The Zoologist— December, 18()9. 1919 



they did not, however, carry this part of the body raised in the air, 

 and, so far as T was able to observe, they had no ventral glands. 



After reading the description of niy larva;, it may perhaps be 

 considered tliat I have no right to call this species by the name of 

 Betulae, Hariig, as there is a considerable difference in the descrip- 

 tions of the larvae by De Geer and myself. However, De Geer says 

 expressly, and Hartig repeats the same words, " Sonst ganz glatt, 

 ohne Punlite und Flecke;" that is to say, in addition to the yellow 

 spots on the sides. I at once acknowledge that this difference is verv 

 great; and yet I am more willing to suppose that De Geer may have 

 been mistaken than that there is a third species agreeing in almost 

 all points with the perspicillaris of King and the Betulee of Hariig, 

 and also, like the latter, feeding on the birch. 



On the 25lh of June the larvas spun up on the surface of the mould, 

 which I had put into the box. The cocoons were of a more or less 

 dark brown and simple : this forms one of the characteristics of the 

 species. The imagos made their appearance on and after the 12th of 

 July. The female is 7 ram. long, expanding to 15 ram.; the male 

 is a little smaller. The head in both sexes is brown as far as the 

 antennae; the margins of the black compound eyes and a crescent 

 above the antennae are brownish yellow, the ocelli black. The 

 antennae are sordid brown with pale rings on the joints. Mouth 

 yellowish white, with shining brown mandibles. 



The thorax in the female is yellowish orange, with three shinin*' 

 black spots on the superior surface and four on the inferior • the 

 former are broadly elliptical, one, in advance, being on the central 

 lobe, the other two a little behind on the lateral lobes (fig. 7). Of the 

 four on the breast two are in the form of triangles on either side of the 

 neck on the prolhorax, while the two others are at the extreme lowest 

 point of the mesothorax. In the male the three dorsal spots are 

 united into a single large round spot, in which the scutellum makes a 

 notch ; this latter is brownish and posterior to it, between and behind 

 the cenchri, is an irregular black spot. The abdomen is orange, paler 

 in the female than in the male. The sheaths of the saw are brown ; 

 the anal styles yellow. Legs yellow ; in the female the posterior tarsi 

 are brownish, decidedly brown in the male. All the claws are brown ; 

 between them are rather large pulvilli. 



The wings are translucent, strongly iridescent, and have a yellow- 

 tinge at the base. The costal and postcostal nervures are yellow 

 margined with black on the inner side ; the externo-median nervure 



