640 The Zoologist — March, 1807. 



the larva, represented at figs. 1 and 2, plate vi., from Mr. H. P. van 

 Kaathoven, taken by him at Noordwijk. This larva spun up the fol- 

 lowing day, but during the spring of 1859 it dried up in the cocoon. 



On the 15th of July, 1860, I received a larva sent to me, by Mr. E. 

 A. de Roo van Westmaas, from Gelderland : this differed in some 

 respects from the former, and, like it, also failed to attain maturity. 



On the 31st of July, of the same year, I found two larva;, resembling 

 the last mentioned, at llozendaal, near Velp, on birch : they both 

 spun up on the 3rd of August ; one produced a male imago, the other 

 a parasite. 



All these larvae had yellowish heads, with an obscure gray margin 

 to the upper lip; the eyes were inserted in round black spots. The 

 first had a broad brown spot on the vertex ; the second, the head of 

 which was of a deeper yellow, had the brown spot more distinctly 

 divided in two ; while the two other larvae, again, had pale yellow 

 heads, but the brown spot was replaced by a small red blotch. To 

 this must be added that the head of the second larva exhibited a 

 longitudinal depression on either side of the vertex, so that that region, 

 looked at from the front, had more of a trifoliate appearance, see fig. 2, 

 which represents the head of the first larva, and fig. 3, representing 

 the head of the second, enlarged. 



The larva from Noordwijk had, moreover, a narrow green dorsal 

 line on the anterior segments, which line was not observed on the 

 other larvae. With this exception all the larvae were alike in form and 

 coloration. Body green, wrinkled, with small round paler green 

 spots on the folds. Stigmata oblong, with brown margins ; around 

 these the skin was somewhat more yellow. Above the stigmata were 

 round excretory ducts; see fig. 4, representing the stigma of the first 

 segment : it must, however, be observed that the oval indentation or 

 setting, as it were, was found on the first stigma only. Below each 

 stigma was a pretty large white wart, and somewhat lower the fold in 

 the skin was also white. The anterior legs were pale green, with black 

 claws, the under surface of the penultimate joint being raised like a 

 pad (fig. 5). Tlie larvae had twenty-two legs. 



These larvae were all found on birch ; the last two, namely, those 

 taken by me at Roosendaal, were the only ones I actually saw feeding, 

 but even these were very nearly full-grown, so that I am as little able to 

 give any account of the earlier stages of the larva as 1 am of the egg. 



The cocoon, which was either enclosed within a curled-up leaf or 

 attached to the flat surface of a leaf, or else stuck against the petiole, 



