From Cavolinia longirostris to twenty-four Diacavolinia taxa, with a phylogenetic discussion (Mollusca, Gastropoda)

The six already known infraspecific taxa in Cavolinia longirostris (De Blainville, 1821), presently in the genus Diacavolinia, are raised to species rank and sixteen species and two formae new to science are described in this genus from different oceanic areas. Some shell structures in the Cavoliniinae are described for the first time and the phylogeny of the group is discussed.