3o8 LEPIDOPTERA. 



upon the whitest walls. Similarly in the north of Ireland 

 white forms may be found quite at home on the black 

 basaltic rocks of the County Derry — where, strange to say, 

 dark varieties are never known to occur. 



At dusk it flies strongly and swiftly, and is readily attracted 

 by sugar or light, or captured flying along the roadsides and 

 the margins of fields ; but does not seem to frequent woods. 

 The only district of the South of England in which it is known 

 to occur is Devon and Dorset — in the latter very rarely, but 

 in the former abundantly in the Dartmoor district, where it 

 sits on granite blocks as well as on stone walls, and where it 

 was first noticed by Curtis early in this century ; it is also 

 found in less numbers on both the north and south coasts of 

 that county. One specimen has been taken at Oxford by 

 the Rev. C. T. Cruttwell, bat at Southam, Warwickshire, it 

 occurs regularly, and thence very soon becomes common in that 

 county, and in Leicestershire, Nottinghamshire, and the 

 Midlands generally, except the eastern portions ; also in 

 Herefordshire and Worcestershire ; further northward 

 common in all the more hilly districts and in many of them 

 plentiful. The darker varieties seem to be more frequent in 

 Lancashire and Yorkshire, and as already stated the darkest 

 forms are found in the south of the latter county, also in the 

 maritime portions of Durham and Northumberland. In 

 North Wales it is recorded from Dolgelly, and doubtless is 

 widely distributed, but I have never seen it in South Wales. 

 In Scotland it seems to return very much to the typical pale 

 colouring, or very rarely to that of the olive-green variety^ 

 and is widely distributed — Roxburghshire, the Clyde valley, 

 abundant and quite normal in Argyleshire and Perthshire, also 

 found in the more eastern districts to Moray — where it even 

 ascends the mountains to 1200 feet above sea level — and to 

 West Ross, though I find no record in the islands. In 

 Ireland, also, it is widely distributed and in many parts 

 common ; being of normal pale forms, and brightly coloured, 

 even in Sligo, Donegal, Derry and Antrim. Abroad, also, its 



