A new start? Revision of the genera Anauchen, Bensonella, Gyliotrachela and Hypselostoma (Gastropoda, Eupulmonata, Hypselostomatidae) of Southeast Asia with description of 46 new species

Hypselostomatidae is a large family of terrestrial pulmonate molluscs currently represented by 284 extant species, most confined to Southeast Asia. The current system of grouping species into genera is based on the morphology of the apertural barriers and the level of last whorl detachment. However, these characters overlap, challenging generic definitions. In this paper, these characters are evaluated and a novel classification proposed for hypselostomatid species belonging to the genera <i>Anauchen</i> (17 species), <i>Bensonella</i> (36 species), <i>Boysidia</i> (7 species, in part) and <i>Hypselostoma</i> (85 species). We assigned all species belonging to the genera <i>Bensonella</i> and <i>Hypselostoma</i> into two and four species groups respectively, which are characterised by combinations of morphological traits. Altogether 46 new species are described, seven species in <i>Anauchen</i>: <i>A.crassus</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>A.evanidus</i> Gojšina & Páll-Gergely, <b>sp. nov.</b>, <i>A.grandiportus</i> Gojšina, Grego & Páll-Gergely, <b>sp. nov.</b>, <i>A.obesus</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>A.picasso</i> Gojšina & Páll-Gergely, <b>sp. nov.</b>, <i>A.turritus</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>A.jokaii</i> Gojšina & Páll-Gergely, <b>sp. nov.</b>; 19 species in <i>Bensonella</i>: <i>B.alycaeus</i> Gojšina & Páll-Gergely, <b>sp. nov.</b>, <i>B.cardiostoma</i> Gojšina, Vermeulen & Páll-Gergely, <b>sp. nov.</b>, <i>B.cristatissima</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>B.dha</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>B.dracula</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>B.exploda</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>B.fracta</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>B.microdentata</i> Gojšina & Páll-Gergely, <b>sp. nov.</b>, <i>B.mitochondria</i> Gojšina, Vermeulen & Páll-Gergely, <b>sp. nov.</b>, <i>B.mirabilis</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>B.montawa</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>B.multidentata</i> Gojšina, A. Reischütz & Páll-Gergely, <b>sp. nov.</b>, <i>B.nitens</i> Gojšina & Páll-Gergely, <b>sp. nov.</b>, <i>B.obex</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>B.perfecta</i> Gojšina & Páll-Gergely, <b>sp. nov.</b>, <i>B.sericata</i> Gojšina & Páll-Gergely, <b>sp. nov.</b>, <i>B.serrata</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>B.spelaea</i> Gojšina, Grego & Páll-Gergely, <b>sp. nov.</b>, <i>B.spinosa</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>; 20 species in <i>Hypselostoma</i>: <i>H.aquila</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>H.bubalus</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>H.circumcarinatum</i> Gojšina, Auffenberg & Páll-Gergely, <b>sp. nov.</b>, <i>H.coriaceum</i> Gojšina & Páll-Gergely, <b>sp. nov.</b>, <i>H.aenigma</i> Gojšina, Grego & Páll-Gergely, <b>sp. nov.</b>, <i>H.fortunatum</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>H.fungus</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>H.geckophilum</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>H.iunior</i> Gojšina & Páll-Gergely, <b>sp. nov.</b>, <i>H.ophis</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>H.platybasis</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>H.populare</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>H.sculpturatum</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>H.similare</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>H.sorormajor</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>H.sororminor</i> Gojšina, Hunyadi & Páll-Gergely, <b>sp. nov.</b>, <i>H.torta</i> Gojšina, Auffenberg & Páll-Gergely, <b>sp. nov.</b>, <i>H.vesovici</i> Gojšina & Páll-Gergely, <b>sp. nov.</b>, <i>H.vicinum</i> Gojšina, Auffenberg & Páll-Gergely, <b>sp. nov.</b>, <i>H.vujici</i> Gojšina & Páll-Gergely, <b>sp. nov.</b> One replacement name is proposed: <i>H.tertiusfrater</i> Gojšina & Páll-Gergely, <b>nom. nov.</b> pro <i>Boysidiasalpinx</i> F. G. Thompson & Dance, 1983, non <i>Hypselostomasalpinx</i> (van Benthem Jutting, 1961) (originally described as <i>Gyliotrachela</i>). <i>Gyliotrachela</i> and <i>Antroapiculus</i> are both treated as junior synonyms of <i>Hypselostoma</i>. An additional 28 species and subspecies are reassigned to the synonymies of other taxa.