146 LLOYDS NATURAL HISTORY. 



outside which the wings have a somewhat bluish tint. The 

 fringes are dentated, spotted with grey and white, and fre- 

 quently varied with yellow ; and are bordered by a row of 

 small crescent-shaped spots, having the concavity directed 

 outwards. The hind-wings are black, with a broad greyish- 

 blue central band, and narrow white hind margins. The 

 fringes are white, bordered by a fine waved black line. 



The larva most commonly lives on poplars, but will also 

 live on ash (Fraxinus), beech, birch, elm, oak, and other trees. 

 The transformations of all the Underwings are very similar, so 

 we will give those of the present species in full, as typical of 

 the others as well. 



The eggs are laid in the autumn, and remain undeveloped 

 until the following May. It is likely that some larvae hatch 

 before the winter, and hibernate, as they are sometimes met 

 with rather advanced in development at the end of May. 



The egg is black, with white reticulated markings, and with a 

 very broad, somewhat interrupted, band round the middle. A 

 few hours before the larva emerges, a slight movement may be 

 detected, and several small air-bubbles appear, probably caused 

 by a minute puncture made by the enclosed larva in com- 

 mencing to break its way out. On first emerging, the young 

 larva is yellowish, and blackish spots and short setiform hairs 

 can be detected by a lens. It is able to move about quickly, 

 and rests on the hinder legs with the body held erect. The egg 

 changes colour after the emergence of the larva, and become s 

 uniform white and translucent. It is not eaten by the larva. 



After the first moult the larva becomes greener, and twelve 

 black dots appear on the back. After the second moult, the 

 black dots become scattered over the whole surface, but are 

 only distinctly visible under a lens. These spots become more 

 distinct, and the colour greener, upon the third moult. After 

 the fourth moult, which takes place five days after the third, 



