NOTODONTID.^. 141 



as it advances northward ; probably having but one genera- 

 tion in the year in most parts of Scotland. 



Larva cylindrical, transversely wrinkled; head large, 

 rounded, shining ; twelfth segment with two projecting 

 upright tubercles. Head pale green with a few dark hairs, 

 similar hairs on the second and thirteenth segments and 

 from the usual lateral spots ; mouth yellow ; body pale 

 whitish-green on the back, shading into dark green on the 

 sides and undersurface ; dorsal line bluish, distinct ; sub- 

 dorsal lines yellow, margined above with a pale grey streak ; 

 spiracular lines distinct, greenish-yellow ; tubercles on the 

 back of the twelfth segment tipped with bright red ; spiracles 

 black, edged with white, each followed by a small red spot ; 

 a line of white dots above the spiracles and other white dots 

 below ; legs and prolegs red. (C. Fenn.) 



Variable — Buckler figures one larva of a lilac colour with 

 white spiracular line and purple head and undersurface ; 

 another with the general colour bright yellowish-brown, with 

 the dorsal line dark purple edged with whitish-yellow, and 

 the spiracular line yellow ; and another with a light brown head, 

 green dorsal region broadly barred with white, sides yellowish- 

 pink, and undersurface purplish-green. It may, however, always 

 be known by its curious pair of slender dorsal tubercles. 



June, July, and in a second generation in September, 

 October, and occasionally even November ; on oak, birch, 

 hazel, sallow, beech, and hawthorn. 



Pupa rounded, slightly elongated, anal segment with a 

 spike ; dull dark purplish-brown. In a silken cocoon mixed 

 with earth, usually attached to a stone or to a root under- 

 ground. (C. Fenn.) Often at the foot of an oak, elm, or 

 beech tree. In this condition through the winter, and 

 occasionally remaining over a second winter. In other cases 

 pupa which have passed through the winter, and from which 

 the moths have not emerged in the spring, produce them at 

 the time of the usual second brood. 



