flattened surface.

Plane: level, flat; applied to a surface.

Planipennia: applied to Neuroptera in which the wings are large and
laid flat on the body wnen at rest; Sialidae, Myrmeleonidae, etc.

Planta -ae: the basal joint of the posterior tarsus in pollen gathering
Hymenoptera: the soles of the posterior tarsal joints: the anal clasping
legs of caterpillars.

Plantigrade: species that walk on the entire foot, not on the claws
alone.

Plantula: a lobe of the divided tarsal pulvillus; one of the soles
or climbing cushions of the foot: see arolium; pulviglus.

Plaques: the small leathery hemelytra in some Naucorids.

Plasma: the liquid portion of animal fluids and cells.

Plasticity: the capacity for being formed, moulded or developed.

Plate: any broad flattened piece or sclerite: = squame, in Coccidae.

Platelet: a little plate or sclerite of chitin in a membrane.

Plates: in Coccidae, the squames; q.v.: in male Homoptera, a pair of
pieces following the last full ventral segment; usually preceded by a
short piece, - the valve.

Platyptera: flat and broad-winged: an ordinal term applied to insects
with four net-veined wings, secondaries longitudinally folded beneath
primaries; mouth mandibulate; prothorax free; transformations
complete: Psocidae, Termitidae, Perlidae and Mallophaga.
{Scanner's comment: These four groups are now placed in totally
separate orders, and not families as these names imply}

Plecoptera or Plectoptera: plaited winged: an ordinal term applied to
net-veined insects in which the secondaries are longitudinally folded
beneath primaries; mouth mandibulate; body loosely jointed;
prothorax free; metamorphosis incomplete: the term Plecoptera was
used by Brauer for Perlidae; Plectoptera by Packard for the
Ephemerida: there has been some confusion since, and both have
been used in the Brauer sense.

Pleon: = abdomen; q.v.

Pleopoda: abdominal legs of larva: posterior legs of an adult.

Plesiobiosis: see symbiosis.

Plesiotype: any specimen identified with a described or named species
by a person other than the describer.

Pleura: plural of pleuron or pleurum: the lateral sclerites between the
dorsal and sternal portion of the thorax: in general, the sides of the
body between the dorsum and sternum.

Pleural areas: on the metanotum of some Hymenoptera, the three
spaces between the lateral and pleural carinae; the 1st or anterior =
spiracular area; the 2d or central = middle pleur