ACRONYCTA] CARADRINIDAE 141 



against 9, and closely resembles a patch of bird's excrement. 

 In the final stage the larva can emit a strong probably pro- 

 tective odour, resembling carburetted hydrogen ; its black and 

 yellow bauds are therefore, as usual, a warning signal. 



3. A. strigosa, F. 28-31 mm. Fore wings ochreous-whitish, 

 sprinkled with brown; costa spotted with dark fuscous; an 

 ochreous-yellow blackish-edged spot towards base of dorsum ; 

 a black submedian streak from base to termen, interrupted on 

 median band, and a black subdorsal dash on median band ; 

 first and second lines whitish, partly edged with dark fuscous ; 

 orbicular and reniform suffusedly pale-edged, partly outlined 

 with blackish, separated by a dark fuscous suffusion. Hind- 

 wings fuscous-whitish, termen fuscous-suffused ; a pale fuscous 

 discal spot. 



Norfolk, Cambridge, local; C. Europe, N. Asia; 6, 7. 

 Larva green, seldom purple-brown ; an irregular dorsal crimson- 

 brown stripe ; scattered blackish, ochreous, and whitish hairs ; 

 12 with dorsal prominence; head dark brown: on hawthorn; 

 7-9. 



4. A. tridens, Schif. 33-39 mm. Differs from A. psi only 

 as follows : forewiugs slightly darker, faintly tinged with rosy- 

 purplish ; median costal mark rather more oblique. 



Britain to Caledonian Canal, E. and W. Ireland, local ; N. 

 and C. Europe, N. Asia ; 6, 7. Larva black ; a broad white 

 dorsal stripe, including a series of orange spots ; lateral series 

 of reddish marks and white tubercles; spiracular line broad, 

 whitish; 5 and 12 with dorsal prominences, 5 with a tuft of 

 black hairs; numerous long blackish, whitish, and yellowish 

 hairs; head black: on hawthorn, oak, birch, etc.; 8-10. 



5. A. psi, L. 35-41 mm. Forewings grey-whitish densely 

 irrorated with light brown; a black median basal streak 

 reaching first line, emitting three short projections; first line 

 edged with dark fuscous ; orbicular and reniform partly black, 

 outlined, almost or quite touching; a dark fuscous median 

 costal mark touching their junction; second line obscurely 

 whitish, blackish-edged posteriorly ; a fine black dash beyond 

 this above middle, and a stronger one traversing it above 

 tornus. Hind wings whitish, more or less fuscous -sprinkled 

 .posteriorly ; sometimes a fuscous postmedian line. 



Britain to Ross, Ireland, very common; Europe, N. and 

 WC. Asia, N. Africa; 5, 6. Larva blackish or slaty-grey; a 

 broad pale yellowish or whitish dorsal stripe; lateral series 

 of orange or reddish marks; spiracular line broad, whitish; 



