254 LEPIDOPTERA. 



trigonate ; eyes purple-brown ; head reddish-drab ; thorax the 

 same colour, very slender ; abdomen thin, pale straw colour. 

 Fore wings narrow, pointed, costa only arched beyond the 

 middle ; apex sharply pointed ; hind margin just beneath it 

 retuse, and very gracefully curved off ; colour pale yellow- 

 drab, with the costa and all the nervures shaded with reddish- 

 buff or fulvous, and the hind margin edged by a line of the 

 same colour ; cilia white. Hind wings narrow, with the hind 

 margin rather flatly rounded ; serai-transparent yellowish- 

 white with a faint tinge of fulvous round the apical margin, 

 and the costal area rather opaque ; cilia white. Female 

 similar. 



Undersides of all the wings pale straw colour, and their 

 middle portions more thickly clothed with scales ; all the 

 costal margins edged and clouded with fulvous and having 

 two or three faint brown dots. Bodj' and legs pale yellow, 

 the hind legs very long. 



On the wing in August and September. 



Larva light yellow-green, with slender reddish lines and 

 black raised dots; head small, glossy black; dorsal plate 

 with two black spots. 



In the spring upon Linaria simria (Milliere). 



Pupa undescribed. 



We have no more rare species than this. A specimen was 

 taken at Cheshuut, Herts, in September 1867, by Mr. W. C. 

 Boyd, and is still in his collection. It was captured while 

 flying at dusk, with an oscillating motion like that of a 

 house fly, in his father's garden, and is absolutely reliable. 

 It seems that no means by which it could have been acci- 

 dentally introduced existed near the place, whereas its food- 

 plant grew in a neighbouring field. Whether at the time a 

 sli"-ht immigration of this species took place there is no 

 evidence to show. It is a delicate little species, extremely 

 slender and inconspicuous, and very easily overlooked. 



