12 EXPLANATION OF TERMS 



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- 

 neuropter'a. 



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: =arquate. 



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: Trichoptcra; 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 medi- 

 astinal, the scapular, and the ulnar veins in Orthoptera, 



Arese or Areolae: wing cells or spaces 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 arese: 

 Hymenoptera; the central of three median areas on the metanotum: =2d 

 median area; upper median area. 



Areolate: with small denned areas, like a network. 



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



Areolet: one of the small spaces 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 pro- 

 duce ordinary farm crops without irrigation, and in which desert condi- 

 tions prevail : see humid. 



Arid transition area: comprises the western part of the Dakotas, northern 

 Montana east of the Rockies, southern Assiniboia, 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 antenna of certain Diptera. 



Aristate: Diptera; that type of antenna 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. 



