D. nigrum.

D. politum.

D. eburneum.

D. elephantinum. The Elephant’s Tooth Shell.

Species in which the tube is striated or ribbed longitudinally; the ribs are generally ten in number; green colour.

D. entale. The common Dentalium. Pl. [33], fig. 1.

Species very minutely striated; white or yellowish colour.

D. pellucidum. The pellucid Dentalium.

Species narrow and thin; pale topaz colour.

D. politum. The ring-striated Tooth Shell.