SERICOKIDM—PENTHINA. 363 



reinaiiuler white shaded with lines of 'gv^\ cloudiug, sliowiiig a 

 white hook into the dark area, and liaviug some black cloud- 

 ing and dots at the apex. 



Antenna) and palpi dark lirowii ; head and thorax black- 

 brown faintly dusted with wliile ; abdomen grey-browu. 

 Fore wings elongated and rather narrow : costa but little 

 arched ; apex bluntly angulated ; hind margin almost per- 

 pendicular ; two-thirds of the wing from the base black 

 mixed with black-brown, but the space between the usual 

 basal blotch and central baud indicated by a white spot on 

 the costa, and a white cloud below it ; margin of this dark 

 area very oblique, and having just above the middle a small 

 white indentation, which is often hooked : remaining area 

 white with faint lines of minute grey clouds, which become 

 distinct and dark as they approach the apex, whore are two 

 or three jet black dots ; cilia black-brown dusted with white. 

 Hind wings pale smok}* brown with white cilia. Female 

 similar, usually a little larger. 



Underside of the fore wings jiale smoky brown with pale 

 yellow dots on the costa and hind margin, and one at the 

 discal cell. Hind wings creamy-white. 



Occasionally in Scotland the apical portion of the fore 

 wings is much blackened, and the general colour so intensi- 

 fied as to suggest that this may be the original of the form, 

 named by Curtis, Grccillana. 



On the wing in May and June, and sometimes as a partial 

 second generation in August and September. 



Lakva hardly described. Ur. Chapman says : " It is a 

 very active green larva, feeding on birch, between leaves flatly 

 united, in August, Se])tembor and October. The birches in 

 the gullies high up the hills are always the most productive." 

 The late Mr. Machin says : " It spins up between two united 

 leaves and lies in pupa during the winter." 



I'li'A very dull and rough ; nervures of the wing covers 

 more glossy ; uniform red-brown ; a strongly raised row of 



