Genus Ancistrosyllis McIntosh, 1878

Diagnosis (after Glasby & Salazar-Vallejo 2021). Pilargids with body depressed, integument papillose to verrucose, present on both segmental and nonsegmental regions. Antennae, 0–3. Palps unfused, biarticulated; palpostyle minute. Paired ventrolateral palpal papillae present. Pharynx distally with terminal papillae (or absent); proximally smooth or, rarely, with denticles. Two pairs of tentacular cirri. Dorsal and ventral cirri digitate to lobate. Notochaetae are hooks, present from chaetigers 3 to 13 and continuing throughout body. Neurochaetae smooth, or spinulose capillaries, often with bidentate tips. Free living in sediments from intertidal to deep sea, or commensal with other invertebrates.