July. 1920 
The Queensland Naturalist. 
7 ^ 
Gradually the bubble enlarges until it breaks away, 
carrying the enclosed insect to the surface. Once there it 
clings to a floating leaf or overhanging blade of grass, and 
thus reaches its own aerial home. 
NOTES ON TWO BUTTERFLIES OF THE GENUS 
DELIAS. 
By R. Illidge. 
(Read i8th August, 1919.) 
Delias nigrina (Fabr). — This is one of our commonest 
butterflies and an exceedingly pretty species. It is found 
around Brisbane, almost throughout the year, in more or 
less abundance. I haA^e bred some hundreds of specimens 
for the purpose of obtaining varieties, but hitherto Avithout 
success. There is sometimes a slight variation on the 
upper side, but inappreciable except on close observation. 
The male, on the under side, is easily distinguishable from 
the female by the smaller size of the apical band of yelloAV 
spots on the fore Aving, and on the hind wing by the attenu- 
ation of the red band. 
Delias argenthona (Fabr) form serninigra (Friih- 
storfer ) — Having again bred a small series of this form of 
D. argenthona^ I am noAV enabled to exhibit them along 
with specimens of typical argenthona of Fabr., which Avere 
bretl in December, those of serninigra having been reared 
in the last Aveek of June. Thus you now see the true 
summer and Avinter forms of this butterfly. In connection 
with seininigra the male is also shown for the first time,, 
Friihstorfer being unacquainted with it. It Avas alsc» 
unknoAvn to Waterhouse and Lyell, the authors of The 
Butterflies of Australia, and a few days ago I had the 
pleasure of presenting males to Mr. Waterhouse. In 
D. argenthona, the summer form, the basal yellow of the 
hind wing is very broad, as are also the submarginal scarlet 
spots, whereas in D. serninigra the yellow is very much 
dusted with black ; the discal area of black is extensive, and 
the scarlet spots are much smaller. As regards appearance,. 
I consider the winter insect neater than, though not aS' 
shoAvy as, its summer relative. 
