| Nominal Species (n = 20) | Present allocation (n = 19) | Ref. |
|---|---|---|
| Protodrilus adhaerens Jagersten, 1952 | Protodrilus adhaerens | 19 |
| Protodrilus affinis Jouin, 1968 | Protodrilus affinis | 19 |
| Protodrilus brevis Jouin, 1970 | Protodrilus brevis | 3477 |
| Protodrilus chaetifer Remane, 1926 | Protodriloides chaetifer | 75097 |
| Protodrilus ciliatus Jagersten, 1952 | Protodrilus ciliatus | 19 |
| Protodrilus corderoi Marcus, 1948 | Protodrilus corderoi | 7866 |
| Protodrilus gracilis Von Nordheim, 1989 | Protodrilus gracilis | 19 |
| Protodrilus hatscheki Pierantoni, 1908 | Protodrilus hatscheki | 19 |
| Protodrilus helgolandicus Von Nordheim, 1983 | Protodrilus helgolandicus | 19 |
| Protodrilus hypoleucus Armenante, 1903 | Protodrilus hypoleucus | 19 |
| Protodrilus indicus Aiyar & Alikuhni, 1944 | Protodrilus indicus | 3477 |
| Protodrilus infundibuliformis Schmidt & Westheide, 1977 | Protodrilus infundibuliformis | 8159 |
| Protodrilus leuckarti Hatschek, 1882 | Protodrilus leuckarti | 3477 |
| Protodrilus minutus Kirsteuer, 1966 | Protodrilus minutus | 2663 |
| Protodrilus mirabilis Czerniavsky, 1881 | Protodrilus mirabilis | 19 |
| Protodrilus oculifer Pierantoni, 1908 | Protodrilus oculifer | 19 |
| Protodrilus rubropharyngeus Jagersten, 1940 | Protodrilus rubropharyngeus | 19 |
| Protodrilus similis Jouin, 1970 | Protodrilus similis | 3477 |
| Protodrilus spongioides Pierantoni, 1903 | Protodrilus spongioides | 3477 |
| Protodrilus ypoleucus Armenante, 1903 | Protodrilus hypoleucus | 3477 |