Shell medium size for genus (maximum height 6.1 mm), spire height relatively high (height-width ratio of holotype 1.13). Shell wall extremely thin, maximum thickness of broken lip 0.05 mm. Surface shiny, yellowish white, periostracum thin. Protoconch diameter 250 µm, surface smooth. Teleoconch whorls 2.7 rounded, smooth; suture deeply impressed. Umbilicus narrow, deep, partially obstructed by reflection of inner lip. Spiral sculpture of faint striae and single narrow ridge deep within umbilicus, terminating at columellar flare. Base of mature shell rounded, that of immature shell with angulation. Axial sculpture of extremely fine growth increments, sharply raised on umbilical slope. Peristome nearly complete. Operculum pale brown, nucleus slightly excentric, final whorl becoming paucispiral. Dimensions. Height 6.1 mm, width 5.4 mm (holotype).
Radula:Typical for the family; the shaft of the rachidian is weakly projecting, the overhanging tip of the rachidian is small but clearly revealed.

Type locality: Alboran Sea, westernmost Mediterranean, west of Cabo de Gata, Spain (extending from 01°30'W and 35°30' to 36°30'N, according to P. Bouchet), 50-100 m.

Choristella nofronn is characterized by its rela¬tively small size and high profile. In addition, small shells have a weak mid-basal ridge, a feature not observed in any other species.
GUBBIOLI & NOFRONI (1986) found this species in 5% of 250 of the egg cases they examined and found that three times as many had specimens of the limpet Addisonia lateralis (Requien, 1848). Both species were noted in 3% of the examined egg cases.
The choristellid affinity was unknown by GUBBIOLI & NOFRONI (1986), who identified it as "Cithna" naticiformis Jeffries, 1883. The basal ridge that characterizes small shells led them to associate the species with Jeffreys' taxon from 1453 m (795 fm) off the Portuguese coast. However, the basal ridge of that species is much more pronounced, and there is a concave rather than convex surface between the umbilical and basal ridges.
GUBBIOLI & NOFRONI (1986) also suggested that "Cyclostrema" valvatoides Jeffreys, 1883, might also be referable to the present species. I have examined the holotype of that species (BMNH 85.11.5.1593). Choristellid affinity is ruled out because it does not have the umbilical ridge characteristic of the family.