366 ZOOLOGY. 



Order 3. Orthoptem. 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; pronotum usually 

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

 Perla, Psocus, white ants). 



Order 5. 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. Larva? aquatic, with large jaws, 

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



Order 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, Arnia, Pentatoma, Cicada, Coccus, 

 Aphis). 



SERIES II. Metcibola, or with a complete metamorphosis. 



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

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

 square. Larvae often aquatic (Corydalus, Chrysopa, M} r r- 

 meleon) 



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

 Larvae like caterpillars (Panorpa, Boreus). 



Order 11. Trichoptera. Wings and body like those of moths; 

 mandibles obsolete in imago. Larvae usually aquatic, liv- 

 ing in cases (Phryganea). 



Order 12. Coleoptera. 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, Ciciudela). 



Order 13. Siphonaptera. Wingless; mouth-parts adapted for 

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

 head and mouth parts (Pulex). 



Order 14. Diptera. But one pair of wings; mouth-parts adapted 

 for lapping and sucking; a complete metamorphosis (Musca, 

 CEstrus, Syrphus, Cecidomyia, Tipula, Culex). 



