Scaphopoda

Scaphopoda, a class of Mollusca (q.v.), the members of which have a univalve shell shaped 1ike a tusk, and composed of white ivory-like material. The animal has a head, and thus belongs to the group Glossophora. The head is, however, somewhat imperfectly developed, is cylindrical in form, has the mouth at the anterior end, and is surrounded by a circle of tentacles. The class is further characterised by the absence in its members of a heart or gills. The shell is open at both ends. The animal lives in the sand along the coast. There are three living genera. Dentalium entale, the common Elephant-tooth Shell, is the best known species. The class dates from the Carboniferous.