SESIIDyE. 79 



third the length of the wing ; in the female these are very 

 slightly indicated. Hind wings transparent with brown 

 nervures and the margins narrowly purple-brown. Cilia all 

 purple-brown. 



Under side of the fore wings pale purple-brown, suffused, 

 especially upon the margins and nervures, with glossy golden 

 scales ; hind wings iridescent blue with the margins, nervures, 

 and cilia, golden purple. Thorax black beneath, with a 

 yellow streak on each side ; abdomen also black, with a 

 broad central yellow belt. Antennte towards the base^ 

 beneath, yellowish. 



On the wing in June and the beginning of July. 



Larva whitish yellow with a darker dorsal line and with 

 scattered solitary bristles ; head and dorsal plate black-brown. 

 Lives in the trunks of poplars — Fojndus nigra andP. tremula — 

 making a gallery under the bark, in which it passes the 

 winter, becoming full fed at the end of May ; changing to 

 the pupa state within the burrow, but having previously 

 gnawed the bark so thin that the pupa is able to break 

 through it. (Hoffmann.) 



Pupa yellow brown. In a cocoon in the larva-burrow, in 

 the bark of the poplar. 



Always a very rare species in this country. Haworth 

 (1803) says " very rare near London." Samouelle (1832) 

 furnishes an accurate figure and description, giving the 

 same locality, and mentioning willow, as well as poplar, as 

 its food. Mr. H. Doubleday (1858) mentions that he has 

 taken three specimens in his own garden at Epping, Essex, 

 all of them near a trunk of aspen, which had been brought 

 in from the woods, and used as a support ; he also mentions 

 the capture of others in the neighbourhood, and of the dis- 

 covery of empty pupa skins protruding from an aspen trunk 

 in a wood. Stephens records it from Birch Wood and 

 Bexley, Kent, and from Colney Hatch Wood, Middlesex. 

 Besides these a few specimens have been obtained at 



