VARIATIONS IN THE COLOUR OF LEPIDOPTERA. LF 
with there, in the case of Hmmelesia albulata, that I proposed for 
them the specific name of Hebudiwm. Partial albinism occurs not 
unfrequently in Satyrus janira, the colour being absent from one 
or more of the wings, producing white patches. 
XantuisM.—In this class I place all those aberrations of 
colour which assume a pallid appearance over the whole extent of 
the wings. JI illustrate this condition by three remarkably light 
yellow varieties of Canonympha pamphilus, one of Satyrus semele, 
one of Canonympha davus, and one of Polyommatus phleas, and 
on the under side of Satyrus hyperanthus. Xanthism is also 
found occasionally in the genus Anthrocera, especially in A. fili- 
pendule, the spots on the wings being sometimes yellow instead 
of red. Many more instances of Xanthism might be given. The 
most remarkable case I ever saw was that of Pyrameis cardui, 
where the two wings on one side were normal, on the other 
xanthic. 
MexanisM.—Pure melanism is rare amongst Lepidoptera, 
and I think it is found only in those species where black obtains 
in the markings, and it really consists in the diffusion of the 
black over the whole of the wings. [I illustrate this condition by 
melanic specimens of Biston betularia. This, commonly called 
the peppered moth, has usually a white ground colour to the 
wings, with small black spots; but it has been found in the North 
of England entirely black, and I believe this melanic variety has 
been perpetuated in confinement by careful selection. I have 
seen almost melanic varieties of Abraxas grossulariata, and 
partial melanism is common in that species. Several of the 
Geometride and Noctuide are found more or less melanic in the 
northern parts of England and in Scotland. Dianthecia conspersa 
is a good illustration of this darkening of colour in northern 
specimens; many, more or less suffused with black, have been 
captured. 
Hereroracinism.—In this class I place mere sports, which 
may occur once or twice, and perhaps never be found again. I 
illustrate this by two specimens of Satyrus hyperanthus from the 
New Forest, one captured by myself. In these two insects the 
ordinary round spots on the under side of the wings are changed 
into lanceolate markings. I have also two specimens of Cano- 
nympha davus with similar lanceolate, instead of round, markings, 
both on the upper and under side of the wings. The aberration 
