150 BRITISH BUTTERFLIES AND MOTHS 



The larva is dark yellow, with a broad, black, dorsal 

 line, and with three black lines on each side above the 

 spiracles ; the head, legs, and spiracles are black ; it 

 feeds gregariously in August and September on oak, 

 lime, nut, sallow, etc. 



The perfect insect appears in June and July ; it is 

 very sluggish ; we sometimes meet with it sitting on 

 grass, etc., or palings ; it flies rather freely to light, and 

 hence is sometimes found in houses. 



Allied to several of the last-named species, there are 

 various others which our space will not permit us to 

 enumerate more particularly. 



FAMILY IV. 

 PSILURA MONACHA. THE BLACK AKCHES. 



(Plate V., Fig. 1.) 



This pretty species is widely distributed in the south 

 of England, and is, perhaps, most plentiful in the New 

 Forest ; it does not seem to range far towards the north, 

 Barnsley and Doncaster being about its northern limit 

 in Yorkshire ; it is not uncommon in Ireland. 



The expansion of the wings varies from 1 \ to 2 inches, 

 the females being generally much larger than the males. 

 The fore-wings are white, with numerous, irregular, 

 wavy, transverse black markings, and some black spots 

 towards the base and along the hind-margin ; the hind- 

 wings are dull grey. The terminal half of the body is 

 pinkish in both sexes ; in the female it is very pointed, 

 and furnished with a protruding ovipositor adapted for 

 depositing the eggs in the crevices of the bark of trees. 



The larva is yellowish-grey, varied with greenish-grey 

 and dull brown ; the dorsal warts are large and black, 



