PREFACE. il 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.