(. chexzvi- ?) 
broad, indeed almost as broad as long, somewhat squarely 
oblong with bluntly dentated apices, having as many as seven 
to nine dentations. The blue scales are, however long, of 
but moderate width, suddenly expanding at about a fifth 
from the apex where it is arched in its contour, and it is only 
this more or less curled tip that is blue, all the rest is sienna 
brown; in some cases the blue apex is decidedly and evenly 
hollowed out, but in the greater number of the scales this is 
not so, the apex being more generally slightly uneven. The 
interesting part is that all the blue colour is entirely confined 
to the apical half and to a large extent to the apical fifth of 
the scale, the brightest part being the apical curved fifth. 
The difference in the method of scaling may be seen even with 
a tenth hand lens, when it can be observed that the scales 
are not wholly blue, they are very irregularly and unevenly 
striated, the striations being very fine; they are densely filled 
with pigment that under transmitted light is golden brown, 
though under a direct light the blue colour is very bright. 
In Morpho aurora, a species more brilliant in its blue than 
most of the Ruralidae and as brilliant as any, the case is 
different. Here we havea colour more susceptible to light than 
any that I have yet examined, for its colour changes somewhat 
according to the intensity and whiteness of the light. Under 
direct light, in bright sun with the light condensed intensely, 
the blue colour is at its highest point; as the light is reduced 
the colour is likewise reduced until it becomes blue grey. 
In the Ruralidae there is no real change of colour, even though 
the hue may be intensified. Under transmitted light, with the 
sunlight transmitted through the scales, the colour becomes 
slightly lilac grey, but scales with the upper ribbed chitine 
removed are absolutely transparent and colourless; under 
very clear white light (as obtainable on a brilliant day with 
white fleecy clouds) the colour is yellowish opalescent. If 
placed under very white artificial light (transmitted) the 
scales are opalescent, showing slightly the colours so well 
known in Australian opals, but not the fiery hues of the 
Mexican stones. In this case, as in all others, these remarks 
apply to isolated scales, directly they begin to overlap each 
other a different effect is produced; the blue asserts itself 
