PREFACE 



Although the butterflies have probably been the subject of study for longer than 

 any other group of insects, no comprehensive account of all their genera has been 

 published since Doubleday and Westvvood's Genera of Diurnal Lepidoptera (1846- 

 50), which was long before the establishment of any Code of Nomenclature. 



The immense task of extracting, collating and verifying the names of these genera, 

 and presenting them comprehensively, together with those of their type-species, 

 could have been carried through only by one with a deep and intimate knowledge of 

 the literature and a thorough understanding of the rules of zoological nomenclature. 

 These attributes were possessed by the late Francis Hemming, who has used them to 

 produce this major contribution to the stability of the generic nomenclature of the 

 butterflies of the world. 



The Trustees are grateful to Mrs. M. F. W. Hemming for affording them the 

 opportunity of publishing posthumously this important work, which the author had 

 completed only a few days before his untimely death on February 22nd, 1964 ; to 

 Mr. N. D. Riley for his valued assistance in preparing the manuscript for the printers, 

 and to Mrs. Joan Newman for compiling the comprehensive index. 



British Museum (Natural History) J. p. Doxcaster, 



London, S.W. 7 Keeper 



23rd September, 1966 Department of Entomology 



