GENERATION OF INSECTS. 441 



shaped mandibles, two scale-shaped max- 

 illae with antenna-like palpi, a slender 

 setiform tongue with lamelliform palpi, 

 and a labium. Genus Pulex. 



Order Diptera. (Flies, Gnats.) 



Two (mesothoracic) wings : the metathoracic pair rudimentary, and 

 called "halteres" or balancers. Larvae apodal. Labium elongated, 

 forming a sheath for the attenuated mandibles and maxillae. 



Families MuscidcB, HippoboscidcE, (EstridcB, SyrphidcB, Cercopidce, 

 Stomoxid<B, BombylidfB, AnthracidcB, Leptidce, Henopidce^ Asilidce, 

 Stratiomydce, TahanidcB, TipKlidce, Culicidce. 



Order Lepidoptera. (Butterflies, Moths.) 



Four wings, covered by small coloured scales. Larvae myriapodal. 

 Maxillae very long and confluent, forming a tube spirally folded 

 between two palpi : mandibles rudimentary. 



Families TineidcB, PyralidcB, Geornetridce, Noctuidm, Bombycidce, 

 HepiolidcBj ZygcenidcB, SphingidcB, PapilionidcB, 



Order Hymenoptera. (Bees, Ants.) 



Four wings, membranous, veined with nervures : larvae, in most;, 

 apodal : tongue and labium elongated : maxillae long and slender : 

 mandibles short and strong. 



A. Securifera. Ovipositor like a saw. Families TenthredinidcBy 



SiricidcB. 



B. PupivoRA. Ovipositor a long and slender perforator. Fami- 



lies Ichneumonidce, CynipidcE, ChrysididcB. 



C. AcuLEATA. Ovipositor modified to form a sting. Families 



Formicid(E, ScoliadcBj Mutilidce^ Pompilldce, 

 BembecidcB, Crabronidce, Vespidce, An- 

 drenidce, ApidcB. 



Order Hemiptera. (Bugs, Plant-lice.) 



Four wings, the first pair wholly or partially coriaceous. Larvae 

 with a thorax and six well-developed legs. Mandibles and maxillae 

 long, filiform, protected by a long sheath-shaped tongue. 



Families Pentatomidce, CoreidcB, NepidcB, Naucoridce, Cercopidce, 

 CicadidcB, Psyllidce, AphididcB, Coccidce. 



Mouth mandibulate. 



Order Strepsiptera. (Screw-wings.) 

 Two (metathoracic) wings, the mesothoracic pair rudimentary and 

 twisted. Larvae apodal. Genera Xenos, Stylops. 



