| Hydractinia van Beneden, 1844 |
| Hydractinia apicata (Kramp, 1959) |
| Hydractinia borealis (Mayer, 1900) |
| Hydractinia carnea M. Sars, 1846 |
| Hydractinia minima (Trinci, 1903) |
| Hydractinia minuta (Mayer, 1900) |
| Hydractinia simplex Kramp, 1928 |
| Hydractiniidae L. Agassiz, 1862 |
| Janaria Stechow, 1921 |
| Janaria mirabilis Stechow, 1921 |
| Podocoryne Lütken, 1850 |
| Podocoryne minima (Trinci, 1903) |