Shell minute, opaque, solid, discoidal, widely umbilicate. Whorls 3 biangled by two prominent spiral keels. Protoconch exceedingly small, of one smooth slightly keeled whorl. Periphery high, formed by upper keel. Lower keel of lesser diameter giving roughly, a flattened pentagonal outline to the shell, in vertical cross section. Umbilicus wide, perspective, about one-third major diameter. Spire slightly sunken. The whole shell crossed by numerous strong rounded axial costae, nodulous where they cross the spiral keels, and anastomosing towards the sutures, forming swollen nodulous sutural bands above and below. Axial costae obliquely retractive between the two keels and convexly arcuate on base. Interstices of ribs crowded with inconspicuous exceedingly fine spiral striae. Aperture subquadrate. Peristome discontinuous thin, overhanging above.. Colour pale-buff. Major diameter 0.74 mm.; minimum diameter 0.64 mm.; height 0.27 mm. (holotype).
Habitat, Awanui or Rangaunu Bay, in 12 fathoms (Mr. W. La Roche, 1922); Mangonui in 6-10 fathoms (type) (Mr. W. La Roche, 1922).
This makes the second species of the genus to be described from New Zealand seas.

Shell minute, maximum diameter from 0.65 to 0.75 mm, opaque, white or glassy, discoidal, whorls 3 to 3,5, with sunken spire, last whorl with 2 carinae at edge, upper one extending somewhat beyond lower one so that the flat periphery of the shell slants slightly inward, umbilicus moderately broad; sculpture on upper surface on whorls consists of short, broad, rather crowded nodose axial ribs tapering at their culmination at a precarinal sulcus, upper carina strongly nodose in early whorls, the nodes becoming less conspicuous in last part of last whorl; carinal nodes continue on the peripheral intercarinal surface as prosocline ribs ending as low nodes on the lower carinae and on the convex base of last whorl as low and rather broad prosocyrt ribs; umbilicus about 1/3 to 1/4 of major diameter; aperture subquadrate.
MEASUREMENTS (mm).—USNM 756212: width 0.65, height 0.26. A single, bleached specimen of this minute species was found in beach drift. Although it differs in some minor respects from the original figure given by Powell and from specimens examined from New Zealand, in overall characters it is so close to the New Zealand species that I hesitate to give it a distinctive name on the basis of one dead specimen.

RANGE.—Northern New Zealand and Easter Island.