CLASSIFICATION OF INSECTS. 



79 



FIG. 66. A 

 scorpion-fly. 



flies on account of the peculiar form of the caudal 

 part of the abdomen of the male (Fig-. 67). This at 

 first sight suggests the corresponding part 

 of a scorpion, but in reality the two are 

 very different. 



Very closely allied to the scorpion-flies 

 are the insects of the genus Bittacus (Bit 1 - 

 ta-cus). These insects have long narrow 

 wings, long legs, and a slender 

 abdomen. They resemble crane- 

 flies very closely when on the wing. In 

 this genus the caudal appendages of the 

 male are not enlarged as in Panorpa. 



The species of the genus Boreus (Bo're- 

 us) are remarkable for occurring on snow in 



the winter in our Northern States. In this 



FIG. 67. 



Tail of a renus the females are windless, while the 



scorpion- 



fly. males have rudimentary wings. 



Order TRICHOPTERA (Tri-chop'te-ra). 

 The Caddice-flies or Caddice-worms. 



T/ie members of this order have four wings ; these 

 are membranous, furnished with numerous longitudinal 

 veins, but with only few cross-veins, and are more or less 

 densely clothed with hairs. The mouth-parts are rudi- 

 mentary. The metamorphosis is complete. 



FIG. 68. A caddice-fly. 



FIG. 69. A caddice-worm. 



This order is composed of the caddice-flies and 

 caddice-worms (Figs. 68 and 69), which are discussed 



