| Species name | Common name | Distribution | Max. Length (cm) |
|---|---|---|---|
| Crassicardia crassidens (Broderip & Sowerby I, 1829) |
Thick Cyclocardia | Northern Pacific and the Arctic | |
| Crassicardia crebricostata (Krause, 1885) |
Many-rib Cyclocardia | Northern Pacific and Arctic |