Genus Discolucina n. gen.

TYPE SPECIES. — Lucina virginea Deshayes, 1832 (here designated).

ETYMOLOGY. — Latin, discus, flat plate.

DIAGNOSIS. — Shell, medium large, subcircular, discoidal, translucent, with projecting arcuate, anterior dorsal area. Sculpture of irregularly spaced, low, commarginal lamellae. Ligament large, set into deep groove, nymph straight. Lunule very small. Cardinal teeth indistinct. Anterior lateral teeth short, close to cardinals. Posterior lateral teeth absent or vestigial. Anterior adductor muscle scar long, dorsal portion extended onto the hinge line above the lateral teeth, long ventral part lies close but parallel to the pallial line.

REMARKS

One of the most distinctive features of this genus is the very long anterior adductor muscle scar that extends dorsally onto the hinge line. Although dissimilar in general morphology, Lepidolucina odontotis n. comb. also has an extended anterior muscle scar and projecting lobate anterior dorsal area (Fig. 21C, D). Another lucinid with a dorsally extended adductor scar is Loripes clausus (Philippi, 1848), from the western Indian Ocean, but this species has a prominent, obliquely inset internal ligament, similar to that of Loripes lucinalis .