296 MR. A. G. BUTLER ON A NEW FOSSIL MOTH. [May 21 , 



Lithopsyche than Calospila leucomela still exists, it is probably to be 

 found in one of the islands between Java and Australia. 



I have already stated my belief that the Nymphalidae, and in fact 

 most Lepidoptera, were originally black and brown, but the Pierinae 

 and, I might add, probably the Geometrites were white, or white 

 with black bodies. It is perhaps worth while to show some reason for 

 this belief beyond those already given. 



Assuming that the Nymphahdse were for the most part originally 

 black, or black and brown forms, there should be a far greater pro- 

 portion of violet, blue, crimson, and reddish orange in this family 

 than in a group such as the Pierinae, presumably developed from forms 

 which were originally either wholly or for the greater part white : 

 the aberrant types also would, I think, be more likely to revert to 

 melanism in the Nymphalidae and other dark groups, and albinism 

 in the Pieridae ^ 



In the Euplceinae, one of the larger subfamilies of the Nymphalidae, 

 a considerable proportion of the species are black or dark brown, many 

 of them snfFused with violet or blue, and in the more highly coloured 

 forms with patches of blue in the centre of the wings. On the other 

 hand, there are not a few genera in which white, pale yellow, or 

 green are the predominant colours, and these may have been modified 

 from forms originally either white or black, most of these genera 

 showing extreme types of colouring in some of their species. 



In the Pierinae there are hardly any genera in which white species 

 do not still exist and forms with white females are abundant ; it is 

 also a significant fact that Ganoris rupee (probably introduced into 

 the United States about 1856-7) suddenly developed the yellow 

 form G. nova7ifflicB. Indeed the change from white to yellow seems 

 so easy that one can almost be certain that the latter has been 

 derived from the former and is the result of a more vigorous con- 

 stitution ". 



In the Geometrites also it is not unusual to find white and bright 

 yellow species in one genus, and occasionally individuals of the 

 same s{)ecies differ in a similar way — Syllexis lucida from Chili is 

 either shining lemon-yellow or silvery white. 



Now I think, if it be admitted that the earliest types of 

 Geometrites were black with white markings or vice versd and that 

 the white was gradually modified into yellow and the black into 

 blue, one can conclude that Milionia, the most highly ornate genus 

 of the Geometrites, was one of the last developed, or at any rate has 

 passed through more stages of development than any of its allies. 

 Assuming that it has been produced from such a form as Lithopsyche, 

 the white bands have first become clear yellow as in Buciruza, then 

 saffron as in Burdeta quadriplngiata, orange as in Milionia zonea, 

 partly crimson as in M. snelieni, or wholly crimson as in M.fjuentheri; 



^ We obtained a singular albino of Hebomoia glaucippe from Dr. Lidderdale's 

 Darjiling series ; in this specimen all the black markings are replaced by white. 



■^ Some years since I found a wild white primrose, which I phmted in my 

 garden and lio]ied to multiply, but it yielded no seed and division of the root 

 destroyed it entirely. 



