200 THE LIBELLULINA. 



depressed, and that of the male is covered on the 

 upper surface with a delicate bluish-white powder, 

 like the bloom on a plum. On fine days in sum- 

 mer this insect may be constantly seen hawking 

 about over ponds almost everywhere, sweeping over 

 their surface in wide circles, and often tantalising 

 the entomologist by dashing continually past him, 

 but still, as if exactly aware of the length of his net- 

 handle, keeping, even in its apparently most reckless 

 nights, just beyond his reach. This, indeed, is a 

 common trick with most of the larger species of 

 Dragon-flies, which are almost incessantly upon the 

 wing, and rarely settle upon plants or other objects 

 except in dull or windy weather. When resting in 

 this way their wings are extended horizontally. 



Besides these we have many other species, which, 

 although inferior to the giants of the order just 

 referred to in their power of flight, are certainly 

 superior to them in elegance of appearance. These 

 are altogether of a more slender form, and have a 

 long cylindrical abdomen, above which their delicate 

 filmy wings are laid together, when, as is often the 

 case, they repose from their predatory flights upon 

 the herbage of the borders of streams or ponds. Of 

 this form is one of the most abundant of our species, 

 the Agrion puella, which may be seen throughout the 

 summer hovering not only near the edges of ponds 

 and large pieces of water, but also over the abundant 

 vegetation of ditches and damp hedge-banks. It 

 measures an inch and a half or rather more in length ; 

 its head is much broader than the thorax, and both 

 these portions of the body are black, with bluish 

 spots and stripes; the wings are very delicate and 

 nearly transparent, traversed by exceedingly fine 



