TRIFID.^. 253 



smooth, dull grey-browu tinged in front with red-brown, 

 the scales a little drawn together at the back; fascicles pale 

 smoky-brown; abdomen flat teued, glossy mouse-colour; lateral 

 tufts very noticeable ; anal tufts small. Fore wings not very 

 broad, blunt, silky or greasy-looking, grey-brown or mouse- 

 colour, almost devoid of markings, except that the orbicular 

 stigma is represented by a black cloudy dot and the reniform 

 by two more, placed perpendicularly ; beyond these is the 

 faintest possible suggestion of a transverse row of smoky- 

 black dashes on nervures ; cilia concolorous. Hind wings 

 broad, rounded, faintly crenulated behind, smoky-white at 

 the base, shading off to smoky-brown at the hind margin, 

 and with a gloss of yellow or reddish over the whole ; extreme 

 hind margin edged by parallel undulating black and yellow 

 lines ; cilia smoky-brown, whiter at the tips. Female a little 

 stouter, but accurately similar. 



Underside of the fore wings pale smoky-brown along the 

 costal and apical regions, shading off to very shining pearl v- 

 white along the dorsal margin. Hind wiug-s dusky-white ; 

 costal region broadly dusted with brown, hind marginal 

 portion with smoky-brown ; central spot smoky-black. Body 

 rather silvery-brown ; legs purple-brown ; tufts paler. 



Variation in this species is but slight — a small degree of 

 darkening of the ground colour or of its being paler; 

 specimens of a pale silvery-grey are in the collections of 

 Messrs. Sydney Webb and Percy M. Bright ; and one very 

 nearly black was taken by Major Still on Dartmoor. 



On the wing in July and August, sometimes in Sep- 

 tember. 



Larva smooth, plump, cylindrical, but tapering very 

 slightly to each extremity ; no raised hump on the twelfth 

 segment ; head rounded, pale greenish-brown or yellowish- 

 green ; body rich green ; dorsal line broad, white, sometimes 

 tinged with pink or yellow, edged with dark green ; subdorsal 

 lines conspicuous, white, spiracular stripe similar ; spiracles 



