True Bubble Shells in the Bullidae Family are egg-shaped and thin shelled that range in size from small to medium. They have exceedingly large body whorls that overgrow the spire leaving a depression or pit where the spire would have protruded. They do not have  an operculum. They have long apertures that extend above the body whorl and lack teeth or folds. In most species, the aperture is comma-shaped. The exterior of the shell is smooth and dark in color. To avoid predation True Bubble Shells can withdraw deep within their shell (compared to Paper Bubble Shells which do not fit within the shell) and many can secrete a toxic chemical from their mantle that envelops their shells.

True Bubble Shells reside on sand, mud, and gravel substrate and with green algae, and sea grasses. They are either depositional feeders, feeding on diatoms and algae cells that are deposited on the bottom, or herbivores, grazing on green algae. They are preyed upon by shore birds, crabs, sea stars, and predatory mollusks. They are found intertidally to depths up to 65 feet.  They live in tropical and temperate seas, worldwide. The Bullidae Family is a small family with only about twenty-four species. Many sources state that there are two species found along the Baja Peninsula, Gould’s Bubble, Bulla gouldiana, and the Spotted Bubble, Bulla punctulata, however the Spotted Bubble is not found along the coasts north of Central Mexico and those reports are in error.