group of Butterflies, Potaro District, British Guiana, 427 
the cell between veins 5 and 7, and three white apical 
spots on the fore-wing are alike found in both A. numata 
and £. nigrofulva, not to mention the general arrangement 
of bands and colours. 
Eueides isabella and Eueides vibilia. 
As already mentioned both of these species have 
occurred but only singly. #. isabella is a perfectly 
normal example. It is remarkable that on the under-side 
with the wings closed it is hardly to be distinguished from 
E. nigrofulva except for the smaller sub-apical yellow spots 
forming a band. The straw-coloured patch of scales be- 
tween veins 5 and 7 is wanting, and points to a more 
recent association with the group or at least with 
Heliconius numata. 
The example of Hueides vibilia is much more removed 
from the normal and illustrates how this species is assum- 
ing a darkened hind-wing above. The black scaling of 
the marginal band shows an extension inwards towards 
the cell, and this is quite a special development in this 
species. The sub-apical straw-coloured spots are smaller 
than in typical examples and follow the pattern Z. isabella. 
It must be confessed that on the under-side this insect has 
little of the general appearance of the majority of the 
group. The strong rayed aspect of the hind-wind without 
any band gives the insect a much more distinct and dif- 
ferent-looking appearance. But it cannot be overlooked 
that the dark suffusion of the hind-wing above is signifi- 
cant of the influence of the more pronounced black hind- 
winged species, and this like the Protogonius is probably a 
resultant of selection for this end made only on the wing. 
FAMILY—DANAIDZ. 
Sub-family—LZ YCOREAN. 
The two members of the family Danaidx both offer 
remarkable instances of the influences of colour and 
pattern, The two species are Lycorea pasinuntia and 
Lycorea ceres. The former shows the influence of the 
darkening tendency in the hind-wing much less than the 
latter, and this is the more remarkable because in other 
