A revision of the patagonian genus Xymenopsis Powell, 1951 (Gastropoda: Muricidae)

Abstract

The genus Xymenopsis Powell, 1951 is revised and restricted to 4 Recent species: Xymenopsis muriciformis (King and Broderip, 1832), X. corrugatus (Reeve, 1848), X. buccineus (Lamarck, 1816) and X. subnodosus (Gray, 1839). Of the 34 nominal species that have been described as or assigned to Xymenopsis by various authors, 3 belong to the buccinid genus Pareuthria and 1 is a trophonine muricid not closely related to Xymenopsis. The taxonomic affinities of each of the remaining 30 names (one is a replacement name) are discussed. Eleven holotypes and ten lectotypes (nine newly designated) are illustrated, many for the first time. Types of 3 taxa were destroyed during World War II and another 5 types are lost. Neotypes are designated for Fusus buccineus Lamarck, 1816, the oldest name to be applied to any species of Xymenopsis, as well as for Buccinum subnodosa Gray, 1839, Trophon brucei Strebel, 1904, Trophon fenestratus Strebel, 1904, Trophon paessleri turrita Strebel, 1904, Trophon ringei Strebel, 1904 and Trophon standeni Strebel, 1904. This is done to remove any ambiguity regarding the identity of these taxa, and thus stabilize the nomenclature of Recent species of Xymenopsis. The gross anatomy and morphology of the radula, egg capsule, protoconch, and shell ultrastructure of the type species of Xymenopsis are described and illustrated. Xymenopsis is compared to, and differentiated from, the genera Xymene, which is restricted to New Zealand, and Trophon, with which it co-occurs in the Magellanic province.