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ARTICULATA. 143 
Southern Atlantic and the intertropical regions of the Pacific. Most of the 
species have been described from wingless individuals, probably larve. 
Orders of Insects. 
The distribution of insects into orders has been one of the chief problems 
of Entomology, 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, : : : 1. TuysaNuRA. 
Ae) 0%). iguetorial (lice), ’ : : 2. PARASITA. 
6. A metamorphosis (fleas), . , : 3. SIPHONAPTERA. 
B. Insects with wings. 
a. Elytroptera, 
(Anterior wing acting as a sheath for the posterior one.) 
* Mouth mandibulate, 
Wing-covers horny, metam. perfect, 4, CoLEOPTERA. 
£ sf $3 impertect, 5. DERMAPTERA. 
6 ‘* coriaceous, “ a 6. ORTHOPTERA. 
** Mouth suctorial, “ pS 7. Henierera. 
b. ees (wings scaltlve): 
* Wings four. 
+ Mandibulate, mandibles distinct. 
Wings reticulated, . ‘ ‘ ‘ 8. NEUROPTERA. 
Son RENEE : ; 9. HyMENOPTERA. 
++ Mouth al mandibles abor een . 10. Lepmorrera. 
** Wings two. 
+ Two twisted halteres before the wings, 11. Ruterprera. 
tt Halteres two, behind the wings, . . 12. Drerera. 
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 several names. The English authors exhibit a fondness for numerous 
orders, separating, for example, the Cicadz 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 (Ametabola of Leach) and Holometabola (Metahola 
of Leach), each of which contains haustellate and mandibulate orders, of 
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