Definition that contains genus spirula
- spirula a small tropical cephalopod of the genus Spirula having prominent eyes and short arms and a many-chambered shell coiled in a flat spiral
- spirula peronii a small tropical cephalopod of the genus Spirula having prominent eyes and short arms and a many-chambered shell coiled in a flat spiral
- spirulidae coextensive with the genus Spirula; included in the order Belemnoidea in some older classifications
- family spirulidae coextensive with the genus Spirula; included in the order Belemnoidea in some older classifications