The shell of this organism displays diverse contours and sizes, often resembling a cap and typically appearing yellow or brown. It can be ovoid or circular and commonly features around four or more lateral spines. When viewed from above, the shell appears spherical and tapers towards the aperture. The surface of the shell is typically rough, although there is usually a smooth region surrounding the aperture, which may be adorned with quartz grains and/or diatom frustules. The aperture itself is invaginated, oval, and situated near the end of the shell.