ISSN 2755-3531
Zhe-Yu Chen, Yi-Feng Fang & Li-Wen Lin
Abstract. Diaphera bagua Z.-Y. Chen, sp. nov. is described and illustrated from Guangxi, China. The new species can be distinguished from Diaphera lini Z.-Y. Chen & Páll-Gergely, 2020, also known from Guangxi, by its glossy shell and closed umbilicus. Two known species, Sinoennea atomaria (Dautzenberg, 1894) from Vietnam and Sinoennea ziminae Yang et al., 2012 from Hubei, China, are reassigned to Diaphera based on shell morphology.
Key words. Asia, carnivorous snail, morphology, new taxa, taxonomy
Published 21 July 2026
DOI. https://doi.org/10.61733/jconch/4575
Richard C. Preece, Tom S. White & Edmund Gittenberger
Abstract. Syntypes of Helix castra W.H. Benson, 1852 in the William Benson collection at the University Museum of Zoology, Cambridge, are a mixture of two species. A lectotype is designated to fix the name and stabilise the nomenclature of this species, now the type species of Sivella W.T. Blanford, 1863 (Helicarionidae, Durgellinae). The lectotype and paralectotype, the only specimens in the type series to match Benson’s description, are illustrated.
Published 21 July 2026
DOI. https://doi.org/10.61733/jconch/4576
Three new species of Clausiliidae (Gastropoda: Stylommatophora) from Shaanxi Province, China
Dimitry M. Palatov, Jozef Grego & Miklós Szekeres
Abstract. Shaanxi Province is divided by the transition line between the vegetation zones of subtropical evergreen and temperate deciduous broadleaf forests, which sets a limit to northward expansion for members of the clausiliid subfamily Phaedusinae. Due to this constraint and a modest interest of malacologists only eight, mostly widespread clausiliid species have been recorded reliably from this province. Here we introduce Euphaedusa vitrea sp. nov., Streptodera chertoprudi sp. nov., and Streptodera qinlingensis sp. nov., which were found during a 2010 trip to the Qinling Mountains in southern Shaanxi. Intriguingly, the new Streptodera species are sinistral members of a genus that previously was considered monotypic and dextral. The three new, apparently narrow endemic species suggest a higher-than-expected diversity of clausiliids in the forested areas of southern Shaanxi.
Published 24 July 2026
DOI. https://doi.org/10.61733/jconch/4577
P. Graham Oliver
Abstract. Some bathyal Thyasiridae from the Faroe-Shetland Channel and Rockall Trough in the North-East Atlantic are described. Four new genera are introduced for species formerly included in Thyasira s.s. namely, Rhombaxinus gen. nov. with type species Cryptodon equalis A.E. Verrill & K.J. Bush, 1898, Thyasirella gen. nov. with type species Cryptodon obsoletus A.E. Verrill & K.J. Bush, 1898, Cryothyas gen nov. with type species Axinus flexuosa var. rotunda Jeffreys, 1881, and Odontothyas gen. nov. with type species Axinus succisa Jeffreys, 1876. The generic status of Mendicula is discussed and M. oblonga (Monterosato, 1880) is transferred to Adontorhina. Comparisons with related taxa from across the entire North Atlantic and adjacent Arctic Ocean are made. Four new species are described: two from the Rockall Trough, Rhombaxinus stellaris sp. nov. and Thyasirella rhamphos sp. nov.; one from east Greenland, Cryothyas milnelandensis sp. nov.; one from the abyssal Norwegian Sea, Mendicula atomus sp. nov. Cryothyas rotundus (Jeffreys, 1881) comb. nov. is recognized from type material discovered in The Natural History Museum (London) and is widespread throughout the Faroe-Shetland Channel from 800–1100 m and ranges from Newfoundland, west and east Greenland, Iceland, Jan Mayen, Svalbard, northern Norway, and into the Barents Sea. It is the earliest available name for all previous records of Thyasira dunbari Lubinsky, 1976, except for the type material of that species from the Canadian High Arctic, which is a separate species and retains its original name. A form of Thyasirella obsoleta (A.E. Verrill & K.J. Bush, 1898) is present at depths below 500 m in the Faroe-Shetland Channel but rarely overlaps with the range of Odontothyas succisa (Jeffreys, 1876) comb. nov. that was found predominantly around the shelf edge at 200–300m. Mendicula pygmaea (A.E. Verrill & K.J. Bush, 1898) was widespread in the Faroe-Shetland Channel at depths from 700 to 1200 m and was found to have a range that included the type locality of off Massachusetts north to Jan Mayen, Svalbard, northern Norway and the Barents Sea. Despite small variations, none are significant enough to warrant the recognition of new species. Mendicula pygmaea is compared with M. ockelmanni (Keuning & Schander, 2010), M. ferruginosa (Forbes, 1844), and two other small Arctic species, Axinulus careyi Bernard, 1979 and Thyasira ottoschmidti Gorbunov, 1946. Mendicula atomus sp. nov. is described from abyssal depths in the Norwegian Sea. A short discussion on thyasirid systematics concludes the paper.
Key words. Taxonomy, shell morphology, North Atlantic Ocean, Arctic Ocean, Bivalvia
Published 28 July 2026
DOI. https://doi.org/10.61733/jconch/4578
Xing-Xiao Wang & Shu-Qian Zhang
Abstract. Phalium flammiferum breviculum Tsi & Ma, 1980 has long been regarded as a subspecies of Phalium flammiferum (Röding, 1798) or sometimes treated as its synonym. In this study, integrative morphological and molecular phylogenetic analyses of P. flammiferum breviculum Tsi & Ma, 1980 and P. flammiferum flammiferum (Röding, 1798) from Chinese waters demonstrate that they represent two distinct species. Morphologically, the two species differ primarily in discrete characters of shell sculpture, particularly in the number of spiral cords and varices. Geometric morphometric analyses and mapping of landmark configurations onto the phylogeny indicate that variation in shell outline is largely continuous and only weakly associated with phylogenetic relationships. Phylogenetic analyses reconstructed by Bayesian inference using concatenated mitochondrial (COI) and nuclear (28S rRNA) genes and species delimitation analysis (ASAP) support the separation of the two species. Herein, we formally elevate Phalium flammiferum breviculum Tsi & Ma, 1980 to species rank.
Supplemental materials (https://doi.org/10.61733/jconch/4579s)
Key words. China Seas, Yellow Sea Cold Water Mass, Mollusca, species distinction
Published 29 July 2026
DOI. https://doi.org/10.61733/jconch/4579
Peter Tattersfield
Abstract. Two new species of operculate land snail, Thomeomaizania cathyae sp. nov. and Afroditropis delimai sp. nov., are described from the island of São Tomé in the Gulf of Guinea. Both are very likely to be single-island endemics. Whether these species should be classified in the Maizaniidae or Cyclophoridae is uncertain pending further study. However, the structure of the operculum, which is distinctive and formed of at least three layers, the outermost comprising a series of tightly coiled spiral lamellae, would suggest that they most likely belong to the Cyclophoridae. Shells of the six operculate species currently known from the island, and details of their opercula, are illustrated. An identification key is provided. Records of three non-operculate terrestrial gastropod species are also given, raising the total number of terrestrial molluscs known from São Tomé from 59 to 64.
Key words. Afroditropis delimai, Thomeomaizania cathyae, operculum, Cyclophoridae, Maizaniidae, Gulf of Guinea islands, Africa
Published 31 July 2026