Shell size to 20 mm; shell trigonal, external sculpture of crowded commarginal lines. Posterior slope with two radial ridges in right valve and one in left valve. Pallial sinus deep, dropping abruptly to join pallial line. Color translucent-white. Shell in image is small, about 7 mm in length, collected by Susan J. Hewitt at Blind Pass, Captiva, in December 2014.