embrace some portions of northern Africa. Tn Britain it appears 

 to be generally more common on the coast than inland, being taken 

 freely in the Scilly Isles and along the South Coast generally to 

 Kent on the East Coast, less commonly as one goes north, but it is 

 met with in Lancashire, Durham, Cumberland, and Northumber- 

 land. In Scotland it occurs at Ardrossan in the Clyde area, which 

 is, I believe, its northern limit. In Wales it is not uncommon ; 

 and in Ireland it has been taken in some numbers about Howth and 

 Malahide in the Dublin district, Kerry in the West, and Cork in the 

 South ; also in the Isle of Man and the Scilly Isles. 



Variation consists largely in the greater or less amount of the 

 grey dusting of the wings and the intensity of the clouding between 

 the sub-terminal transverse line and the margin, some specimens 

 taken in the Scilly Isles having this character very much intensified. 

 Also, in the whitish or yellowish (bone-coloured) tint of the 

 ground colour, and the intensity or otherwise of the transverse 

 lines. Occasionally aberrational individuals, possessing characters 

 not included in the above lines of variation, occur : to some of these 

 I may refer later. Speaking generally, the lighter forms, either by 

 reason of the whiteness of the ground colour as found in some of 

 the Devon and Cornish specimens, or the absence of grey scaling, 

 are found on the south coast, the darker or most heavily powdered 

 in the north, as at Ardrossan, where some of the darkest forms are 

 met with, but no hard and fast rule can be laid down, as is testified 

 by a specimen from Corfe Castle in the Bankes' collection, which 

 is quite of the bone-coloured, unspeckled form which predominates 

 on the south-east coast. The Irish, Isle of Man, and Scilly speci- 

 mens are generally of the darker well speckled form. 



Throughout the greater part of its range there appears to be only 

 one brood in each year, such continental authors as I have been 

 able to consult giving its time of appearance as May and June or 

 June and July ; there is only one brood in the more northerly 

 districts in Britain ; but on our south coasts there are undoubtedly 

 two fairly well defined emergences, the first appearing in June and 

 extending to about the middle of July, the second com- 

 mencing about the middle of August and continuing until well 

 into September. But although the emergences are fairly distinct, 

 not so the broods. For example, ova deposited by moths of the 

 June emergence will hatch in from ten days to a fortnight, and the 

 larvfe all grow evenly for a time; then some of them will grow 

 rapidly and make the August emergence, but others, possibly some 

 25%. of the brood, will grow slowly, hibernate as winter approaches, 

 and the moths from them will not emerge until the following June ; 

 so that while a part of this brood become imagines within a couple 

 of iBonths from the time that the eggs are laid, the other part take 

 a full year to complete their life cycle. So is it with the brood from 

 the August emergence ; the larva; all hibernate, and the majority of 

 them that survive the winter produce imagines in June, but a few 



