( elxxxiv ) 
the basal area being pale golden brown becoming rapidly 
reddish, almost the colour of a pale garnet stone; in many 
cases they are entirely reddish. 
Ornithoptera brookeana is the only one of the Rhopalocera 
I have examined that forms an exception to the rule that 
greens in butterflies have for a basis pinks to reds including 
pinkish violet; the beautiful sheen that this species has in 
its metallic green transverse bands is well known. The scales 
are very different from those of the genus Papilio, being almost 
_. paddle-shaped with a broadish base, and the apex slightly 
‘truncated; the deep lines and reticulations of that genus are 
quite lacking, the surface being lined, but so exceedingly fine 
is this lining that the lines are on the average but ;,45 m.m. 
wide as against ~i, m.m. in Polyommatus galathea, in which 
species the ribbing is rather fine than coarse for the Ruralidae. 
The brilliant glossy green of the brookeana scales retain their 
colour under transmitted light, becoming lighter and losing 
much of the metallic sheen. Now at last I thought I shall 
find some green pigment: such however was not to be the 
case. The scale itself behind the green looked and proved 
to be very solid, they look to be filled with dense black pigment 
as they lie over each other, the metallic gloss being partial; 
on removing the upperside of the scale, I found there was 
left nothing but a dull greyish brown colour on the lower 
part of the scale sack; on removing the lower surface of the 
sack, the upper finely lined chitinous side retained all its 
lustre, this upper side I discovered to be very hard and brittle; 
it can be split and is easily broken, but in all cases the colour 
is retained, and I have come to the conclusion that in this 
case the chitine itself must be coloured. I am aware that the 
colour can be dissolved to a considerable extent, and I am 
now testing this but it is not completed; I believe however 
that in this instance the real colouring matter is not in the 
scale sack but, contrary to the Ruralidae at least, the chitine 
itself is coloured, 2. e. the colour is subcutaneous. 
Ornithoptera priamus is quite different. Whilst the struc- 
ture and pattern of the scale is almost precisely similar to 
brookeana (the shape is somewhat different however), the 
colouring matter is quite diverse; its brilliant and almost pure 
