A new genus-level classification of the Conoidea is presented, based on the molecular phylogeny of Puillandre et al. in the accompanying paper. Fifteen lineages are recognized and ranked as families to facilitate continuity in the treatment of the names Conidae (for ‘cones’) and Terebridae in their traditional usage. The hitherto polyphyletic ‘Turridae’ is now resolved as 13 monophyletic families, in which the 358 currently recognized genera and subgenera are placed, or tentatively allocated: Conorbidae (2 (sub)genera), Borsoniidae (34), Clathurellidae (21), Mitromorphidae (8), Mangeliidae (60), Raphitomidae (71), Cochlespiridae (9), Drilliidae (34), Pseudomelatomidae (=Crassispiridae) (59), Clavatulidae (14), Horaiclavidae new family (28), Turridae s. s. (16) and Strictispiridae (2). A diagnosis with description of the shell and radulae is provided for each of these families.

The superfamily Conoidea constitutes one of the most diverse and taxonomically challenging groups among marine molluscs. Classifications based on shell or radular characters are highly contradictory and disputed. Whereas the monophyly of the Conidae and Terebridae has not been challenged, the other constituents of the superfamily are placed in a ‘trash’ group, the turrids, the non-monophyly of which has been demonstrated by anatomical and molecular evidence. We present here a new molecular phylogeny based on a total of 102 conoidean genera (87 ‘turrids’, 5 cones and 10 terebrids) and three mitochondrial genes [cytochrome oxidase I (COI), 12S rRNA and 16S rRNA]. The resulting tree recognizes 14 clades. When the Conidae (Conus s.l.) and Terebridae are ranked as families for consistency of usage, the ‘turrids’ must be split into 12 families of comparable rank. A new genus-level classification of the Conoidea is published in an accompanying paper.

Recent deep‐sea explorations in the South Pacific have documented around New Caledonia the most diverse fauna of gastropods of the family Volutomitridae anywhere in the world. Fourteen species (nine new, two remaining unnamed) are recorded, all essentially confined to the 250–750 m depth range. The high number of species in the New Caledonia region does not appear to be an effect of sampling intensity, but appears to result from four factors: regional spatial heterogeneity, frequency of hard substrates, syntopy, and a historical heritage shared with Australia and New Zealand, which until now ranked as the major centre of volutomitrid diversity. In the New Caledonia region, volutomitrids show a marked preference for hard bottoms and up to three species may co‐occur in the same dredge haul. Many species appear to have extremely narrow geographical distributions within the region (e.g. a single seamount or a single submerged plateau); conversely, Microvoluta joloensis, the only non‐endemic volutomitrid present in New Caledonia, ranges from the Mozambique Channel to Tonga.