248 BKITISH BUTTERFLIES. 



above it a ruddier tone by comparison, and the lower half of the slopes 

 a pale one, though these two areas are of much the same tint. There is 

 a dark dorsal line. On the abdomen this occupies the whole of the 

 dorsal plain, which is very narrow. On the meso- and metathorax 

 there is a pale space on each side of it, where the dorsal plain becomes 

 the anterior slope. The lateral slopes are very flat. The oblique lines 

 are on the 2nd and 3rd thoracic and 1st to 7th abdominal segments ; 

 the prothoracic plate is nearly square, with diagonals across the segment 

 and longitudinal ; it has a double dark dorsal line, and a dark shade to- 

 wards the lateral angles. Head and legs black. There is still a double 

 dorsal crest of hairs, and a lateral one ; the slopes are well covered 

 with very short hairs, all pale ochreous, nearly white. (2) Two other 

 larvae assumed to be in the third instar (one just moulted, 6mm. long ; 

 the other somewhat grown, 10*5mm._ long) : The larger one (10*5mm. 

 long) is reddish-brown, with black, smooth, and shining head. Head 

 nearly 1mm. across ; body about 3*0mm. from metathorax to the 6th 

 abdominal segment ; the chief tapering at the ends, i.e., at the pro- 

 thorax, and in the 9th and 10th abdominal segmental areas, so that the 

 ends look rounded. On the abdominal segments the two dorsal flanges 

 or ridges are very close together, and give a long slope, which is fairly 

 flat from dorsal to lateral flange. The larva is much flatter and 

 thinner than that of Iiuralis betulae, i.e., the slopes are not nearly 

 so steep. The dorsal flanges separate on meta- and mesothorax, but, 

 on each segment, it is in a separate curve, and it is hardly present on 

 the prothorax, so that, though there is a front slope between the 

 flanges, it is not so trim and exact a triangle as in Iiuralis betulae. 

 The dorsal and lateral flanges try, not quite successfully, to be white, 

 and present, therefore, pale lines ; on the prothorax they do not 

 continue, but there is, on either side, a short line in front of the 

 prothoracic plate, and a larger one (obliquely outwards and backwards) 

 outside it. The pale dorsal triangles (so marked in the larvae of 

 Callophrys rubl) are present on the metathorax and lst-6th abdominal 

 segments, but modified on the 7th and 8th abdominals to lines; they are 

 outlined by the pale dorsal line, and an oblique pale line from a little 

 outside the flange in the front of the segment, outward and backward 

 at an angle of about 45° to posterior margin of segment; the included 

 area is paler than the lower portion of the slope. The oblique line is 

 shown up by another dark oblique line forming a lower border to it. 

 The segments are divided into two subsegments, and this is well seen 

 where the division crosses the oblique lines. The dorsal lines, it should 

 have been noted, are interrupted, and only occur on the posterior half, 

 or two-thirds, of the segments. The prothoracic plate is shining, slightly 

 fuscous ; the anal plate is small, round, dark, and has a pale 

 bordering line. There are still crests of hairs along the dorsal and 

 lateral flanges, those on the slope being much shorter. (3) Seven 

 other larvae assumed to be in the same instar (May 11th, 1907) : 

 Length 9mm. Colour and markings much as in last skin, a deep 

 rich brown, with dark dorsal plain, widened on thorax, bordered 

 by a pale (yellowish-white) line down the dorsal ridges. The latter 

 are about 0'12mm. apart on the abdomen, about l'5mm. on the 

 mesothorax. The oblique lines art.' pale, edged with darker beneath ; 

 on the 7th and 8th abdominal segments they are straighter, almost 

 parallel with dorsal lines ; on the 10th abdominal segment 



