32 LEPIDOPTERA. 



and especifilly so toward the costal margin before the apex. 

 In Scotland the tendency is toward a deeper darker slate- 

 grey, occasionally intensified to grey-black. This last form 

 has been found in Perthshire, but is comparatively common 

 in the Shetland Isles, where the species is more plentiful than 

 in the south, and it is stated that the blackest specimens are 

 found in those portions of the islands in which the rocks and 

 soil are blackish, while in districts close at hand, in which 

 the rock is of paler colour, ordinary grey examples are found. 

 The blacker Shetland specimens are sometimes wholly of the 

 slate-black colour, but often have the two stigmata and the 

 transverse lines outlined, faintly or distinctly, with whitish 

 or yellowish, while the usual black spots are somewhat in- 

 conspicuous, or else that between the stigmata is sharply and 

 intensely black. In these dark forms the hind wings are 

 tinged with smoky-grey, darker along the hind margin and 

 at the apex. Intermediate specimens occur in all shades of 

 slate-grey ; the pink clouding seems to be here unknown. 

 Along with these variations in colour, alterations in shape 

 occur, some individuals ha\nng their fore wings conspicuously 

 narrow. In Morayshire this peculiar form of the fore wings 

 is found associated with a clear pale grey colouring. Very 

 curious specimens are occasionally found in South Yorkshire. 

 One described by Mr. G. T. Porritt has the fore wings of a 

 rich chocolate-brown, the paler markings becoming very 

 distinct ; it has also dark hind wings ; at Sheffield obscure 

 dark slate-grey varieties occur along with those of ordinary 

 colouring. In the collection of Mr. S. .1. Capper are two 

 individuals having the usual black spot which precedes the 

 orbicular stigma produced into a sharp horizontal wedge, the 

 point of which is toward the base of the wings. 

 On the wing in August and September. 



Lakva smooth, cylindrical, or very slightly tapering toward 

 the head, which is a little smaller than the second segment, 

 and of a pale brownish-grey colour; general colour of the 



