Conch (Lat. concha, Gr. κόγχη), a shell, particularly one of a mollusc; hence the term “conchology,” the science which deals with such shells, more used formerly when molluscs were studied and classified according to the shell formation; the word is chiefly now used for the collection of shells (see Mollusca, and such articles as Gastropoda, Malacostraca, &c.). Large spiral conchs have been from early times used as a form of trumpet, emitting a very loud sound. They are used in the West Indies and the South Sea Islands. The Tritons of ancient mythology are represented as blowing such “wreathed horns.” In anatomy, the term concha or “conch” is used of the external ear, or of the hollowed central part leading to the meatus; and, in architecture, it is sometimes given to the half dome over the semicircular apse of the basilica. In late Roman work at Baalbek and Palmyra and in Renaissance buildings shells are frequently carved in the heads of circular niches. A low class of the negro or other inhabitants of the Bahamas and the Florida Keys are sometimes called “Conches” or “Conks” from the shell-fish which form their staple food.