CIIEQUEllED MHITE. 27 



one was taken in June in White "Wood, near Gamlingay, Cam- 

 bridgcsliiie. Stephens captured one on the 14th. of August, 

 1818, in the meadow behind the Castle of Dover, where others 

 have since been taken by Mr. Le Plaistrier, of Dover. My 

 excellent friend, J. C. Dale, Esq., has also recorded the capture 

 of one about the same time near Bristol. 



Two broods occur in the year, the earlier one in April and 

 May, and the latter in the end of July and August. 



The caterpillar feeds upon Avild woad, base rocket, and wild 

 cabbage, and various species of Reseda and cruciferous plants. 



It is described by Boisduval as being of a bluish ash-colour 

 above, and on the sides covered with small black rais-cd dots, 

 and with fovir white stripes along the sides; beneath, whitish, 

 as are the legs, each with a yellow spot above it. 



The chrysalis is greyish, dotted with black, with several 

 reddish stripes. 



This fly varies in the expansion of its wings, from not quite 

 an inch and three-quarters to nearly two inches. The wings 

 are white, with a shade of cream-colour. The fore wings, 

 which are unusually pointed, the outer margin being slightly 

 concave, are blackish at the base, and there is a rather large 

 black spot about the centre of the Aving, where the transverse 

 veins appear of a white colour. The tip is irregularly marked 

 Avith black, irrorated with white, which is widest towards the 

 front margin ; the black j)atch is also marked with four irregular 

 white spots. The hind wings are white, the markings of the 

 under side shewing faintly through. 



Underneath, the marks of the fore wind's are of a crvcenish 

 colour, and there is a spot on the inner edge. The hind wings 

 are yellowish green, with three large M'hite spots, forming a 

 triangle, towards the outer corner of the wing, succeeded by an 

 irregular white bar beyond its middle, crossed by yellowish 

 veins, and with five white club-shaped spots on the outer 

 margin. 



In the female the black patch on the fore wings, which are 

 of a convex and rounded form, is darker than in the male, and 

 there is another small black patch near the inner margin. The 



