366 ZOOLOGT. 



Order 3. Orfhoptera. — Wings net-veined; fore-wings narrow, 

 straight, not often used in flight; metamorphosis incom- 

 plete; pupa active (Caloptenus, Locusta, Phaneroptera, 

 Acheta). 



Order 4. Platyptera.—BoAY usually flattened; prpnotum usually 

 large and square; often wingless (Mallophaga or bird-lice, 

 Perla, Psocus, white ants). 



Orders. Odonata. — Prothorax small; thorax spherical; both pairs 

 of wings of nearly the same size, net-veined. Larva and 

 pupa aquatic; labium forming a large mask (Agrion, Libel- 

 lula). 



Order 6. Plectoptera. — Mouth-parts nearly obsolete; wings net- 

 veined, hinder pair small, sometimes wanting; abdomen 

 ending in three filaments. Larvae aquatic, with large jaws, 

 and with gills on the side of the hind body (Ephemera). 



Ord&r 7. Thysanoptera. — Mouth-parts forming a short conical 

 sucker; palpi present; wings narrow, fringed; abdomen end- 

 ing in a long ovipositor (Thrips). 



Order 8. Hemiptera. — Mouth-parts forming a sucking beak; pro- 

 thorax usually large; fore-wings often thickened at base; 

 pupa active (Coreus, Arma, Pentatoma, Cicada, Coccus, 

 Aphis). 



Sbbieb II. Metabola, or with a complete metamorphosis. 



Order 9. Neuroptera. — Wings net -veined; mouth -parts free, 

 adapted for biting; ligula large, rounded; prothorax large, 

 square. Larvae often aquatic (Corydalus, Chrysopa, Myr- 

 meleon) 



Order 10. Mecaptera. — Wings somewhat net-veined, or absent. 

 Larvae like caterpillars (Panorpa, Boreus). 



Order 11. TriclwpUra. — Wings and body like those of moths; 

 mandibles obsolete in imago. Larvae usually aquatic, liv- 

 ing in cases (Phiyganea). 



Order 13. Goleoptera. — Fore-wings thick, ensheathing the hinder 

 pair, which are alone used in flight; mouth-parts free, 

 adapted for biting; metamorphosis complete (Doryphora, 

 Clytus, Lucanus, Harpalus, Cicindela). 



Order 13. Svphmmptera. — Wingless; mouth-parts adapted for 

 sucking. Larva maggot-like, but with a well-developed 

 head and mouth-parts (Pulex). 



Ord&r 14. Diptera. — But one pair of wings; mouth-parts adapted 

 for lapping and sucking; a complete metamorphosis (Musca, 

 GEstrus, Syrphus, Cecidomyia, Tipula, Culex). 



