INSECT. 



877 



2. Ilemiptera. Wings four, the upper pair seini- 

 erustaceous and incumbent (bugs, locusts, tree- 

 hopper?, plant-lice, &c.). 



3. Lt'piduptem. Wings four, imbricated with scales 



(butterflies, moths). 



4. Neuroptera, Wings four, membranaceous, anus 



unarmed (dragon-flies, Sac.}. 



!). Hymenvptera. Wings four, membranaceous, 

 anus armed with a sting (bees, wasps, ants, 

 saw-flies, &c.). 



6. Diptera. Wings two, halteres two in the place 



of the posterior wings (flies). 



7. Aptera. Wings none (spiders, crabs, centipedes, 



fleas, &c.). 



We have shown above that the possession of wings 

 is the chief characteristic of the Ptilota, which may 

 therefore be regarded as the type of the other anmilose 

 animals, that is we may consider them as the fur- 

 thest removed (as concerns their organisation), from 

 the other animal sub-kingdoms ; hence we find, that 

 the orders or first general divisions of insects are 

 characterised from the structure of the wings (vm^M, 

 a wing) ; and hence this Greek word, together with 

 some other prefixed to it, is employed as the name of 

 orders. We have thus Coleoptera, sheath-winged, 

 Ncnroptcra, nerve-winged, &c, ; but it soon became 

 evident, that the characters of the wings were too 

 general ; and Fabricius, a disciple of Linnaeus, fell 

 into the opposite error of regarding the variations of 

 the mouth as alone affording the most satisfactory 

 distribution of insects. 



The system of Fabricius introduced a number of 

 new orders, which he was pleased to name classes ; 

 and to which, in addition to such of the Linnasan or- 

 ders as he retained, he gave a series of exceedingly 

 harsh names, founded upon the structure of the mouth, 

 as follows : 



Insects with masticating mouths. 

 Two pairs of jaws. 



Eleutherata. Maxillae palpigerous, uncovered 



(beetles). 

 Ulonata. Maxillas palpigerous, covered with a 



galea (locusts, mantes, &c.). 

 Synislata. Maxilla: palpigerous, connate with the 

 lower lip (lace-winged flies, &c., with the 

 white ants and sugar lice). 



Piczata. Maxillae palpigerous, distended, thin, co- 

 riaceous (bees, wasps, saw-flies, &c.). 

 Odonata. Maxillae palpigerous, horny, toothed, 



labium not palpigerous (dragon-flies). 

 Mitosata. Jaws and maxillae not palpigerous (cen- 

 tipedes, &c.). 



A pair of jaws resembling scissors. 

 Unogata (scorpions and spiders). 

 More than two pairs of jaws. 



Polygnnata. Jaws closed by the lower lip (sea 



and wood lice, Oniscus). 

 Klcistagnala. Jaws external, closing the mouth 



beneath (crabs). 



Exochnata. Jaws external, but covered by the 

 palpi (lobsters, &c.). 



Insects with suctorial month. 1 !. 

 Glossata. Mouth with a spiral tongue (butterflies, 



moths). 



Rhyngota. Mouth with a membranous jointed 

 sheath, inclosing horny lancets (bugs, tree- 

 hoppers, &c.). 



Antliata. Mouth with a soft mijointed proboscis 

 (flies, lice, and mites). 



As the Linnaean system, founded upon the wings, 

 was found to violate nature by uniting masticating 

 and suctorial insects, so the Fabrician system was, in 

 some respects, even more artificial, as when the wing- 

 less sugar-lice, which undergo no metamorphose*, 

 were introduced amongst the nietarnorphotic lace- 

 winged flies, &c., and the lice and octapod mites 

 (Acari) were united with the two-winged flies. The 

 system of Fabricius has met with but few followers, 

 except in Germany, his chief merit consisting in 

 his definition of a great multitude of new species. 

 To the labours of the French naturalists, Cuvier, La- 

 treille, and Lamarck, we are mainly indebted for the 

 great advances made towards a more natural mode of 

 distribution, wherein the natural affinities of the 

 various groups are more or less recognised. It would 

 occupy too much time to trace the gradual improve- 

 ments, or suggestions for improvements, which have 

 been made during the present century, in which En- 

 tomology has made such rapid strides towards perfec- 

 tion. We shall, therefore, content ourselves with 

 translating for the student the characters of the 

 various orders of metamorphotic insects, given in the 

 last work of Latreille, the Cours d'Entomologie, 

 published shortly before his death, and which are 

 generally adopted. Latreille, however, has intro- 

 duced the spring-tailed insects (Thymnovra), and lice 

 (Anopltira), at the head of the class of insects which, 

 as above stated, we have, with MacLeay, united with 

 the Amctabola, as they undergo no metamorphoses. 



I. Wings none, metamorphoses complete (perfect}. 



larva apod, pupa inactive, mouth formed of 

 an inferior syphon, directed backwards, com- 

 posed of a bi-valved articulated sheath, 

 inclosing a sucker of three setae, with two 

 scales at the base , body very compressed, 

 formed for leaping. Insects parasitic (fleas). 

 Order, Siphonaptera, Mr. Kirby's name, 

 Aphaniptcra, ought to be retained in pre- 

 ference either to Latreille's name, or that 

 of Suctoria, given to the flea by De Geer. 



II. Wings, sometimes, however, obsolete; eyes 



faceted, and occasionally ocelli. 

 1. Elytroptera. Posterior wings, covered by the 

 anterior, which are either entirely or partly 

 crustaceous or coriaceous. 

 A. Mouth with upper jaws, and lower jaws ; 

 elytra of an uniform consistence. 



"Order, Coleoptera, characterised by, 

 Elytra entirely crustaceous, always horizontal, with 

 a straight suture ; wings folded cross-wise ; external 

 lobe of the maxillae not helmet-shaped ; metamor- 

 phoses complete (pupa incomplete), beetles. 



Order, Dermaptcra, 



Elytra entirely crustaceous, horizontal with a 

 straight suture ; wings folded transversely and partly 

 longitudinally, so as somewhat to resemble a fan ; 

 maxillte with the terminal lobe helmet-shaped ; two 

 strong pincers at the posterior extremity of the abdo- 

 men in both sexes ; demi-metamorphoses (pupa com- 

 plete and active), ear-wigs. 



Order, Ort/ioptcra, 



Elytra (tegmina) coriaceous, deflexed or inclined, in 

 some horizontal, and folding on each other at the in- 

 ternal edges in the others ; wings longitudinally 

 folded throughout their entire length ; maxillte, with 

 the terminal external lobe, helmet-shaped ; abdomen 

 terminated by articulated appendages in both sexes 

 in some ; in the others, the abdomen furnished with 



