Taxon classification Animalia Archaeogastropoda Hydrocenidae

Family HYDROCENIDAE Troschel

Short description.

Shell (very) small, dextral, ellipsoid to ovoid to conical. Last whorl without a pore near the aperture, on the inside without a constriction. Sculpture absent, or inconspicuous to distinct spiral and/or radial sculpture present, often fused to nodular structures. Aperture rounded to somewhat angular above; peristome usually not thickened. Umbilicus usually covered by a thickened callus, an extension of the peristome. Operculum calcareous, paucispiral, with a central calcareous peg projecting from the inner surface (Family description adapted from Barker 2001; Kobelt 1876; Suter 1913; Herbert and Kilburn 2004; Thompson and Dance 1983).

Habitat and distribution.

Widespread in humid terrestrial environments, often associated with limestone habitats. Palearctis, Africa, but most diverse in Southeast Asia to Australia and Oceania.

Remarks.

The family is poorly known and has not been revised in the past 140 years and as a consequence, the status of the various genus names (including Georissa) is uncertain.