MICRODONTA BICOLORA. 77 



paper, on which they rested, scarcely one touching 

 another, although rather close together. 



The egg was of a good size and circular shape, 

 convex above and apparently flat beneath, the shell of 

 a delicate straw-yellow and glistening. By the evening 

 of the 25th the shell had become more opaque and 

 of a duller tint approaching a pearly buff, and showing 

 two dusky specks through the surface, some of them 

 showed in addition a faint ochreous central dark spot, 

 of which these dark specks formed a part ; these all 

 grew deeper in colour, and by the afternoon of the 26th 

 the large head of the embryo was plainly visible in the 

 centre at the top of the egg, the crown of the lobes 

 being of a dingy red colour, and the ocelli and mandibles 

 black. The rest of the shell, which was fuller and 

 plumper, had a faint greyish-buff tint, and with the 

 surface duller than before. In the morning of the 27th 

 four were hatched. 



The young larva escaped by a hole eaten through 

 the side of the shell and was tolerably active ; the 

 shining head had the lobes dark purplish-brown, the 

 front of the face light ochreous, the body a faint tint 

 of green and all the legs a dingy pink. By the 1st of 

 July their bodies had become an ochreous yellow-green 

 and the small narrow brown plate on the middle of the 

 second segment looked still smaller from the growth 

 of the larva ; they partly skeletonised patches by eating 

 the cuticle from either the upper or under surface of 

 the birch leaves on which they fed. When at all dis- 

 turbed they moved the fore part of the body quickly 

 from one side to the other. 



After their first moult, between the 3rd and 4th of 

 July, they were olivaceous yellowish-green, the head 

 with the face reddish, the dark purplish-brown of the 

 crown of the lobes melting gradually into the paler 

 colour of the face ; minute blackish dots marked the 

 situation of the previous brown plate, the whole skin 

 was as glossy as though varnished; the three hind 

 segments were often elevated a little free from the 



