Noetia ponderosa, or the ponderous ark clam, is a marine clam in the family Noetiidae. It can be found along the Atlantic coast of North America, ranging from Virginia to Florida, West Indies, Gulf of Mexico, and Caribbean Central America.
N. ponderosa typically resides in shallow water on the ocean floor. The shape of the shell is rounded trigonal, almost as high as long. It has a distinctive brown or black periostracum. It also has 27-31 squared radial ribs divided by fine incised lines. The exterior and interior of the shell is a white color. The length is usual 50-60 mm.
