| Odontosyllis twincayensis Russell, 1989 |
| Odontosyllis undecimdonta Imajima & Hartman, 1964 |
| Opisthodonta Langerhans, 1879 |
| Opisthodonta luquei (San Martín, 1990) |
| Opisthodonta mitcheli Kudenov & L. Harris, 1995 |
| Opisthodonta russelli San Martín, López & Aguado, 2009 |
| Opisthodonta spinigera Russell, 1987 |
| Opisthodonta templadoi (San Martín, 1991) |
| Opisthodonta uebelackerae Russell, 1987 |
| Opisthodonta uraga (Imajima, 1966) |
| Opisthosyllis Langerhans, 1879 |
| Opisthosyllis brunnea Langerhans, 1879 |
| Opisthosyllis japonica Imajima, 1966 |
| Opisthosyllis longidentata San Martín, 1991 |
| Paedophylax Claparède, 1870 |
| Paedophylax dispar Webster, 1879 |
| Paedophylax veruger Claparède, 1868 |
| Paraehlersia San Martín, 2003 |
| Paraehlersia articulata (Kudenov & L. Harris, 1995) |
| Paraehlersia ferrugina (Langerhans, 1881) |