Taiwanassiminea phantasma n. sp. a terrestrial assimineid (Caenogastropoda: Truncatelloidea) from Middle Osborn Island, Kimberley, Western Australia

A new terrestrial assimineid gastropod, Taiwanassiminea phantasma n. sp. (Truncatelloidea: Assimineidae), is described. Taiwanassiminea phantasma is characterised by its translucent, conical shell with deeply impressed sutures, spiral groove surrounding a wide umbilicus, relative lack of pigmentation and long distal penial papilla. The species differs from most assimineids in having a subcircular aperture and an operculum with a central nucleus. Taiwanassiminea phantasma has anatomical similarities to other members of Taiwanassiminea, and this relationship is supported by a partial cytochrome oxidase I mitochondrial analysis. Taiwanassiminea phantasma lives in leaf litter in vine thickets on Middle Osborn Island in northern Kimberley, Western Australia, where it is possibly endemic. No terrestrial assimineid is otherwise known from mainland Australia or its adjacent islands, including Tasmania. http://zoobank.org/urn:lsid:zoobank.org:pub:A14ACAAE-4BAD-402D-9F9D-3BC9D928411A