GREY BIRCH. 317 



sub-marginal line is whitish, inwardly shaded with dark greyish, 

 especially at the middle and towards the front margin. The 

 hind wings have two cross lines corresponding with the first 

 and third on the fore wings. There is a good deal of variation 

 in the amount of dark speckling, and this is occasionally so 

 heavy that the insect becomes dark grey in colour ; I have 

 taken such specimens at Oxshott in Surrey. Dark aberrations are 

 perhaps more frequent in the north of England, but the species 

 is more local and less plentiful in that part of the country. 



The caterpillar, which may be beaten from birch, and some- 

 times alder, in July, is bright apple green with yellowish lines 

 on the sides and back ; the ring divisions are yellow, and the 

 head is tinged with that colour. (Adapted from Porritt.) Some- 

 times the caterpillars are brownish, or greenish grey in general 

 colour. The moth, which is out in May and June, will be found 

 in woods, or on heaths, where birches grow. It rests on the 

 trunks of the trees and may be boxed, as a rule, with ease. On 

 some occasions, however, it is very lively, and the net will have 

 to be brought into action for its capture. 



The distribution of this species extends through England, but 

 it is far more plentiful in the south than in the north, although 

 it has been recorded from several places in Yorkshire, and from 

 Coal Law Wood in Northumberland. It is found also in Wales, 

 and in Scotland up to Moray. In Ireland it is not frequent, but 

 has been noted from Mucross, and the Upper Lake of Killarney, 

 in Kerry, and from Tinahely in Wicklow ; Kane also gives 

 Clonbrock in Galway, and adds that " some specimens from 

 this locality have the spots very large on a clear whitish ground, 

 so that they have a superficial resemblance to Cleora glabraria.^'' 



The range abroad spreads to East Siberia, Amurland, and 

 Japan. 



Note. — Staudinger places the last four species in Boarmia^ 

 Treitschke ; but Prout and others refer them to the genus 

 Ectropis, Hiibner. The latter will probably have to be adopted. 



