On October 3, when one hundred and one days old, the caterpillar was pale primrose-yellow, and the stripes of a slightly darker hue, the white lateral line showing clearly, and spiracles brownish; the head pale buff with a faint lilac tinge, with a black patch above the mouth and brownish at the sides. In the previous stage the caterpillar was whitish-green with a rather dark green line along the middle of the back, this line bordered on each side by an almost white, very fine line, followed by alternate darker and lighter lines, the lightest being extremely fine; "then a subdorsal darker green line, bordered laterally by a conspicuous whitish line, which is again bordered below by a paler and indistinct green line, and a very faint spiracular whitish stripe, on which the spiracles are placed; they are white, outlined by a dark but indistinct ring; the under surface is whitish-green." About the middle of October the hibernaculum was formed by spinning two blades of grass together at the edges, so making a tube, in which the caterpillar remained during the winter. On March 21 it left its retreat, but did not seem to feed, and generally remained quiet, lying along a grass-blade. On April 3 "it had drawn together with silk six blades of grass at the ends, forming a tent-like structure, and along the surface of one of the broadest a little carpet of silk was spun, upon which it rested with its head uppermost; a silk cord also encircled its body round the fourth segment." It assumed the chrysalis state on April 8, and had then passed two hundred and eighty-nine days in the caterpillar condition. The chrysalis measures five-eighths of an inch in length, is fairly cylindrical, but tapering to the tail. "Dorsal view: the head is pointed in front in the form of a short conical beak; the eyes are rather prominent; the thorax is swollen in the middle, the widest part, and then gradually tapers towards the last segment, which is elongated and flattened. Lateral view: the beak is slightly upturned, the thorax convexed, and the segment next to the thorax is rather swollen in the middle, so forming a rather decided depression at the base of the thorax, where the silken cord passes round; the body gradually tapering to the last segment, which terminates in a long compressed curved process furnished with long hooks; the wing-cases extend down two-thirds its length, and only very little, if at all, swollen; the antennæ and legs are but feebly modelled; the tongue is well defined, it is dusky at the base, blending into black at the apex; the colour is of a very pale primrose-yellow, shading into pearly grey, and semi-transparent on the head, wings, and flap; a dark medio-dorsal line commences at the base of the beak, and passes down the entire length, gradually fading off in the anal extremity; it is blackest on the head and first abdominal segment, and palest on the thorax, where it is light brown; there are two