{317} The caterpillar, which may be beaten from birch, and sometimes alder, in July, is bright apple green with yellowish lines on the sides and back; the ring divisions are yellow, and the head is tinged with that colour. (Adapted from Porritt.) Sometimes the caterpillars are brownish, or greenish grey in general colour. The moth, which is out in May and June, will be found in woods, or on heaths, where birches grow. It rests on the trunks of the trees and may be boxed, as a rule, with ease. On some occasions, however, it is very lively, and the net will have to be brought into action for its capture. The distribution of this species extends through England, but it is far more plentiful in the south than in the north, although it has been recorded from several places in Yorkshire, and from Coal Law Wood in Northumberland. It is found also in Wales, and in Scotland up to Moray. In Ireland it is not frequent, but has been noted from Mucross, and the Upper Lake of Killarney, in Kerry, and from Tinahely in Wicklow; Kane also gives Clonbrock in Galway, and adds that "some specimens from this locality have the spots very large on a clear whitish ground, so that they have a superficial resemblance to _Cleora glabraria_." The range abroad spreads to East Siberia, Amurland, and Japan. NOTE.--Staudinger places the last four species in _Boarmia_, Treitschke; but Prout and others refer them to the genus _Ectropis_, Hubner. The latter will probably have to be adopted. {318} HORSE CHESTNUT (_Pachycnema hippocastanaria_). The rather long and somewhat oval fore wings of this species (Plate 137, Figs. 8, 9) are brownish grey, inclining to purplish grey; the two cross lines are blackish, edged with whitish, but generally indistinct; when the lines are well defined, the enclosed central area is sometimes darker than the other parts of the wings; there is a black central dot, and occasionally there is a well-marked dusky central shade. Hind wings, whitish, more or less tinged with smoky grey; frequently there is a dusky, curved line beyond the middle, and this is sometimes outwardly edged with whitish. The caterpillar is greyish brown, dotted with black, and marked on the back and sides with reddish brown. When at rest on the twigs of its food plant, heather or ling (_Calluna vulgaris_), this caterpillar agrees so well with its surroundings that it is not at all easy to see; at least, we may see it, but fail to distinguish it from the twigs of the plant. It may be obtained in June and July, and again in the autumn. (Figured on Plate 140, after Hofmann.) The first flight of the moth occurs in April and May; the second in August, but specimens of the later generation are usually small in size and in number, as compared with those of the early brood.