Iphionidae Kinberg, 1856

Salazar-Vallejo, Sergio I., Piotrowski, Christina N. & Paulay, Gustav, 2024, Revision of Iphione Kinberg, 1856 (Annelida, Aphroditiformia, Iphionidae), Zootaxa 5548 (1), pp. 1-84 : 12-13

Key to genera of Iphionidae Kinberg, 1856

1 With 13–14 pairs of elytra.............................................................................. 2

- With about 20 pairs of elytra; elytra without fimbriae; prostomium with 2 pairs of eyes; lateral antennae minute; neurochaetae thin without annulations................................................... Iphionides Hartmann-Schröder, 1977

2(1) Prostomium with 2 pairs of eyes; palps with longitudinal series of papillae; lateral antennae on anterolateral margins; neurochaetae of a single type, with fine annulations, usually thick (13 pairs of elytra); elytra with or without fimbriae......................................................................................... Iphione Kinberg, 1856

- Prostomium without eyes; palps smooth; without lateral antennae; elytra with lateral fimbriae; neurochaetae of two types (straight verticillate, and falcate subdistally denticulate)....................................................... 3

3(2) Falcate neurochaetae thick with series of fine annulations (13 or 14 pairs of elytra)...................................................................................................... Thermiphione Hartmann-Schröder, 1992

- Falcate neurochaetae thin without transverse series of annulations (13 pairs of elytra)........... Iphionella M’Intosh, 1885

Alternative key to genera of Iphionidae Kinberg, 1856

(for damaged or incomplete specimens)

1 Neurochaetae thick, rarely thin, with subdistal rings of denticles................................................ 2

- Neurochaetae thin, with denticles, not forming rings.......................................................... 3

2(1) Eyes usually present; prostomium anteriorly bifid; with lateral antennae (13 pairs of elytra; margins smooth or fimbriate, fimbriae complex, never filiform)....................................................... Iphione Kinberg, 1856

- Without eyes; prostomium completely bifid; without lateral antennae (13 or 14 pairs of elytra; lateral margins fimbriate, fimbriae filiform, often with globular bacterial masses)........................ Thermiphione Hartmann-Schröder, 1992

3(1) With eyes; prostomium entire anteriorly; lateral antennae minute (up to 20 pairs of elytra, margins smooth)..................................................................................... Iphionides Hartmann-Schröder, 1977

- Without eyes; prostomium completely bifid; without lateral antennae (13 pairs of elytra, lateral margins fimbriate, fimbriae filiform, sometimes branched)....................................................... Iphionella M’Intosh, 1885