This genus took its name from its resemblance to an elephant’s tooth. It
is an attenuated conical tube, slightly bent, and open at both ends.
Shell tubular, regular, symmetrical, lightly curved longitudinally,
conic, attenuated insensibly posteriorly, and open at each extremity by
a round orifice.
Dentalium elephantinum.
D. aprinum.
D. fasciatum.
D. entale.
D. Tarentinum.
D. corneum.
D. octoganum.
D. novemcostatum.
D. dentale.
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.
Species finely pointed, solid, striated annularly; generally rosy or
pink colour.
_D. rectum._ The straight Tooth Shell.
Species entirely straight, with longitudinal ribs.
_D. eburneum._ The Ivory Tooth Shell.
Species of a reddish or pale yellow colour, with the tip frequently
tinged with orange or pink.
FAMILY III.
AMPHITRITÆA. Four genera.
The similarity of the four genera comprising this family is such, that
it was thought sufficient to give only one type (the sabellaria
crassissima), as the student may easily recognise the others.