Pre-scutellar bristles: in Diptera, are in a transverse row in front of the scutellum.
Pre-scutellar callus: = post-alar callus: q.v.
Pre-scutellar rows: in Diptera, short rows of small bristles in front of the scutellum.
Pressure plate: a structure at base of pulvillus, which exerts a pressure on the sole of the pad.
Pre-sutural bristles: in Diptera, in a trigonate depression at outer ends of transverse suture, near dorso-pleural suture.
Pre-sutural inter-alar bristle: the single bristle of the interalar series, situated before the transverse suture.
Primitive: simple in character; of an early or ancient type.
Principal sector: in Odonata, extends from its point of separation From the median sector to the outer margin, at or just below the apex:= media 1 (Comst.).
Principal sulcus: in Orthoptera, a transverse impression of the prothorax, at or behind the middle.
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.
Procerebrum: the anterior part of the brain, formed by the ganglion of the first primary segment; also termed ocular lobe, froth part it innervates. Process: a prolongation of the surface, margin, or an appendage: any prominent portion of the body not otherwise definable.