A revision of the antarctic genus Chlanidota (Gastropoda : Neogastropoda :Buccinulidae)

The genus Chlanidota is revised to contain two subgenera, Chlanidota sensu stricto and Chlanidota (Pfefferia). Chlanidota s.s. has a broad distributio n throughout the Antarctic region, and contains five species: Chlanidota (C hlanidota) vestita (Martens, 1881), C. (C.) densesculpta (Martens, 1885), C . (C.) paucispiralis Powell, 1951, C. (C.) pilosa Powell, 1951, and C. (C.) signeyana Powell, 1951. The subgenus Pfefferia, which differs from Chlanid ota primarily in the morphology of its operculum, is endemic to South Georg ia Island, and is known from three species: Chlanidota (Pfefferia) chordata (Strebel, 1908), C. (P.) palliata (Strebel, 1908), C. (P.) invenusta, new species. With its bulliform shell lacking a siphonal canal, the monotypic, circum-Antarctic genus Neobuccinum is conjectured to be the sister taxon of Chlanidota, but is readily distinguished by its smoother, higher-spired sh ell, radula in which the central cusp of the lateral teeth is medially plac ed, and a penis lacking a papilla.