154 LEPIDOPTERA. 



is the undersurface. When younger, of a rather yellower 

 green. (CoudeAsed from Buckler.) 



August and September on poplar. On the Continent, also 

 in May and June. 



Pupa rather short and thick, rounded, with the limb- 

 cases well developed, undersurface a little flattened, tail 

 blunt ; shining brownish-black. In an ovate silken cocoon 

 of a semi-transparent drab colour, between two poplar leaves. 

 In this condition through the winter. (Buckler.) 



Only three specimens of this species are known to have 

 occurred in these islands. The first was taken on the trunk 

 of a poplar in Ongar Park Wood, Essex, in June 1839, and 

 the second in the same place in June 1841. Both are females, 

 and are in the collection of the late Mr. H. Doubleday, now 

 in Bethnal Green Museum. Of the remaining specimen, 

 which is in his collection, the Rev. Joseph Greene writes : 

 "In 1853 I was residing at Halton, Bucks. On the 18th 

 August of that year, returning home past a large black 

 poplar, I gave a branch a blow with my stick, and a 

 caterpillar fell into the grass. It was of a dull green and 

 with square brick-red dorsal spots. I placed it in a box with 

 moss and it went down at once. In the same month I left 

 Halton for Dublin. Before doing so I went to the rooms of 

 the Entomological Society, and consulted Hiibner. In one 

 of his plates I found that my larva was crcnata. I carried 

 the box containing the pupa, and those of other rarities, in 

 my lap, to Dublin, where I placed it in a greenhouse. One 

 day in the following March I found in it a small dull- 

 coloured moth just emerged. It was crcnata. I sent it for 

 exhibition to the Entomological Society in 1854." That 

 casual specimens should thus appear at long intervals is most 

 perplexing. 



Abroad it is found in France, Belgium, Holland, Germany, 

 Piedmont, and Central Russia. I do not see any suflBcient 



