Lepidolucina, Glover & Taylor, 2007

Glover, Emily A. & Taylor, John D., 2007, Diversity of chemosymbiotic bivalves on coral reefs: Lucinidae (Mollusca, Bivalvia) of New Caledonia and Lifou, Zoosystema 29 (1), pp. 109-181 : 142-144

Genus Lepidolucina n. gen.

TYPE SPECIES. — Lucina venusta Philippi, 1847 (here designated).

ETYMOLOGY. — Greek lepidos, scale, a reference to the fine, scale-like sculpture.

INCLUDED SPECIES. — L.venusta ( Philippi, 1847) n. comb., L. odontotis ( Salisbury, 1934) n. comb., L. belepina n. sp.

DIAGNOSIS. — Medium sized, subcircular, inflated, sculpture of around 50-60 closely spaced radial ribs, that are wider in the anterior and posterior sectors of the shell, ribs bear closely spaced, dorsally inclined, semicircular or arcuate scales. Hinge with one or two small cardinal teeth and very small (pimple-like) anterior and posterior lateral teeth.Anterior adductor muscle scar medium-long,detached from pallial line at angle of around 25°. Interior margin of shells serrate with superimposed fine denticulations.

REMARKS

A similar genus is Lucinisca Dall, 1901 (type species Lucina nassula Conrad, 1846 ) with species in the western Atlantic and tropical Eastern Pacific, to which L. venusta n. comb. has often been referred ( Chavan 1937). Species of Lucinisca can be distinguished from Lepidolucina n. gen. by the large anterior and posterior lateral teeth, the shell sculpture that, in L. nassula , consists of fine radial ribs crossed by widely spaced, thin, commarginal lamellae, with scales forming at their intersection.

Lepidolucina venusta ( Philippi, 1847) n. comb. ( Fig. 21A, B , E-H)

Lucina venusta Philippi, 1847: 206 , pl. 1, fig. 2. — Reeve 1850: pl. 3, fig. 15.

Lucina (Myrtea) layardii A. Adams, 1855: 225 .

Lucina (Myrtea) strangei A. Adams, 1855: 226 .

Codakia strangei – Hedley 1909: 187.

Myrtea venusta – Hedley 1913: 266, pl. 16, fig. 10.

Phacoides (Lucinisca) venustus – Lamy 1920: 186.

Codakia golikovi Zorina, 1978: 196 , figs 4, 5 (cited fig. 6 corresponds to Pillucina vietnamica Zorina, 1978 ).

TYPE MATERIAL. — L. venusta : not located.

L. layardi : holotype, Sri Lanka ( BMNH 1963556).

L. strangei : holotype, Moreton Bay, Queensland, Australia (BMNH 1963557).

C. golikovi : syntypes, Gulf of Tonkin, Vietnam (ZISP, see Lutaenko 2000: 384, pl. 1, figs 7, 8).

TYPE LOCALITY. — Unknown.

MATERIAL EXAMINED. — Sri Lanka. ( BMNH).

Thailand. Kampuan, Ranong ( BMNH).

Philippines. Luzon I., Manila ( BMNH).

Indonesia. Moluccas ( BMNH).

China. Daya Bay ( BMNH).

Australia. Moreton Bay, Queensland ( BMNH; AMS).

DISTRIBUTION. — Central IWP from Sri Lanka to Queensland.

DESCRIPTION

Small to medium size (H to 31 mm, L to 34 mm), subcircular, inflated, white, umbones low. Lateral edges of dorsal margins rounded. Sculpture of around 50 narrow, closely-spaced, radial ribs; ribs are broader in anterior and posterior sectors of shell. Each rib bears closely spaced, dorsally curved, arcuate scales. The scales are wider and flaring on the anterior broader ribs. Lunule short, lanceolate, asymmetrical, greater part in right valve. Escutcheon narrow, dorsal edge with slightly extended scales. Hinge plate narrow, LV with two cardinal teeth and small anterior and posterior lateral teeth; RV with two cardinal teeth, and very small anterior and posterior lateral teeth. Ligament external, straight. Anterior adductor muscle scar medium long, detached from pallial line for 2/3 of length. Posterior adductor scar oval. Pallial line entire, broad. Shell outside of pallial line glossy and shell margin serrate with finer denticulations ( Fig. 21F ). Shell within pallial line dull, with small circular pallial attachment scars. Pallial blood vessel scar often visible.

REMARKS

The type specimens of L. layardi and L. strangei are very similar to Philippi’s figure of L. venusta .

Figures

FIG. 21. — A, B, E-H, Lepidolucina venusta (Philippi, 1847) n. comb.; A, B, Isle of Luzon, Philippines (BMNH 1969119/2); A, exterior left valve; B, interior left valve; E, detail of sculpture, Borneo (BMNH 77.4.26.43); F, inner shell margin, Borneo; G, H, detail of hinge teeth, Borneo (BMNH); C, D, L. odontotis (Salisbury, 1934) n. comb., holotype, Sarawak (BMNH 1893.9.1.12-1), interior and exterior of right valve. Scale bars: A-D, 10 mm; E, 1 mm; F, 0.5 mm; G, H, 2 mm.