The Scottish Naturalist. 115 



main some days in the cocoon, until the limbs become firmer, 

 and get divested of the pupal covering, which sometimes ap- 

 pears to be a difficult matter. At this time the abdomen is 

 greenish. 



The larvae described by De Geer (Memoirs, 2., pp. 266-7., 

 No. 20, pi. 38., fig. 8-db), have been given by authors as those 

 of this species; but those reared by me, and they were taken in 

 different localites, do not agree with his account, in as much as 

 their heads were green with a yellowish tint, not pale orange- 

 yellow, and the dorsal vessel was not at any time remarkably 

 conspicuous like his. I have, however, found, but failed to 

 "rear, some larvae which agreed perfectly with his description, 

 and their habits were identical, so that it may be after all 

 merely a variety. 



Imago. — Head narrow, reddish-yellow ; eyes and a spot 

 on the top covering the ocelli, black ; lower half of the face whit- 

 ish-yellow; mandibles brownish-black. The antennae of the same 

 colour as the head, and about the length of the abdomen. Wings 

 long, with brownish nervures ; costa and stigmal spot pale testa- 

 ceous ; feet, light reddish-yellow ; the points of the posterior 

 tarsi, blackish. The upper surface of the body is sometimes 

 entirely black, with the exception of the last segment or two, 

 but occasionally all the thorax is reddish yellow, or only the 

 pro thorax, or it may be of that colour with black spots. Some 

 specimens have the last four or five segments also of that 

 colour. Two white oblong spots are close to the scutellum, 

 and on the anal segment are two sharp projecting prongs. 

 The anal segment is covered with short hairs. The underside 

 of the body is entirely reddish-yellow. Long. corp. 3^-4-lines ; 

 Exp. alar. 7-8-lines. 



Variety, of the female. Antennae, blackish-brown. 



The saw is short and narrowish, slightly bent at the base ; 

 the teeth, twelve in number, somewhat triangular, more of a 

 square shape at the apex, straw-coloured, with black lines going 

 across from the teeth to the back. 



The perfect insects made their appearance towards the end 

 of May, and may be beaten out of the birch trees during June, 

 but the larvae have not been met with earlier than August. 



After, a careful examination of this insect, I can see no 

 adequate reason why it and its allies should be formed into a 



