Quadrangular, compressed, left valve slightly smaller than right valve, lunule impressed, solid, surface radially granular with ca. 12 strong, sharp radial ribs on anterior half to three-fourths, dull white, margin smooth but plicated by exterior ribs. Massachusetts to Florida, Bermuda, Bahamas, West Indies, Gulf of Mexico, South America (Suriname, Brazil). Length 3 mm (to 5 mm). Formerly in Verticordia.