| Lophosiphonia mexicana E.Y. Dawson, 1944 |
| Lophosiphonia obscura (C. Agardh) Falkenb., 1897 |
| Lophosiphonia saccorhiza Collins & Herv., 1917 |
| Lophosiphonia subadunca (Kütz.) Falkenb., 1901 |
| Lophosiphonia villum (J. Agardh) Setch. & N.L. Gardner, 1903 |
| Melanothamnus Bornet & Falkenb., 1901 |
| Melanothamnus bajacali (Hollenberg) Díaz-Tapia & Maggs, 2017 |
| Melanothamnus cheloniae (Hollenberg & J.N. Norris) Díaz-Tapia & Maggs, 2017 |
| Melanothamnus concinnus (Hollenberg) Díaz-Tapia & Maggs, 2017 |
| Melanothamnus eastwoodiae (Setchell & N.L. Gardner) Díaz-Tapia & Maggs, 2017 |
| Melanothamnus ferulaceus (Suhr ex J. Agardh) Díaz-Tapia & Maggs, 2017 |
| Melanothamnus forfex (Harvey) Díaz-Tapia & Maggs, 2017 |
| Melanothamnus gorgoniae (Harvey) Díaz-Tapia & Maggs, 2017 |
| Melanothamnus hancockii (E.Y. Dawson) Díaz-Tapia & Maggs, 2017 |
| Melanothamnus johnstonii (Setchell & N.L. Gardner) Díaz-Tapia & Maggs, 2017 |
| Melanothamnus masonii (Setchell & N.L. Gardner) Díaz-Tapia & Maggs, 2017 |
| Melanothamnus pseudovillum (Hollenberg) Díaz-Tapia & Maggs, 2017 |
| Melanothamnus savatieri (Hariot) Díaz-Tapia & Maggs, 2017 |
| Melanothamnus simplex (Hollenberg) Díaz-Tapia & Maggs, 2017 |
| Melanothamnus sphaerocarpus (Børgesen) Díaz-Tapia & Maggs, 2017 |