144 ZOOLOGY. 



which the former contains two : 1^ Rhynchofa ; 2, Gijmnognatha ; and the 

 latter four : 3, Antliata, Fabr. {Diptera^ Linn.) ; 4, Piezata^ Fabr. {Hymcno- 

 ptera^ Linn.); 5, Glossata^ Fabr. {Lepidoptera^ Linn.); and 6, Eleutherata^ 

 Fabr. {Coleoptera^ Linn.). For all these, except the second, Bnrmeister adopts . 

 the names of Fabricius. The peculiarity of this arrangement is the reduc- 

 tion of the orders to six, and the distribution of the minor parts of each, as 

 will be observed in the following sketch. 



The Rhynchota are made to include the tribe and iamWy Pediculina (the 

 lice), or haustellate Anoplura ; whilst the mandibulate Anoplura, or bird 

 lice, form the second tribe of his order Gymnognatka, under the name of 

 Mallophaya, the first tribe being the Phy.wpoda, from which Ilaliday and 

 most English entomologists form tlieir order Thysanoptera. The order 

 Thysaniura of preceding authors forms a tribe^ next to which succeed the 

 Orthoptera (including Blattet) ; Dennatoptera {Forficula^ pjl. 81, figs. 1-3) ; 

 Corrodentia {Termes.^ Emhia) ; SabuUcornia {EpjTiemera., Lihelhdd) ; 

 Plecoptera {SemUis)\ Tnchoptera ; and Plannipennia {Sialis, etc.), all as 

 t?ihes of the same order. It results from this, that the JSfeuroptera and 

 Orthoptera., as well as other groups usually considered orders, form but one 

 order, in the opinion of Burmeister. Erichson (in Agassiz's Nomenclator) 

 places the Thysanura as an order, except that the Lephmidm are withdrawn 

 and placed in the order Ortlwptera., which is further enlarged by the 

 addition of the Lihellulidw. which are abstracted from the remaininir 

 NeuropteTa. Erichson admits the orders Thysamoptera., Epizoa (lice), and 

 Suetoria (fleas). 



Burmeister states the principle upon which he establishes his orders as 

 follows: "The more marked the transformation the more heteroofeneous is 

 the individual in the several stages of its existence ; and as all insects 

 proceed from the same point, those necessarilj-, whose metamorphosis we 

 call complete, must attain a higher grade than the rest, which transform 

 themselves incompletely. We thus obtain two chief groups among insects, 

 Jlcminu'tahola and Ilolometalola. Both commence a new development in 

 the organization of the mouth, as they at first exhibit to us abortive, setiform, 

 oral organs, only adapted to suction, but in the higher grades these suctorial 

 organs develope themselves into free mandibles, with a lip covering them. 

 Thus each grouj) has Insecta Jiaustellata and Insecta mandibidata. Each 

 of these groups may then be further subdivided, according to the form of 

 the larva, the structure of the wings, and the entire internal organization, 

 and these divisions constitute tlieir orders. We thus obtain an arrangement, 

 the principles of w^hich are deduced from the idea of the entire insect, and 

 which, as this idea becomes separated according to its several characters 

 and constituents, it consequently necessarily and spontaneously forms itself 

 by the philosophical laws of thought." 



The orders of Latreille will be chiefly followed here, not because they are 

 considered to be correct, but because the accuracy of the modifications 

 proposed hj Erichson and Burmeister has not been sufiiciently tested. 

 Moreover, the views of these celebrated entomologists do not correspond. 



Order 1. Thysanura {pi. 17^ figs. 79-84). Li this order, established by 

 348 



