78 MICRODONTA BIOOLORA. 



surface to which the larva was attached, and this same 

 habit was observed before it laid up for the first moult. 

 At this stage they no longer skeletonised the leaves but 

 ate through the birch leaf from the top leaving the 

 midrib, in some instances eating out roundish portions 

 from near the top. 



On the 8th of July most of them had moulted the 

 second time and were then 9 mm. long, the head green, 

 the crown of the lobes darker olive-green, the body 

 green, showing a faintly darker green dorsal line, the 

 subdorsal stripe faint whitish, next below it a fine 

 yellowish line, and the spiracular line beneath ; the 

 twelfth segment slightly tumid on the back, the fine 

 tubercular dots blackish, anterior legs black. After 

 lying still for two or three days six of them moulted 

 the third time on the 13th, in four days they had 

 grown, but the larva was still slender for a Bombyx, 

 the length now being 19^ mm. or three-quarters of an 

 inch, the back was pale yellow, the dorsal line thin and 

 very dark green, the subdorsal line of pale yellow was 

 raised and separated from the pale back by a thin line 

 of dark green and was bordered below by another such 

 dark line, a thin pale yellow line followed, then a stripe 

 of darkish green, and next the inflated spiracular stripe 

 of bright and deeper yellow, the belly green, spiracles 

 black, having a halo of yellow, the head light yellowish - 

 green. 



The subdorsal stripe was rather lighter and brighter 

 than the back. At this time they ate away large por- 

 tions from the leaves, though the midribs still remained 

 uneaten. 



With some of the larvse the fourth moult began on 

 the 18th of July, others were two or three days later; 

 after this operation the colours were very bright, the 

 anterior legs were still black, but had greenish joints, 

 and the ventral prolegs bore each a black outside bar 

 above the feet, but there was no such bar on the anal 

 prolegs, which were shorter and were often held free 

 from contact with any object. By the 20th of July the 



