582 Div. 3. ARTICULATA.— IXSECTA. Class 3. 



a mass, the anterior being very short and the two others united into one.* The wings are 

 crossed horizontally upon the body ; the abdomen mostly suspended to the hind part of the 

 thorax by a slender thread or peduncle ; the tarsi are 6-jointed, none of the joints being 

 bilobed. The borer or sting [both of which are described in a note as being ty])ically com- 

 posed on the same model], are formed for the most part of three long and slender pieces, 

 two of which serve as a sheath to the third in those which have a borer, and of which the 

 upper has a groove at its under side to encase the two others. 



M. Jurine has found in the articulation [of the nerves] of the wings good auxiliary charac- 

 ters for the distinction of genera, making use of the presence or absence, number, form, and con- 

 nexion of the two kind of cells situated near the external apex of the fore wings, which he 

 terms radial [or marginal], and cubital [or submarginal] cells. The middle of the fore mar- 

 gin of the wings has often a callous spot, termed the stigma, whence a nerve extends which 

 runs to the tip of the wing, and forms with the fore-edge of the wing the radial cell, some- 

 times divided into two ; a second nervure also extends from the stigma, which also extends to 

 the apex of the wing, leaving between it and the first-mentioned nerve a space occupied by the 

 cubital cells, of which the number varies from one to four. 



The Hymenoptera undergo a complete metamorphosis ; the majority of their larvae are 

 vermiform, and are destitute of feet, such as those of the second and following familes; those of 

 the first family have six hooked feet, and often from twelve to sixteen others, which are simply 

 membranous ; the head in all is scaly, with mandibles, maxillae, and a lower lip, at the extre- 

 mity of which is a spinneret for the passage of the silken matter of which the cocoon of the 

 pupa is composed. Some feed upon vegetable substances ; others, always footless, upon the 

 dead bodies of Insects, in all their states of egg, larva, pupa, and imago. In order to supply 

 their weakness, the female supports them with provisions, sometimes carrying their food to 

 the nests which they have prepared for them, often with surjjrising skill, and sometimes 

 by placing their eggs in the bodies of larvae and pupa; of insects, upon which their young feed. 

 Other equally footless larva; of Hymenoptera are fed on more elaborated animal and vegetable 

 food, and more constantly renewed. These are reared in common by individuals destitute of sex, 

 united in societies, charged exclusively with such works, and whose labours and regime are the 

 theme of continual admiration. The Hymenoptera in the perfect state subsist almost exclu- 

 sively on dowers, and are commonly most abundant in southern climates. The extent of their 

 existence, from their birth till their final change, is confined to a year. 



[The natural classification of these insects has been but comparatively little attended to. 

 Various plans of arrangement, founded not only upon the structure of the imago, but also 

 upon Its habits, and the peculiarities of the preparatory states, have recently been proposed 

 by Saint Fargeau, Dahlbom, Hartig, Hallday, &c. I must however refer to the 2nd vol. of 

 my Introduction to Entomology for an investigation of these arrangements. 



I divide this order into two sections, [Terebrantia and Aculeata]. 



The first, that of the Terebrantia, is characterized by possessing a borer in the females. 



I divide the Terebrantia into two great families, [the Securifera and Pupivoral. 



THE FIRST FAMILY OF THE HYMENOPTERA,— 



The Securifera, — 



Is distinguished from the following by the sessile abdomen, of which the base is united to the thorax 

 by its entire width, and appears to be but a continuation of it, without any proper motion. The 

 females have an ovipositor, for the most part like a saw, which is used not only in depositing tlie egg9, 

 but also in preparing a place for their reception. The larvae have always six scaly feet, and often 



• In II note Lntreille ndoi)tB the theijrr that the mctathornx is a Tery 

 narrow st-gnit-nt, and that the hind part of llie thorax \\-hich has t\i-o 

 •plraclen at the sides, is in rtftlity lUt: firtit uiHlouuviU Kcgmeut, vo 



that in the pedunculated rivmenoptcra, the peduncle it the ■eccmd 

 and not the first abdoraioal leKiueDt. 



