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, 

 forminrr a sheath for the attenuated mandibles and maxillae. 



Families Muscidce, Hippoboscidce, (Estridce, Syrphidce, Cercopidce, 

 StomoxidfP, BombylidfF, Anthracidce, Leptidoe, Henopidce, Asilidce, 

 StratiomydcE, Tabanidce, Tipulidce, CuUcidce. 



Order Lepedoptera. (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 Tineid(B, Pyralidce, Geometridce, ^ocfuidcp, Bomhycidce, 

 HepioUdcE, Zygcenidce, Sphingidce, PapilionidcB. 



Order HiiiENOPTEKA. (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. Secl'rifera. Ovipositor like a saw. Families TenthredinidcB, 



Siricidce. 



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



lies Ichneumonidce, Cynipida, Chrysididte. 



C. AcuLE.iTA. Ovipositor modified to form a sting. Families 



Formicidce, Scoliadce, Mtitilidce, PompUid<E, 

 BembecidcB, Crabronidce, Vespidce, An- 

 drenidcB, Apidce. 



Order Hejuptera. (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, Coreidce, XepidcB, XaiicoridcB, Cercopidce, 

 Cicadidce, Psyllidce. Aphididct, Coccidce. 



Mouth mandibiilate. 



Order Strepsipteka. (Screw-wings.) 



Two (metathoracic) wings, the mesothoracic pair rudimentary and 

 twisted. Larvae apodal. Genera Xe/tos, Sfylops. 



