Caterpillar, yellowish above and greyish beneath; a dusky line along the middle of the back, and one, dotted with black, low down on the sides; head dark brown, almost blackish. It feeds in May and June on oak, but only at night; it constructs a leafy chamber in which it sits tight during the day, and is not easily evicted unless its apartment is forcibly opened. The reddish chrysalis is enclosed in a flimsy cocoon between, or among, leaves. Although September is the month during which the moth usually emerges, it is sometimes seen earlier. It is so partial to sugar, that it may often be seen at an old patch before the new feast has been set out for the evening entertainment. The species is fairly well distributed throughout England and Wales, and most common in the south of the former country. It extends into Southern Scotland, but {92} apparently does not occur in Ireland. Abroad it is found in Central Europe, Belgium, North Germany, North Italy, and North-east Asia Minor. THE YELLOW HORNED (_Polyploca flavicornis_). In the South of England this species is greenish grey, sometimes speckled or dusted with darker grey; the reniform and orbicular marks are generally clear and distinct, but in some examples they are united and form a whitish blotch outlined in blackish; the cross lines are usually well defined, but in the dark grey dusted form are very obscure. Specimens from Scotland are generally larger, there is less green, if any, in the ground colour, and the markings are often more pronounced and brighter. This form is the var. _scotica_, Tutt, and may be more or less identical with the var. _finmarchia_, Schöyen, from Norway and Lapland (Fig. 7, Plate 39, shows the English form, and Fig. 8 the Scotch form).