The Grass Cerith
As implied by its vernacular name, the Grass Cerith, Bittiolum varium (Pfeiffer, 1840), lives in seagrass beds. The Grass Cerith is one of the most common species of mollusks in that particular type of ecosystem, where it supposedly grazes on the microalgae that grow on the seagrass blades. Its shell is small, rarely reaching beyond 4 mm (about 0.16 inch). The shell sculpture shows spiral lines and weak axial ribs that intersect forming raised nodules. The last whorl usually