250 BRITISH BUTTERFLIES. 



lines indicating them, for they are very flat, separate on meso- and 

 metathorax. A large quadrangular prothoracic plate, but with the 

 angles situated as anterior, posterior, and lateral, oehreous, with fine 

 hairs ; a yellow transverse line behind it, and yellow lines between it 

 and lateral yellow line. Mesothorax but slightly above prothorax. 

 Seen laterally, each segment rises high above the deep incisions ; some 

 small lenticles round the inconspicuous spiracles ; general surface 

 covered with very small pits, leaving intermediate ridges that, in 

 places, run, in some degree, into line. Fourth (and last) instar : As in 

 so many Kuralids, there seem to be only three larval moults and four 

 larval instars. In the last, the hairs are exceedingly numerous, very 

 short and very thick, so thick and short as to be almost another sort 

 of hair from those in the earlier instars. They are of various lengths, 

 but the longest on the abdominal dorsum (representatives of tubercles 

 i and ii) are much shorter, not much more than half the length of the 

 seta3 of i in the first instar, but they are two or three times as thick ; 

 short, straight, rather thickened in the middle (or perhaps narrower at 

 their bases) ; the spiculseare acute and recurrent, running down the shaft 

 a long way. The hair-bases have the radiating lines, and the sections 

 are more rounded (and petaloid) than in previous instars. The margins 

 of the spiracles are spread out in a flange, and in this are embedded 

 four to eight small lenticles ; there are lenticles generally distributed, 

 but a group of six to seven occurs near the spiracles (most of them 

 above). The edges of the lenticles present irregularities of margin, 

 variously developed in different specimens, in some looking like five or 

 six spicules radiating from the margin, in others like a widening of 

 the margin and its divisions by lines like those in the hair- bases ; the 

 latter is more likely correct, as the lenticles are certainly more allied 

 to hair-bases than to hairs. The skin-surface is finely reticulated in 

 a pavement-epithelium pattern in very transparent colourless lines. 

 The ventral line throughout is, as before, spiculated. The prothoracic 

 plate has a definite median suture (wanting in previous instars) ; it 

 has about 60 very short hairs on each side, and about fifteen lenticles. 

 The hairs on the true legs look smooth and of ordinary pattern when 

 slightly magnified, but a stronger lens shows them to be spiculated 

 like the others. The anal plate is nearly round, with about 60 very 

 short hairs and lenticles. The prolegs have the two pads of hooks 

 practically united into a continuous set, but with an angle where they 

 meet ; the hooks are about 24 in the front group and 35 in the 

 posterior, in one row of alternating larger and smaller hooks, the large 

 ones being largest in the front portion ; the inner row is of about 24 

 rather smaller hooks, also of two alternating sizes (Chapman). Final 

 instar: Just before its last moult it is 8mm. long, but, in the last instar, 

 it grows considerably, and, when fullgrown, is 16mm. long and not 

 quite 5mm. wide. The head is small, rounded, and entirely retractile 

 into and under the prothorax ; viewed from above, the prothorax is 

 longest, and tapers to the head; the width is almost even from the 

 mesothorax to the 8th abdominal, the latter a little narrower than the 

 rest, whilst the 9th abdominal is much narrower, and tapers roundly 

 in almost a circular curve. Viewed sideways, the back arches in a 

 curve, highest at the 1st and 2nd abdominal segments. The segments 

 are strongly divided, each sloping forward so that the back edge of the 

 next rises like a notch, except between the pro- and mesothorax, for 



