PREFACE. 



MY readers will naturally ask wliy I have delayed ■writing this 

 book for six years after my return ; and I feel bound to give 

 them full satisfaction on this point. 



When I reached England in the spiiag of 1862, 1 found myself 

 surrounded by a room full of packing-cases, containing the collec- 

 tions that I had from time to time sent home for my private use. 

 These comprised nearly three thousand bird-skins, of about a thou- 

 sand species ; and at least twenty thousand beetles and butterflies, 

 of about seven thousand species ; besides some quadrupeds and land- 

 shells. A large proportion of these I had not seen for years ; and in 

 my then weak state of health, the unpacking, sorting, and arranging 

 of such a mass of specimens occupied a long time. 



I very soon decided that, until I had done something toward 

 naming and describing the most important groups in my collection, 

 and had worked out some of the more interesting problems of varia- 

 tion and geographical distribution, of which I had had glimpses 

 while collecting them, I would not attempt to publish my travels. I 

 could, indeed, at once have printed my notes and journals, leaving all 

 reference to questions of natural history for a future work ; but I felt 

 that this would be as unsatisfactory to myself, as it would be disap- 

 pointing to my friends, and uninstructive to the public. 



Since my return, up to this date, I have published eighteen pa- 

 pers, in the Transactions or Proceedings, of the Linnaean Zoological 

 and Entomological Societies, describing or cataloguing portions of 

 my collections ; besides twelve others in various scientific periodicals, 

 on more general subjects connected with them. 



Nearly two thousand of my Coleoptera, and many hundreds of my 

 butterflies, have been already described l)y various eminent natural- 

 ists, British and foreign ; but a much larger number remains unde- 

 scribed. Among those to whom science is most indebted for this la- 

 borious work, I must name Mi-. F. P. Pascoe, late President of the En- 

 tomological Society of London, who has almost completed the clas- 

 sification and descriiJtion of my large collection of Longicom beetles 

 (now in his possession), comprising more than a thousand species, of 



