Shell elliptical or ovate, compactly involute, generally solid and with a mottled color pattern; spire sunken, umbilicated. Aperture as long as shell, rising above vertex, narrow above, expanded below; lip simple, columella short and concave. Type, B. ampulla Linnaeus.

Shell oval or ovate, compactly involute, generally solid and with a mottled color-pattern; spire sunken, umbilicated. Aperture as long as the shell, rising slightly above the vertex; its upper portion narrow, expanded toward the base; lip simple, flexuous; columella short and concave, with a crescentic, white, reflexed callus; parietal wall smooth, with a light parietal callus. (Tryon and Pilsbry, Manual of Conchology.)
TYPE. Bulla ampulla Lamarck.
DISTRIBUTION. Mediterranean, Atlantic, Gulf of Mexico, Indo-Pacific, west coast North America.