In the var. rustica, shown on the same plate, it will be noted that the males assimilate somewhat to the female coloration; the specimens (Figs. 1, 2), were bred by Mr. Robert Adkin in 1887. This form was not known to occur in the British

Isles until 1885, when Mr. de V. Kane detected specimens in a collection of insects made in Co. Cork, Ireland. It was next heard of from Belfast, and then, in 1886, again, in Co. Cork, an example of each sex was taken. The female specimen laid eggs, and some of these were sent to Mr. Adkin, who not only was successful in rearing the moths, but in 1889 obtained a pairing between an almost white male rustica and an ordinary English female. Only four eggs were laid, and from these two male moths resulted in May, 1890, both intermediate in colour between the two forms. In all its early stages rustica is identical with ordinary mendica.

Male specimens with pale yellowish grey coloured wings have been reared from eggs laid by a female captured at Eltham, Kent, exhibiting a tendency to the rustica form. In the Barnsley district, Yorkshire, the males are paler than usual, but in the Sheffield area of the same county the males are black. From North Durham chrysalids, I have a smoky greyish form of the male.

The caterpillar is brownish grey covered with yellowish brown hairs arising from greyish-ringed pale brown warts; a paler line along the middle of the back, and some white dots forming a broken line below the black outlined spiracles. Head pale chestnut brown, glossy. When newly hatched it is whitish, tinged with yellow and semi-transparent; the dots and hairs are dark grey. After the first moult the colour is greyish with black dots and blackish hairs. Head yellowish, brown tinged. It feeds in July, sometimes earlier, and August, and seems to thrive on the foliage of many kinds of low-growing plants, such as dandelion, dock, plantain, chickweed, etc., and also eats the leaves of birch and rose. Chrysalis, very dark brown, almost black, glossy, but minutely pitted, giving a roughened appearance; enclosed in a close fitting cocoon composed of silk and the caterpillar's hairs, with particles of earth on the outside (Plate [79]). The moth flies at night, and except that a female may occasionally be seen on the wing, this species is rarely observed in the daytime. May and June are the usual months for this moth, but in 1906 a specimen was attracted to light on November 3.

Pl. 78.
1, 2, 3, 4, 6, 7.Muslin Moth varieties.
5.White Ermine, var. walkeri.

Pl. 79.
Muslin Moth.
Eggs, natural size and enlarged; caterpillar, chrysalis and cocoon.

Widely distributed, and often common in most English counties, in parts of Wales, and in Scotland as far north at least as Ross. In Ireland one male specimen of the typical form has been obtained in Co. Galway, and one in Co. Clare; var. rustica occurs in Co. Dublin, and Kings Co., Waterford, Cork, Kerry, and Galway.