482 



INSECTA. 



the extremity with a galea ; the lower wings folded in two directions, or simply longi- 

 tudinally, and the sheaths ordinarily coriaceous, mostly crossing at the inner margin. 

 They only undergo the semi-metamorphosis.* 



The seventh order, Hemiptera, has six feet ; four wings, the two upper having the 

 form of coriaceous sheaths, membranous at the extremity, or similar to the inferior pair, 

 but larger and stronger ; the mandibles and maxillae are replaced by setae, forming a 

 sucker, inclosed in a sheath of a single, articulated, cylindrical, or conical beak-like 

 piece. 



The eighth order, Neuroptera, has six feet ; four membranous, naked wings ; and 

 mandibles and maxillae for mastication. The wings are finely reticulated, the lower pair 

 generally of the size of the anterior, or more extended in one of their diameters. 



The ninth order, Hymenoptera, has six feet; four membranous, naked wings; man- 

 dibles and maxilla? for mastication ; the lower wings smaller than the superior ; the 

 abdomen of the females nearly always terminated by a borer, or sting. 



The tenth order, Lepidoptera, has six feet; four membranous wings, covered with 

 little coloured scales, like dust ; a horny piece, like an epaulette, directed backwards, 

 inserted in front of each of the fore-wings ; the maxillae replaced by two tubular fila- 

 ments united, and composing a kind of tongue rolled up in a spire. f 



The eleventh order, RinriPTERA, has six feet; two membranous wings, folded like a 

 fan ; two crustaceous, moveable bodies, in the form of small elytra, situated at the fore 

 extremity of the thorax}; and the organs of manducation consist of a pair of simple, 

 setiform maxilla?, with two palpi. 



The twelfth order, Diptera, has six feet ; two membranous wings, extended, and 

 accompanied, in nearly all, by two moveable bodies, in the form of balancers, situated 

 behind them ; and the organs of manducation consist of a sucker, containing a variable 

 number of seta?, inclosed in an inarticulated sheath, often under the form of a proboscis, 

 terminated by two lips. § 



THE FIRST ORDER OF INSECTS,— 



MYRIAPODA (Mitosata, Fab.),— 



Commonly called Centipedes or Millepedes, are the only animals of this class which have more 

 than six feet in the perfect state, and in which the abdomen is not distinct from the trunk (or 

 thorax). Their body, destitute of wings, is composed of a generally extensive series of seg- 

 ments, nearly of equal size, each generally bearing, with the exception of the anterior segments, 



• De Geer first established this order, which he called Dermaptera, 

 changed, without propriety, by Olivier, into Orthoptera. I retain the 

 latter, because the French naturalists have generally adopted it. [Dr. 

 Leach, to add to the confusion, employed the name Dermaptera for an 

 order consisting of the family of the Earwigs. The name ought cer- 

 tainly to be restored to the mandibulated Hemiptera of LinnamsJ. 



t The thorax of the Lepidoptera has more analogy with that of the 

 Neuroptera than with the Hymenoptera, the medial segment appearing 

 to form part of the abdomen, whilst in the latter and the Diptera, it is 

 incorporated with the thorax. 



t Formed, as I presume, of pieces analogous to the pterygoda of the 

 Lepidoptera. [Such is not the case, as is proved by the dissections of 

 the thorax published by Curtis and myself, being rudimental elytra, 

 similar to those of Situris, Atractocerui, and certain Phasing]. 



§ [It would be cut of place to enter into a review of the various 



systems proposed by different celebrated authors, as Fabricius, Leach, 

 Kirby, M'Leay, Laporte, and others; but as the school of English 

 Entomologists adopt various orders not employed by Latreille, it will 

 not be improper to observe, that the orders Myriapoda, Thysanura, and 

 Parasila, are generally, by most English authors, excluded from the 

 class of rnsects, forming a distinct class— Ametabola. The family of the 

 Earwigs is raised to the rauk of an order by Kirby and Leach, under 

 the name of Dermaptera, which, to prevent further confusion, I have 

 changed to Euplexoptera. The genus Thrips has been formed into an 

 order by Mr. Haliday, named Thysanoptera ; Phryganea, or the Cad- 

 dice-flies, compose the order Trichoptera of Kirby; the suctorial 

 Hemiptera, with the fore-wings entirely of a membranous consistence, 

 arc separated as the order Homoptera of Latreille ; whilst the Forest- 

 flies (Hippobosccc, Linn.) form the order Homaloptera of Leach, sepa. 

 rated from the Diptera.] 



