All six main spicules of nearly equal size and equidistant, thin, lanceolate, compressed, somewhat shorter than diameter of hexagonal shell. Sheaths nearly prismatic, conical in distal third, each with twelve prominent parallel crests, separated by twelve deep furrows; contracted distal opening or mouth denticulate. Sheaths as long as radius of shell, enveloping two-thirds of spicules. Sutural pits polygonal, separated from one another by protruding crenulate border. Diameter of shell: 0.15 mm, thickness of wall: 0.08 mm; length of spicules: 0.1 mm, of sheath: 0.007 mm; breadth of latter: 0.04 mm.