THE PURPLE HAIRSTREAK 
275 
fringe is black and white. The ventral surface of the body 
and the legs are white. 
Female . The female is larger and a deeper brown in 
colour. The fore wing has a discal bar as in the male, followed 
by a very broad, curved, fulvous-orange band, extending almost 
across the wing. The hind wing is similar to that of the male, 
but has three fulvous spots at the anal angle. The under side 
is similar to that of the male, except that the fulvous colouring 
is richer and deeper. 
Flight. The Brown Hairstreak flies very swiftly, but only 
during sunshine. Immediately the sun is obscured, it instantly 
settles and remains motionless until the sun reappears. 
Life of Imago. The life of this butterfly is about twenty-one 
days. 
Aberration. Aberration is chiefly confined to the develop¬ 
ment of the ochreous blotch in the male, sometimes developed 
into two or three extra markings, approaching that of the smaller 
banded females, which are sometimes much reduced in size. 
Striking aberrations are but seldom met with. Occasionally 
in the female, a more or less distinct sub-marginal fulvous 
band exists. Gynandrous examples are extremely rare. 
Genus THECLA, Fabricius , 1807 
THE PURPLE HAIRSTREAK 
Thecla quercus (Linn., 1758). 
(Plate XXIV, facing page 289) 
This is the most beautiful and most abundant of the British 
Hairstreaks and, like the Purple Emperor, the only other 
British butterfly having the wings shot with glowing purple ; 
it also possesses very similar habits in haunting the upper 
branches of the Oak. But it is the male only of the Purple 
Emperor that is adorned with this lovely colour, whereas it is 
sexually reversed in the Puqfle Hairstreak, in which species 
it is the female only that possesses this purple radiance. 
Haunts and Distribution. This very active little butterfly 
frequents the higher parts of Oak and Ash trees, where it may 
