Length 70 mm, height 55 mm, breadth 12 mm. Shell thin, discoidal, rather stout. Both ears subequal in size and shape. Left valve brownish purplish in color with weak growth lines and inconspicuous radial lines. Darker and paler colorations accord with those obsolete sculptures. White spots scatter in umbonial region. Right valve white in umbonial region but becomes brownish marginally. Interior white, margined with brownish color. Internal radial ribs never reach to umbo, about 40 on the left and 25 pairs on the right valve.
Distribution:
Gulf of Mexico, West Indies, off Suriname. Sublittoral to shelf.
Remarks:
This species has more indistinct radials than in P. lineolaris and has different color pattern externally. Both species have large stocks in the surveyed area.