Preface. 



It is now twenty years since the completion of Doubleday, Hew- 

 itson, and Westwood's "Genera of Diurnal Lepidoptera", a work which 

 included a complete Catalogue of all the species then known. The 

 great advance which has since been macLe in our knowledge of this 

 group, has rendered necessary another Catalogue brought down to the 

 present date, a want which has hitherto been only partially supplied 

 by various monographs and catalogues of limited extent. 



Although full materials for a natural arrangement of all the spe- 

 cies could not be obtained, it was thought better to attempt some 

 kind of arrangement, however imperfect, than to place the species al- 

 phabetically. Those species which are entirely unclassed will be found 

 at the end of their genus, either under a line, or in alphabetical order. 

 The unclassed Hesperidce are included under Pamphtta. The fol- 

 lowing genera, among others, must be understood to be only provisio- 

 nally retained in their entirety : Acrcea, Axiocerses, Plebeim, Theda, 

 Pierisj and Pa/pilio. It is to be regretted that Mr. Butler's revision 

 of the genera of Pierince was published too late to be made use of. 



The great length to which this work has extended, necessarily 

 precludes the addition of a Bibliography, but a list of authors' names 

 has been drawn up, which will to some extent compensate for the 

 omission. Those authors whose works have been examined througout 

 are marked thus (*), and those a part only of whose works were ac- 

 cessible, thus: (f). 



Some slight errors in the dates of publication of certain works 

 which affect the synonymy, will be found corrected in the Appendix? 

 and some typographical errors in the Index; but it has not been 

 thought necessary to add a list of errata. 



A repeated number followed by a letter indicates a doubt as to 

 whether the second species may not be a synonym or variety of the 

 first. Intercalated species are indicated by a repeated number followed 

 by "bis", and, in the Appendix, also by the signs (*f) &c. 



