THE STUDY OF ENTOMOLOGY 225 



rest. When flying the four wings are set out from 

 the body, and very materially alter the appearance of 

 the insect, and make it look far larger. The length 

 and narrowness of the wings, their peculiar appearance 

 when folded together, and their general characteristic 

 shape will prevent the angler from confusing the stone- 

 flies with the caddis-flies. In some species the wings 

 of the males are so abnormally short — even reduced 

 to mere scales — that the insects are incapable of flight. 

 Some genera of Perlidee have two ciliated, multi- 

 articulate caudal setae or tails. 



Fig. 37. Alder (Female) x 3 



Fig. 2)"] shows an alder in profile as it appears 



when crawling along on a 



Alder. post or rush. Although, as 



will be shown later on, it is not 

 a fly which is often found on the water, still it is so 

 plentiful on the banks of most of the rivers and streams 

 in this country that the angler will see many specimens. 

 Kingsley, in his " Chalk-Stream Studies," has brought 

 it so prominently before his angling readers, and sur- 

 rounded it with such an atmosphere of admiration, 

 that it must be included in the list. It can be easily 

 Q 



