Prothoracic shield: = cervical shield: q.v.
Prothoracotheca: the pupal covering of prothorax.
Pro-thorax: the first thoracic ring or segment: hears the anterior legs but no wings: when free, as in Coleoptera. is usually referred to as "thorax" merely.
Protocerebral segment: = ocular seginent; q.v.
Protocerebrum: the primitive anterior cerebral vesicle.
Protocosta: the thickened costal margin of Lepidopterous wings.
Protocranium: the posterior part of the epicranium: sometimes used as Occiput.
Protogonia: the apical angle of the primaries.
Protograph: all original description by a figure or picture made from the original type.
Proto-lepidoptera: proposed for those forms (Eriocephalidae) in which lacinia and mandibles are obvious and the spiral tongue is not developed: see neolepidoptera and paleolepidoptera.