in 



be easily understood, when reading my interpretation of the so-called tails and 

 lobes of the wings of butterflies, that I am unable to agree when Snellen also 

 adopts the view of the attributing even generic value to these. Nor, of course 

 do I attach any weight to the same in reference to colour or the blending 

 of colours. On the other hand I agree with him, and principally for the same 

 reason, when he refuses to acknowledge several of the genera into which at 

 present the old genus Lycaena is frequently divided. Snellen took objection 

 to this because, in his opinion, the characteristics indicated are not permanent 

 whereby many species become very doubtful. 



Now, while in a systematic treatment of the Lycaenidae in general it may 

 be necessary to split up large genera into several smaller ones, the case is 

 different where only the fauna of a single island is dealt with and the admission 

 of a large number of genera is apt rather to create confusion than to afford 

 facilities for identification. Since, however, under each species the literature 

 is indicated as fully as circumstances permit, anyone can at a glance see to 

 which genera any given species has been referred by the various authors. 

 Considerable differences will be noticed in this respect. I have, however, found 

 it necessary in some instances to depart from Snellen's classification. By 

 mounting many of my duplicates my series, even of the species known to 

 Snellen, have increased to such an extent, that in respect to these some of 

 his views did not appear to me sufficiently warranted and I have therefore 

 been unable to adopt these. Thus on the one hand I have had to reject a 

 few new species described by him, while on the other hand my material has 

 yielded additional species and on consulting the Fruhstorfer collection I have 

 become acquainted with several forms known neither to Snellen nor to me, 

 or at least not from Java. A study of the writings on the Austro-Malayan 

 Lycaenidae recently published by this lepidopterist has also proved of great 

 use to me. 



Descriptions, especially of such small butterflies as most of the Lycaenidae 

 are, appear to me of little use. Another drawback is that the indication of the 

 shades of colour, of great importance in the case of not a few Lycaenidae, is 

 very uncertain with different observers ; moreover, individual deviations are 

 generally too little taken into account. For this reason I have as a rule given 

 little notice to this, but have rather made special efforts to render my illustrations 

 as accurate as possible. The small, but very important, differences between 

 individuals of the same species on different islands especially are much more 

 easily demonstrated and grasped bij means of good illustrations. Only in 

 respect of the larvae and pupae a somewhat detailed description is, in addition, 

 mostly indispensable. In those cases where Snellen has described new species 



