Typically (Plate 129, Figs. 1 [male], 3 [female]) the wings are white, "peppered" with black, and with more or less distinct cross lines, also black. The black speckling varies in amount, in some examples it is almost absent, whilst in others it is so dense that the wings appear to be black sprinkled with white. Specimens of the last form are intermediate between the type and the melanic ab. _doubledayaria_, Milliere (Fig. 2). This black form, which seems to have been unknown about sixty years ago, is now much commoner than the type in the South-west Riding of Yorkshire, and has spread into Lancashire, Cheshire, and southwards to Lincolnshire. On the wolds of the latter county, and on Cannock Chase, Staffordshire, it is said to be the dominant form of the species. The aberration also occurs in the eastern and the southern counties of England to Hampshire. Northwards, the form has extended to Clydesdale in Scotland, where one was reared from a caterpillar obtained near Paisley. In Wales _doubledayaria_ is in the ascendant at Newport, Monmouth, and in Ireland one example of this variety together with some intermediate and typical specimens were reared from caterpillars collected at Castle Bellingham, Co. Louth. Possibly the liberal distribution of the eggs of _doubledayaria_ may have had something to do with the comparatively rapid extension of this form, at least to districts far away from its original locality. What is known as the buff var. of this species dates back to {302} the year 1874, when a buff female, paired with a black male, was captured at Heaton Park. From the eggs she deposited caterpillars hatched, and in due course pupated, but the moths reared from them were all either typical, or black. Some of the female moths were, however, given to other collectors to pair with black males with the result that buff specimens appeared among the moths reared by seven collectors. Subsequently, by breeding only from buff males and females 80 per cent. of this form were said to be obtained. By the year 1880, however, the race was extinct. In all the examples of the buff var. that I have seen, including a pair in my own collection, the ground colour is normal, but the usual black markings of the wings are brownish buff; I understand, however, that there are specimens in which the ground colour is ochreous. The vapour of chlorine will change an ordinary specimen to a buff var.; and it is said that caterpillars reared in an apartment where this vapour is present will produce these buff varieties. Mr. Mansbridge has recently described ab. _ochrearia_, and in this form the typical black markings are present on an ochreous ground. The specimen, a female, was captured at St. Annes, Lancashire, June, 1891. Gynandrous examples have been obtained, and seven of these abnormal forms occurred in a single brood reared from eggs by Mr. A. Harrison.