Irregularly elongated oval with undulating margins, deeply cupped, with flat upper right valve fitting well into deep lower left valve, moderately compressed, solid, grayish white often blotched with purple, with irregular commarginal lamellations; interior glossy white with purple elongated muscle scar, margin smooth (chomata absent), anal funnel absent. Florida Keys, West Indies, Gulf of Mexico, Caribbean Central America, South America (to Uruguay). Length 85 mm. Formerly considered a subspecies or form of C. virginica (see following). Compare Crassostrea virginica, which has a smaller, rounder purple adductor muscle scar, and Ostrea equestris, which is greenish internally. Note: The habitat of this species is estuarine.