| Scientific Name | Author | English Name |
|---|---|---|
| Pseudoceros ater | Hyman, 1959 | |
| Pseudoceros bimarginatus | Meixner, 1907 | |
| Pseudoceros caeruleocinctus | Hyman, 1959 | |
| Pseudoceros canadensis | unspecified | |
| Pseudoceros fuscogriseus | Hyman, 1959 | |
| Pseudoceros indicus | Newman & Schupp, 2002 | |
| Pseudoceros liparus | Marcus, 1950 | |
| Pseudoceros luteus | (Phehn, 1898) | Polyclad flatworm |
| Pseudoceros montereyensis | Hyman, 1953 | |
| Pseudoceros perviolaceus | (Schmarda, 1859) | |
| Pseudoceros tristriatus | Hyman, 1959 | |
| Thysanozoon brocchii | (Risso, 1818) | Carpet flatworm |
| Thysanozoon californicum | unspecified | |
| Thysanozoon nigropapillosum | (Hyman, 1959) | |
| Thysanozoon nigrum | unspecified | Warty flatworm |
| Thysanozoon sandiegense | Hyman, 1953 |