tooth shell
tusk shell

The tusk shell is naturally open at both ends, and can easily be strung on a thread.

The tusk shells or scaphopods are a class of shelled marine molluscs.

Entalinidae is a family of tusk shells, marine scaphopod mollusks in the order Gadilida.

Dentaliidae is a family of relatively large tusk shells, scaphopod mollusks in the order Dentaliida.

Gadilida is an order of very small tusk shells, marine scaphopod molluscs.

The apex of tusk shells is the small, open posterior end, and the opening itself is usually called the apical aperture.

Antalis is a genus of tusk shells, marine scaphopod mollusks.

Scaphopoda, which are called tusk shells in English is a class of marine molluscs.

Cadulus is a large genus of small tusk shells in the family Gadilidae.

Gadilidae is a family of tusk shells in the order Dentaliida.