The caterpillar, when full grown, is pale ochreous grey, sometimes tinged with pink or purplish brown, or with yellowish, and especially on the hind rings; a yellow stripe along the back is edged here and there with brownish; the diffuse dusky line along the area of the black margined spiracles is edged with yellowish. It is occasionally found on poplar, but sallows and willow are the more usual food plants, and it feeds upon these in June and July and again in August and September. The reddish brown chrysalis is enclosed in an earthen cocoon just under the surface of the ground at the roots of tree or bush upon which the caterpillar fed. The moth emerges in May and June from chrysalides of the previous year, and in August as a second generation. Three broods in the year have been obtained in confinement, but this is probably exceptional.
Widely distributed throughout the British Isles, but seems to have a preference for fens and marshy ground. It occurs all over Central and Northern Europe, its range extends through France to Spain, Italy, and Corsica, and it has been recorded from Armenia and Amurland. { 72}
THE IRON PROMINENT (_Notodonta dromedarius_).
The specimen shown on Plate 31 is from Surrey, and represents the form most frequently obtained in the south of England. Northwards the species becomes darker in colour, and the reddish and yellow marking much reduced. The form _perfusca_, as figured by Stephens, has the fore wings dark purplish grey, streaked with dark brown; a pale patch at the base is russet marked, the line before the middle of the wing is russet, and a dash of the same colour lies at the lower extremity of the line beyond the middle; the hind wings are brownish grey with a broad whitish cross line. The specimen, which is of the female sex, was from Dublin, and the form was not then supposed to occur in any other part of the British Isles. It is now, however, well known in Scotland and the North of England, and also in Ireland. Some examples that I have seen from Scotland are much larger and darker than the figure referred to. In his description of this form Stephens states that the fore wings are fuscous mixed with chestnut, with darker clouds. The caterpillar, which is figured on Plate 30, is green, becoming yellowish on the back; a rather broad stripe on the back of the front rings and the markings on the humps and on other parts of the body are purplish brown. It feeds on birch, alder, and sometimes hazel, usually on the former, in June, July, and August. In some seasons, and localities, the moth appears twice in the year: the caterpillar may then be found in September and October. The chrysalis is blackish-brown and rather glossy, enclosed in a cocoon composed of silk and sand or other soil, and may be obtained by lightly digging up the earth and sods at the roots of trees.