| Spio caudatus Delle Chiaje, 1828 |
| Spio filicornis (O.F. Müller, 1776) |
| Spio maculata (Hartman, 1961) |
| Spio mecznikowianus Claparède, 1870 |
| Spio pacifica Blake & Kudenov, 1978 |
| Spio pettibonae Foster, 1971 |
| Spionidae Grube, 1850 |
| Spionides Webster & Benedict, 1887 |
| Spiophanes Grube, 1860 |
| Spiophanes anoculata Hartman, 1960 |
| Spiophanes berkeleyorum Pettibone, 1962 |
| Spiophanes bombyx (Claparède, 1870) |
| Spiophanes duplex (Chamberlin, 1919) |
| Spiophanes fimbriata Moore, 1923 |
| Spiophanes kroeyeri Grube, 1860 |
| Spiophanes lowai Solís-Weiss, 1983 |
| Spiophanes missionensis Hartman, 1941 |
| Spiophanes pigmentata Reish, 1959 |
| Spiophanes wigleyi Pettibone, 1962 |
| Streblospio Webster, 1879 |