144 LEPIDOPTERA. 



which the whole band is occupied by this white colour except 

 the margins. Veiy often it only exists as a white ring round 

 the discal spot, and sometimes it is entirely absent, leaving 

 the central band of uniform dark colour. lu a specimen 

 whicii I took in a wood in South Wales the baud itself has 

 alnif).st disa[)pearod, being represented only bj' a small ovate 

 brown blotch around the discal spot and a much smaller spot 

 on the dorsal margin, in the collection of the late ilr. F. 

 Bond are specimens in whicli it is even more nearly oblite- 

 rated ; Mr. J. J. F. X. King has one taken in the south of 

 England, in whicli nothing remains of the usual markings 

 except a small oval brown spot near the costa ; and another 

 is on record having the baud divided into three separate 

 spots. Going to another extreme, there is a specimen in 

 Mr. Sydney Webb's collection entirely suffused with smoky- 

 black, with the nervures blacker, and but faint traces of the 

 central band. This was. 1 think, taken in South "^'orkshire. 

 In the Shetland Isles is found a distinct range of variation, 

 the specimens rather smaller in expanse, decidedly so in the 

 breadth of the fore wings ; the ground-colour more deeply 

 tinted and clouded with fawn-colour or light bright brown, 

 so as to form additional bands in the hinder area, sometimes 

 approaching in depth of colour to that of the central band ; 

 sometimes also the band itself is almost or quite divided into 

 stripes, or only the margins are dark, leaving the whole other 

 surface of the wing covered with pale brown clouding. In 

 these the white subterminal line is broadened and more dis- 

 tinct than usual. With these are normal and possible inter- 

 mediate forms ; further, Mr. Webb has one in which the 

 central band is blue-black, and I\[r. F. J. llanlnii-y one in 

 which the band is of the white ground-colour, but its margins 

 deep black and thickened, especially so in the middle, while 

 the outer areas are clouded with horizontal tawny dashes. In 

 the Orkneys the normal forms very greatly iirepouderate. yet 

 there is sometimes a tendency in the direction of those from 

 Shetland, some being of a soft pale fawu-bronn with the 



