2 Pl. 46. 1. PORTLAND RIBBON WAVE. 2. PLAIN WAVE. 3-6. RIBAND WAVE. 7-10. SMALL FAN-FOOTED WAVE. 9, 12. SINGLE-DOTTED WAVE. 8, 11. TREBLE BROWN-SPOT. 13, 14. LACE BORDER. [Illustration] 2 Pl. 47. 1, 1a. SINGLE-DOTTED WAVE: _eggs and caterpillar_. 2. RIBAND WAVE: _caterpillar_. 3, 3a. PLAIN WAVE: _eggs, caterpillar and chrysalis_. {119} THE PLAIN WAVE (_Acidalia_ (_Ptychopoda_) _inornata_). Somewhat similar to the last in appearance, but without reddish bands, and front edging to the fore wings; the second or outer line of the fore wings is generally distinct, but the others, especially the central, are often obscure. This species, one example of which is shown on Plate 46, Fig. 2, may be distinguished from the plain form of _A. aversata_ by its generally smaller size and more silky appearance; the cross lines are less distinct, and the outer one of the fore wings is not indented below the front margin. The eggs (Plate 47, Fig. 3a) are laid in strings of from 6-20; at least this is so in captivity. Like the eggs of other species in this genus that I have seen, they are at first whitish bone colour, changing to reddish. They were laid in July, and most of the caterpillars that hatched from them attained the moth state in September; about one-third hibernated, but died off during the winter. The much-wrinkled and rough-looking caterpillar is pale reddish brown, varying to greyish; the back with V-shaped marks, and a light coloured spot on rings 5 and 6. It feeds, from August to June, on dandelion, dock, and other weeds, also on sallow, bramble, heather, etc. The moth is out in July, earlier or later in some seasons; it affects woods in which there is plenty of heather or bilberry, and may often be seen resting on tree trunks, especially those of the pine. It is on the wing in the evening, and is said to visit the sugar patch, as well as flowers growing in its haunts. Widely distributed over England and Scotland to Moray, but does not appear to have been noted in Wales. Reported from Kingstown, Killarney, and Londonderry in Ireland. {120} THE RIBAND WAVE (_Acidalia_ (_Ptychopoda_) _aversata_).