XIX 



same phenomenon may be observed. I possess specimens of these species from 

 Java, the upperside of which is bright shiny emerald green, others in which the 

 green is apparently mixed with yellow, thereby becoming much paler, and one 

 that is a still lighter shiny yellow copper colour. This shows what a mistake 

 it is to distinguish races or ever species by such shades of colour. Bethune- 

 Baker has correctly observed that shades differ sometimes in the same species, 

 but found no explanation for it. 



This would also explain the mutual relation of three species L. Celeno Cram 

 (Plate XX, 36«.<5.), L. Alexis Stoll (Plate XX, ZTa.b.) and L. Cleodus Felder 

 (Plate XX, 35) which so far has been a regular puzzle, and cannot be understood 

 without a knowledge of colour- evolution. In all these three forms the genitalia 

 are the same, which although it is not enough to justify them being regarded 

 systematically as the same species, certainly shows that they must be very 

 nearley related. They resemble each other externally also so much, that most 

 writers do not even reckon L. Alexis Stoll as a separate species, but regard 

 it as a form of L. Celeno Cram belonging to the dry season. This is another 

 of the not uncommon lepidopterological legends, which the one writer copies 

 from the other; for, apart from the fact that such well defined and constantly 

 different forms in the dry and rainy season in Java do not occur in any species, 

 I possess eight specimens of L. Celeno Cram, captured in Batavia, Buitenzorg 

 and the Bantam mountains, in August and September, that is the middle of the 

 dry season, which in no way differ from my specimens taken in various months 

 of the rainy season. The only real difference between these three kinds is that 

 on the upperside the colour of L. Cleodus Felder is a distinct shiny blue, 

 although of a light shade, while that of the two other kinds is decidedly white 

 with only a faint bluish shade, which is even absent altogether in many specimens. 

 This difference of shade can be clearly seen on inspection ; it can be best 

 expressed perhaps by saying, that L. Cleodus Felder is whitish blue, while 

 the other two are bluish white. A further distinguishing mark of L. Cleodus 

 Felder is supposed to be that the colour of the markings on the underside 

 of the secondaries is visible upon the upperside; but this distinction is 

 erroneous, the same phenomenon is found in many specimens of L. Celeno 

 Cram also. The ground colour of the underside of L. Cleodus Felder is 

 greyish brown, usually distinctly darker than in L. Celeno Cram, while the 

 shade of L. Alexis Stoll is still lighter and more whitish, and the same design 

 of vertical white lines is visible on the underside of the primaries of all three. 

 In L. Celeno Cram the two innermost of these vertical lines are somewhat 

 variable in their relative position; whether this is so in L. Cleodus Felder I 

 am unable to say, owing to insufficient material of this form. In L. Cleodus 



