[1] This species can reach a maximum length of 5.1 centimetres (2.0 in) in males.

The valves are black with an intermittent white stripe that runs dorsally.

The girdle is granular and is composed of bristles that are a "reddish-brown" color.

[2] N. californica is endemic to the western coast of North America, specifically California and Baja California, hence its specific epithet and common name.

[3] It is intertidal and can be found in rock crevices, nearby barnacles and mussels.