|Pholadidae, the angelwings and piddocks, have fragile shells that are elongate to oval in shape. The elongated posterior end gapes widely. Sometimes a calcareous plate covers the posterior gape. The dorsal margin on the posterior end and sometimes the anterior end is flared, rolling up and outward. Some, especially the angelwings, have a hard spoon-shaped protuberance extending from underneath the beak (apophysis). The angelwings bore into soft mud. The piddock bore into harder substrates such as shells, driftwood and limestone. Some can cause considerable damage to rocky or wooden structures in harbors and other coastal areas. There are 8 species found in Texas waters.