TRIFID.ii. 355 



lower enclosing the spiracles, which are blackish, but in some 

 examples quite black, and attended each by two black spots 

 beneath, on each segment from the sixth to the eleventh ; 

 head and dorsal plate pale grey-brown, the latter strongly 

 marked with the browner longitudinal stripes ; legs black ; 

 prolegs and undersurface yellowish-white or very pale grey ; 

 usual raised spots of the ground colour, each bearing a short 

 hair. 



According to Mr. Buckler, when younger they are greyish- 

 brown on the back, blackish-green on the sides ; subdorsal 

 stripes broadly blackish-green ; dorsal line pale grey, thin, 

 enclosed between, the subdorsal stripes. Along the middle 

 of the side runs in an undulating manner a pale greenish- 

 grey line, somewhat interrupted and irregular in thickness ; 

 and at some distance below, immediately under the black 

 spiracles, is a broad stripe of dirty whitish, having a fine line 

 of dirty whitish-green running through the middle of it. In 

 the middle of June, probably after a moult, much more 

 brightly coloured, pinkish or pinkish-ochreous on the back, 

 the dorsal line passing through a pear-shaped marking of 

 pinkish-grey on each segment, the small end of the pear 

 behind ; the sides dark pinkish-grey with opaque whitish 

 ragged lines below the spiracles, and the whole of the under- 

 surface and the prolegs white, rather shining, and having a 

 lovely opalescent gleam of pinkish. After ten days these 

 bright colours begin to fade and the adult colouring to be 

 assumed. 



Probably from October to July, on Helianthemum vnlgarc, 

 and doubtless on many other herbaceous plants, growing in 

 the chinks and crevices of rocks, and high up on rocky hill- 

 sides. Mr. Gregson says that he obtained a number of larvte 

 by digging out the vegetation from the lines of softer strati- 

 fication in the sides of rocks, finding the larvae among the 

 roots of the plants. Mr. Buckler's specimens were found 

 early in June, at which time they differed greatly in size, the 

 smallest being very dark, 



