work 

 consists of twenty-seven volumes, and it may fairly claim to be one 

 of the most important aids to the study of Systematic Ornithology 

 which has ever been produced. The first volume appeared in 

 June 1874. The others have followed at intervals averaging 

 rather less than a year. The publication of the work has therefore 

 been very nearly coincident with Dr. Giinther's administration of 

 the Zoological Department of the Museum. It is to him that the 

 general arrangement and supervision of the work is due, although 

 each contributor has been allowed a considerable latitude in 

 following his own views as to the details of classification and 

 nomenclature. 



It was at first contemplated that Dr. E. Bowdler Sharpe would 

 undertake the whole work, and the first four volumes were com- 

 pleted by him between the years 1872 to 1879, It, however, 

 soon became apparent that continually increasing curatorial duties 

 (which rapidly augmented, in consequence of the inflow of spe- 

 cimens mainly stimulated by the publication of these volumes) 

 required very much of his attention, and notwithstanding the 



