Shell ovoid, tending to globular, with a small spire. There are 2-3 postlarval whorls which are tumid and have a slight subsutural shelf and peripheral flattening. Last whorl is large (occupies about 85 % of shell height). The sutures are deep and a little incised. Protoconch lies across apex of spire, exposed. There are about twenty spiral ridges on the last whorl and about ten on the penult; in addition, prosocline growth lines are present, sometimes dividing the spiral ridges into squarish areas. The aperture is a broad oval (occupies 55-60 % of shell height), narrow adapically, broad at the base, where the lip is often out-turned. The outer lip is often rather straight towards the periphery and shows an anal sinus and peripheral bulge. Umbilical groove and umbilicus are distinct. Tooth is obvious.
Up to 2 x 1.3 mm.
The animal has short, rather broad tentacles, each with a shallow lateral groove. The eyes lie between their bases and the mentum stretches forwards from under the bases as a rounded structure tapering to its tip. The end of the pallial exhalant channel is visible at the right side of the mantle skirt. The foot has a narrow, nearly straight anterior end, the lateral corners hardly projecting; posteriorly it broadens and is rounded. Body milk-white.
At LWST and below.
A southern species ranging from the Mediterranean to a northern limit in the British Isles, where shells have been found off most coasts but recent and live finds are limited to south-western coasts, where the animals may be found, but rarely (Distr. N. dolioliformis).