214 NOTODONTINA [HYDRIOMENA 



portions of its range than it is here, and no distinct line of 

 demarcation can at present be drawn. Probably the two races 

 may be species in process of formation. 



14. H. silaceata, Hb. 25-29 mm. Forewings rather dark 

 fuscous, with darker striae ; edge of basal patch whitish, 

 obtusely angulated above middle ; veins on antemedian space 

 and beyond median band, usually also on lower half of median 

 band pale ochreous; edges of median band white, anterior 

 angulated in middle, posterior sinuate, followed by a whitish- 

 ochreous stria ; a blackish discal mark ; subterminal line white, 

 preceded by blackish -fuscous spots; an irregular white-edged 

 blackish-fuscous subapical blotch. Hindwings light grey, with 

 darker striae and discal dot. 



Britain to Ross, Ireland, rather common ; N. and C. Europe, 

 N. Asia, N. America ; 5, 6. Larva slender, pale green ; a 

 dorsal series of reddish - brown dots : on Epilobium and 

 Circaea ; 7. 



15. H. corylata, Thnb. 24-28 mm. Forewings yellowish- 

 brown ; basal patch rather dark brown, edge white, irregular ; 

 median band rather dark brown, sometimes interrupted below 

 middle, edges white, irregularly waved; a blackish discal 

 mark ; subterminal line white ; a terminal median, and apical 

 spot suffused with white. Hindwings pale whitish -fuscous; 

 a dark grey discal dot ; a faint pale darker-edged postmedian 

 fascia. 



Britain to Sutherland, Ireland, common ; N. and C. Europe, 

 N. Asia ; 5, 6. Larva reddish-ochreous, greenish-tinged, with 

 brown tubercles ; dorsal stripe of four reddish-brown lines, on 

 5-10 replaced by dark diamond-shaped marks : on blackthorn, 

 hawthorn, etc.; 7-9. 



16. H. suffumata, Hb. 28-32 mm. Forewings yellowish- 

 fuscous mixed with dark fuscous ; basal patch dark brown, 

 edge white, curved : two yellow-whitish striae before and three 

 beyond median band ; median band dark brown, anterior edge 

 dentate, posterior with strong double median projection ; a black 

 discal mark; subterminal line white, interrupted; a white 

 oblique apical streak. Hindwings light grey, with faint darker 

 striae ; an angulated whitish postmedian fascia. 



Britain to the Hebrides, Ireland, rather common ; N. and 

 C. Europe, NW. Asia; 5. Larva pinkish-grey, greenish-grey, 

 or ochreous-browri ; dorsal line pale on 2-4, dark on 10-13 ; on 

 5-9 a series of dark grey V-shaped marks ending in pink tri- 

 angles enclosing a white dot : on Galium ; 6-8. 



