INSECTA. 
482 
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.* * * § |S 
The seventh order, Hemiptera, has six feet ; four wings, the two upper having the r 
form of coriaceous sheaths, membranous at the extremity, or similar to the inferior pair, ||j 
but larger and stronger ; the mandibles and maxillae are replaced by setae, forming a r 
sucker, inclosed in a sheath of a single, articulated, cylindrical, or conical beak-like r 
piece. I 
The eighth order, Neuroptera, has six feet ; four membranous, naked wings ; and p 
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- I 
dibles and maxillae for mastication ; the lower wings smaller than the superior ; the i 
abdomen of the females nearly always terminated by a borer, or sting. || 
The tenth order, Lepiuoptera, has six feet ; four membranous wings, covered with |.! 
little coloured scales, like dust ; a horny piece, like an epaulette, directed backwards, I; 
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, Rhipiptera, 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 maxillae, 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 setae, 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 exeeption of the anterior segments. 
* De Geer first established this order, which he called Dermaptera, 
chang'ed, 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 Linnaeus]. 
t The thora.x 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 Sitaris, Atractocerus, and certain Phasmae]. 
§ [It would be out 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 
Parasita, are generally, by most English authors, excluded from the 
class of Insects, forming a distinct class — Ametabola. The family of the 
Earwigs is raised to the rank 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, 
are separated as the order Homoptera of Latreille ; whilst the F'orest- 
flies {Hippohosca, Linn.) form the order Homaloptera of Leach, sepa- 
rated from the Diptera.] 
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