TYPE TUACHEATA. 515 



norpa, the Scorpion-fly, the abdomen terminates in a pair of 

 forceplike processes similar to those of the Dermaptera. 



The metamorphosis is complete, the larvae differing from 

 those of the orders already described in possessing in addi- 

 tion to the three pairs of thoracic legs eight pairs of abdom- 

 inal proplike appendages. 



12. Order Trichoptera. 



The Trichoptera, also a small order, includes the Caddis- 

 flies {Fhryganea, Anaholia). They possess two pairs of wings, 

 the anterior pair usually differing slightly in appearance 

 from the posterior, which are larger and folded when at rest 

 in a fanlike manner, the venation consisting principally of 

 longitudinal veins, with but few transverse ones. The body 

 and the wings are generally abundantly covered with hairs, 

 which in some forms are scalelike. The antennae are 

 usually long and filiform, and the mandibles rudimentary, the 

 maxillae and labium forming a short sucking proboscis. 



The metamorphosis is complete, the larvae being aquatic 

 and provided with spinning-glands with which they bind to- 

 gether small twigs and particles of sand to form cases within 

 which they live. They possess tracheal branchiae upon the 

 sides of the abdominal segments, and the last segment bears 

 a pair of short but stout processes which are provided with 

 hooks. The pupa is formed within the larval case, but before 

 transforming into the imago it leaves the case and crawls to 

 land, where the imago emerges. 



13. Order Lepidoptera. 



This is a large order, including the Butterflies and Moths, 

 all of which, with the exception of the females of a few forms 

 {Orgyia), possess two pairs of wings covered with overlapping 

 scalelike hairs, and with but few transverse veins. When at 

 rest the wings are rarely folded, but are either held erect, as 

 in the Butterflies, or lie one over the other, resting upon the 

 abdomen. The body, like the wings, is covered with hairs or 

 scales. 



The antennae differ considerably in shape in different 



