Shells minute, « relatively high-spired, smooth or with spiral cords » (A. M. Keen: Sea Shells of Tropical West America 2nd.ed., Stanford 1971, p.370), sometimes with radial folds (in some members of the genus Pisinna), or even carinate (Anabathron contabulatum, lene, hedleyi…); aperture round, entire, sometimes protruding (Badepigrus, Nodulus); no umbilicus. Operculum flat.
 

Shell pupiform with convex whorls; sculpture very weak, made up of thin spiral sculpture and commarginal axial growth marks; suture marked; aperture broadly oval, protruding (body whorl uncoiling anteriorly); « outer lip orthocline to weakly prosocline, non-varicose, with blunt edge […]. Protoconch of about 1½ whorls, dome-shaped, sculptured with rather irregular pits, the surface between sometimes raised into weak, irregular wrinkles… » – W. F. Ponder: “Review of the genera of the Barleeidae (Mollusca: Gastropoda: Rissoacea)”, Records of the Australian Museum vol.35, Sydney 1983, p.256. « Operculum with 2 pegs » (op. cit. p.251).
 

Shell « pupiform to elongate-ovate or ovate-conic, non-umbilicate. Aperture subcircular, with simple peristome; inner lip usually broad, attached to parietal wall; outer lip prosocline to opisthocline, with or without varix. Sculpture of axial or spiral ribs or both, or surface smooth […]. Protoconch dome-shaped, of about 1½-2 whorls, surface minutely pitted, pits usually in close spiral rows… » – W. F. Ponder: op. cit. p.256.