"Shell small, thin, brownish white, concentrically undulate and with both valves similarly reticulately sculptured, equivalve, somewhat equilateral; beaks (showing small, polished prodissoconch) small, pointed, the left one rising al little higher than the other; hinge line straight, ears subequal, sharply pointed, byssal notch and fasciole distinct, sculpture like that of the disk; surface of the valves with about four easy, wide, rounded undulations; surface sculptured with numerous fine, squarish, radial and concentric threads subequal and subequally distributed, so that the meshes are mostly square, without nodulation at the intersections, and the interspaces are wider than the threads; disk short, kite-shaped, a little produced in front, suddenly constricted at the margin; interior white, polished, the umbonal cavities extending under the hinge line; the pit and resilium small." (fide Dall, 1908) Size: Normal adult size range is 10 to 15 mm.

Reported off Oregon to northern Peru, including the Galapagos Islands.
Habitat: Deep water, on fine muddy bottoms.