Peripodal membrane: the cell layer surrounding the peripodal cavities. Peristaltic: that periodic motion of the alimentary canal by means of which the food is forced toward the anal extremity. Peristethium: the meso-sternum. Peristoma -ium: the border of the mouth or oral margin in Diptera; sometimes used as := epistoma: q.v. Peristome: a membranous tissue surrounding the mouth parts at base, and forming the true ventral wall of the head. Peritoneal: applied to the membrane surrounding the viscera, trachea, and other internal structures. Peritracheal: surrounding the trachea. Peritreme: the corneous selerite surrounding a spiracle. Peritrophic membrane: a funnel-like extension of the fore-gut, extending back tube-like, through the chylific ventricle in some insects. Perivisceral: the cavity containing the alimentary canal and its appendages. Perlate: beaded: bearing relieved, rounded points in series. Perpendicular: upright: at right angles to horizontal. Persicinus: the red of peach blossoms. Persistent: remaining constantly; always present. Personate: gaping wide open; masked; disguised. Pes, Pedes: a foot feet. Petiolar area or Petiolarea: on the metanotum of some Hymenoptera, the apical or hindmost of the three median cells 3d median area; apical area. Petiolate: that series of Hymenoptera in which there is a slender stalk between the thorax and abdomen: = apocrita. Petiolate: supported or placed on a stem or stalk; usually applied in describing venation and the method of attachment of abdomen to thorax. Petiole: a stem or stalk: specifically the slender segment between the thorax and abdomen in many Hymenoptera, and some Diptera. Phaeism: applied to a duskiness of butterflies occurring in a limited region. Phagocyte: a corpuscle or cell that devours or absorbs noxious organisms and also absorbs the organs of the larval stage in the developments to the adult condition. Phagocytosis: the destruction or devouring of bacteria or other microorganisms by phagocytes. Phalaenae: a Linnean term embracing most of the heterocerous Lepidoptera: more specifically applied to the Geometridae. Phalanx -ges: a joint or joints of the tarsus: a division of classification of uncertain value: similar to tribe. Phalerated: beaded. Phallus: =penis: q.v. Pharyngeal pump: = sucking pump; q.v. Pharynx: the back part of the mouth and upper part of the throat: a slight enlargement at the beginning of the oesophagus: in Diptera is sometimes restricted to the space between the hypopharynx and sub-clypeal pump, and is then = sub-clypeal tube. Phauloptera: an ordinal term for the scale insects (Laporte 1835). Phleboptera: = Hymenoptera; q.v. Phonetic: sound producing; applied to stridulating structures. Phosphorescent: shining or glowing in the dark, like phosphorus. Photogenic: a light producing structure; producing a Phosphorescent glow.