This species frequents oak woods, or the borders thereof, in July and August, and is often more easy to see than to capture, as it has a tantalizing trick of flying around the upper branches of the trees. Occasionally it resorts to lower growing aspens, probably to feast on the honey dew, the secretions of Aphides, with which the leaves are often covered in hot summers. It seems to be pretty generally distributed in all parts of England and Wales, and in Scotland as far north as Ross. In Ireland it appears to be more local, and has only been recorded from the east and south. It is found in all parts of Europe, except the northern. [Illustration: _Pl._ 96. =Purple Hairstreak.= 1 _male_; 2, 3 _female_. =Black Hairstreak.= 4, 6 _male_; 5 _female_. =Green Hairstreak.= 7 _male_; 8, 9 _female_.] [Illustration: _Pl._ 97. =Black Hairstreak.= _Eggs, natural size and enlarged; caterpillar and enlarged; caterpillar and chrysalis._ =Purple Hairstreak.= _Egg enlarged; caterpillar and chrysalis._ =Green Hairstreak.= _Eggs, natural size and enlarged; caterpillar and enlarged; caterpillar and chrysalis._] The Black Hairstreak (_Thecla pruni_). This butterfly is figured on Plate 96. In colour it is dark brown or, when quite fresh, brownish-black; there are some orange marks on the outer margin of the hind wings, and these are most distinct in the female, in which sex there are orange spots on the fore wings also. The male has a pale sexual mark at the end of the cell of the fore wings, but this is less distinct than in the following species. The under side is brown, with a bluish-white interrupted transverse line on each wing, that on the hind wings angled before reaching the inner margin. All the wings have an orange band on the outer margin, but on the fore wings of the male this is often indistinct; there are some white-edged black spots before it, and, on the hind wings, beyond it also. The eggs are laid in July on the twigs of blackthorn, but the caterpillars do not hatch until the following spring. The egg figured on Plate 97 was reddish-brown and appeared rather shiny. The caterpillar is described as yellowish-green, with a darker green furrow and purplish ridges along the back; the latter are edged with whitish and the divisions between the rings are yellowish. The head is pale brown. The chrysalis, which is attached by the tail and has a silken thread around it, is black, marked on the head and body with yellowish-white. The caterpillars feed on blackthorn (_Prunus spinosa_) in a state of nature, but will eat the leaves of damson in confinement. They may be obtained in May, in their particular haunts, by beating sloe bushes with a beating tray, or an inverted open umbrella, held under to intercept the evicted caterpillars, etc.