Shell. Tubular, regular, symmetrical, slightly curved longitudinally, tapering gradually to the rear, and opening in a round orifice at each end. Inhabits the British seas. Twenty-one species.
- Dentalium elephantinum.
- D. aprinum.
- D. sulcatum.
- D. fasciatum.
- D. pseudo-antalis.
- D. radicula.
- D. antalis.
- D. arictinum.
- D. octogonum.
- D. deforme.
- D. novemcostatum.
- D. sexangulaire.
- D. striatum.
- D. dentalis.
- D. corneum.
- D. nigrum.
- D. politum.
- D. eburneum.
- D. clava.
- D. fissura.
- D. coarctatum.
FAMILY III.
Amphitritæa. Four Genera.
1. Genus Pectinaria. Pl. [V].
Animal. Respiratory organs in general known, and disposed at or near the anterior part of the body; not separated or covered by an operculum.
Shell. A membranous papyraceous tube in the form of a reversed cone; unfixed; exterior covered with sandy adhesions. Two species.
- Pectinaria capensis.
- P. belgica.*
2. Genus Sabellaria. Pl. [V].
Animal. But slightly differing from the Pectinaria.
Shell. Tubes numerous, united in a common mass, composed of agglutinated particles of marine substances, cellular at the base; orifice expanded. Found in the Indian Ocean. Two species.