THE PEBBLE HOOK-TIP. I33 



claspers, therefore have only fourteen legs, that is, six true legs 

 and eight false legs (pro-legs). The last ring of the body is 

 more or less tapered, sometimes terminating in a point ; the 

 back is roughened Avith raised spots and warts, or humped. 

 They feed on the leaves of trees and bushes, usually exposed, 

 and they pupate in a silken cocoon, spun up between leaves, or 

 in a folded leaf, of the food plant. 



Of the eleven species occurring in the Pal^arctic Region, 

 seven are European, and six of these are found in the British 

 Isles. 



The Pebble Hook-tip {^Drepana falcatarid). 



The fore wings are brown, whity brown, or whitish ; the 

 central area is crossed by three blackish wavy lines, a blackish 

 blotch in the third line and two blackish dots between it and the 

 second line ; beyond there is a dark brown, or reddish-brown 

 curved line from the tip of the wing to the inner margin. Hind 

 wings similar in colour to the fore wings, but paler on the front 

 area ; crossed by five wavy dusky lines, sometimes not well 

 marked except on the inner margin ; generally, there is a black 

 central dot. The paler forms have a dusky shading on each 

 side of the curved line on the fore wings. 



The Q^'gg is yellow freckled with orange, chiefly at one end. 

 Caterpillar green, the back reddish-brown, except towards the 

 black-marked yellowish head ; two conspicuous warts on rings 

 two to five, and less noticeable raised spots on the other rings, 

 all bearing hairs. In a younger stage it is blackish, with white 

 marks on the fourth and seventh rings ; later it becomes greenish 

 below, and the markings on the back of rings four, seven, eight, 

 and ten are whitish or creamy. Until nearly full grown it 

 usually lives on the underside of a leaf, the edges of which are 

 turned over and held down by silken threads ; sometimes it may 

 be seen on the upper side of a leaf under a slight web. It feeds 



