Shell small, waxen white, superficially resembling M. granitica, but differing in the following particulars: It has one rib less; the two prominent spiral cords on the early whorls are strongly nodulous when they cross the ribs, especially the posterior cord, even on the last whorl; the spiral sculpture on the last whorl in front of the fasciole comprises 10 strong flattish cords, separated by very sharp, narrow grooves, with no spiral sculpture on the back of the canal, which is distinctly shorter; aperture relatively shorter and wider; the nucleus apparently similar but eroded, the number of whorls is the same but the shell is shorter. Height of shell, 11.5; of last whorl, 6.5; diameter, 4.5 mm. (Dall.)
TYPE in United States National Museum, No. 208560a

Type locality, Station 1413, Granite Cove, Port Althorp, Alaska.
RANGE. Known only from type locality.