Margin: that portion of a surface within the edge, bounded on the inner side by the sub-margin and consisting of a more or less dilated imaginary line.

Marginal: of, belonging to, or near the margin.

Marginal area: in Orthoptera; see mediastinal area.

Marginal bristles: in Diptera; are inserted on the posterior margin of the abdominal segment.

Marginal cell: in Diptera (Williston):= subcostal (Shiner):= radial (Comst.): in Hymenoptera:= radial and 2 (Comst.): in general that cell beyond the stigma.

Marginal field: in tegmina = costal field: q.v.

Marginal nervure or vein: in Orthoptera, = costa (Comst.): in Hymenoptera (Norton) = radius 3 (Comst.): in general, the vein forming the marginal cell.

Margined -ated: bounded by an elevated or attenuated margin: when the margin is edged by a flat border.

Marmorate -us: spots and lines irregularly disposed, as in marble: marbled. Mask: in the nymphs of Odonata, the modified labium which, when at rest, conceals the other mouth parts.

Masticate: to chew.

Masticatory: formed for chewing or grinding; applied to the mouth parts and to the grinding structures in the gizzard.

Mastigium -ia: telescopic a.n.a.l organs in certain caterpillars, serving to repel attacks of parasites.

Matrix: the formative substance from which cells and other structures are derived.

Maxilla: without any qualifying adjective, the second pair of jaws in a mandibulate insect; the most persistent when the mouth is modified, and represented by some functional part in all insects in which the mouth structures are useful: second maxillae, = the labium, or third pair of jaws in a mandibulate insect.

Maxillary: attached or belonging to the maxilla; e.g. palpi.

Maxillary palpi: the first pair of palpi, borne on the maxilla.

Maxillary pleurites: the lateral pieces, epimera and episterna of the maxillary segment.

Maxillary segment: the sixth segment of the head, bearing the maxillae.

Maxillary tendons: two slender rods in basal third of the muscid proboscis the remnant of the palpifer, to which muscles for flexing the proboscis are attached: see lora.

Maxillary tentacle: in female p.r.o.nuba: a specialized process of palpifer.

Maxillulae: a pair of appendages in Thysanurids, between mandibles and first maxillae.

Maxime: very much or very large.

Mealy: with a flour-like dusting: = farinose.

Mecaptera: = Mecoptera, q.v.

Meconium: the substance excreted by certain metabolic insects soon after their emergence from the chrysalis or pupa.

Mecoptera: long-winged: neuropterous insects with similar, large, unfolded wings; mouth mandibulate, prolonged into a beak: head free; thorax agglutinated; transformations complete: the scorpion flies or Panorpidae. Medi-: prefix, = middle.

Media: the fourth of the longitudinal veins extending from base through approximately the middle of the wing, not more than four branched, the branches numbered on margin from nearest apex, to 4 nearest a.n.a.l angle: in Orthoptera; it is the median or externomedian: in Lepidoptera (Pack.), is cubitus (Comst.).

Mediad: toward the median plane or middle.

Mediafurca: a process extending internally from the meso-sternum, to which the muscles are attached.

Medial: referring to, or at the middle.

Medial cells: (Comst.), are anteriorly bounded by the media or its branches: in Hymenoptera (Mort.), includes median and cubital (Comst.)

Medial cross-vein: (Comst.), is between media 2 and 3.

Median 1: in Lepidoptera (Pack.), = media 2 (Comst.).

Median 2: in Lepidoptera (Pack.), = media 3 (Comst.).

Median 4: in Lepidoptera ( Pack.), = cubitus 2 (Comst.).

Median area: of wings in Orthoptera, lies between the radial and ulnar veins, radius and media (Comst.): of meta-thorax of Hymenoptera, is the middle of the dorsum, divided into three s.p.a.ces or cells; 1st or basal area, 2d or Lipper median or areola; 3d or apical or petiolar area.

Median carina: Orthoptera; of head, is usually applied to a median dorsal carina, but has been also used for that which extends down the middle of front from the fastigium, and then = frontal costa: of prothorax, extends along the middle of p.r.o.notum.

Median cell: in Lepidoptera, is the closed area formed by a line extending from the end of subcostal to the end of the median veins, = radial (Comst.): in Hymenoptera, 1st median (Pack.), = medial (Comst.); 2d median (Pack.), - medial 4 (Comst.); 3d median (Pack.), = medial 2 (Comst.); 4th median (Pack.), = medial 1 (Comst.).

Median cross-veins: in Odonata; are those which cross median s.p.a.ce.

Median foveola: in Orthoptera; the foveate depression of the vertex between the eyes: = central foveola.

Median forks: in Orthoptera, refers to the forks of the median vein.

Median furrow: lies between radius and media: in some Heteroptera, separates the embolium from the remainder of the corium.

Median lines: on the primaries of many moths: the first or t.a.

crosses about one-third from base; the second or t.p. crosses beyond the outer third and is usually sinuate.

Median lobe: of labium in Odonata, is the partly divided glossa or ligula; probably corresponds to united glossa and paraglossae (Butler).

Median longitudinal carinae: on the metanotum of Hymenoptera, extend one on each side of the middle.

Median nervules: in Lepidoptera (Holland)1st = cubitus 2 (Comst.): 2d cubitus 1 (Comst.); 3d = media 3 (Comst.).

Median notch: in Coccidae, a notch in the edge of the pygidium, at the posterior extremity of the body.

Median plate: in Hymenoptera := sessiliventres, is the dorsal plate connecting the thorax and abdomen.

Median sector: in Odonata, = media 3 (Comst.).

Median segment: applied to the basal segment of the abdomen when it forms part of the metathorax: see propodeum.