New and revised marginelliform gastropods (Mollusca Volutoidea) from the South Pacific

Several marginelliform species from the South Pacific collected in Fiji, Western Samoa and Pitcairn Islands are revised on the basis of their shell morphology. The species Volvaria (Volvarina) pygmaea Garrett, 1873 described from Fiji is re-assigned to the genus Gibberula Swainson, 1840, and a lectotype is designated. The species Gibberula vomoensis Wakefield et McCleery, 2004 described from Vomo Island (Western Fiji) is illustrated by a specimen from the same area (Beqa Island, Western Fiji) as a complement to the original description of the species. The species Crithe cossinea Cossignani, 1997, described from the Philippines, is reported from Western Fiji and its biogeographical status is discussed herein. Six species are described as new: Gibberula aureola n. sp. from Western Samoa and G. dixoni n. sp. from Pitcairn, Cystiscus turbinatus n. sp. from Pitcairn, Volvarina storea n. sp. from Western Samoa, Granulina vitiensis n. sp. from Western Fiji, and G. biplicata n. sp. from Pitcairn.