14 ENTOMOLOGY 



smaller, complexly reticulate, not plicate. Larvae thysanuriform or in 

 some cases cruciform, and aquatic, or terrestrial. Example, Chrysopa 

 (Fig. 24). About six hundred species have been named. 



11. Mecoptera. Metamorphosis indirect. Mouth parts mandib- 

 ulate, at the end of a deflexed rostrum, or beak. Prothorax small. 

 Wings four, elongate, membranous, naked, coarsely reticulate, or else 

 rudimentary or absent. Larvae cruciform, caterpillar-like, with numer- 

 ous prolegs, carnivorous. Example, Bittacus (Fig. 25). A single family, 

 Panorpidae, comprising but few known species. 



12. Trichoptera. Metamorphosis indirect. Antennae filiform. 

 Mouth parts of imago rudimentary or imperfectly suctorial; mandibles 



FIG. 26. Molanna cinerea. A, Larva; B, imago. X 4 diameters. After FELT. 



rudimentary or absent. Prothorax small. Wings four, membranous, 

 hairy, veins moderate in number, cross veins few; hind pair almost 

 always the larger, with plicate anal area. Larvae suberuciform, aquatic, 

 usually case-forming. Example, Molanna (Fig. 26). Between five and 

 six hundred species are known. 



13. Lepidoptera. Metamorphosis indirect. Mouth parts suctorial, 

 mandibles absent or rudimentary (except in a few generalized species). 

 Prothorax small. Wings four, similar, membranous, clothed with scales, 

 veins moderate in number, cross veins few. Larvae eruciform (caterpil- 

 lars), phytophagous (almost never carnivorous), mandibulate. Some 

 fifty thousand species have been described. Two suborders, not sharply 

 separated from each other. 



Suborder Heterocera. Antennae of various forms, but not ter- 



