The Harp Shells of the Harpidae Family consists of two groups of shells, the Harps and the Morums. Harp Shells are egg-shaped and have a polished exterior that have strong ribs running the length of the shell that may form points where they join the shoulder. Their body whorl makes up the great majority of the shell, they have low spires and the aperture is large and flared with a notch at the bottom. The shells are beautifully decorated with scalloped patterns that may include dark brown, purplish brown, lavender, rose, and tan. The shell does not have an operculum and the animal is larger than the shell and the foot extends well beyond the shell.

Morum Shells differ from Harp Shells in that they have a higher spire and the aperture may have dentition (“teeth”) along the outer lip.

Harp Shells bury in sand during the day and emerge at night as nocturnal predators that feed on crabs and shrimp. They feed by covering their prey with their foot and enveloping it in mucous. In turn they are preyed upon by crabs, fish, and predatory mollusks.  As a defense mechanism, Harp Shells have the ability to amputate a rear portion of their foot. The amputated foot continues to wiggle, distracting the predator, while the Harp Shell crawls away. Harp Shells are generally found in very shallow to moderately shallow water with the exception that one genus within the Family is found in very deep water. Harp Shells are found in the tropical and sub-tropical regions of the Western Atlantic, Indian, and Pacific Oceans. There are about fifty-five species in the Harpidae Family, the majority of which are found in the Indo-Pacific but only two species are found in the coastal waters along the Baja Peninsula.