This species is very abundant in the neighbourhood of Wellington. It has also occurred at Palmerston North, and is probably common throughout the whole of the North Island. In the South Island it has been taken in the Otira Gorge, and at Dunedin, Otara and Invercargill. The expansion of the wings is about 1-3/8 inches. _The fore-wings of the male vary from pale orange-brown to dull yellowish-brown_; there is a doubly curved dark brown transverse line near the base; _a broad straight line a little before the middle; a very strongly curved line a little beyond the middle, and a less strongly curved line near the termen, often composed of a series of triangular white dots edged with dark brown_; all these lines are much stronger on the costa, and are sometimes almost obliterated elsewhere. The hind-wings are pale yellow, with several brown-edged white spots at the tornus, and an indistinct line parallel to the termen. The apex of the fore-wing is considerably produced, and there is a large rounded projection on the termen. The hind-wings have several small projections on the termen. In the female the fore-wings are pale yellow or orange, the transverse lines and white spots are usually more conspicuous, and the projections on the termen of the fore- and hind-wings larger. This is a very variable insect, especially in the male, some specimens of which sex are very much clouded and dappled with dark brown both on the fore- and hind-wings. {89}Many of these darker forms might readily be taken for distinct species, when compared with the pale orange-brown variety, but a good series of specimens presents numerous intermediate forms which completely connect these extreme varieties. The females also vary, but are never as dark as the males. The larva feeds on _Todea hymenophylloides_, a fern which grows in shady places in the depths of the forest. The length of the caterpillar when full grown is about 1¼ inches. It is very variable; some specimens are dull brown, with a row of green or pale brown lunate spots down each side, and a dark brown line down the back. Others are bright green, with a diagonal reddish-brown stripe on the side of each segment; the segmental divisions are reddish-brown, intersected by numerous very minute whitish lines. The pupa is enclosed in a loose cocoon on the surface of the ground. The perfect insect appears from November till March, and is very common in forest regions. It may often be dislodged from the dead fronds surrounding the stems of tree-ferns, and is also met with in great abundance towards the end of summer on the blossoms of the white rata. Genus 4.--SESTRA, Walk.