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.

Metopidium: the anterior declivous surface of prothorax in Membracidae.

Micans: shining: also a surface of which only parts are shining.

Microchaetae: small bristles, as opposed to macrochaetae, in Diptera.

Microergates: the dwarf workers among ants.

Micron: the unit of microscopic measurement = 001 mm.: represented by the symbol µ: the symbol µµ represents .001 of a micron. {Scanner's note: the µµ notation would no longer be valid.}

Micropterous: small winged.

Micropterism: the tendency to produce small wings; applied to a line of variation.

Micropyles: minute openings in the egg, through which spermatozoa enter.