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 Nymphalide, and in fact 
most Lepidoptera, were originally black and brown, but the Pierinze 
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 Nymphalide 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 Pierine, 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 Nymphalide and other dark groups, and albinism 
in the Pieride ’. 
In the Eupleeine, one of the larger subfamilies of the Nymphalide, 
a considerable proportion of the species are black or dark brown, many 
of them suffused 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 Pierinz 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 rape (probably introduced into 
the United States about 1856-7) suddenly developed the yellow 
form G. novanglie. 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 species differ in a similar way—Sylleais 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 versé 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 Bociraza, then 
saffron as in Bordeta quedriplagiata, orange as in Milionia zonea, 
partly crimson as in M, snelient, or wholly crimson as in M. guenthert; 
. 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. 
2 Some years since I found a wild white primrose, which I planted in my 
garden and hoped to multiply, but it yielded no seed and division of the root 
destroyed it entirely. 
