Members of the family Euphrosinidae have been included with the Amphinomidae by some workers (eg Day, 1967), however, most authors maintain the separate family designation used in this database. Euphrosinids differ from amphinomids in lacking harpoon chaetae, in lacking any kind of notochaetae that readily detaches, in possessing notochaetae arranged in transverse rows across the dorsum (not in tufts as in amphinomids) and having branchiae that are shorter than the notochaetae.

Fauchald (1977) records 17 genera of amphinomids worldwide, of which 7 occur in Australian waters. There are only 4 genera of euphrosinids in the world, with only 1 genus occurring in Australia. This database includes 16 Australian amphinomid species and 4 Australian euphrosinid species. All known Australian species included are based on published descriptions (except where indicated otherwise), and species provisionally identified from major benthic surveys of soft sediments in southeastern Australia. The principal areas surveyed are Bass Strait and Port Phillip Bay (material held in Museum Victoria, Melbourne) and Jervis and Botany Bays (material held in Australian Museum, Sydney). Many taxa undoubtedly remain to be described from Australian waters, especially beyond the soft sediment communities of southeastern Australia which have generated much of the material covered here.