72 LEPIDOPTERA. 



brownish-white or whitish-grey ; basal line obscnrel}* black ; 

 first line a rather faint grey oblifjue stripe bent back at the 

 costa ; in the middle of the wing is a similar but broader 

 stripe, embracing the short black discal spot and from it bend- 

 ing back and becoming a black cloud to the costa ; just 

 beyond this is a parallel similar stripe, also a little blackened 

 -as it bends back at the costa, in this are several small black 

 wedges on nervures; the outer edge of this stripe seems to 

 correspond with the ordinary " second " line, a very slender 

 grey thread there running through a narrow rivulet of the 

 ground colour ; hind marginal region nearly filled up with 

 darker grey except that a clouded and broken white sub- 

 terminal line intersects it ; below the discal spot is a black 

 streak on the median nervure ; cilia dark grej' ; all these 

 markings dull and obscure. Hind wings small, fnlly rounded, 

 greyish-white ; central spot black ; nervures of the dorsal 

 half streaked with black ; along the hind margin is a broad 

 dark grey band ; cilia dark grey. Female similar. 



Underside of the fore wings shining smoke-colour ; discal 

 spot black ; on each side of it is a pale yellow costal spot, and 

 along the hind margin a grey shade. Hind wings whitish- 

 grey ; central spot black ; beyond it is a slender curved 

 transverse row of blackish streaks. Body and legs grey. 



Not apparently very variable in any one locality, but the 

 ordinary brownish-white ground colour of the southern dis- 

 tricts alters gradually to greyer-white in the Midlands, and 

 in the North of England and West of Scotland produces, 

 along with various shades of pale grey, a fine smoky-black 

 form, very frequent at Paisley, and now well known, but which 

 when first met with was a cause of some perplexity. Indeed 

 the general shape of this species is so accurately that of several 

 others that in the absence of markings and of the usual 

 colour, the identification of this curious variety was a matter 

 of some delicacy. After many efibrts it was finally 

 accomplished by the late Mr. W. H. Tugwell. Mr. J. E. 

 Robsou tells me that in rearing this species he finds that 



