86 



The expanse of wing varies from one and three eighths inches to 

 shghtly over two inches. The smallest specimen is a dwarf male, 

 which emerged on the last day of September. With this exception 

 all the very small specimens — about half a dozen — are females, and 

 were the last to emerge. The sexes are on the whole of about equal 

 size — that is to say, the size varies in both to the same degree, the 

 largest males being fully equal to the largest females in expanse 

 of wing. 



A few specimens are abnormally shaped. One female has the tip 

 of the left fore-wing prolonged, and another has both fore-wings 

 narrower and more pointed than usual. One male has the right 

 fore-wing shorter than the left, though quite as broad, the abnormal 

 wing being very bluntly pointed and the hind margin strongly convex. 

 Another male has both wings on the right side deeply notched, 

 evidently caused by the belt of the pupa; several others are also 

 slightly marked from the same cause. 



There is no variation of any importance in ground-colour, though 

 some of the small females are rather paler than usual. The dark 

 borders of the wings vary in breadth, sometimes extending in a 

 narrow streak along the inner margin of the fore-wings, but in others 

 only just including the anal angle. In the males this border is 

 always dusted with yellow scales on the fore-wings, but more so in 

 some specimens than in others. In thickly dusted specimens the 

 yellow scales are also present in the borders of the hind-wings, but in 

 a much less degree. One male has the yellow ground-colour dusted 

 with black scales for a short distance from the margin of the dark 

 border of the fore-wings. Other males also show slight indications 

 of this black dusting. The veins of the fore-wings are seldom marked 

 with yellow scales where they cross the dark border, except those 

 near the costa and the one which touches the anal angle. Sometimes, 

 however, all the veins are so marked, but not across the whole 

 breadth of the border, the yellow colouring always failing to reach 

 one or both of the edges. In the borders of the hind-wings the 

 veins near the anal angle are sometimes slightly marked with yellow, 

 but this is more frequently absent altogether. In the female the 

 borders are never dusted with yellow scales ; but the yellow spots of 

 the border vary from mere points to large and conspicuous blotches, 

 both on the fore- and hind-wings. The smaller spots disappear 

 entirely in dark specimens. 



The central spot of the fore-wings varies greatly in size. At times 

 it is narrow and crescent-shaped, and in one or two specimens it is 

 unusually large and almost circular. It is sometimes centred with 

 yellow, and at others dusted with yellow scales. 



The underside varies in depth of tint, both in ground-colour and 

 markings. The spots forming series parallel with the hind margins 

 of both fore- and hind-wings, black in the former and rust-colour in 

 the latter, vary in size and number. The spots nearest the anal 

 angle are the largest, the others gradually diminishing in size, and in 



