11 
PREFACE. 
Indeed without the liberality I have experienced it would be impossible that a work 
of this nature could have been successfully completed; and I am proud to bear my tes¬ 
timony to the liberal spirit which has been manifested towards me by the scientific world 
in general. Among those to whom I am especially indebted I may mention the Earl of 
Derby, Prince Massena of Paris, M. Temminck, M. John Natterer of Vienna, Dr. Lichten¬ 
stein of Berlin, W. Swainson, Esq., Sir William Jardine, Bart., and T. C. Eyton, Esq. My 
thanks are also due to my friend Mr. Martin, of the Zoological Society of London, for the 
kind manner in which he has at all times rendered me his assistance in this and my other 
publications. 
With two exceptions my drawings have been taken from actual specimens; my 
reasons for these exceptions are given in the letter-press accompanying the respective 
Plates. 
