356 [NSECTS ABROAD. 



group, called Libellulidse, the head is rounded, and in the other, 

 called Agrionidse, it is very much wider than long, almost cylin- 

 drical, and set on the body like the head of a hammer on its 

 handle. 



We will begin with the former group. On Plate VII. Fig. 1 

 is represented Palpopleura marginata. 



This is a small, holdly-coloured, exceedingly variable insect. 

 Except that the ends of the wings are always colourless, it is 

 not easy to describe the distribution of the hues, so varied are 

 they in different individuals. As a rule the ground colour of 

 the wings is shining yellow, which in many cases forms a sort 

 of edge to the wings, thus giving to the insect the specific title 

 of marginata. The rest of the wing is covered with rich brown, 

 in some specimens being almost black and covering nearly the 

 entire wing, while in others it is very pale, and only occupies a 

 few patches set at distant intervals from each other. 



The handsomest of this genus in point of colour is Palpopleura 

 fasciaf.a. It is really a most lovely insect, its wings glittering 

 with iridescent hues of metallic purple, green, blue, and gold, 

 these colours being brighter at the base than towards the ex- 

 tremity of the wings. 



The illustration on the next page represents an insect belong- 

 ing to the typical genus. It is a native of Southern Africa (the 

 specimens in the British Museum having been taken in the 

 neighbourhood of Natal), and its name is Libcllula variegafa. 



During life the body of this insect is bright red, but after 

 death the colour fades so completely that only an experienced 

 eye can detect the least trace of the hue that was formerly so 

 conspicuous. All entomologists know that our own Dragon 

 Flies are similarly disposed to lose their colour, and have 

 lamented that the brilliant hues which decked the insects when 

 they were taken must inevitably fade into dirty browns and 

 blacks. There is no help for it, as far as our present knowledge 

 goes. It is possible, by dissection and paint applied internally, 

 to retain the colours of the abdomen, but no art has yet been 

 discovered by which those of the thorax and head can be 

 preserved. 



And even if all these colours could be made durable, nothing 

 can replace the wondrous brilliancy of the eyes. In the living 



