[1] The shell of Nacella concinna grows to about 6 centimetres (2.4 in) long with deep water specimens being rather smaller.

It is an elongated ovate, moderately elevated cone with a low apex somewhat towards the anterior margin and angled in that direction.

There are about 30 faint radial ribs and a series of fine concentric lines that indicate the annual growth rings.

[2] Nacella concinna is found on the seabed of the Scotia Sea between Tierra del Fuego and the Antarctic Peninsula.

These structures are considered likely to improve fertilisation rates as sperm flows have been observed to cascade down the towers in calm water situations.