1878.] MR. D. G. ELLIOT ON THE GENUS PTILOPUS. 501 



probably beyond all others, through the material brought to France 

 by the scientific expeditions known as the voyages of the 'Astrolabe,' 

 * Coquille,' 'Venus,' 'Zele,' ' Pole Sud,' &c. Many types are among 

 these specimens ; and it has been by their assistance I have worked 

 out the synonymy of the species of the Polynesian subregion. All 

 the species figured by Bonaparte in his ' Iconographie des Pigeons ' 

 are also in the Museum, and have been invaluable in enabling me to 

 arrange the synonymy and determine the species to which they be- 

 long, which has not been always possible from the work itself, some 

 curious and unaccountable errors having been committed by the 

 authors. 



Man is fallible, and it is not to be supposed that in an extensive 

 review of some seventy species no errors have been committed ; but, 

 having eudeavoured to verify every statement made in this paper 

 (taking nothing for granted), I may venture to hope that inaccuracies 

 have been reduced to a minimum. 



The pleasing duty now alone remains for me to express my thanks 

 to those who have assisted me with material during the time I have 

 been occupied with this memoir, without whose aid it certainly never 

 could have been properly completed. To my friend Prof. A. Milne- 

 Edwards, to whom I have already so often given my testimony as to 

 his willingness to accord every facility for the study and examination 

 of the unequalled collection of birds and quadrupeds under his charge, 

 I am again under obligations for every assistance rendered to me 

 during the months I have been engaged upon this group. Not only 

 was every" specimen the Museum contained continually at my dis- 

 posal, but also many books from his own library were placed at my 

 service as, from time to time, I had need of them. It is only by 

 such enlightened assistance and cooperation from those who are at 

 the heads of great departments in European museums that any satis- 

 factory work can be accomplished by a naturalist who may not be 

 himself attached to such institutions. To Dr. Oustalet, Aide-Natura- 

 liste, I also desire to express my thanks for much assistance continu- 

 ally and freely given. To my friend Count T. Salvadori I would 

 acknowledge my indebtedness for a very valuable series of specimens 

 not otherwise obtainable, procured by the consent of the Marquis G. 

 Doria from the Museum at Genoa, among which were some types of 

 Count Salvadori's lately described species. To Count H. Turati I 

 am also obliged for specimens from his magnificent museum. To 

 my friend Dr. Sclater I am indebted for opportunities of examining 

 the collection of the ' Challenger ' Expedition, and also those sent to 

 him from different islands in the Pacific, containing various types of 

 the species described by him from time to time ; and to Messrs. Sal- 

 vin and Godman for specimens from their collection obtained by Mr. 

 Layard, and which I brought to Paris for comparison with those in 

 the Museum collection. To Mr. Sharpe, who placed at my disposal 

 all the specimens of this genus in the British Museum, among which 

 were various types of much service in determining some doubtful 

 points, I am greatly obliged. And, lastly, to the Directors of 

 the Museum Godeffroy, who sent me the types of Ptilopus pona- 



