224 THE DRY-FLY MAN'S HANDBOOK 



wings of nearly equal length, the hinder ones lying 

 under the fore wings. The lens will further reveal 

 maxillary palpi, i.e. feelers attached to the maxillae, and 

 labial palpi attached to the labium. In all the females 

 he will find that the maxillary palpi are five-jointed, 

 and in the males the number of joints varies from three 

 to five; but the labial palpi are three-jointed in both 

 sexes. The mandibles or upper jaws are atrophied, 

 so that the mature insect is incapable of feeding. On 

 the fourth joint of the legs, the tibia or shank, there 

 are movable spurs in addition to hairs and strong 

 spines, and the disposition and number of these spurs 

 are important factors in classification. The wings are 

 more or less covered by short hairs, and the remaining 

 parts of the caddis-flies are also clothed more or less 

 Fig. 36. Willow-Fly x 3 densely with hairs and spines. 



The wings of butterflies and 

 moths are covered with scales, 

 and this is the feature by which 

 the caddis-flies with hairs on their 

 wings are distinguished. The 

 position of the wings lying nearly 

 flat will tell the fisherman at a 

 glance that the fly is not one of 

 the Ephemeridse. 



The accompanying, Fig. 36, 



shows the 



Stoneflies. willow-fly, 



one of the 

 stoneflies or Perlids, in its normal position when at 



