Key to Synamphichaeta species

1 Frontal vitta in front of ocellar triangle about 0.5 times as wide as one fronto-orbital plate; gena almost 0.2 times as high as maximum diameter of eye; scutum with 3+4 dorsocentral setae; third costal section of wing 2.0–2.2 times as long as second costal section; vein R 1 entirely setose dorsally, with 5–6 apical setulae ventrally; vein CuA 1 with 1–4 basal setulae dorsally; bend of vein M forming a right angle; abdominal tergites without median discal setae; median marginal setae on tergite 3 about 0.8–0.9 times as long as tergite........................................... S. hirtivena Gilasian & Ziegler, sp. nov.

- Frontal vitta in front of ocellar triangle 1.3–2.0 times as wide as one fronto-orbital plate; gena 0.30–0.35 times as high as maximum diameter of eye; scutum with 3+3 dorsocentral setae; third costal section of wing 3.0–4.0 times as long as second costal section; wing veins R 1 and CuA 1 bare; bend of vein M forming an obtuse angle; abdominal tergites 3 and 4 each with a pair of median discal setae; median marginal setae on tergite 3 very long, about 1.5–2.0 times as long as tergite.............................................................................................. S. tricincta Villeneuve, 1936