THE GENUS ACRONYCTA AND ITS ALLIES. 219 



sub-spiracular tubercles are smaller and paler. Except the 

 post-spiracular, which appears to be obsolete, all the tubercles 

 are highly developed and have 5-10 hairs. The inner dorsal 

 tubercles, however, of 3 and 4, are worthy of special note, 

 they stand up, leaning somewhat forward, as great mammillae, 

 narrowing towards the apex. Other tubercles somewhat 

 approach this form. When full-fed in this skin the larva has 

 a riband-like aspect due to the sides being parallel and the- 

 back flattened, and the flattening appears more complete than 

 it really is, from the arrangement of the colouring, viz.,hro3.d\y 

 noted, a yellow larva with the flat dorsum coloured dark claret 

 or deep red, in which are three yellow lozenges stretching 

 across segments 5, 7 and 10, and in the others, two yellow 

 spots, marking the outer ends of such lozenges, these being 

 smallest on 6. 



After the third moult (in fourth skin) it is a red larva with 

 black and yellow markings, a black lump on 6th segment 

 (with two yellow dots behind) a yellow raised patch (hump ?) 

 on 5, 7 and 10, and a small black hump on 12. The red 

 colour is due to the trapezoidals which are so coloured and of 

 large size. On the yellow patches (5, 7 and 10) they are 

 yellow, and on 6 black ; on 12 their inner halves are black. 

 The back is otherwise black from the upper margin of the 

 supra- spiracular tubercles, with two very narrow yellow dorsal 

 lines indicated, one between and one below the trapezoidals ; a 

 conspicuous yellow (nearly white) patch is present on each 

 side in front of hump on 12. The sides are marked by several 

 alternate lines of yellow and fuscous, the lower parts are very 

 delicate and transparent still, and may be called colourless or 

 pale fuscous. The hairs are whitish and longer than the 

 diameter of the larva, more than twice this on 2, 3, 4, 12 and 

 13. The head is black with yellow marblings and a yellow- 

 patch at upper end of clypeus, and one on each side of this. 



From this to the last skin there is little change except in 

 the abundance and conspicuousness of the hairs. In the last 

 skin these are either rufous or whitish, but always so abundant 

 as to make it rather a hairy larva, they especially hang 

 abundantly over the head Skye-terrier fashion. 



A specially pale larva possesses yellow lozenges on segments 

 4 to 10 or II, encircling and including the trapezoidals, much 

 like those on A. alni. On 5, 7 and 10 the tubercles are of 

 same colour, on 9 only, the posterior trapezoidals are red and 

 linked together by a red band, in the others (4, 6, 8, 11), 



