New records and taxonomic review of Triphoridae (mollusca: Gastropoda) from the Samoan Islands

The extant Triphoridae of the Samoan archipelago are reviewed, and 21 new Samoan records are discussed and illustrated based on recent collections from the island of Tutuila, American Samoa. Confident identifications are provided for the following 9 species: Bouchetriphora pallida (Pease, 1871); Coriophora cnodax (Jousseaume, 1884); Coriophora fusca (Dunker, 1860); Costatotriphora iniqua (Jousseaume, 1898); Iniforis fusiformis (Kosuge, 1961); Mastonia iris Laseron, 1958; Nanaphora triticea (Pease, 1861); Triphora collaris Hinds, 1843; and Triphora taeniolata Hervier, 1898. Provisional records are provided for 7 species: Inella cf. numerosa Jousseaume, 1898; Iniforis cf. douvillei Jousseaume, 1884; Mastoniaeforis cf. chaperi Jousseaume, 1884; Nanaphora cf. tricolor Laseron, 1958; Opimaphora cf. coralina Laseron, 1958; Triphora cf. fulvescens Hervier, 1898; and Metaxia cf. brunnicephala Kay, 1979. A further 5 species are recorded from Samoa that cannot be definitively assigned to currently described taxa and may represent undescribed species: Monophorus aff. strictus (Laserson, 1958); Nanaphora aff. triticea (Pease, 1861); Obesula aff. pantherina Jousseaume, 1898; Opimaphora aff. coralina Laseron, 1958; and Triphora aff. laddi Kay, 1979. Two species previously recorded from Samoa based on tentatively identified fossil material are now validated as currently present: Iniforis albogranosa (Kosuge, 1961) and and Viriola pagoda (Hinds, 1843). Of the 13 other species previously recorded from Samoa, 2 are currently considered synonyms; 4 are questionable records not based on any specimens that can be located; 2 are questionable names that may represent synonyms; 1 is a likely misidentification; and 4 are valid records of which one, Mastonia cf. rubra (Hinds, 1843), was recollected. Based on this analysis, the currently documented triphorid fauna of Samoa consists of 33 species, although additional species are undoubtedly present. The current total is also subject to change as taxonomic and nomenclatural problems are resolved.