TRTFTD.E. 103 



has the fore wings pale drab. In the fens of Norfolk, where 

 the insect is plentiful, there is great variation towards dusky 

 red of various degrees, and also in some degree towards 

 brown, also in another direction towards the increase of the 

 dark clouding upon the median nervure, with corresponding- 

 darkening of the costal an-a ; a comparatively rare form from 

 this district is of a dull purplish-drab, deeply shaded with 

 smoky-brown, and having very dark hind wings. Another 

 form, found in Scotland, has the fore wings dark purple-red 

 with the uervures hardly darker, but the hind wings very dark 

 smoky-brown ; it is also smaller than ordinary specimens, and 

 with it are females tinged with the same red colour ; but also, 

 everywhere, are the ordinary paler and whitish-drab forms. 

 In Ireland the males are said to vary almost to brick-red. 

 On the wing at the end of August and in September. 



Larva of uniform moderate stoutness from the fourth 

 segment, though tapering a very little behind ; in front 

 becoming rapidly narrower from the third segment to the 

 head, which is remarkably small and tapering ; all the 

 segmental divisions rather deep ; intermediate wrinkles 

 numerous ; skin much dimpled along the sides. Head . 

 glossy, light brown, mouth darker brown, ocelli black ; dorsal 

 plate pale brown with the front margin darker ; body shining, 

 of a pallid flesh-colour with a deeper dirty flesh-coloured 

 internal vessel sliding to and fro between the third, fourth, 

 and fifth segments ; dorsal stripe pale yellowish-pink, softly 

 defined between broader stripes of a shade of grey-brown ; 

 spiracular stripes broad, pinkish-grey-brown, through which 

 is visible the tracheal thread of dark grey from the spiracles, 

 which are black; anal plate rough, light brown with a 

 narrow additional plate in front of it ; raised dots minute, 

 dusky-brown, only perceptible under a good lens, each bearing 

 a short bristle ; ventral surface pale flesh-colour ; legs light 

 brown. When about to pupate all the stripes disappear and 

 the skin becomes porcelain-white, strongly contrasting with 



