PREFACE. 



South African Museum, for some interesting specimens of Petrels, with their eggs, 

 from Tristan da Cunha, which he has lately sent me. My acknowledgments are 

 likewise due to the authorities of the Pauahi Museum at Honolulu for the loan of 

 the type of (Estrelata newelli. There are others whose names are mentioned 

 throughout the work, to all of whom I return my grateful thanks. Most of my 

 readers will, I feel sure, fully appreciate Mr. Keuleman's excellent drawings ; 

 while the colouring of the plates has been entrusted to Dr. Sharpe's talented 

 daughters, whose work will speak for itself. 



It only now remains for me to acknowledge my indebtedness to my Publishers, 

 Messrs. Witherby & Co., for their care in the production of the work, and for the 

 patience they have exercised, notwithstanding the many delays unavoidably caused 

 by recurring illness. 



On the eve of completing this work I have to deplore the sudden death of 

 Dr. Sharpe, a loss to the ornithological world at large, and as a collaborator 

 one who has rendered me invaluable aid in placing his extensive knowledge most 

 generously at my disposal. It is, however, a source of gratification to me that he 

 lived to see the practical conclusion of the Monograph and to revise the proofs of all 

 but the last few pages. 



F. D. G. 



March 29th, 1910. 



XI 



