THE LONG-TAILED BLUE 
203 
withered, curled-up leaf for its puparium, in which it spins a 
layer of silk as well as a covering of silk over the opening 
between the folded-up edges, also a girdle round its body ; 
it then settles down for its transformation, which occupies 
three days. 
The larval stage lasts twenty-four days. 
Pupa. The pupa measures frorr\ 10*50 mm. to 12*70 mm. in 
length. It is generally smooth and rounded ; the head is 
round ; the thorax swollen, sunken at the waist; the second 
abdominal segment is bulging, then curves to the anal seg¬ 
ment, which is without any cremastral hooks. The wings 
bulge slightly near the tips, and there is a slight angular 
projection at the base. The whole surface is covered with 
very fine reticulations and sprinkled with dark brown lenticles 
along the sides ; there are also a few minute bristles. The 
spiracles are very inconspicuous, being the same colour as 
the body and not black as stated by authors. The ground 
colour at first is a pale flesh tint, gradually becoming paler, 
and when the pupa is mature is a pale creamy-ochreous. A 
dusky stripe runs down the back, the abdomen is spotted 
with deep purplish-brown along the sides, and the whole 
surface is more or less speckled with dark brown. Different 
individuals vary in the development of the markings ; some 
are only slightly speckled, others are heavily blotched and 
spotted. 
The pupa is attached by a cincture round the waist and 
sometimes by a few r loose strands of silk over it, but having 
no hooks, the anal extremity is free. The pupal stage lasts 
about ten days. 
Imago. The sexual difference is distinct. The expanse of 
wings average 34mm. in the male; 36mm. in the female. 
Large examples from Collisure, Eastern Pyrenees, have a wing 
expanse as great as 41 mm. 
Male. ( Upper Side.) The ground colour is light purple. 
There is a narrow black marginal border to both fore and 
hind wings, which are clothed with long, light, silvery-blue 
plumose scales, covering the whole of the fore wing except 
for the costal and outer marginal portions ; they also cover 
the greater part of the hind wing. These scales give a soft 
and very beautiful silvery-blue and purple lustrous effect to 
