ARCTIID^. 251 



the costa are partly white aud partly yellow, while in Kent 

 the yellow deepens to orange and occupies these two spots 

 completely, sometimes extending to the third. Mr. A. E. 

 Hall has a specimen with all the spots of the fore wings 

 pale orange, and Ur. P. B. Mason one in which they are large 

 and reddish, while one in the collection of the late Mr. F. 

 Bond has them all of a lovely yellow. Others exist in 

 several cabinets in which these spots are all dull black, the 

 remainder of the fore wings being of the usual brilliant 

 green-black, or even bluish-black. Another phase of vari- 

 ation is in the colour of the hind wings, which occasionally, 

 though rarely, become pale yellow, bright yellow, dull 

 golden, or orange, or the black spots are bordered with yellow. 

 Mr. S. Webb has one with the hind wings black, another in 

 which they are suffused with smoky-black, and a magnificent 

 specimen in which the spots of the fore wings are very large, 

 pai'tly confluent and wholly white. 



The form with yellow hind wings seems to have been 

 described, as a species, under the name Rossica, Kolenati ; and 

 that with the pale spots tinged with reddish has been called 

 BitkyniccL On the wing in June. 



Larva rather elongated : head rounded, shining black : 

 body black, with a broad bright yellow dorsal stripe, much 

 intersected by the black ground colour, and enclosing two 

 white spots on each segment ; similar lateral stripes, each 

 with one wliite spot on each segment ; below these a row of 

 white spots ; usual spots raised into shining black warts 

 emitting bunches of black bristles ; legs black. (0. Fenn.) 

 When young the tubercular spots are white, and the yellow 

 interrupted stripes paler in colour. 



July or August to May, hybernating, when small, close to 

 the ground among its food-plants, coming forth in April and 

 then rapidly feeding up. At this time it is extremely active, 

 and feeds eagerly in the sunshine, Polyphagous, aud appar- 

 ently having local tastes as to food plants. In the chalk 



