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Show XX SYSTEMATIC INDEX. (Edionychua Paylliodes Dibolia .!l.ltica proper Longitarsua CLAVIPALPI Erotylus Erotylus proper Trip lax Languria Phalacrus Agathidium Tfimera. FUNGICOLlE 561 561 562 562 562 562 563 563 564 564 564 564 565 Eumorphus 565 Eumorphus proper 565 Dapsa 566 Endomychus 566 Lycoperdina APHIDIPHAGI Coccinella Lithophilns Coccinella proper Clypeaster PSELAPHII Pselaphus Chennium Dionix Pselaphus proper Bithynus Areopagus Ctenistes Byraxis Claviger Claviger proper Articerus S66 566 567 567 567 568 568 569 569 569 569 570 570 570 570 570 570 570 THIRD GREAT DIVISION OF THE ANIMAL KINGDOM. CRUSTACEA, ARACHNIDES, AND I.NSECTA: OR ARTICULATED ANIMALS WITII ARTICULATED I<'EET(l ). These last three(2) classes of the Articulata, which were united by Linnmus under the general name of Insecta, are distinguished by at least six(3) articulated feet. Each articulation is tubular, and contains the muscles of the succeeding one, which always moves by gynglymus, that is, in but one direction. The first articulation, which attaches the foot to the body, ( 1) For the sake of brevity, I have designated them by the term Condylopu. This series of art:culations, of which their body is composed, has beeu compared i1y some Naturalists to a skeleton, or the vertebral column. But the use of this denomination is so much the more fallacious, in as much as these articulations or pretended vertebra: are mere portions of thickened skin, and as this skin is continuous, simply being thinner, and almost membranous o.t intervals or at the joints. A general character, which serves to distinguish these animals from all other Invertebrata, consists in theit• exuviability, or habit of changing theit· skin. The situation of the encephalon, pharynx, and eyes, as in the more elevated animals, establishes the limits of the back and abdomen, and of their respective appendages. (2) Dr Leach forms a separate class of the M:yriapoda. The Arachniues Tra· chenric:e, considered anatomically, might also constitute anothe.r, but they are so closely allied to the Pulmonaric:e in so many other particulars, that we have not thought proper to separate them. (3) Hexapoda. Those which have more than six, are termed by Savigny the Spiriopoda. I desigllQte them more precisely by the appellation of Hyperhexapoda, (more than six feet). VoL . Ili.-A |