A Revision of the Chilodontidae (Gastropoda: Vetigastropoda: Seguenzioidea) of Southern Africa and the South-Western Indian Ocean

All species of Chilodontidae known to occur in the south-western Indian Ocean are discussed (27 species, of which eight new, belonging to nine genera, of which three new). Keys to genera and species are provided. Observations on protoconch form, shell microsculpture, radula morphology, operculum shape and external anatomy are given, together with summary biological observations. The genus AgathodontaCossmann, 1918 is not considered to be applicable to the extant species for which it has been recently used and a new genus is proposed for these living forms. Type specimens of a number of extralimital species examined for comparative purposes are illustrated. New genera: Ascetostoma, Clypeostoma and Pholidotrope. New species: Clypeostoma reticulatum, Danilia boucheti, Danilia textilis, Herpetopoma serratocinctum, Herpetopoma stictum, Pholidotrope gloriosa, Vaceuchelus cretaceus and Vaceuchelus jayorum. New synonyms: Cantharidus pliciferusSchepman, 1908 = Perrinia angulifera (A. Adams, 1853); Turcica (Perrinia) waiwailevensisLadd, 1982 and Herpetopoma eboreumVilvens & Héros, 2003 = Herpetopoma xeniolum (Melvill, 1918); Trochus alabastrumReeve, 1858 = Euchelus asper (Gmelin, 1791). New combinations: Agathodonta elongataVilvens, 2001, A. meteoraeNeubert, 1998, A. nortoniMcLean, 1984, Euchelus townsendianus Melvill & Standen, 1903 and Turcica salpinxBarnard, 1964 are transferred to Clypeostoma gen. n.; Diloma verruca Gould, 1861, Euchelus seychellarum G. & H. Nevill, 1869, Euchelus xeniolumMelvill, 1918, Turcica helixBarnard, 1964 and T. waiwailevensisLadd, 1982 are transferred to Herpetopoma; Euchelus gemmulaTurton, 1932 is transferred to Vaceuchelus; Euchelus providentiaeMelvill, 1909 and E. ringensSchepman, 1908 are transferred to Ascetostoma gen. n.; Stomatella cumingii A. Adams, 1854 is transferred to Granata; Turcica konosBarnard, 1964 is transferred to Perrinia. New records for the south-western Indian Ocean: Clypeostoma meteorae (Neubert, 1998); Clypeostoma cf. nortoni (McLean, 1984); Granata cumingii (A. Adams, 1854); Herpetopoma instrictum (Gould, 1849); Herpetopoma ?naokoaePoppe, Tagaro & Dekker, 2006; Herpetopoma xeniolum (Melvill, 1918); Perrinia angulifera (A. Adams, 1853). New records for South Africa: Ascetostoma providentiae (Melvill, 1909); Herpetopoma ?naokoaePoppe, Tagaro & Dekker, 2006; Perrinia angulifera (A. Adams, 1853). Lectotypes designated for: Euchelus favosusMelvill & Standen, 1896; Euchelus gemmulaTurton, 1932; Euchelus natalensisSmi