Discolucina, 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 : 146

publication ID	https://doi.org/ 10.5281/zenodo.5392295
persistent identifier	https://treatment.plazi.org/id/039087F4-FFE4-6A07-13ED-FDC6FC11D6C6
treatment provided by	Marcus
scientific name	Discolucina
status	gen. nov.

Treatment

Genus Discolucina View in CoL 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 View FIG ). 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 .

Discolucina virginea ( Deshayes, 1832) View in CoL n. comb. ( Figs 23B View FIG ; 24 View FIG A-D)

Lucina virginea Deshayes, 1832: 379 View in CoL .

Lucina argentea Reeve, 1850 View in CoL : pl. 2, fig. 6.

Lucina sulcata Reeve, 1850 View in CoL : pl. 4, fig. 20.

Phacoides argenteus – Lamy 1920: 176.

Lucinoma argentea – Chavan 1938: 83.

TYPE MATERIAL. — L. virginea : holotype, 1 sh, L 46.9 mm, H 43.6 mm ( MNHN).

L. argentea : syntypes, 3 sh ( Fig. 24E, F View FIG ), Moluccas ( BMNH 1963113-4).

L. sulcata : syntypes, 2 sh ( Fig. 24G, H View FIG ), no locality given (BMNH 1963188-9).

TYPE LOCALITY. — Amboina, Indonesia.

MATERIAL EXAMINED. — Touho. 2 stn, 0-4 m, 3 v.

DISTRIBUTION. — Indonesia, Amboina (MNHN); Hitulama, Hitu, Ambon (ZML); Moluccas (BMNH; ZMA). Philippines, Calapan, Mindoro (Museum of Comparative Zoology, Harvard University); Lubang Island (NMGW).

DESCRIPTION

Shell large, H to 44 mm, L to 47 mm, subcircular to discoidal, compressed,shell colour white,translucent, anterior dorsal area extended as arcuate projection. Sculpture of fine, low, irregularly but closely spaced, commarginal lamellae and growth increments with faint radial striations between the lamellae; anterior parts of shell with an irregular, radial crumpled zone. Lunule very small, triangular, asymmetric with larger part in RV.Umbones low. Ligament sunk into long deep groove; posterior dorsal area marked by elevated lamellae along the escutcheon. Hinge large, straight, RV with single, small, cardinal tooth, no posterior lateral, anterior lateral with small knob and low ridge. LV with two cardinal teeth the anterior larger and bifid, posterior lateral absent, anterior lateral a low ridge and knob. Anterior adductor muscle scar long, dorsal part extending onto the hinge line and anterior dorsal area above the lateral teeth; ventral part broader, closely parallel to the pallial line, detached for 2/3 of length. Posterior muscle scar oval. Pallial line broad and prominent. Shell interior dull white with numerous mantle attachment scars, impression of pallial blood vessel prominent.Shell outside pallial line shell glossy, margin finely dentate.

REMARKS

This is the first record of this species outside of the central IWP area of Indonesia and Philippines. The type shells of L. sulcata and L. argentea are similar to the Deshayes holotype.