« Shells minute, discoid, spire slightly raised, flat or slightly sunken, widely umbilicate. Aperture quadrate, the dorsal part of the outer lip typically bent downwards slightly in front of the posterior sinus. » – W. F. Ponder: “The Classification of the Rissoidae and Orbitestellidae with Descriptions of Some New Taxa”, Transactions of the Royal Society of New Zealand, Zoology vol. 9(17), Wellington 1967, p.221.
Orbitestella Iredale, 1917:
« Shell thin, pellucid, discoidal, dextral, of few whorls and of peculiar sculpture: widely umbilicate, columella vertical, aperture never variced, irregular in shape, edges thin. » – T. Iredale: “Molluscan name-changes, generic and specific”, Proceedings of the Malacological Society of London vol. 12(6), London 1917, p.327.
