It is distributed throughout Central and Northern Europe, except the Polar region, and its range extends through Northern Asia to Amurland, Ussuri, and China. The Purple Hairstreak (_Zephyrus quercus_). The butterfly (figured on Plate 96) has the sexes differently ornamented, as in the last species. The male is strongly tinged with purplish-blue, the veins are blackish; the outer margin of the fore wings are narrowly, and the costa and outer margin of the hind wings are broadly, bordered with black. The female is purplish-black, with two patches of bluish-purple in the discal cell and space below; often there is a smaller patch of the same colour between them, the whole forming a large blotch interrupted by the blackish veins. Under side greyish with blackish shaded white lines; two or three blackish clouds on the outer margin of fore wings above the inner angle; these are sometimes edged with orange; a black spot on anal angle of the hind wings, with an orange one above it, and a black-centred orange spot between veins 2 and 3. Variation in this species is exceptional. An aberration known as _bella_, Gerhard, has a yellowish mark at end of the cell on the upper side of the fore wings, and at least one such variety has been taken in England. Sometimes the blotch on the female is rather blue than purple; a male specimen with blue streaks on the costa of the fore wings has been recorded, and Barrett mentions a gynandrous specimen in which the right side was that of the male. The egg is pale brown tinged with pink, and over this is a whitish network. The caterpillar is reddish-brown and downy; a black line along the back has a whitish edge, and there are whitish oblique stripes, with blackish edge, on each side of the central line; the segmental divisions are well marked, and the spiracles are blackish with pale rings. The head, which, when the caterpillar is resting, is hidden within the first body ring, is brownish and glossy, and there is a greyish shield-like mark on the second ring. The chrysalis is red-brown, with darker freckles; the body is downy, and there are traces of oblique marks thereon. It does not appear to be fastened by the tail, but the cast larval skin remains attached; there are a few strands of silk around and about the chrysalis, but these are very flimsy, although they hold it in position on the ground or under a leaf. The eggs are laid in July or August on twigs of oak, but the caterpillars, it is said, do not hatch out until the following spring. In May and early June the caterpillars are full grown, and may be obtained by beating or jarring the branches of oak trees in places where the butterfly is known to occur. They have also been found on sallow.