| Patellariopsis clavispora (Berk. & Broome) Dennis, 1964 |
| Patouillardina Bres., 1906 |
| Patouillardina cinerea Bres., 1920 |
| Perelegamyces R. F. Castañeda & W. B. Kendr., 1990 |
| Perelegamyces parviechinulatus W. B. Kendr. & R. F. Castañeda, 1990 |
| Periconia Tode, 1791 |
| Periconia byssoides Pers., 1801 |
| Periconia cookei E. W. Mason & M. B. Ellis, 1953 |
| Periconia digitata (Cooke) Sacc., 1886 |
| Periconia echinochloae (Bat.) M. B. Ellis, 1971 |
| Periconia jabalpurensis D. P. Tiwari & P. D. Agrawal, 1972 |
| Periconia lateralis Ellis & Everh., 1886 |
| Periconia minutissima Corda, 1837 |
| Periconia prolifica Anastasiou, 1963 |
| Periconia shyamala A. K. Roy, 1965 |
| Peridiniella Kof. & J.R. Michener, 1911 |
| Peridiniella catenata (Levander) Balech, 1977 |
| Peridiniella danica (Paulsen) Okolodkov & J.D. Dodge, 1995 |
| Peridiniella globosa (P.A. Dang) Okolodkov, 2006 |
| Peridiniella sphaeroidea Kof. & J.R. Michener, 1911 |