| Species name | Common name | Distribution | Max. Length (cm) |
|---|---|---|---|
| Hydrallmania clavaformis Galea, 2019 |
Western Central Pacific | ||
| Hydrallmania distans Nutting, 1899 |
Loose spiral hydroid | Eastern Pacific | |
| Hydrallmania falcata (Linnaeus, 1758) |
Sickle hydroid | Atlantic and Pacific Oceans | |
| Hydrallmania franciscana (Trask, 1857) |
Eastern Pacific |