Pillucina copiosa, Glover & Taylor, 2007

Pillucina copiosa View in CoL n. sp.

( Figs 32 View FIG ; 34D View FIG )

TYPE MATERIAL. — Holotype: 1 sh, L 2.9 mm, H 2.7 mm, T 0.9 mm ( MNHN). GoogleMaps

Paratypes: from type locality, 42 shells, 37 v ( MNHN) GoogleMaps ; 4 v ( BMNH 20050577 ). — Figured paratypes: from type locality, 1 sh, L 1.5 mm, H 1.5 mm; 1 RV, L 3.0 mm, H 2.9 mm, T 1.2 mm; 1 LV, L 3.3 mm, H 3.2 mm, T 1.1 mm; 1 LV, L 2.8 mm, H 2.8 mm, T 1.0 mm; 1 shell, L 2.5 mm, H 2.2 mm ( MNHN) GoogleMaps .

TYPE LOCALITY. — New Caledonia, Anse de Koumac, 20°34’S, 164°16’E, 0-2 m, Expédition Montrouzier.

ETYMOLOGY. — Latin copiosus, abundant, a reference to the frequency of the species at Koumac.

MATERIAL EXAMINED. — Koumac. 22 stn, 0-120 m, 188 v, 61 live.

Touho. 10 stn, 0-30 m, 76 v, 2 live.

Other New Caledonia. Secteur de Nouméa, Pointe Magnin, stn 1355, 7- 10 m, 5 v. — Platier Îlot Maitre, stn 1351, intertidal, 2 v.

DISTRIBUTION. — Known only from New Caledonia.

DESCRIPTION

Shell small, white to grey, H to 4.2 mm, L to 4.1 mm, moderately inflated, longer than high, ovoid to obliquely oval (H/L 0.97). Umbones prominent. Protoconch 150 µm, PI about 70 µm, PII with regular growth increments. Shell sculpture of fine radial ribs (c. 40-48), that both bifurcate and intercalate, more distinct at posterior and anterior. Ribs crossed by fine, regularly spaced, slightly elevated, commarginal lamellae.Ribs strongly divergent in anterior third of shell. Juvenile shell to around 350 µm with commarginal lamellae only. Lunule broad, lanceolate, asymmetric, greater part in right valve. RV with two cardinal teeth the posterior much larger, a small anterior lateral, and short, posterior lateral. LV with two cardinal teeth, no anterior lateral and a short, posterior lateral. Ligament internal, short, occupying an obliquely extended triangular resilifer. Anterior adductor muscle scar short, detached for about one third of length. Posterior adductor muscle scar ovate. Pallial line patchily discontinuous. Ventral shell margin slightly thickened and finely dentate.

REMARKS

Previously, Glover & Taylor (2001: 270) included the New Caledonia specimens within our concept of Pillucina pisidium (Dunker, 1860) , but the new species is smaller, more elongate, with fewer, more prominent radial ribs. Pillucina neglecta Habe, 1960 , from Japan has a more scooped lunule, a larger posterior lateral tooth and fewer ribs (c. 30). Pillucina australis Glover & Taylor, 2001 , from southwestern Australia is similar in shape and ribbing but has a prominent anterior lateral tooth in the left valve and a single cardinal tooth in the right valve.