Myonera Dall

Myonera Dall & E. A. Smith, 1886 Type species: Myonera paucistriata Dall, 1886. Composition: Twenty-one extant valid species, of which twenty are listed in MolluscaBase (2025) and one is newly described here. Myonera acutecarinata (Dautzenberg & H. Fischer, 1906), Myonera alleni Poutiers, 1995, Myonera angularis (Jeffreys, 1876), Myonera atlasiana Utrilla, Rueda & C. Salas, 2020, Myonera bicarinata E. A. Smith, 1896, Myonera canariensis (De Boer, 1985), Myonera dautzenbergi Prashad, 1932, Myonera dispar (Dall, Bartsch & Rehder, 1938), Myonera garretti Dall, 1908, Myonera gigantea (A. E. Verrill, 1884), Myonera kaiwa Oliveira & Absalão, 2009, Myonera lamellifera (Dall, 1881), Myonera limatula (Dall, 1881), Myonera lischkei (E. A. Smith, 1891), Myonera pailoloana (Dall, Bartsch & Rehder, 1938), Myonera paucistriata Dall, 1886, Myonera pretiosa A. E. Verrill & K. J. Bush, 1898, Myonera rostra Poutiers & F. R. Bernard, 1995, Myonera sulcifera (Jeffreys, 1882), Myonera tasmanica (Knudsen, 1970) and Myonera aleutiana Machado & Sigwart, sp. nov. Diagnosis Shell small to medium size (3.5 to 24 mm in length), thin, fragile, outline variable, inequilateral, rostrate (mostly) or posterior end truncate, usually inflated, right valve generally larger than left, with margins overlapping. Externally with concentric and / or radial ornamentation, usually covering the entire shell, starting from the umbones. Hinge plate feeble, edentate in both valves. Ligament internal, resilifer posteriorly pointed or nearly vertical; presence of lithodesma. Labial palps small. Muscular septum usually with four pairs of pores (after Knudsen (1970), Allen and Morgan (1981), Poutiers and Bernard (1995) and Coan and Valentich-Scott (2012)).