45 



appreciation of these evolutional modifications; whereas in C. Leda L. no 

 difference in this respect manifests itself. 



3*^. That the difference in colouring in C. Leda L. arises almost entirely 

 from a greater or lesser diffusion of the black pigment, frequently in a finely 

 divided condition over a less clear ground colour, making it more difficult to 

 distinguish a definite colour pattern than is the case with the polymorphic 

 species, referred to, with their lighter and more distinct colours. 



The fact that this solution of the Cyllo problem simply carries us back to 

 the same evolutionary processes which manifest themselves in other butterflies, 

 undoubtedly presents a strong presumption in favour of its correctness ; that, 

 moreover, only an acquaintance with these processes and especially with the 

 theory of colour evolution can lead to such solution is also incontestably a 

 strong argument on behalf of its accuracy. 



I imagine that the foregoing observations will enable the reader to appre- 

 ciate my conviction that the numerous species of Cyllo invented by Moore, 

 de NicKviLLE and others, each provided in addition with a dry-and wet-season 

 form, do not in reality exist and simply indicate various stages of development 

 in one and the same species. Together with Cramer's species Phedama, 

 Mycena, and Arcensia, which simply represent colour forms of Leda, I am 

 constrained to reject Moore's and Bingham's Melanitis Bela, under which the 

 latter, moreover, includes Moore's species M. Varaha, M. Gokala, and 

 M. Fambra ; Hkewise Fruhstorfer's subspecies Simessa, Lacrima, and 

 I3MEN1DES. Even Cyllo Zithenius Herbst, mentioned by Fruhstorfer under 

 the forms Gnophodes Btlr. and Gruescens from Java, is simply based on 

 wrongly understood specimens of C. Leda L. For a long time I have been 

 in doubt concerning the form K (PI. XV, fig. 300) of which I have received 

 from the mountains of W. J. numerous specimens differing sVightly />//er se and 

 invariably exhibiting the same under side K' (PI. XV, fig. 30/). Seeing, 

 however, that the marking of this under side agrees completely with that of 

 man)' indubitable Leda 9 and that transition forms occur besides, I was unable 

 to separate this form either from Cyllo Leda L. Cyllo Suyudana Moore alone, 

 which is not the same as Phedima Cr. with which Fruhstorfer confuses it, 

 I recognize as a distinct species since no transitions between this and C. Leda L. 

 have come to my knowledge, although both are very closely allied in their 

 colour development. The larger specimens from the Moluccas, however, I 

 cannot regard otherwise than as a race of the same species, a view which I 

 am prepared to modify only if, on examination of the generative organs, 

 specific differences are shown to exist. 



Of the different forms of this butterfly occurring in Java I have figured the 



