TRIFID&. 125 



Underside of the fore wings dark smoky-brown, with two 

 yellowish-white clouds in the middle. Hind wings smoky- 

 white dusted with brown, and with a broad smoky-brown 

 band occupying the hind marginal space ; central spot very 

 small, black ; cilia of all the wings white, strongly spotted 

 with smoky-brown. Body and legs dull smoky-brown, fore 

 tibiae barred with white. 



Variable in size, specimens sometimes occurring of less 

 than one-half the ordinary area of wings, with all inter- 

 mediate sizes. Mr. Porritt has recorded the rearing from 

 larvae found in Kent, of the smallest form, in some numbers. 

 Variable also in the ground colour and general tone of colour 

 of the fore wings, from silvery whitish-grey to deep slate- 

 grey, brown-grey, and purple-grey. A specimen taken on 

 Dartmoor by Major Still in September 1894, and now in 

 Mr. Hanbury's collection, is of a very rich velvety-black, 

 with the Y-mark conspicuously silvery-white — a most 

 remarkable example. Another almost as unusual, in the 

 collection of Mr. Sydney Webb, has the silver Y reduced 

 to a V. 



On the wing at apparently all times of the year — even 

 sometimes emerging in December and January — but common 

 in the spring and early summer, and most abundant towards 

 autumn, being sometimes to be seen in myriads in August. 



Larva attenuated in front, the ordinary raised dots emit 

 long pale bristles ; it loops in walking, possessing only 

 twelve legs ; head small, rounded, shining, pale green with a 

 conspicuous black dash on the outside of each lobe ; body 

 velvety, pale or dark green, pulsating dorsal line darker, 

 edged on each side by a very sinuous white thread ; sub- 

 dorsal line also much waved, dark green; between it and 

 the white edging of the dorsal line is a broad whitish shade ; 

 spiracular line distinct, whitish or yellowish, margined above 

 by a darker shade of the ground colour; usual spots distinct, 

 whitish surrounded with green ; undersurface slightly darker 



