The species is so often confused with that previously mentioned that its distribution in our islands has not, so far, been clearly ascertained. However, it certainly occurs in the following northern counties of England—Lancashire (Liverpool district); Cheshire (Delamere Forest); Yorkshire (Cleveland district); North Durham (Birch woods); Cumberland (Carlisle). In Scotland it is found in Clydesdale, Perthshire, where it was first noted by Weaver in 1851, Kincardineshire, Aberdeen, and probably further north; in Ireland at Belfast and Enniskillen. Prout notes that he has seen a specimen from Swansea in South Wales.
Small Autumnal Carpet (Oporabia (Epirrita) filigrammaria).
This is most probably a small moorland form of O. autumnata, but it rarely assumes the silvery white typical coloration of that species. A male specimen and two examples of the female are depicted on Plate [77], Figs. 10 ♂, 11, and 12 ♀.
The caterpillar, which feeds in the spring on bilberry and heather, is green, with yellow lines, a line of darker green between the two central yellow lines along the back; head, green, inclining to brown above.
The moth appears in August and early September, and may be found on the moors, resting on rocks, stones, and even on the ground, as well as on the stems of its food plants.
As a British species it was first recorded by Weaver, who obtained it in the Isle of Arran in 1841; but Edleston, writing in 1842, states that he had taken specimens off stone walls near Staley Bridge, in the Manchester district, "every year for the last three years." It appears to be peculiar to the British Isles and is found in suitable localities from North Staffs., through Cheshire, Lancs., Yorks., and northwards over England and Scotland to the Hebrides and the Orkneys. In Ireland it is known to occur in Antrim, Derry, Mayo, Galway, and Limerick.
The Welsh Wave (Venusia cambrica).
This moth, of which two portraits are given on Plate [78], Figs. 9 ♂, 10 ♀, is known also by the English name of "Cambric Wave." It was not ascertained to be an inhabitant of Britain until 1839, when it was figured and described by Curtis from specimens obtained in Cardiganshire in Wales.