Genus Liralucina n. gen.

TYPE SPECIES. — Phacoides sperabilis Hedley, 1909 (here designated).

INCLUDED SPECIES. — L. sperabilis n. comb., L. craticula n. sp., L. lifouina n. sp. and L. vaubani n. sp.

DIAGNOSIS. — Shells small (<10 mm), subcircular, inflated, with prominent radial ribs (up to 35) crossed by regularly spaced, very thin, commarginal lamellae. Radial ribs obsolete at posterior dorsal margin. Lunule heart-shaped to lanceolate, symmetrical. Hinge teeth small, LV with anterior lateral, 2 cardinal teeth and posterior lateral; RV with anterior lateral, a single cardinal and posterior lateral. Anterior adductor muscle scar short, slightly detached from pallial line. Interior shell margin coarsely crenulate.

ETYMOLOGY. — Latin lira, ridge, in reference to the radial ribs.

REMARKS

Many small species of lucinids with fine commarginal lamellae and radial ribs have been referred to Parvilucina Dall, 1901 (type species: Lucina tenuisculpta Carpenter, 1864 from the temperate northeast Pacific), but we think that several distinct taxa have been included within this concept. Parvilucina tenuisculpta differs from Liralucina n. gen. in having a much smoother shell with numerous, indistinct, fine radial ribs, a longer ligament, relatively larger teeth, a longer anterior adductor scar and a finely crenulate inner shell margin (see Hickman [1994] and Coan et al. [2000] for illustrations of Parvilucina species from NE Pacific).