20 LEPIDOPTERA. 



is in many districts even more plentiful, and in this the per- 

 pendicular line is usually obliterated. Intermediate forms 

 retaining the division, but having the outer portion almost 

 any shade of brown paler than the inner, are not infrequent. 

 In some parts of the South Coast, and especially in the Isle 

 of Wio'ht, the brown of the basal half is invaded with white, 

 so as in some instances to leave a dai-ker central band and 

 even to furnish its lower half with a dark brown or black bar, 

 while in others the orbicular stigma and an oblique blotch 

 below it become white ; in all these the white outside the 

 perpendicular line has a chalky tint. In these localities the 

 female in some instances has similarly divided colouring. 

 In Berkshire and elsewhere inland the basal half is not 

 seldom of a rich purple-red or purple-brown, and the hind 

 marginal cloud similar or darker. But language altogether 

 fails to express the intermingling of all these variations. 

 One, however, stands broadly out from the rest in having the 

 fore wings unicolorous yellowish-drab, varying but little 

 darker or paler. This is a most remarkable form and has 

 repeatedly been mistaken for a distinct species — especially 

 when found, as in some parts of the Irish coast, in great 

 abundance and without admixture of the more typical forms. 

 Slightly intermediate specimens however do occur, though 

 rarely, either showing the central division, or more distinctly 

 the dark cloud of the hind margin. Various names have 

 been given to these forms, in the first place under the im- 

 pression that they formed distinct species, more recently as 

 varieties — one, rufuncida, often ascribed to this species, 

 belongs, I think, to the previous ; the rest, from our greater 

 knowledge of the intermediates, have lost all definite meaning 

 and seem to be of little value. 



On the wing from July to September. 



Larva, when two-thirds grown, three-quarters of an inch in 

 length, very smooth and shining, cylindrical and plump, but 

 tapering a little at both extremities; head very small and 



