L1TH0STEGE NIVEARIA. 105 



rather slender, flattened beneath, of uniform bulk 

 throughout ; the head full large, and rounded. 



The colour is very variable ; the larva? reared on 

 Erysimum cheiranthoides were mostly paler than the 

 captured ones sent me by Mr. Brown, and as these 

 did not vary much among themselves, we have taken 

 their colouring and markings to form 



Var. 1. Ground colour dull olive-green all over 

 except the spiracular region, which is pale yellow; 

 very fine dorsal line of darker tint of the ground 

 colour ; sometimes there is a similar line on either 

 side of it, and sometimes again these appear only as 

 a pair of olive-brown or purplish wedge-shaped dashes 

 just before each segmental fold; subdorsal line 

 greenish-grey with darker edgings ; the spiracles 

 black, and just above and behind them, in the yellow 

 spiracular stripe, are suffused blotches of the colour 

 of the dorsal wedges. 



Var. 2. Ground colour of a fresher, more yellowish 

 green ; dorsal region full green ; spiracular region 

 yellowish, and the blotches in it of a darker purplish 

 tint than in var. 1, and more clearly defined. 



Var. 3. Ground colour greenish-white ; three very 

 fine purplish-brown or blackish lines down the back, 

 of which the central one becomes wider and darker 

 just before each segmental fold, and the other two 

 across the fold ; sometimes these lines are interrupted, 

 appearing only in the thickened parts ; sometimes 

 again they are all united by a transverse band just 

 before the segmental fold ; the subdorsal line paler 

 than the ground, but edged below with the dark 

 colour ; the spiracular region not differing from the 

 rest of the ground colour, with its wedge-shaped 

 blotches, not only above the spiracles, but also with 

 similar ones below them, in some specimens the 

 spiracular stripe being itself interrupted by these 

 pairs of upper and under blotches becoming partially 

 united ; the anal flap and the anal pair of legs dark 

 blackish-green or purplish-brown. 



