The grass cerith, Bittiolum varium, is a small cerithiid gastropod with an elongate, turreted shell consisting of around 10 whorls. The aperture is notably rounded, with a smooth lip and a short, distinct siphonal canal. The intersections of the spiral lines and axial ribs form raised nodules. Color is highly variable, ranging from light to dark brown to gray-white to bluish black to reddish, sometimes with darker flecks or mottling. The soft tissues of the animal itself are often colored similarly to the shell and the sole of the foot is white with opaque spots. The operculum is light brown and translucent (Qurban 2000, STRI undated, BMSM undated).