120 INTRODUCTION TO CLASSIFICATION. 



The anterior wings may be more or less dissimilar to the 

 posterior, and simulate elytra. 



Metamorphosis is incomplete ; that is, tlie insect remains 

 active through all its changes, from the larval to the perfect 

 condition, except in the case of the male Coccidse, which undergo 

 a complete metamorphosis. 



The Bugs, Cicadas, Lantern-flies, Plant-lice, Cochineal Insects 

 and Lice belong to this order. 



The proper grouping of the insects which do not fall into 

 any of the orders which have now been mentioned is still a 

 matter of doubt. 



Those with a complete metamorphosis have been distinguished 

 under the following heads 



1. STREPSIPTEEA. The jaws are abortive and useless for 

 mastication. The maxillary palpi are present, while those of 

 the labium are absent. 



The anterior wings are represented by twisted rudimentary 

 appendages of the mesothorax. The posterior wings are large, 

 folding longitudinally. 



The larvaa, which are parasitic on the bodies of Hymenoptera, 

 are at first six-legged and active, but lose their limbs and 

 become vermiform. 



The females remain in this condition throughout life, while 

 the males undergo a complete metamorphosis and are extremely 

 active in the imago state. 



2. TRICHOPTEBA. The jaws are abortive, but both maxil- 

 lary and labial palpi are developed. 



The wings are dissimilar, hairy or scaly ; the posterior wings 

 are usually folded. 



The larvae resemble those of the Lepidoptera. They have 

 masticatory jaws and are aquatic, constructing cases in which 

 they reside and eventually undergo their metamorphosis. They 

 commonly breathe by tracheal gills. 



The Caddis-flies exemplify this group. 



3. NEUROPTEKA. The jaws are well developed and masti- 

 catory ; both maxillae and labium are provided with palpi. The 

 wings are similar and membranous. 



