Bittiolum variumBittiolum varium, common name the grass cerith, is a species of sea snail, a marine gastropod mollusk in the family Cerithiidae.DistributionBittiolum varium occurs in shallow waters of the Western Atlantic between the East Coast of the United States and Brazil.DescriptionThe maximum recorded shell length is 6.5 mm.HabitatThe minimum recorded depth for this species is 0 m; maximum recorded depth is 11 m.