THE BRIMSTONE 
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and angular at the tips ; the hind pair are angular at the 
middle of the outer margin. There is a very distinct sexual 
difference in colouring. 
Male. (Upper Side.) The upper side is a brilliant lemon- 
yellow and there is usually a very slight greenish-yellow tinge 
on the hind wings. Each wing has a deep orange central spot, 
The Brimstone hibernating. Sketched from life. 
much larger in the hind pair. At the end of each nervure is 
a very small chocolate-coloured dot, and the apical half of 
the fore wing is finely margined with the same colour. (Under 
Side.) The under surface is duller in colour, inclining to 
huffish on the hind wings, and in some specimens on the 
apex of the fore wings. 
Female. The female is dimorphic, one form having the 
