150 THE BNTOMOLOaiST. 



head pressed against a small outstanding twig. When paired, 

 the male is usually upside down — the only time it assumes this 

 position — and is consequently rather difficult to see. Both sexes 

 also sit on posts or the trunks of birches, if these occur in their 

 chosen haunt. The males are very fond of sunshine, and some- 

 times spread their wings and bask like a butterfly. We saw one 

 male even flying in the sunlight, low down and very swiftly. 

 Their true flight-time I did not discover, but probably it is at 

 night, which is also the time of emergence. The insect appears 

 to be very sluggish, clinging very tightly, and finally falling with 

 legs drawn up, feigning death, the wings either tightly closed or 

 held up over the back. 



We never met with a really worn specimen, though they 

 continue to emerge the whole of April. In captivity the first 

 emerged on January 31st, and the last on May 7th, in 1902. 

 The insect is very local, many apparently suitable spots being 

 quite untenanted. In all cases, however, they were near a small 

 stream, doubtless owing to the abundance of their food-plants in 

 such a situation. 



The males vary only slightly in depth of colour and thickness 

 of the black bands, and in ground colour both of fore and hind 

 wings, which is white or pale grey. One I obtained was so dark 

 grey as to appear almost uniformly smoke-coloured. In two others 

 the reverse occurred; the black bands had almost vanished, being 

 represented only by two thin black lines and a black discal spot. 

 The scales on thorax and abdomen were also much whitened. 



The females vary in the amount of orange dusting. In some 

 it is absent altogether ; while in one I took it is so intense that 

 the insect appears to have an orange ground colour. In two 

 others dull yellow replaces all the orange, and the hair is very 

 short. I also found a female in which the rudimentary flaps 

 representing the fore wings were more than twice the usual length, 

 the hind flaps being normal ; doubtless a case of reversion. 



I have one other remark to make. The scales on the under 

 surface of both wings are present, very thin, and not overlapping, 

 it is true, but no thinner than on the upper surface ; certainly 

 not totally absent, as Barrett has described in his recent work. 

 To the naked eye, however, the under surface does appear smooth 

 and shiny. 



[Nyssia la'pyonaria was made known as a British insect in 

 1871, but only one specimen was then obtained. This example, 

 a male, was taken in Perthshire by Mr. Warrington (Knaggs, 

 Ent. Mo. Mag. vii. p. 282 ; Ent. Ann. 1872, p. 116 ; 1874, pi. i. 

 fig. 2). About ten years ago Mr. William M. Christy obtained 

 the species in Scotland ; and in 1895 he sent ova to Mr. F. W. 

 Frohawk, who was thus enabled to study the metamorphoses of 

 N. laiyponaria, and to describe and figure its stages from ovum 

 to imago (Entom. xxviii. pp. 163, 237). — Ed.] 



