Metamorphosis: is that series of changes through which an insect passes in its growth from egg through larva and pupa to adult: it is complete when the pupa is inactive and does not feed; incomplete when there is no pupa or when the pupa is active and feeds. Metamorphosis dimidio: an incomplete transformation. Metamorphosis perfecta: a complete transformation. Metanotum: the primitively upper surface of the third or posterior thoracic ring: in Diptera, the oval arched portion behind, beneath the scutellum best developed in flies with long, slender abdomen: e.g. Tipulidae. Metaphragma: the hindmost internal thoracic septum. Metapleura: in Diptera, a swollen space at the outside of the metanotum, between it, the pteropleura and the hypopleura; in Hymenoptera, the piece behind and below the insertion of the hind wings. Metapleural bristles: in Diptera, are inserted in the metapleura. Metapneustic: larva, chiefly dipterous, in which the spiracles are confined to the posterior segment. Metapnystega: that circular area of metanotum behind the postscutellum. Metapodeon: the abdomen behind the podeon or petiole in Hymenoptera. Metasternal: relating or attached to the metasternum. Metasternal epimera: small sclerite separating the metasternal episterna from the ventral segments. Metasternal episterna: sclerite situated on each side of the Metasternum, immediately behind the mesosternum epimera. Metasternellum: the sternellum of the metathorax. Metasternum: the underside or breast of the metathorax. Meta-stethidium: = meta-thorax; q.v. Metastigma: in Odonata, the spiracles of third thoracic segment. Metastoma: in Orthoptera:= hypopharynx: q.v. Metatarsus: applied to basal joint of tarsus, where that differs greatly in length or otherwise from the other joints: see sarothrum. Metatergum: = metanotum; q.v. Metathoracotheca: the pupal covering of the meta-thorax. Metathorax: the third thoracic ring or segment; bears the hind legs and second pair of wings; variably distinct; sometimes closely united with the mesothorax and sometimes appearing as a portion of the abdomen. Metatype: is a specimen named by the author after comparison with the type; according to some, it should be also a topotype. Metazona: in Orthoptera, the dorsal surface of the prothorax behind the principal sulcus. Metepimeron: in Odonata, lies behind the second lateral suture and extends ventrally to the sternum. Metepisternum: in Odonata, is the sclerite between the first and second lateral thoracic sutures. Meter: the standard of length in the metric system = 39.37 inches: see centimeter and millimeter. Meticulose -us: is a maculation in the form of a series of colored flames. Metinfraepisternum: in Odonata; the sclerite just above base of 3d coxa; below metepisternum and before metepimeron. Metochy: the relation borne to ants by the tolerated guests in ant-hills; demanding nothing from and giving nothing to the ants; see symphily and synecthry.