THE GENUS ACRONYCTA AND ITS ALLIES. 195 



2nd skin (after the ist moult), the tubercles are black, and so 

 closely packed as to make the larva at first look black ; lo is 

 a weak, and ii a very weak segment, as regards the develop- 

 ment of the tubercles ; on the others, the anterior trapezoidals 

 form a large boss, each spiculated like a hedgehog by the 

 bases of the hairs, which are 8 or g in number, 5 or 6 on the 

 posterior trapezoidal, and 6 or 7 on the supra-spiracular, the 

 post-spiracular already dwindled to little more than a point 

 with I hair. The alternation of light and dark segments is 

 still very plain, the posterior spiracular tubercle is very small; 

 on segment 12 the trapezoidals are welded into one boss, the 

 nth is still markedly small. The larva gets thicker from i to 

 5, remains nearly uniform in 6 and 7, tapers again to the nth 

 segment, the 12th being again large. In some specimens, 

 there is a lighter region, almost amounting to a band, between 

 the trapezoidal tubercles, and, in a very few, a white patch on 

 the dorsum of the 3rd segment. They still like to feed 

 gregariously, but a solitary larva does not appear altogether 

 unhappy, as is the case with distinctly gregarious larvae, such 

 as }'oung Moma orion or Endromis versicolor. 



After the 2nd moult (in 3rd skin), the colour is rufous, 

 marbled in two shades, with an indication of a paler line be- 

 tween the anterior and posterior trapezoidals, most marked on 

 3.4, 6.7, 10 and II, and there is a decided white spot above the 

 subspiracular tubercles of 2, 3, and 4 ; roughly speaking, how- 

 ever, the general tone and tint is fairly uniform, and shows up 

 the black tubercles distinctly ; these possess 3 or 4 strong and 

 6 or 8 paler bristles, they are not quite so large as in ruuncis, 

 the post-spiracular still exists as a dot. 



The 5th segment is the largest, and thence the larva tapers 

 regularly backwards, the 12th segment being a doubtful excep- 

 tion, owing to the rather larger size of its tubercles. \Mien 

 full grown (in 3rd skin), the dorsal region, extending to the 

 anterior trapezoidals, is darker (brownish fuscous), and a 

 yellowish band may be described between the trapezoidals, 

 whilst below them the sides are marbled with brownish fuscous 

 and a dirty yellowish white. 



In the 4th skin, when the larva has attained a length of 

 14 mm., the colours are black and orange, the bluish grey 

 sides and yellow subdorsal band contrasting with the black 

 tubercles, somewhat suggest the full-grown larva of Pontia 

 brassiccE. The dorsal area, between the anterior trapezoidals, 

 is a deep reddish brown, almost black; between the trape- 



