XOTODONTIDAE 305 



5, 8. Larva pale grey, brownish, or green, with darker lines ; 

 strong prominences on 6-8 and 12; a darker brown or grey 

 dorsal line ; spiracular brown or reddish-brown : on poplar or 

 sometimes birch ; 6, 7, 9. 



4. N. torva, HI). 42-46 mm. Forewings fuscous, sprinkled 

 with pale greyish-ochreous; first and second lines waved, 

 darker, externally pale-edged ; a darker pale-edged discal mark ; 

 praesubterminal line rather darker. Hindwings grey ; a pale 

 postmedian line. 



Norfolk, very scarce but possibly overlooked ; C. Europe, N. 

 Asia; 5, 8. Larva closely resembling that of N. ziczac, but 

 much darker : on aspen ; 6, 7. 9. 



3. DRYMONIA, Hb. 



Characters of Notodonta, but eyes glabrous; dorsal scale- 

 tooth sometimes slight. 



A rather small genus, apparently confined to the Northern 

 hemisphere, especially in temperate regions. Larva without 

 prominences or with one on 12 only. 



1. Forewings with blackish subdorsal streak . 2. 



,, without blackish subdorsal streak . 3. 



2. Tornal mark of forewings white . .1. dictaeoides. 



brown, white-edged 2. tremula. 



3. Forewings with whitish posterior fascia . . 4. 



without whitish posterior fascia 3. trepida. 



4. Forewings with dark fuscous discal mark . 5. chaonia. 



,, without dark fuscous discal mark 



4. trimacula. 



1. D. dictaeoides, Esp. 42-50 mm. Forewings whitish, 

 towards middle of costa mixed with pale brownish ; an elongate 

 blackish posterior costal blotch, marked with brown veins; a 

 broad blackish brown -suffused subdorsal streak, white-edged 

 beneath towards base and in middle, included dorsal space whitish- 

 ochreous anteriorly, brown posteriorly, with an elongate- 

 triangular white tornal mark ; a brown subterminal suffusion. 

 Hindwings whitish -fuscous, disc more whitish ; a dark fuscous 

 tornal suffusion. 



Britain to Sutherland, N. and E. Ireland, rather common ; 

 N. and C. Europe ; 5, 6, 8. Larva glossy purplish-brown ; a 

 prominence on 12 ; spiracular stripe yellow : on birch ; 7, 9. 



2. D. tremula, Cl. (dictaea, Esp.) 45-54 mm. Differs from D. 

 dictaeoides as follows : forewings more brownish-mixed, tornal 



x 



