Figure 3 :  Bolitophilidea.
Basiala of the wing of  Bolitophila  maculipennis WALK.  (Bolitophilidae). Diagrammatic. The veins indicated from top to bottom are :  C = Costa, SC = Subcosta, R = Radius, M = Media, CuA = Anterior Cubitus, CuP = posterior Cubitus, An₁ = first Anal vein.
Ch = chaetarium  [ = patches of bristles having a mechanical function].
+  means :  lying on a convex  ( =  arched upwards) spot or ridge.
-  means :  lying on a concave  ( =  scooped out) spot or groove.
(After ROHDENDORF, 1946)