Key to species of Ancistrosyllis found in Brazilian waters

1. Neuropodium with capillaries only....................................................................... 2

- Neuropodium with capillaries and modified chaetae.......................................................... 3

2. Median antennae absent, tentacular cirri about 1.6x longer than lateral antennae...... Ancistrosyllis hamata (Hartman, 1960)

- Median antennae present, tentacular cirri about 2.2x longer than lateral antennae....... Ancistrosyllis jonesi Pettibone, 1966

3. Neuropodia with bidentate chaetae, and serrated capillaries, deep-set eyes present...................................................................................................... Ancistrosyllis hartmanae Pettibone, 1966

- Neuropodia with serrated capillaries only, deep-set eyes absent............ Ancistrosyllis cf. g roenlandica McIntosh, 1878