Medi-thorax: =mesothorax; q.v. Medius: middle. Mega- Megalo-: large. Melanic: with a blackish suffusion. Melanism: an abnormal or unusual darkening: a suffusion with blackish. Mellifera: honey-makers: applied to bees as a whole. Melliferous: honey-producing, or producers of honey. Mellisugous: honey-sucking: a feeder on honey. Member: any one of the external appendages. Membranaceous: thin, skin-like, semi-transparent, like parchment: of a thin, pliable texture. Membrana retinens: the stretched part of the membrane around the rectum of butterfly larvae, used in the change to the chrysalis. Membrane -ana: any thin, transparent, flexible body tissue: specifically the wing tissue between the veins: in Heteroptera, the thin membranous tip of the hemelytra. Membranous or eous: composed of membrane or skin-like tissue. Membranule: the small opaque expansion at base of wings in Odonata. Meniscoidal: with one side concave the other convex, like a round segment from a hollow sphere. Menognatha: insects in which both young and adults feed by mandibles; e.g. the Orthoptera: see menorhyncha and metagnatha. Menorhyncha: forms in which both young and adult take food by suction e.g. Hemiptera: see metognatha and metagnatha. Mental suture: in Coleoptera, the line between mentum and gula. Mentigerous: bearing or having a mentum. Mentum: a labial sclerite bearing the movable parts; attached to and sometimes fused with the sub-mentum; corresponds to the (united) stipes of maxillae: in Coleoptera, what is usually called mentum is really submentum: in Diptera, the term is applied to the posterior oral margin: in Hymenoptera, is part of "tongue," the second joint bearing the labial palpi, paraglossae and ligula. Merdivorous: feeding upon dung or excrement: see scatophagous. Meriaeum: the posterior inflected part of the metasternum in Coleoptera. Meroistic: ovaries that secrete yolk or vitellaginous cells as well as ova. Mesad: extending or directed toward the median plane. Mesal: pertaining to, situated on or in the median plane of the body. Mesenchym: that portion of the mesoderm that produces the connective tissues of the body. Mesenteron: the mid-gut, stomach or chylific ventricle: the middle portion of the primitive intestinal canal, lined with entoderm. Mesepimeron: in Odonata: the sclerite between humeral and first lateral suture. Mesepisterna: in Odonata,- the oblique lateral pieces of mesothorax, meeting dorsally in a ridge. Mesially: at or to the middle. Mesinfraepisternum: a sclerite formed between propleuron, mesepisternum, mesepimeron and second coxa. Meso: middle: as prefix, drops the o when stem begins with a vowel. Mesoblast: the middles germ layer of the embryos: = mesoderm. Mesoderm:= mesoblast: gives rise to muscular and circulatory systems. Mesodont::= amphiodont: q.v. Mesomeros: the 2d to 5th abdominal segments in Lepidoptera. Meson: the middle plane of the body.