Subfamily UMBONEINAE Lyssenko & Aliev, 1987 (Fig. 3G) Umboneidae Lyssenko & Aliev, 1987: 117 TYPE GENUS. — Umbonea Pchelintsev, 1965 (1965: 85). TYPE SPECIES. — Nerinea dilatata d’Orbigny, 1852 (1852: 146). SUBFAMILY CHARACTERS. — Shells with hollow columella; whorls almost triangular in outline, siphonal notch located on acute extension of aperture. The columellar, parietal and palatal plaits are small. The umbilicus may be covered by a thin lamella. REMARKS This group is assigned to the Ptygmatididae because of the typical siphonal portion which protrudes at about 60° into the umbilicus. It has been named Diozoptyxisidae by Pchelintsev (1965). Diozoptyxis Cossmann, 1907 belongs, in fact, to the Campaniloidea (see Kollmann & Peza 1997 a; Kollmann 2005). Ptygmatididae species originally assigned to this family are allocated to the Umboneinae Lyssenko & Aliev, 1987.

Published as part of Kollmann, Heinz A., 2014, The extinct Nerineoidea and Acteonelloidea (Heterobranchia, Gastropoda): a palaeobiological approach, pp. 349-383 in Geodiversitas 36 (3) on page 356, DOI: 10.5252/g2014n3a2, http://zenodo.org/record/4538503