Nuculana acuta: Elongated trigonal, with sharply pointed rostrum, white with light yellow periostracum, with shallow groove from umbo to ventral margin at both ends of valve, with coarse subequal commarginal ridges extending across posterior ridge. Eastern Canada to Florida, West Indies, Gulf of Mexico, Caribbean Central America, South America (to Brazil). Length 6 mm (to 10 mm).

Nuculana acuta: Nuculana jamaicensis: Elongated trigonal, with sharply pointed rostrum, white, with strong rounded ridge on posterior slope from umbo to tip of rostrum and with radial furrow on anterior slope, with strong regular commarginal sculpture. North Carolina, Florida Keys, West Indies, South America (Suriname). Length 3 mm. Note: The sepia-toned drawings are the original illustrations of the species.

Nuculana acuta (Conrad, 1832) Distribution: Massachusetts to Texas; West Indies; Brazil. Size: 6 to 9 mm (¼ to ½ in). Pointed Nut Clam Description: Color whitish; outline broad and elongate; sculpture of numerous, regular, concentric, modular ridges with a ridge on the posterior dorsal margin; a distinct escutcheon and lunule are present; triangular chondrophore with numerous teeth found on either side. Habitat: Sandy, shelly bottoms. Depth range 0 to 274 m (900 ft). Remarks: Dead shells are often found at Stetson Bank at depths from 21 to 30 m (70 to 100 ft). Usually taken alive at depths from 36 to 137 m (120 to 456 ft). Similar to N. unca, but broader and with finer concentric threads. See Pulley (1952a); Odé and Speers (1970a); Andrews (1977); Odé (1980b); Hyde (2000).