Notharinia sinensis sp. nov., first record of Notharinia from China, with a preliminary geometric morphometric analysis of the relationship of Notharinia and Arinia s. l. (Gastropoda: Caenogastropoda: Diplommatinidae)

A new species, Notharinia sinensis sp. nov., is described from Guangxi, China, extending the known range of the genus. Geometric morphometric analysis distinguishes Notharinia from Arinia s. l., supporting its generic validity. Two East Asian species, Notharinia japonica (Pilsbry & Hirase, 1903) comb. nov. and N. chejuensis (Kwon & Lee, 1991) comb. nov., are reassigned to Notharinia based on morphological and geometric morphometric evidence. The study also reveals that several Bornean species traditionally placed in Arinia s. l. may be more appropriately assigned to Arinia (Leucarinia), warranting further taxonomic revision.