394 LEPIDOPTERA. 



is of uuiform deep purple-brown to brown-black or dull black, 

 often with the subterminal line more visible and yellow, or 

 dotted with yellow ; often also with blacker marbling on the 

 central band ; very often with a brightly contrasting yellow, 

 orange, or white reniform stigma. It may be remarked that 

 this stigma is most eccentric in colour, varying through yellow, 

 brown, and white, in every different form of the insect, and 

 apparently in no way governed by any tendency in them to 

 darker or paler. In all varieties the thorax follows the 

 colour of the fore wings, except that the back crest or the 

 portion lying between its tufts is erratic in colour, usually 

 not differing, but in some examples, without reference to their 

 colour, yellow, orange, reddish-brown, or even chestnut. It 

 is impossible without excessive verbosity to convey a full idea 

 of all the variations and shades of variation in this species ; 

 all are united by intermediates, though it must be admitted 

 that some of the extremes are decidedly more frequent than 

 their less pronounced allied types. Where every collection 

 contains curious variations it is hardly practicable to particu- 

 larise, but I must mention a specimen of which the dorsal 

 half of the wing and the broad hinder band are of a pale 

 cream colour, with the costal region and hind marginal clouds 

 blackish-brown, in the collection of Major A. Ficklin ; and 

 another from Ireland which is actually tinged with rosy- 

 purple. All the striking varieties were at one time supposed 

 to be distinct species and received a number of names — 

 i-niger, rava, furca, didyma^ but all were united by that 

 excellent entomologist, the late Henry Doubleday, and the 

 existence of intermediate forms has rendered these names 

 almost valueless. 



On the wing in July and August. 



Larva thick-skinned, suiooth and shining, cylindrical, 

 though a little stoutest at the thoracic segments, whence it 

 tapers to the rather narrow-pointed and flattened head, and 

 also gradually to the anal segment; head light brown, mouth 



