ARTICULATA. 



143 



Southern Atlantic cand the intertropical regions of the Pacific. Most of the 

 sjiecies have been described from wingless individuals, probably larvi"e. 



Orders of Insects. 



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

 of Entomolog}^, and one about which 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 1806, 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), 



1). A metamorphosis (fleas), . 



B. Insects, with wings. 

 a. Elytroptera, 



(Anterior wing acting as a sheatii for the poster 



* Mouth mandibulate, 

 Wing-covers horny, metam. perfect, . 



" " " " imperfect, 



" " coriaceous, " " . 



*" Mouth suctorial, " " . . • 



5. Gymnoptera (wings alike) 



* Wings four. 



f Mandibulate, mandibles distinct. 

 Wings reticulated, .... 



" veined, 



f f Mouth suctorial, mandibles abortive, . 

 ** Wings two. 



f Two twisted halteres before the wings, 

 f f Halteres tvv^o, behind the wings, . 



1. tuysanura. 



2. Parasffa. 



3. SlPHONAPTERA. 



ior one.) 



4. COLEOPTERA. 



5. Derm AFTER A. 



6. Orthoptera. 



7. Hemiptera. 



8. Neuroptera. 



9. Hymenoptera. 



10. Lepidoptera. 



11. Rhipiptera. 



12. DiPTERA. 



It must be borne in mind that the same name is in some cases not given 

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

 has seveml names. The English authors exhibit a fondness for numerous 

 orders, separating, for example, the Cicadte from the Hemiptera, under the 

 name of Homoptera. 



After various modifications, Burmeister proposed, in 1839, a very different 

 arrangement, founded principally upon the metamorphosis, of which he 

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

 insects Hemimetabola {Amefabola of Leach) and Ilolometahola {Metahola 

 of Leach), each of which contains haustellate and mandibulate orders, of 



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