ndibles.

Oral segment: that ring or segment which bears the mouth.

Orbicular: round and flat, the diameters of the plane equal: in sonic
moths, a round or oval macula in the median cell.

Orbit: an imaginary border around the eye: in Diptera the orbits are
divided into vertical or superior; frontal and facial or anterior; of the
cheek or inferior; occipital or posterior.

Orbital sclerite: a narrow sclerite encircling some eyes.

Order: one of the primary divisions of the Class Insecta, based largely
on wing structure and then usually ending in -ptera.

Ordure: excrement; usually applied to such as is foul or offensive.

Orichalceous: = aurichalceous; q.v.

Oriental: in geographical zoology as used by Wallace, that part of the
earth's surface including Asia east of the Indus River, south of the
Himalayas and the Yangtse-kiang watershed, Ceylon, Sumatra, Java
and the Philippines.

Orificium: the anal or genital opening.

Original type: is the actual specimen from which a published
description is prepared.

Orismologia -y: the defining of scientific or technical terms.

Orthoptera: straight winged: an ordinal term applied to insects in
which the primaries are not used in flight, but cover the longitudinally
folded secondaries; mouth mandibulate; head set into prothorax, the
latter free; metamorphosis incomplete.

Orthorrhapha: that section of Diptera in which the pupa escapes from
larval skin through a T-shaped opening on back: see cyclorrhapha.

Orthorrhaphous: straight-seamed.

Os: the mouth of insects, in general.

Oscillation: a vibrating or swinging from side to side.

Osculant: intermediate in character between two groups or series.

Osmaterium -ia: fleshy, tubular, eversible processes producing a
penetrating odor, capable of being projected through a slit in the
prothoracic segment of certain Papilionid caterpillars, and from
openings elsewhere in the bodies of other forms.
{Scanner's comment: currently the only spelling I can find is
"osmeterium". This given spelling is almost certainly an error
on someone's part. Not only do the earliest books that I can
find spell it "osmeterium", but the Greek root is "osme".}

Osmosis: the tendency of liquids to pass or diffuse through a
membrane or septum.

Osselet: = ossicle; q.v.

Ossicle: a small nodule of chitin resembling a bone.

Ossicula: small corneous pieces that serve in the articulation of the
wings to the thorax.

Ostia: the slit-