ARTICULATA. 



143 



Southern Atlantic and the intertropical regions of tlie Pacific. Most of the 

 species have been described from wingless individuals, probably larvae. 



Orders of Insects. 



The distribution of insects into orders has been one of the chief problems 

 of Entomology, and one about wliich there is a great want of unanimity. 

 Latreille, the father of modern Entomology, who was born in 1762, and 

 devoted a long life to the science, proposed a system in 1796, which he 

 subsequently modified in various editions of his works, in 1800, 1817, 1825, 

 1829, and 1832. In these he adopted the following arrangement of the 

 orders, which is still very generally followed : 



A. Insects without wings. 

 a. Without metamorphosis. 



* Mouth mandibulate, 

 ** " suctorial (lice), 



h. A metamorphosis (fleas), . 



B. Insects with wings. 

 a. Elytroptera, 



(Anterior wing acting as a sheath for the poster 



* Mouth mandibulate. 

 Wing-covers horny, metam. perfect, . 



" " " " " imperfect, 



" " coriaceous, " " . . 



*'• Mouth suctorial, " '' . . 



h. Gymnoptera (wings alike). 

 " Wings four. 



f Mandibulate, mandibles distinct. 

 Wings reticulated, .... 



" veined, 



f f Mouth suctorial, mandibles abortive, . 

 -X-* Wings two. 



f Two twisted halteres before the wings, 

 f f Halteres two, behind the wings, , 



1. Thysanura. 



2. PARAsrrA. 



3. SiPnONAPTERA. 



ior one.) 



4. coleoptera. 



5. Dermaptera. 



6. Orthoptera. 



7. Hemiptera. 



8. Neuroptera. 



9. Hymenoptera. 

 10. Lepidoptera. 



n. RmPIPTERA. 

 12. DiPTERA. 



It must be borne in mind that the same name is in some cases 

 to the same group by different authors, and that the same order 

 has several names. The English authors exhibit a fondness for 

 orders, separating, for example, the Cicadas from the Hemiptera, 

 name of Tlomoptera. 



After various modifications, Burmeistei* proposed, in 1839, a ver 

 arrangement, founded principally upon the metamorphosis, of 

 admits two grades, one half, the other entire, according to which 

 insects llemimetahola {Ainetabola of Leach) and Jlolovietahola 

 of Leach), each of which contains haustellate and mandibulate 



not given 

 sometimes 

 numerous 

 under the 



y difterent 

 which he 

 he names 

 {Metahola 

 orders, of 

 34V 



