Aquatilia: cryptocerous Hemiptera of truly aquatic habit.

Arachnoideous: resembling or similar to a cobweb.

Araneiform: spider-like in appearance.

Arboreal: living in, on, or among trees.

Arborescent: branching like the twigs of a tree.

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 h.o.m.optera; 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 s.p.a.ces between veins.

Arenicolous: applied to species frequenting sandy areas.

Arenose: a surface that is sandy or gritty.

Areola: a small cell on the wings of certain Hemiptera: see also areae Hymenoptera; the central of three median areas on the metanotum: = 2d median area; upper median area.

Areolate: with small defined areas, like a network.

Areole: Lepidoptera; see accessory cell, cell and cellule.

Areolet: one of the small s.p.a.ces between veins of net-veined insects.

Argentate: shining, silvery white.

Argenteous: silvery.

Argillaceous: of the texture, appearance or color of clay.

Arid: Applied to regions in which the normal rainfall is insufficient to produce ordinary farm crops without irrigation, and in which desert conditions prevail: see humid.

Arid transition area: comprises the western part of the Dakotas, northern Montana east of the Rockies, southern a.s.siniboia, small areas in southern Manitoba and Alberta, the higher parts of the Great Basin and the plateau region generally, the eastern base of Cascade Sierras and local areas in Oregon and California.

Arista: a specialized bristle or process on antennae of certain Diptera.

Aristate: Diptera; that type of antennae that bears an arista: = athericerous.

Aristiform: of the form or appearance of an arista.

Armature: applied to the spinous or chitinous processes on the legs, body or wings; or the corneous parts of genitalic structures.

Armatus: set with spines, claws or other chitinous processes.

Armillate: with a ring or annulus of raised or different tissue.

Arolium -ia: cushion-like pads on the tarsi of many insects: one of the lobes of the pulvillus; in Orthoptera, used only for the terminal pad between the claws: see empodium; pulvillus; palmula; plantula; onychium, paronychium, pseudonychium.

Arquate: see arcuate.

Arrhenotokous: capable of producing male offspring only, as in worker bees and some saw-flies.

Arrhenotoky: parthenogenetic reproduction when the progeny are all males: see thelyotoky and deuterotoky.

Arthrium: Coleoptera; the minute, concealed tarsal joint in pseudotetramera and trimera.

Arthroderm: the outer skin or covering of articulates.

Arthrodial: an articulation that permits motion in any direction.

Arthromere: a body segment or ring: = somite.

Arthropleure: the side piece of an arthromere.

Arthropods: all those articulates having jointed legs.

Article: a joint or segment.

Articular pan: the cup or dish-like depression forming the socket into which an articulation is fitted.

Articulate: that branch of the animal kingdom whose members are made up of rings, segments or articulations.

Articulate: divided into joints or segments.

Articulated apex: see clasp filament.

Articulation: the point or place where two parts or segments are joined: also applied to an individual joint or segment.

Articulatory epideme: the partly chitinized membrane by which the wings are attached to the thorax.

Artus: the organs of locomotion generally.

As.e.xual: applied where the reproductive organs are incompletely developed and eggs or young are produced by cell-budding: = parthenogenetic.