174 DRAGON-FLIES. 



active insects that are with great truth called 

 Dragon-flies. Their habits and peculiarities would 

 demand a volume ; and here they can but be men- 

 tioned. Plate F, fig. 6, shows the common Flat 

 Dragon-fly, that may be seen chasing and following 

 flies of all sizes, and even butterflies. Fig. 8 is the 

 elegant Demoiselle, the male of which is shown here, 

 with its dark purple spots on the wings and dark 

 blue body. The female is of a uniform green. Its 

 larva is shown at fig. 8 a, where the singular leafy 

 gills may be seen at the end of its tail. Fig. 7 shows 

 another very common Dragon-fly, very thin and 

 ringed with blue circlets. 



On the same plate, fig. 12, may be seen several 

 varieties of the objects known to fishermen as " Cad- 

 dis " cases. These are residences built by the larva 

 of the common Caddis, or Stone-fly, which is re- 

 presented on the same plate, fig. 9. 



Still keeping to plate F, and referring to fig. 1, is 

 seen the horrid-looking Water-scorpion, a creature 

 which, though it does not sting, has much of the 

 scorpion nature, and so bites. Fig. 1 a shows the 

 same insect as it appears when flying. 



At fig. 3 is seen the Water Boatman, so called be- 

 cause it lies on its back, which is ridged like the keel 

 of a boat, and then rows itself about by means of its 

 middle pair of legs, which closely resemble oars. 



Fig. 5 shows a very curious object which is common 

 enough on the margin of pools, and runs on the 



