The Rissoininae (Gastropoda: Rissoidae) of the Pitcairn Islands, with the description of two new species

This paper reviews the Rissoininae from the four islands that comprise the Pitcairn Group. The material was collected during the Sir Peter Scott Commemorative Expedition to the Pitcairn Islands between October and December 1991. Twelve species belonging to this subfamily are reported, including two undescribed taxa. The well-known species are listed with synonymies and the poorly known species are (re)described and illustrated. The shells of two new species, Rissoina (Rissoina) fratercula and Rissoina (Rissoina) schubelae, are described in detail. The biogeographical relationships of the fauna are briefly discussed.