Type species: Calwellia bicornis Wyville Thomson, 1858
Image below is of the original genus definition, from Wyville Thomson, 1858.
Prepared by courtesy of Mary Spencer-Jones,
Copyright © Natural History Museum, London.

This genus includes the species:
| Calwellia bicornis | Wyville Thomson, 1858 | Recent | Australia, New Zealand |
| Calwellia gracilis | Maplestone, 1882 | Recent | Australia, New Zealand |
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| Calwellia bicornis |
Harmer notebook - entry for Calwellia