In the following cases the dark varieties were found originally only in the South. _Boarmia rhomboidaria_ gave rise about 40 years ago to a unicolorous smoky variety called _perfumaria_. This was at first peculiar to the London district, but it has since been taken in Birmingham and other large cities. More lately coal-black specimens have been found at Norwich, and others similar but hardly so dark were taken in the South of Scotland and at Cannock Chase. _Eupithecia rectangulata_ is a similar case. Formerly the light forms were prevalent but within sixty years they have almost entirely been replaced in the South of London by a nearly black form. _Tephrosia_ (_Boarmia_) _consortaria_ and _Tephrosia consonaria_ are exceptionally interesting, for they have both given off dark forms in the same wood near Maidstone, which is far from the usual "centres of melanism." They were discovered in this locality by Mr. E. Goodwin. That of _consortaria_ is a dark grey, but that of _consonaria_ is a full black, and nothing like either has been found anywhere else. These examples are all taken from the Geometridae but others, though of a less conspicuous kind, could be given from the Noctuidae or the Micro-Lepidoptera. _Acronycta psi_, for instance, has a suffused form which is believed to be becoming more frequent in the London district. _Polia chi_ has two dark forms, _olivacea_, a yellowish grey with dark markings, and _suffusa_ which is a darker, blackish-slate colour. Both occur in the North of England, sometimes together, sometimes separately, or mixed with the type and many intermediates. The distribution is peculiarly irregular. At Huddersfield, where the very dark form appeared suddenly about 1890, some 30 per cent. are said to be now dark and about 6-7 per cent. very dark, but at Saddleworth, 12 miles away, only the pale forms occur.