248 PEESH-WATEE AQUAEIA. 



The ^schnidcB may be generally known by their large and 

 almost hemispherical heads, by their exceedingly great eyes, 

 which meet together above, and by their long and rather 

 slender bodies. These insects keep their wings extended 

 when at rest. The largest British Dragon-fly (Anax formosus) 

 belongs to this sub-family, and is about Sin. long ; and the 

 ^schna grandis is nearly as large, measuring not much less 

 than 4in. across its expanded wings. 



The Libellwlides have heads, eyes, and wings very like the 

 2EschnidcB, but their bodies are generally broader, shorter, and 

 flatter. They also keep their wings extended when not flying. 

 The commonest representative of this sub-family is Libellula 

 depressa. Perhaps this insect more than any other is called 

 the "Horse-Stinger." It is about 2in. long, and its body is 

 broad and flattened. The male is covered with a lovely violet- 

 blue powder, and the female has a yellowish-brown abdomen, 

 spotted with yellow upon the sides. Another well-known species 

 belonging to the lAhellulides is Sympetrum vulgatum. It is about 

 2in. long, and has a yellow cylindrical body and clear wings. 



The Agrionides are the smallest, the most elegant, and the 

 most delicate-looking of all the Dragon-flies. It is owing 

 perhaps to their graceful forms that the French call them 

 and all their relatives "Demoiselles." The English name, 

 however, seems the more appropriate, for the LibellulidoB are 

 certainly about the most predaceous and bloodthirsty "of 

 all British insects. The eyes of the Agrionides are separated 

 from one another by a wide crown. The abdomen is cylin- 

 drical, extremely slender, and flattened a little at the ex- 

 tremity. These Dragon-flies when at rest place their wings 

 close together over their backs. Agrion puella is about the 

 best-known member of this sub-family. It is a little more 

 than lin. long. The body of the male is prettily spotted, or 

 rather ringed, with blue, while that of the female is marked 

 with brassy-black. Calopteryx virgo is also very abtmdant in 

 certain parts of the country. The abdomen of the male is 

 blue and that of the female is greenish. The former insect has 

 beautiful metallic-blue wings, while those of the latter are of 

 a pretty brown ; hence the generic name. 



