[1] Notaulus entirely absent, rarely mesoscutum with sha...
[20] Antenna with different number of segments
[29] Wings fully developed, usually reaching or surpassin...
[50] Submarginal vein in forewing closely approximated to...
[53] A2 inserted at apex of A1
[54] Vertex not elevated, normally arched (figs. 58, 61, ...
[55] All tarsi more or less cylindrical, as hig...
face or entire head (often also mesoscutum or syntergite) with dense, fine, semiappressed pilosity (figs. 1.93, 2, 3.94, 4); antennal shelf between toruli not developed, space rounded; distance between toruli larger than or subequal to distance between torulus and inner orbit (fig. 93); frenal gutter of forewing sharply angular (fig. 94); female antenna 11-segmented; aquatic in habits; Neartic and Neotropical [mf]
face or other parts of body glabrous or with only a few scattered long hairs or bristles; antennal shelf between toruli sharp, carinate; distance between toruli subequal to or shorter than distance between torulus and inner orbit; frenal gutter of forewing not angular; female antenna predominantly 12-segmented; only a few aquatic species