The fore wings of this rather variable species (Plate 63, Figs. 5-7) are yellowish or reddish grey, with a darker basal patch and central band; a reddish blotch below the tip of the wing is edged with white, and the central band is also outwardly edged with white. Hind wings, whitish, with two lines, and dusky hind marginal border, the latter sometimes inclining to reddish. Occasionally, the fore wings are entirely pale ochreous, and the basal patch and the central band only very slightly darker, but the limiting lines are reddish, and the patch under the tip of the wing is bright orange red. Var. _insulicola_, Staud., from the isles of Scotland, has the fore wings rather narrower, and suffused with purplish brown or deep violet grey; the hind wings are smoky grey. The female is usually smaller than the male, and often more yellow in colour. Eggs, whitish brown, mottled with darker. The early stages are shown on Plate 67, Figs. 2-2b. The long caterpillar is pale yellowish brown, with three lines along the back, the central one dark brown, and most distinct at each end; the others are white, irregularly shaded above {166} with reddish; another white line along the region of the spiracles. It feeds, in May or June (earlier or later in some seasons), on sallow and birch. The moth is out in July and August, and frequents heaths and bogs more especially, but is also found in or around woods, and I have captured male specimens as they flew along hedgerows bordering fields, at dusk, in Middlesex. The female is rarely seen on the wing. The species, which ranges through Central and Northern Europe to the Ural and Altai, is generally distributed throughout the British Isles; it is found also in the Atlantic States of America. NORTHERN SPINACH (_Lygris populata_). The fore wings are yellow, with a reddish or purplish-brown basal patch, central band, and small patch on outer margin below tip of the wing, the central band more or less clouded or mottled with yellow. Hind wings, whitish, tinged with yellow. The female is usually smaller, the colour generally paler, and the markings frequently only represented by cross lines. Specimens from the Isle of Arran have the ground colour of fore wings more or less dappled with brown of the same tint as that of the central band and other markings; the hind wings are tinged with a smoky hue. In other parts of Scotland the brown colour becomes more and more general, until the fore wings are uniformly brown, and the hind wings dusky. On the mountains in the north nearly black specimens occur, and these seem to be referable to ab. _musauaria_, Freyer. (Plate 63, Figs. 8-10.)