Type species. Polynoe paradoxa Storm, 1888
Diagnosis. Body long, with up to about 100 segments. Elytra 15 pairs, covering dorsum, overlapping, on segments 2, 4, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 26, 29, and 32, leaving long tail uncovered. Prostomium bilobed, with distinct cephalic peaks and three antennae; lateral antennae inserted ventrally to median antenna. Notopodia with prominent, digitiform acicular lobe; neuropodia with prominent, subtriangular acicular lobe with tip extended to supra-acicular process; tips of noto- and neuroacicula penetrating epidermis. Notochaetae stouter than or as stout as neurochaetae, with blunt tip; neurochaetae more numerous, with uni- or bidentate tip.
Remarks. Loshamn (1981) established the genus Neopolynoe for Polynoe paradoxa Storm, 1888, a species often associated with corals in the Northeast Atlantic. Bock et al. (2010) redescribed a second species within the genus, Neopolynoe acanellae (Verrill, 1881). This species is rather widely distributed in the North Atlantic and is associated with corals and sponges. Neopolynoe antarctica (Kinberg, 1858) n. comb., redescribed below, represents the third species within the genus and is the first species known from the southern hemisphere.
Neopolynoe differs from other long-bodied genera by the combination of the following characters: prominent notopodium, 15 pairs of elytra (never more!), distinct cephalic peaks, and presence of a neuropodial supra-acicular process. In contrast, Polyeunoa has 15 or more pairs of elytra, the cephalic peaks are absent or poorly developed, and the supra-acicular process is absent or digitiform. Polynoe Savigny in Lamarck, 1818 has also 15 pairs of elytra, but the notopodia are much shorter and notochaetae are more slender than neurochaetae. For differences to other genera, see also Table 1.