144 ZOOLOGY. 



which the former contains two : 1^ Ehynchota ; 2, Gymnognatlia ; and the 

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

 ptora, Linn.); 5, Glossatcc, Fabr. {Lejndoptem, Linn.); and 6, Eleutherata^ 

 Fabr. {Coleoptera^ Linn.). For all these, except the second, Burnieister 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 Rlajncliota are made to include the tribe and family' Pediculina (the 

 lice), or hanstellate Anoplura ; whilst the mandibulate Anopliira, or bird 

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

 Mallophaga^ the first tribe being the PTiysopoda^ from which Llaliday and 

 most English entomologists form their order Thyaanoptera. The order 

 Thysanura of preceding authors forms a tribe., next to which succeed the 

 Orthoptera (including Blatta) ; Dennatoptera [Forficula., pi. 81, jigs. 1-3) ; 

 Corrodentia {Termcs., Einlda) ; Sahidicornia {EptJiemera., Libellida) ; 

 Plecoptera {Semhlis) ; Trichoptera ; and Plannipennia {Sicdis, etc.), all as 

 tribes of the same order. It results from this, that the Neuroptera and 

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

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

 places the Thysanura as an order, except that the LepismidcG are withdrawn 

 and placed in the order Orthoptera., which is farther enlarged by the 

 addition of the Libelhdidce., which are abstracted from the remaining 

 Neuroptera. Erichson admits the orders Thysaiioptera., Epizoa (lice), and 

 Siictoria (fleas). 



Burmeister states the principle upon which he establishes his orders as 

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

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

 proceed from the same point, those necessarily, 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, 

 Hembrietabola and Ilolometahola. 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 develoj^e themselves into free mandibles, with a lip covering them. 

 Thus each group has Insecta haustellata and Insecta mandibulata. 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 their orders. We thus obtain an arrangement, 

 the principles of which 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 by Erichson and Burnieister has not been sufliciently tested. 

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



Order 1. Thysanura {p)l. 77, figs. 79-84). In this order, established by 

 348 



