The ringiculids possess an external shell that is quite different to that of other head shield slugs. The small shell is white, glossy, sturdy, rounded, somewhat inflated, and conical with spiral sculptures but may be smooth. The shell has a large aperture impinged upon by up to four strong columellar folds on the inner lip, a considerably thickened outer lip and an anterior sinus.
Ringiculids do not possess an operculum but the animal can retract completely into the shell. The head shield is bilobed, broad and short extending posteriorly and diagonally to partially cover the dorsal surface of the shell. Posteriorly the head shield forms a medial exhalent siphon Eye spots are deeply imbedded and may not be observable.
The foot is shorter than the shell and rounded posteriorly. Anteriorly it is separated from the head shield by a deep fold but merges with it at the sides. Large defensive glands are located on the lateral edges of the foot and the posterior edge of the head shield.
The body is usually colourless or translucent white and may have brown marks on the edges. The gill is not visible externally.
They live infaunally burrowing through fine, usually clean sand. Diet knowledge is limited but is believed to include foraminiferans and copepods. They are preyed upon by aglajid sea slugs.