S-JILPXOTIA] OCXERIADAE 175 



crest. Abdomen densely hairy, hardly crested. Posterior 

 tibiae without middle-spurs. Fore wings : 10 free, sometimes 

 out of 9 near base. Hindwings : 6 and 7 stalked. 



At present restricted to one species. Larva without specially 

 developed tufts. 



1. S. salicis, L. 42-54 mm. Tibiae and tarsi black with 

 white rings. Forewings and hindwings rather thinly scaled, 

 white. 



Britain to Ross, common ; N. and C. Europe, WC. and N. 

 Asia ; 7, 8. Larva grey irrorated with dark grey ; dorsal area 

 black, with a row of whitish blotches or interrupted streak ; 

 subdorsal line whitish ; subdorsal, spiracular, and sometimes 

 dorsal rows of red spots ; head blackish : on poplar and 

 Salix ; 9-6. 



8. OCNERIA, Hb. 



Palpi with terminal joint concealed. Abdomen not crested. 

 Posterior tibiae with middle-spurs. Forewings : 10 out of 9 

 below 7. Hindwings : 6 and 7 approximated. 



A rather considerable Indo-Malayan group, extending into 

 Europe, Africa, and Australia. Larva without specially de- 

 veloped tufts. 



Thorax black-marked . . . .1. monacha. 



,, not black-marked . . .2. dispar. 



1. 0. monacha, L. 36-52 mm. Abdomen suffused with rosy. 

 Forewings white, sometimes ochreous-tinged ; an irregular black 

 mark from base of costa, followed by a transverse series of black 

 dots; first, median, second, and praesubterminal lines irregu- 

 larly dentate, black, dilated on costa ; orbicular dot black ; 

 discal spot crescentic-oblong, black-edged, absorbed in median 

 line. Hindwings grey, whitish-mixed, darker terminally. 



England to York, common ; N. and C. Europe ; 8. Larva 

 whitish, marked with brown and blackish ; dorsal streak 

 brown, interrupted on 4, 8, and 9 ; two black spots on 3, 

 and smaller ones on 5-12; sometimes red dorsal marks on 9 

 and 10 : on oak, apple, fir, etc. ; 5-7. This larva is sometimes 

 excessively destructive to fir-forests on the Continent, stripping 

 the trees so completely as to kill them. 



2. 0. dispar, L. 39-60 mm. Forewings in pale brownish 

 sprinkled with dark fuscous, in 9 whitish ; an interrupted 

 dark fuscous mark from base of costa ; lines darker fuscous ; 

 first and second waved, stronger and darker on costa ; median 

 thick, cloudy ; subterminal waved, in 9 nearly obsolete ; a 



