Fam. 10.—Columbellidae. Spire of shell prominent, aperture narrow, canal very short, columella crenelated; foot large. Columbella.
Fam. 11.—Coralliophilidae. Shell irregular; radula absent; foot and siphon short; sedentary animals, living in corals. Coralliophila. Rhizochilus. Leptoconchus. Magilus. Rapa.
Fam. 12.—Volutidae. Head much flattened and wide, with eyes on sides; foot broad; siphon with internal appendages. Valuta. Guivillea. Cymba.
Fam. 13.—Olividae. Foot with anterior transverse groove; a posterior pallial tentacle; generally burrowing. Olivia. Olivella. Ancillaria. Agaronia.
Fam. 14.—Marginellidae. Foot very large; mantle reflected over shell. Marginella. Pseudomarginella.
Fam. 15.—Harpidae. Foot very large; without operculum; shell with short spire and longitudinal ribs; siphon long. Harpa.
Tribe 2.—Toxiglossa. No jaws. No median tooth in radula. Formula: 1 : 0 : 1. Poison-gland present whose duct traverses the nerve-collar.
Fam. 1.—Pleurotomatidae. Shell fusiform, with elongated spire; margin of shell and mantle notched. Pleurotoma. Clavatula. Mangilia. Bela. Pusionella. Pontiothauma.
Fam. 2.—Terebridae. Shell turriculated, with numerous whorls; aperture and operculum oval; eyes at summits of tentacles; siphon long. Terebra.
Fam. 3.—Conidae. Shell conical, with very short spire, and narrow aperture with parallel borders; operculum unguiform Conus.