250 LEPIDOPTERA. 



of the face, the upper part of the latter being reticulated 

 with the same colour; towards the mouth are several dark 

 brown streaks, whilst on each mandible, and also on each 

 side, is a dark brown spot ; dorsal stripe green, very narrow ; 

 spiracles oblong-oval, black, encircled with greyish- white ; 

 the hump on the ninth segment is darker than the ground 

 colour, the dark colour extending into a somewhat horse- 

 shoe-shaped mark ; the back of the ridge on the twelfth 

 segment is of the same ; segmental divisions pink. Ventral 

 surface greenish-white, with a large and conspicuous dull 

 black triangle on segments 7, 8, 9, 10, and 11 ; and paler, 

 more rust-coloured marks on the centre of segments 3 and 4 ; 

 legs and prolegs greenish-white, the former long and tinged 

 on the outside with pink ; the last three pairs of the latter 

 large and spread out ; hairs greyish- white. 



When half-grown the head is considerably wider than any 

 of the following segments and the colours throughout are 

 of a darker shade. (G. T. Porritt.) 



May to July on poplar — Populus nigra, P. tremula, and 

 P. alba — resting at full length on the twigs or small 

 branches, and from the form of the legs and prolegs, having 

 a sprawling appearance. 



Pupa of ordinary form, purple plum-colour, covered with 

 a greyish-white powder like the bloom of a ripe plum. In a 

 loose cocoon among dead leaves. 



The moth usually sits during the day upon the trunk of a 

 tree, to which its colour and markings closely assimilate it. 

 At dusk it flies, and has been taken at sugar and other 

 sweets, and even in bottles of such mixtures placed among 

 fruit-trees to destroy wasps. When sipping the sugar placed 

 upon a tree-trunk it sits with wings upraised, and must have 

 a very fine appearance. Always a rare species, probably only 

 occurring with us as a migrant, since there is no record, so 

 far as I am aware, of the finding its larva in these Islands. 

 No certain record of the earliest capture seems to exist. 



