INTRODUCTION. 17 



of these organs. The mouth parts are fonned for sucking, and 

 sometimes take the form of a proboscis, which can be retracted at will. 

 The usual larval form is a small grub or maggot without feet. 



Those which most interest us are the Tipulidce or Crane-flies 

 (plate 1, figs. 1-5) ; they are all useful to anglers, but in their larval 

 stages, a scourge to farmers, doing great damage to the roots of their 

 crops. The Winter Gnats (Limnobince) also belong to this family. 



Examples of the Mosquitoes {Culicidce), of which we have about 

 ten varieties, and the Gnats (ChironomidcB), of which two hundred 

 species are indigenous to this country, are shown on plate 1, figs. 6-10. 



Included in the Diptera are the Syriphidce or Hoverers, of brilliant 

 yellow and black, which possess such marvellous powers of flight ; 

 the Woodflies (Sarcophagidce) ; the Blow-flies {Bihionidce) ; the 

 Oakflies (Lepiidce), dear to the angler more from early association 

 than actual use ; the Empidce or Snipe Flies, which prey on other 

 insects ; their head and mandibles resemble that of a woodcock, 

 and of necessity to catch their prey, they are exceedingly quick 

 of flight. (Plate 2.) 



In aU, we have over four thousand varieties of Diptera, indigenous 

 to this country, plates 1 and 2 showing a few typical varieties. 



There are also two now mentioned for the first time, which 

 are favourites, and yet new to the angling world at large ; one is 

 the Silver Tail {Theriva nohilata), plate 2, fig. 21, and the other, 

 fig. 27, of the Metallic-flies or DoUchopidce, which are exceedingly 

 common at the waterside, and quite worth imitating. 



V. Hemiptera. — Many of these are purely aquatic, including 

 the -Water Boatmen, which are, no doubt, familiar to most anglers. 

 These are fierce insects, which attack other insects, tadpoles, and 

 small fry. They have a powerful beak which renders their attacks 

 very formidable, and swim with a curious jerky motion, coming to 

 the surface occasionally to take in air. They are good fliers, and on 

 the wing, look rather like a bee. The largest is Notonecta glauca. 

 The elytra fold up over the body compactly " roofwise " (plate 7, 

 fig. .72). In the water it- is readily distinguished by the fact that 



B 



