294 Dr. Frederick A. Dixey on the 
P. swainsonii, relieved by dustings of pale pinkish or 
bluish grey, which do not seem to bear any particular 
relation to the lighter patches in Catasticta or Hucheira. 
These greyish areas are often, especially in the females 
(including those of the species named), brightened up 
into bars or broader expanses of vivid red (P. lewcodro- 
sime) or blue (P. telthusa), and the aspect thus produced 
is very unlike that of nearly all the members of the allied 
genera. But as has been shown above, at pp. 281 and 
285, an indication of affinity in coloration with those 
genera is preserved in the red and yellow patches of the 
underside of the hindwing ; and, what is very remarkable 
indeed, there are two species of Catasticta, namely C. 
teutamis and C. ctemene, the males of which are of the 
usual Catasticta type, while the females present, together 
with the ordinary Catasticta neuration and structure, the 
aspect characteristic of P. charops 9 and other highly 
coloured members of the genus Pereute. In the case of 
these two Catastictas there can, I think, be no doubt 
that it is the male rather than the female that represents 
the ancestral colouring of the group, and we are thus led 
to the conclusion that some common cause has brought 
about the divergence in the same direction of these 
female Catastictas and both male and female Pereutes 
from the ordinary character of their nearest relatives. 
This cause I believe to be mimicry, the models for which 
in the present instance are to be found in certain species 
of Heliconius, particularly H. melpomene, H. phyllis, and 
their allies.* ‘lhe resemblance is not perfect,t but in all 
probability is quite sufficient to be of much service to the 
Pierine mimics; and we find exemplified here, as in 
many other cases, the much greater readiness with which 
the female assumes the protective coloration. As we 
“ T also think it exceedingly likely that Papilio euterpinus, Godm. 
& Salv. (Ecuador), forms one of this mimetic group. It is, how- 
ever, remarkable that its range seems not to coincide with that of 
the Pierine, namely P. charops 9, which probably resembles it 
most closely in size as well as colour. 
+ The red colour of the species of Heliconius here mentioned (to 
which may be added H. vulcanus and H. hydara), as they occur in 
collections, is by no means so vivid as that of their supposed 
imitators. But Mr. A. G. Butler and Mr. F. A. Heron both 
inform me that the red in Heliconii has a special tendency to lose 
its brightness, even in specimens carefully preserved in the dark. 
