. Cuvier's animal kingdom : arranged according to its organization. Animals. Fig. B, head of Mu following families they are only composed of two or three joints, the last of which is generally fusiform or lenticular, with a small styliform appendage, or hair, either simple or bearded. The mouth is only fit for extracting and drawing forth fluid matters, and when these are inclosed in proper vessels, with an envelope easily pierced, the pieces of the sucker act as lancets, piercing this envelope, and forming a passage for the liquid, which ascends by the pressure of these lancets together
. Cuvier's animal kingdom : arranged according to its organization. Animals. Fig. B, head of Mu following families they are only composed of two or three joints, the last of which is generally fusiform or lenticular, with a small styliform appendage, or hair, either simple or bearded. The mouth is only fit for extracting and drawing forth fluid matters, and when these are inclosed in proper vessels, with an envelope easily pierced, the pieces of the sucker act as lancets, piercing this envelope, and forming a passage for the liquid, which ascends by the pressure of these lancets together, to the pharynx, situated at the base of the sucker, the sheath of which serves only as a defence to these lancets, and is gene- rally folded upon itself in their action. This sheath appears to represent the lower lip of mas- ticatory insects, and the seta;, at least in those with the most comphcated mouth, represent the other parts, such as the labrum, mandibles, and maxillae. The clypeus, or epistome as I call it, is represented by the basal part of the proboscis preceding the sucker and palpi ; the base of the proboscis mostly bears two filiform or clavate palpi, composed in some of five joints, but in most of only two. The wings are simply veined, and generally horizontal. As in the Ilymenoptera, their veins furnish good secondary characters of groups. The use of the balancers is not known ; the insect moves them with great rapidity. Many species, especially those of the terminal families, have above the balancers two membranous pieces, like the two valves of a shell, attached together at one side, and which are termed alulets. One of these pieces is united to the wing, and partakes of its movements, at which time the two valves are upon the same plane. The size of these winglets is in inverse propor- tion to that of the haltères ; the prothorax is always very short, and often its lateral portions are alone visible. In some species of Scenopinus, Culicidœ, and Psychoda,
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Keywords: ., bookcentury1800, bookdecade1840, bookpublishe, booksubjectanimals
