| Janthina exigua Lamarck, 1816 |
| Janthina globosa Swainson, 1822 |
| Janthina janthina (Linnaeus, 1758) |
| Janthina pallida (Thompson, 1840) |
| Janthina prolongata Blainville, 1822 |
| Janthina umbilicata d'Orbigny, 1841 |
| Nystiella Clench & Turner, 1952 |
| Nystiella atlantis Clench & Turner, 1952 |
| Opalia H. Adams & A. Adams, 1853 |
| Opalia (Dentiscala) de Boury, 1886 |
| Opalia (Dentiscala) crenatoides P. P. Carpenter, 1864 |
| Opalia (Dentiscala) mexicana Dall, 1908 |
| Opalia (Nodiscala) de Boury, 1889 |
| Opalia (Nodiscala) eolis Clench & Turner, 1950 |
| Opalia (Nodiscala) sanjuanensis (Lowe, 1932) |
| Opalia (Nodiscala) spongiosa P. P. Carpenter, 1864 |
| Opalia abbotti Clench & Turner, 1952 |
| Opalia andrewsii (Verrill, 1882) |
| Opalia aurifila (Dall, 1889) |
| Opalia crenata (Linnaeus, 1758) |