Shell stout, strong, inflated, with a thin ochre-yellow or pale olive epidermis and recurved, pointed, posterior end; beaks approximate, full, incurved, not high, slightly anterior; anterior end evenly rounded, produced; posterior end vertically compressed, produced, recurved, pointed but not rostrate ; base evenly arcuate; radiating sculpture of occasional faint microscopic striations near the ends of the shell, usually absent, and a marked but not sharp-edged ridge in each valve, ex¬tending from the beak to the posterior point and bounding the posterior dorsal area in each valve; concentric sculpture of numerous fine regular continuous rounded threads, separated by narrower grooves; this sculpture, however, becomes suddenly obsolete on the cheeks of the valves and in front of the ridges above mentioned; the threads are stronger above and behind the ridges, but fade out in a central cordate area which, though not impressed, may be taken to represent the escutcheon ; there is no obvious lunule ; interior polished, muscular and pallial scars faint, the former small; pallial sinus shallow, small, and terminal; teeth V-shaped, anterior sixteen, posterior thirteen, all developed; fos¬sette internal, deep set, subtriangular, short; maximum longitude of shell 14.5; altitude 10; diameter 6.8; vertical of beaks behind the anterior end 6.25mm.

Shell thin, with pointed rostrum. Sculpture of fine rounded commarginal riblets,
becoming obsolete on central slope. Escutcheon very wide, deep. Periostracum light olive to brown, dull to silky. Length to 18 mm.
San Diego, California (32.7°N) [USNM], to the Golfo de Panama (6°N) [USNM] and the Islas Galapagos (0.6°S) [USNM], in 1,150 - 3,000 m.
The relationship of this species to Nuculana (Jupiteria) agapea (Dall, 1908), described from the Golfo de Panama, merits additional investigation.

This is a remarkably plain, stout, and simple species, notable for its recurved tip, broad, flattened posterior dorsal area and arcuate base. It has somewhat the form of L. chuva Gray, but is proportionally longer and has a different sculpture.

Near the Galapagos Islands, Pacific.