Anodontia (Loripinus) senegalensis Cosel 2005

Anodontia (Loripinus) senegalensis Cosel in Taylor & Glover, 2005

(Figs 21C, D; 22)

Anodontia (Loripinus) senegalensis Cosel in Taylor & Glover, 2005: 326, figs 11B, 12B, 42F-I, 43.

TYPE MATERIAL. — Holotype: Senegal, S of Gorée, 110-112 m, lv., dredged RV Gérard Tréca, leg I. Marche-Marchad, 18.II.1954 (MNHN).

Paratypes: Dakar region, 14°50.2’N, 17°29.5’W, 150 m, dredged RV Tenace, 15.III.1967, leg. I. Marche-Marchad, 2 rv. (MNHN); 1 lv. (BMNH 20040238).

TYPE LOCALITY. — Dakar, Senegal.

MATERIAL EXAMINED. — Mauritania. Off Cap Blanc, 20°34’N, 17°47’W, 90 m, trawled RV Président Théodore Tissier, 1936, 2 rv., 6 lv. (MNHN).

Senegal. Dakar region, 14°53.8’N, 17°30.8’W, 205-230 m, dredged RV Gérard Tréca, 18.III.1958, leg I. Marche-Marchad, 4 rv., 3 lv. (MNHN). — S of Gorée, 65 m, dredged RV Gérard Tréca, 18.II.1954, leg I. Marche-Marchad, 1 rv. (MNHN). — Baie de Gorée, 125-160 m, dredged RV Gérard Tréca, 14.II.1958, leg. I. Marche-Marchad, 1 juv. lv. (MNHN). — Dakar region (no precision), 129-150 m, dredged RV GérardTréca, 24.I.1958, leg. I. Marche-Marchad, 1 rv. (MNHN). — Dakar region (without any precision), leg. I. Marche-Marchad, 1 chipped rv. (MNHN).

DISTRIBUTION. — Off Mauritania (20°30’N) and Senegal.

DESCRIPTION

Shell to 37 mm long, thin but solid, equivalve, inequilateral, very inflated, variable in outline, subcircular, somewhat longer than high, length/height ratio 1.1-1.2. Umbones prominent, well protruding over the dorsal margin, directed forward, beaks in front of the vertical midline. Anterior part short, anterior margin with a broadly rounded antero-dorsal corner, towards ventrally convex. Ventral margin well rounded and evenly convex. Posterior part broad, posterior margin well rounded, postero-dorsal corner indistinct, no postero-ventral corner.

Exterior without regular sculpture and only with fine, irregular growth lines and coarser growth stages. A few very shallow and almost indistinct radial waves may be visible on large specimens, especially under a lens at certain angle of view. Anterior and posterior angle absent. Lunule very small and short, rather narrow, almost symmetric, not sunken; escutcheon absent.

Ligament moderately long, not sunken, on a narrow nymph, which is slanting towards the interior of the valves; therefore ligament and hinge plate appearing still narrower at a horizontal view of the valve inside, full width of the ligament only visible from ventrally.

Hinge plate very narrow and toothless. Anterior adductor scar with a short and rather broad diverging part, the pallial line meeting the scar above its middle, occasionally at almost one third the length of the scar. Posterior adductor scar very small. Anterior, ventral and posterior margin on the inner side almost smooth, occasionally the vestiges of inner crenulations are visible.

Valves white, periostracum not observed.

Measurements are provided in Table 11.

BIOTOPE

Most probably muddy bottom, on the deeper shelf between about 60 and 230 m.

REMARKS

This species is distinguished from Anodontia chevalieri by the smaller size, the shorter and broader diverging part of the anterior adductor scar and the narrower and shallower ligament, which is less slanting towards the interior of the valves. The inner margin is smooth (see also Taylor & Glover 2005).