GENEBATION 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. LarviE apodal. Labium elongated, 

 forming a sheath for the attenuated mandibles and maxillae. 



Families Muscidce, HippoboscidcE, CEstridce, SyrphidcB, Cercopid<E, 

 Stomoridce, BombyUdfEj Anikracidce, Leptidce, Henopid(B, Asilidte, 

 Stratiomydce, Tabanidce, Tipulidte, Culicidce. 



Order Lepidopteba. (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 Tineidce, PyralidcB, Geometrida, NoctuidtE, Bombycida, 



HepiolidcB, ZygcBnidce, Sphinffidce, Papilionidte. 



Order Hymekoptera. (Bees, Ants.) 



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

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

 mandibles short and strong. 



A. Securifera. Ovipositor like a saw. Families Tenth redinidiB, 



Siricidce. 



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



lies lchneumonid<B, Cynipidce, ChrysididtB. 



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



FormicidcB, Scoliadce, Mutilidce, PompilidtB, 

 Bembecidce, CrabronidcB, VespidcB^ 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 PentatoinidcB, Coreid<s, Xepid^, Naucorid<B^ Cercopidce, 

 CicadidfB, PsyllidcB, Aphididce, Coccidce. 



Mouth mandibulate. 



Order Strepsiptera. (Screw-wings.) 



Two (metathoracic) wings, the mesothoracic pair rudimentary and 

 twisted. Larvae apodal. Genera Xenos, Stylops. 



