Diplommatina yipingica , Zhang 2025, sp. nov.

Diplommatina yipingica Zhang sp. nov. Material examined. Holotype SDNU. Gas.0337.01.001 (Figs 9, 13 O); paratypes SDNU. Gas.0337.02 (Fig. 10) (coll. G. Zhang, 11 July 2018). Type locality. Beijiushui, Laoshan, Qingdao City, Shandong Province, 36.205 ° N, 120.591 ° E, altitude 413 m a. s. l. Description. Shell dextral, with about 5.5 whorls. Protoconch smooth, completely covered with small pits. Penultimate slightly expanded, body whorl nearly equal in width. Constriction at middle of parietal wall. No spiral striation visible. Teleoconch with strong, widely spaced, radial ribs; about 8–12 (9.8 ± 1.8) ribs per 0.5 mm on penultimate whorl, 5–9 (7.3 ± 1.9) ribs per 0.5 mm on body whorl. Dorsal fold absent. Umbilicus closed. Double lip absent. Columellar tooth present. Columellaris strong. One short horizontal palatalis just above columella. No vertical palatalis present. Shell with one palatalis and two parietalis; Prt 1 shorter than Prt 2. Diagnosis. Penultimate slightly expanded, body whorl nearly equal in width. Shell with one palatalis and three parietalis. Prt 1 shorter than Prt 2. Etymology. The name is derived from the Chinese word yiping [= yishengpingan], which means a fully peaceful and safe life. Distribution. Known from type locality only. Ecology. Lives in leaf litter. May climb up on plants after rain (Fig. 11). Remarks. Diplommatina yipingica is similar to Diplommatina pupinella, D. futilis, D. intermedia, D. paxillus longipalatalis, D. paxillus hunanensis, D. yunnanensis and D. schmackeriana in terms of general shell shape. (Fig. 3). Diplommatina schmackeriana differs in having a smooth shell. Diplommatina paxillus hunanensis has more widely-spaced ribs. Diplommatina paxillus longipalatalis has weaker ribs. Lip morphology differs from species with a double lip, such as D. futilis. Additionally, the occurrence of Diplommatina yipingica is isolated far away from the known distributions of other congeners in China. The shell sizes of D. kyobuntoensis and D. typosenica from the Korean Peninsula are significantly smaller compared to the new species. In both of these species, the penultimate whorl is broader than the body whorl (Kuroda and Miyanaga 1939). Similarly, the Korean species D. changensis and D. chejuensis also exhibit a wider penultimate whorl compared to the body whorl and have more whorls than new species (Kwon & Lee, 1991).