| Cryptonemia veleroae (Dawson) E.Y. Dawson, 1954 |
| Halymenia C. Agardh, 1817 |
| Halymenia abyssicola E.Y. Dawson, 1944 |
| Halymenia actinophysa M. Howe, 1911 |
| Halymenia agardhii De Toni, 1905 |
| Halymenia bifida E.Y. Dawson, 1954 |
| Halymenia californica G.M. Sm. & Hollenberg, 1943 |
| Halymenia duchassaingii (J. Agardh) Kylin, 1932 |
| Halymenia echinophysa Collins & M. Howe, 1916 |
| Halymenia elongata C. Agardh, 1822 |
| Halymenia floresii (Clemente & Rubio) C. Agardh, 1817 |
| Halymenia floridana J. Agardh, 1892 |
| Halymenia gardneri (Kylin) P.G.Parkinson, 1980 |
| Halymenia gelinaria Collins & M. Howe, 1916 |
| Halymenia hancockii W.R. Taylor, 1942 |
| Halymenia hollenbergii I.A. Abbott, 1967 |
| Halymenia megaspora E.Y. Dawson, 1954 |
| Halymenia polydactyla Børgesen |
| Halymenia pseudofloresii Collins & M. Howe, 1916 |
| Halymenia refugiensis E.Y. Dawson, 1944 |