Priodont: applied to those forms of male Lucanids that have the smallest mandibles: see teleodont, mesodont, amphiodont.

Prismatic: formed like a prism: a play of colors similar to that produced through a prism.

Pro-: anterior: used as a prefix to designate the parts of the first thoracic segment.

Proboscidea: an ordinal term for the Coccidae.

Proboscis: generally applied to any extended mouth structure; usually applied to the extensile mouth of the Diptera; frequently to the beak of Hemiptera; sometimes to the tongue of Lepidoptera; and rarely, to the mouth of long-tongued bees.

Procephalic: relating or belonging to the procephalon.

Procephalic lobes: in the embryo, form part of the anterior, overhanging portion of the head.

Procephalon: that segment of the head in the embryo which is formed by the coalescence of the first three primitive segments.

Procerebral: that segment of the brain containing the median protocerebrum and optic ganglia; also called optic segment.

Procerebral lobes: the central portion of the cerebrum, made up of the fused median lobes, giving rise to the mushroom bodies; q.v.