Bittium varium: Shell with seven or eight more or less rounded whorls, with a distinctly marked suture; sculpture consisting of delicate, longitudinal, slightly curved ribs, which are cut into nodules by revolving grooves; there are about three of these grooves on .each whorl; on the body whorl there are additional grooves extending over the base, which is scarcely nodulous; outer lip somewhat patulous; aperture oval; canal not produced, feeble; at some distance back of the lip there is a nearly smooth varix. Color varying from purplish white to purple brown, variously clouded.
Length, 5 mm, diameter, 1.8 mm.

Bittiolum varium (Pfeiffer, 1840) Grass Cerith
Distribution: Maryland to Florida, Texas; Brazil. Size: 5 to 6 mm.
Description: Color variable, typically with whitish-tan base stained with darker shades of brown; shell turriculate; 7 to 8 convex whorls; suture incised and distinct; axial ribs crossed by spiral ridges, producing small squares and giving a nodulose appearance; aperture oval, thin with adjacent varix; siphonal canal poorly developed; operculum corneous, light brown.
Habitat: On seagrass in bays just below low-tide line to a depth of 11 m (36 ft). Remarks: Food for sciaenid fishes. See Andrews (1977); Turgeon et al. (1998). Synonym: Diastema varium (Pfeiffer, 1840).