Mesonotum: the primitively upper surface of the 2d or middle thoracic ring. Mesophragma: an internal prolongation of the metapraescutum, affording attachment to some of the wing muscles. Mesopleura: in Diptera, the space before the root of the wing between the dorso- and sternopleural sutures: in Hymenoptera, the piece below the insertion of the wings. Mesopleural bristles: in Diptera, are inserted in the angle formed by the dorso-pleural and meso-pleural sutures. Mesopleural suture: in Diptera, runs from the root of the wings downward and separates the meso-pleura from the pteropleura. Mesopleuron: the lateral surface of the meta-thorax. Mesosternal cavity: in Elateridae, the opening into which the prosternal spine or mucro is fitted. Mesosternal epimera: in Coleoptera; the narrow pieces separating the meta-sternal from the meta-sternal episterna. Mesosternal episterna: Coleoptera; on each side of mesosternum between anterior border and epimera; generally separated by a distinct suture. Mesosternal lobes: in Orthoptera; = mesosternellum, q.v. Mesosternellum: in Orthoptera, two median lobes of the mesosternum, one on each side of the deep median notch: in general, the sternellum of the mesothorax. Mesosternum: the underside or breast of the meta-thorax. Mesostethidium: = meso-thorax: q.v. Mesostethium: the middle piece of the underside of meta-thorax, between the middle and hind legs. Mesostigma: in Odonata, the spiracles of second thoracic segment. Mesosulcus: a central longitudinal furrow of mesosternum in Hymenoptera. Mesotarsus: the tarsus of the middle leg. Mesothoracotheca: the pupal covering of the meso-thorax. Mesothorax: the second or middle thoracic ring; bears the middle legs and the anterior wings. Mesotergum: = mesonotum; q.v. Meta-: posterior: used as a prefix to designate the third thoracic ring and its parts. Metablastic: relating to the ecto- or meta-blast or ectoderm. Metabola: insects with a complete metamorphosis in which the larva does not resemble the adult, and the pupa is quiescent. Metabolism: is transformation: the whole process or series of changes of food into tissue and cell-substance and of these latter into waste products the first of these changes being anabolic, the second katabolic. Metabolous: undergoing metamorphosis or transformation. Metacoxal plate: in Coccinellidae, that portion of the first ventral segment included above the ventral lines visible on that segment. Metagnatha: insects which feed with jaws when young and by suction, with tubular mouths when mature; e.g. the Lepidoptera: see menognatha and menorhyncha. Metagonia: the hind or anal angle of a wing. Metallic: having the appearance of metal: applied to a surface or color. Metaloma: the sutural or inner margin of primaries. Metamere: a segment, somite or athromere. Metameric: made up of segments or metameres. Metamerism: the arrangement in metameres. Metameros: in Lepidoptera. the 6th to 8th abdominal segments.