Wing of male of Periscelis annulata from McAlpine (1981, fig. 3) Periscelididae,
Manual of Nearctic Diptera
, Ottawa, p.895-898, (1981)
[1].

Wing venation of Cyamops. The image was drawn by Giancarlodessi.

Wing venation of Periscelis. The image was drawn by Giancarlodessi.