160 AMERICAN ENTOMOLOGY. 



Vertex, that part of the face which lies between the occipiif, eyes 



dM^i front } (Diptera) the superior portion of ihe front. 

 Fo'ircaZ, perpendicular ; at right angles with the horizon. See 



erect. 

 Verticillate, placed in whirls. 

 Vesicular, beset with prominences that are internally concave, or 



with little bladders. 

 Vihratile, this term is used to express the almost continual 



movement of the antennae of some Ichneumons and Mutillae j 



and of the wings of some Diptera. 

 Vihrissse, curved bristles or hairs in some Diptera situated be- 

 tween the mystax and the antennae. 

 Villi, soft hairs. 

 Villous, soft haired ; clothed with long, soft hair. See hirsute, 



pubescent. 

 Violaceous, violet color ; a mixture of blue and red. 

 Viscid, covered with a resinous or greasy matter. See glutinous. 

 Vitellinus, yellow, with a slight tinge of red. 

 Vitta, a longitudinal colored line. 



W. 

 Whii'ls, or whorls, generally on the antennae, consisting of small 



hairs placed round the joints, like spokes round the cave of a 



wheel. See verticellate. 

 Wing-cells, the areas. 

 Winglets, small concavo-convex scales generally fringed at tip, 



placed under the base of the elytra in Dytiscus marginalis. 

 Wings, membranaceous, reticulated instruments of flight, affixed 



laterally to the thorax, comprehending superior or anterior, 



and inferior or posterior wings, elytra and hemelytra. See 



posterior angle, nervure, stigma. 



