102 MESSES. H. J. ELWBS AND JAMES EDWARDS: 



to use these characters for building up any system of chissincation, as we consider 

 the time is hardly come for their adoption for any sucli purpose. But we have found 

 them invaluable in deciding points of specific distinction where the external characters 

 are not clearly defined. In some cases a slight external feature distinguishes wo 

 forms, which is sometimes greatly strengthened by a marked divergence in the male 

 genitalia, and sometimes no difference can be traced in these organs. In the former 

 case a specific difference between two similar forms can safely be conceded, while in 

 the latter the opposite course should be followed." 



As regards the arrangement of genera, we have adopted that proposed by AVatson in 

 his last paper, "A Key to the Asiatic Genera of the Hesperiidse," published in the 

 Journal of the Bombay Natural History Society for 1895, which in some respects 

 is an improvement on his earlier paper before referred to. We have been compelled 

 to propose a few new genera and some seventy species ; and though probably there 

 are still many additions and corrections to be made to the list, especially in the Malay 

 islands and Indo-Chinese countries, yet we have spared no efforts to procure for 

 examination all the material which Elwes's collection did not previously contain. In 

 doing so we have to acknowledge the very great assistance which has been afforded 

 us by Mr. L. de Niceville and Captain Watson in India, who have sent us advance 

 copies of all their papers and descriptions. In Europe Dr. Georg Semper, of Altona, 

 has been good enough to lend us authentic specimens of all the species included 

 in his great work ' Die Schmetterlinge der Philippiuischen Inseln.' Dr. O. Staudinger 

 has sent us a large number of specimens from Borneo and other Malayan islands, 

 the novelties amongst which he has kindly permitted us to describe. Herr P. C. 

 T. Snellen, of Eotterdam, has been equally liberal with specimens from Java and 

 Sumatra. M. Charles Oberthxir has enabled us to examine some of the new and 

 rare forms in his magnificent collection from China, and Mr. Leech has also been 

 most obliging in lending types described in his ' Butterflies of China &c.' and other 

 specimens for examination. The Hon. Walter Eothschild kindly allowed us to select 

 from and describe several species of interest in his collection ; and we are indebted 

 to Mr. O. Salvin and Sir G. F. Hampson for advice and assistance in many points 

 of difficulty and for the loan of specimens. Col. Swinhoe has also lent us many of his 

 types and allowed us to describe new species in his collection ; and so far as we 

 know there is no collection containing many types to which we have not had access, 

 except that of M. Mabille, which we have not visited ^ Some species which have 

 been described by the latter and by Plotz we have, in common with Captain Watson, 

 failed to identify, and we have possibly overlooked a few others ; yet we think that the 

 material at our disposal has been hitherto unrivalled, and the localities given for 



' Since the above was written M. Mabille has been liind enough to lend us a number of his tyjies, which we 

 have been able to identify with certainty and put in their proper order ; so we do not thinlc that there can exist 

 in Europe, at present, any important sources of information in this family of which we have not availed 

 ourselves. 



