| Thyridaria Sacc., 1875 |
| Thyridaria macrostomoides (De Not.) M. E. Barr, 1990 |
| Togula M. Flø Jørg., S. Murray, & N. Daugbjerg, 2004 |
| Togula britannica (Herdman) M. Flø Jørg., S. Murray, & N. Daugbjerg, 2004 |
| Torpedospora Meyers, 1957 |
| Torpedospora radiata Meyers, 1957 |
| Torula Pers., 1794 |
| Torula herbarum (Pers.) Link, 1809 |
| Torula verrucispora (P. N. Mathur & G. P. Singh) B. Sutton, 1993 |
| Torulopsis Berl., 1894 |
| Torulopsis taboadae Ulloa & T. Herrera, 1978 |
| Tremiscus (Pers.) Lév., 1846 |
| Tremiscus helvelloides (DC.) Donk, 1958 |
| Tretospeira Piroz., 1972 |
| Tretospeira ugandensis (Hansf.) Piroz., 1972 |
| Triceratium Ehrenb., 1839 |
| Triceratium americanum Ralfs, 1861 |
| Triceratium antediluvianum (Ehrenb.) Grunow, 1867 |
| Triceratium antillarum Cleve, 1878 |
| Triceratium arcticum Brightw., 1853 |