Hydractinia angusta — Totton, 1930: 138; Cerrano et al., 2000: 488–493, figs 2–5; 2001: 577–580; Peña Cantero et al., 2013: 737–739, figs 3g –h, 4a –c.
Remarks. See Peña Cantero (2015) for a re-description of this species and a wide discussion about it. The only reliable record for this species is from the Bellingshausen Sea (cf. Peña Cantero 2015). Other records, including those from the Ross Sea [i.e. from McMurdo Sound (Totton 1930) and Tethys Bay (Cerrano et al. 2000, 2001; Peña Cantero et al. 2013)], need confirmation.