Archaic: ancient; no longer dominant; of the olden time.
Archiptera: those Neuroptera with incomplete metamorphosis = Pseudo-neuroptera.
Arctic Zone: is that part of the boreal region above the limit of tree growth in the U. S. is restricted to the area above timber line on the summits of high mountains: = alpine.
Arcuate: curved like a bow: = arcuate.
Arcuato-emarginate: with a bow-like or curved excision.
Arculus: Odonata; a small cross vein between radius and cubitus near the base, leaving an elongate triangle between them: Trichoptera; a point, often hyaline, on the forewing where the cubitus (or post cubitus) runs into the margin: in Homoptera; a cross-veinlet nearly reaching posterior margin at same point as in Trichoptera: in other orders applied to a cross-vein in similar position, apparently giving rise to the median.
Arcus: a bow; part of a circle; but less than one half.
Area mediastinal, scapularis and ulnaris: the areas in front of the mediastinal, the scapular, and the ulnar veins in Orthoptera.
Areae or Areolae: wing cells or spaces between veins.
Arenicolous: applied to species frequenting sandy areas.