and feeding and cleansing mechanisms of Stephopoma roseum are described in detail, with the anatomy of the head, foot and pallial cavity. The species is a ciliary feeder, having but few detailed resemblances to the vermetids previously described in life. There is a ciliary method of food collection by the gill filaments most resembling that of Crepidula, and in addition, a supplementary mode of feeding by pro-extruding the anterior fourth of the gill from the pallial cavity to form a sweeping net of cirrus-like filaments. This method of feeding has not been previously described in gastropods. A pedal mucus gland for the extrusion of food-collecting mucous traps is not developed in Stephopoma. The alimentary canal differs to a considerable extent from that of previously described vermetids. An account is given of its structure, histology, and function, with suggestions as to the nature of the digestive mechanism.

Pyxipoma weldii, a member of the siliquariid group of Vermetidae, is validly represented in New Zealand. The operculum, radula, and embryonic shell are described and figured. The anatomy of the head, foot and pallial cavity is closely comparable with that of Stephopoma, and the significance of the pallial slit and shell fissure is considered. The female reproductive system in Stephopoma and Pyxipoma is described, with details of histology. In Pyxipoma there is a spacious brood pouch in the trunk of the female, opening anteriorly at the base of the right tentacle.

The resemblances between Stephopoma and Pyxipoma are emphasised and a tabular summary is provided, showing the dissimilarity between these genera and previously described Vermetidae. The family Vermetidae as at present constituted is concluded to be diphylectic and a separate family the Siliquariidae is proposed. The diagnostic characters of this family are listed, and its relationships with the Turritellidae are discussed. The genus Vermicularia is suggested to be most closely allied to the Siliquariidae.