PLATE XXII. 
No. 1.—The Purple Hair-streak Butterfly (Thecla No. 6.—The Green Hair-streak Butterfly (Thecla 
Quercis). Rubi). 
No. 2.—The Female of the Purple Hair-streak But- No. 7.—The Female of the Green Hair-streak But- 
_terfly. terfly. 
No. 3.—The Under side of the Purple Hair-streak No. 8.—The Under side of the Green Hair-streak 
Butterfly. Butterfly. 
No. 4.—The Caterpillar of the Purple Hair-streak No. 9.—The Caterpillar of the Green Hair-streak 
Butterfly. Butterfly. 
No. 5.—The Chrysalis of the Purple Hair-streak But- No. 10.—The Chrysalis of the Green Hair-streak 
terfly. Butterfly. 
THECLA QueERcUS (the Purple Hair-streak). This species is by far the handsomest of the 
British Theclas. It is also a very interesting species, as exhibiting most strikingly a peculiarity 
that distinguishes this genus. This peculiarity consists in the characteristic markings of the 
females, which, contrary to those of most other genera, are more conspicuous and brighter than 
those of the male. In Thecla Betule (Plate xxi.), we have seen that the female is distinguished 
by a fine patch of orange on the anterior wings, which is not found on those of the male. In 
Thecla Pruni the female has a border of orange on the fore wings, while those of the male are 
entirely brown. In the species now under description, the markings of the female are still more 
conspicuously different from those of the male—and of much greater comparative brightness, as 
they consist of large patches of the brightest metallic azure, while the wings of the males are 
of unvarying dusky purple, verging towards brown. The bright metallic blue resembles that 
which forms the ground colour of the wings of the male “ Purple Emperor ;” the female of which 
species has the ground colour of the wings of dusky brown—heing, in fact, much less brillant 
in its colouring than the male; and this and other similar instances led our English entomolo- 
gists to conclude that the most dusky toned of the sexes in Thecla Querciis was necessarily the 
female. This supposition has been now satisfactorily disproved, as the individuals with the 
wings brightly blotched with azure have been observed in the act of depositing their eggs. There 
are also distinctions in the form of the anterior feet of the two sexes, analogous to those of some 
preceding families, which also serve to prove that the largest and most brightly coloured indi- 
viduals in this genus are invariably the females. The character of the feet in the genus Theclu 
was first noticed by Dr. Horsfield, in his description of some of the magnificent Theclas of the 
island of Java. The male is represented at No. 1, the female at No. 2, and the under side at 
No. 3. The Caterpillar (No. 4) feeds upon the foliage of the Oak in May and June, and some- 
times burrows in the ground at the time of its change to the Chrysalis state, though it is most 
frequently found attached to a branch or the under side of a leaf, by a silken web. Réaumur 
gives a most interesting and a detailed account of the manner in which the Caterpillars of this 
genus attach the web round the body, which secures them during the Chrysalis state. The per- 
fect insect appears in July. 
It is pretty generally dispersed, and plentiful in the Southern counties, and is also found in 
