Bubble Nutmeg Shell, Trigonostoma bullatum: The Bubble Nutmeg Shell is a member of the Cancellanidae Family all of which have cancellate sculpture (i.e. lattice work) on some part of their shells.
Within the column there are a few strong folds, the aperture is moderately large, and the anterior canal is short. Due to a unique complex radula they are believed to feed on soft-bodied microorganisms. They are primarily deep water species and therefore they are poorly studied and knowledge about their biology is virtually nonexistent.
The Bubble Nutmeg Shell is inflated with low ridges and blunt nodes. The color of the shell varies from whitish tinged with brown to brown (as pictured below).
The maximum length of this shell in the literature is 3.0 cm by 2.5 cm; the shell below is significantly larger than these published sizes.
In Mexico, they are found within the confines of the Sea of Cortez and along the coast of the mainland south to Guatemala at depths between 100 and 250 feet.
They are obtained as a by-catch of deep water shrimp trawlers. They are sold commercially with a limited (presumably due to rarity) internet trade.