POECILOCAMPA POPULI. 471 



large, surface dull, numerous scattered hairs. The body pale bluish or 

 slaty-grey, much mottled with dark blue or blue-black, also with 

 yellow or orange on the lateral areas ; a well marked subdorsal reddish- 

 brown band present, not uniform in width, expands particularly at the 

 2nd-3rd abdominal incision, where it is also paler, and at the posterior 

 margin of 2nd abdominal segment encloses a conspicuous white spot ; 

 the band also forms a broad yellowish blotch on the 10th abdominal 

 segment (this widening can be traced towards the close of the first 

 stadium, but the lines are rather intercepted in this stage) ; tubercles 

 black, supraspiracular inconspicuous, forming merely a group of hairs 

 rising from skin-surface ; the lower lateral tubercles conspicuous, 

 especially on thoracic segments, being raised on projections of the skin 

 as in E. quercifolia ; hairs black and brown ; iv and v give rise to 

 lateral tufts or loose pencils of hair which curve downwards to resting- 

 surface ; this is also the case with the hairs from vii. (The hairs 

 appear to be raised and lowered to a slight extent, before moving 

 and on ceasing to crawl, much less so, however, than in E. 

 quercifolia.) In the third stadium. (May 19th) there is little change, 

 the ventral surface is still flatter ; the ground colour paler (dirty 

 white), the yellow (or reddish) subdorsal band less conspicuous, 

 although the pale extension on abdominal segment 2 is still 

 noticeable. Head dull black. The tubercles very inconspicuous, their 

 position, however, well marked by groups of hairs ; on dorsal area 

 their position is marked by black blotches, and on the 8th and 9th abdo- 

 minals are slightly raised above the skin - surface ; the subspiracular are 

 still raised on short fleshy processes which go to form the subspiracular 

 flange (broken at segmental incisions) ; the hairs long, slender, taper- 

 ing, simple and not serrated, mostly black on dorsal area, whitish on 

 lateral area, great diversity as to length occurs, some (the grouped 

 hairs) being quite long, others (the secondary) short ; the lateral area 

 is tinged with yellowish in addition to the dirty white and black mottling. 

 In the fourth stadium. (May 24th) the head is now greyish-white, mottled 

 with black ; the scutellar area is red or reddish-brown ; two white 

 dorsal spots on the meso- and metathorax, and four on each of the ab- 

 dominal segments to the 8th ; the other colours are much as in the pre- 

 ceding instar, with considerable individual variation, some being 

 greyer, others browner ; the venter and inner side of prolegs dull 

 yellowish-white, with a fine blackish medio-ventral line that enlarges 

 into a black central spot on each segment" (these form large blotches 

 on the abdominal segments 3-6) ; the lateral tufts or brushes of hair 

 are rather stronger and more compact, and the prolegs are widely 

 spread ; the larva is soft and flaccid, a condition that allows it to fit 

 exactly any contour of the twig on which it may be resting ; the 

 spiracles are large, black, situated directly above the lateral ridge. By 

 July 6th the larva? were full-grown in the ? sixth stadium ; there is then 

 no important change from the fourth instar ; the black ventral spots on 

 the yellowish ground colour are strongly marked, and there is considerable 

 individual difference in colour, some being much darker than others 

 (Bacot). Todd remarks that when twenty days old (after the second 

 moult) the larva? are greyish, just as if sprinkled over with the dust of 

 bran, the markings indistinct, with a reddish flame on each side of the 



* This character of the markings reminds one of the similar arrangement 

 found on the venter of the larvse of the Catocalas, Miselia oxyacanthae, and other 

 twig-resting larvre. 



