Turricostellaria amphissa, Simone & Cunha, 2012

Simone, Luiz Ricardo L. & Cunha, Carlo M., 2012, Taxonomic study on the molluscs collected in Marion-Dufresne expedition (MD 55) to SE Brazil: Xenophoridae, Cypraeoidea, mitriforms and Terebridae (Caenogastropoda), Zoosystema 34 (4), pp. 745-781 : 758-759

Turricostellaria amphissa n. sp.

( Fig. 5 A-D)

TYPE MATERIAL. — Holotype: Brazil, Espírito Santo, off Itaúnas, continental slope of Abrolhos, 18°59’S, 37°50’W, 295 m depth, MNHN 25230 ( Fig.5A ) ( MD 55, stn DC 75, Bouchet, Leal & Métivier coll., 27. V.1987). Paratypes: same data as holotype, MNHN 25231, 2 shells ( Fig. 5B, C ), MZSP 102691, 2 shells ( Fig. 5D ).

TYPE LOCALITY. — Brazil, Espírito Santo, off Itaúnas, continental slope of Abrolhos, 18°59’S, 37°50’W, 295 m depth ( MD 55, stn DC 75).

DISTRIBUTION. — Known only from type locality.

ETYMOLOGY. — The specific epithet refers to the similarity of the species in fashion and size with columbellid genus Amphissa H. & A. Adams, 1853.

DIAGNOSIS. — Shell up to 5 mm, wide (width c. half length). Sculpture axial, strong; shoulder narrow. Protoconch wide, paucispiral.

DESCRIPTION

Shell: size up to 5 mm, outline oval; width c. 48% of length. Colour pure white, translucent. Protoconch mammillate, comprising c. 15% of shell length and c. 35% of shell width; c. 1.5 rounded, smooth, glossy whorls; suture plane ( Fig. 5B, C ); transition with teleoconch unclear. Spire c. 50% of shell length, spire angle c. 40°. Teleoconch up to three glossy whorls; each whorl with narrow shoulder, remaining weakly convex. Sculpture of strong axial threads, slightly arched, from suture (shoulder) to suture; c. 12 in penultimate whorl; interspaces of axial threads roundly concave, with c. double threads width. Ventral region of body whorl with inferior ⅓ lacking spiral threads ( Fig. 5A, D ), with axial threads disappearing gradually. Aperture elliptic, weakly oblique; comprising c. 50% of shell length and c. 40% of shell width. Outer lip simple, rounded, lacking folds. Inner lip slightly concave, lacking callus; four oblique folds uniformly distributed in middle region, comprising c. 60% of inner lip area; upper and inferior folds smaller than second and third folds ( Fig. 5A, D ). Canal narrow, somewhat pointed, slightly projected forwards. No umbilicus.

MEASUREMENTS (in mm). — Holotype: 4.6 × 2.1; paratype MNHN 25231 : 4.4 × 2.2; paratype MZSP 102691 : 3.6 × 1.6.

HABITAT. — Sandy-mud bottoms, 295 m depth.

Figures

FIG. 5. — Costellariids: A, Turricostellaria amphissa n. sp., holotype MNHN 25230, apertural view (L 4.6 mm); B, paratype MNHN 25231 (1), detail of apex, apertural view; C, same, dorsal view; D, paratype MZSP 102691 (1), apertural view (L 3.8 mm); E, Vexillum sp., MNHN (stn DC73), apertural view; F, dorsal view (L 8.4 mm); G, Turricostellaria jukyry n. sp., holotype MNHN 25232, dorsal view (L 12.3 mm); H, same, apertural view; I, same, detail of apical region in profile; J, same, detail of aperture, apertural-slightly right view; K, paratype MZSP 102858,apertural view (L 7.8 mm);L, Turricostellaria apyrahi n.sp.,paratype MNHN 25238,apertural view (L 17.9 mm); M, same, dorsal view; N, same, detail of apex in profile; O, paratype MZSP 102862, apertural view (L 15.9 mm); P, holotype MNHN 25234, detail of inner lip, apertural-slightly right view; Q, same,apertural view (L 23.7 mm); R, same, right view. Scale bar: C, 0.5 mm.