NEUROPTERA. 129 



The second family may be known by the hammer-like, 

 transversely-placed head, the wide-apart eyes, and above 

 all by the position of the wings, which, when at rest, meet 

 back to back over the back of the insect. The wings differ 

 in form in the two families as well as in position. In the 

 first family (Libellula, &c., see fig. 47, ^Eshna cyanea) 

 the fore-wings are narrow at the base and wider towards 

 the tip ; the hind- wings are broadest at the base, some- 

 times, especially in the males, forming an angle thera In 

 the second family (Agrion, &c., the smaller species of 

 which have a comparatively feeble flight) the four wings are 

 alike and are very narrow at the base, increasing in 

 width towards the tip. Most Dragonflies have a dark 

 spot or stigma on the front margin near the tip of the 

 wing, but this is absent in Calepteryx. 



To the second family belong the exquisite little, slender, 

 crimson and sky-blue Agrions, most fairy-like insects, 

 which are common everywhere ; and the splendid but 

 more rare Calepteryx, a more beautiful object than which 

 can hardly be met with in the insect world. The body is 

 about If in. long, slender, burnished, and of an intense 

 dark steel-blue or dark emerald green, it is almost impos- 

 sible to tell which, as the glancing light gives one colour 

 or the other to its lustrous surface. The wings are 

 large, clear, and gauzy, with a large dark-brown cloud 

 on each, nearly filling the hinder half, but leaving the 

 base and tip clear. These wings add greatly to the 

 brilliancy of the insect, their delicate and innumerable 

 veins being of the same burnished green or blue as the 

 rest of the body. Add to this the prismatic colours re- 

 flected from their membranous part, and the picture is 

 complete. This is the male. The female is similar in 

 form and of nearly equal size. The body is of a brilliant 



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