Appearance
The shell of T. gallina is typically 3⁄4 to 1+5⁄8 in (1.9 to 4.1 cm) high and wide, though it may be slightly higher than wide.
The imperforate, heavy, solid, thick shell has a conoidal shape and is elevated. Its colors show alternating whitish and purplish-grey or blackish crowded, slanting axial stripes, speckled with whitish. The stripes occupy the interstices between close, narrow superficial folds of the surface, which may be well-marked, or obsolete, continuous or cut into granules by equally close spiral furrows, the latter sometimes predominating.

