Pseudosimnia lacrima, 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 : 752-754

Pseudosimnia lacrima n. sp.

( Fig. 3 M-O)

TYPE MATERIAL. — Holotype: Brazil, Espírito Santo, off Itaúnas, continental slope of Abrolhos, 18°59’S, 37°48’W, 607-620 m depth, MNHN 25217 ( Fig. 3 M-O) ( MD 55, stn DC 73, Bouchet, Leal & Métivier coll., 27. V.1987). Paratype: off Regência, 19°40’S, 37°48’W, 790-940 m depth, MZSP 104319, 1 shell (stn CB 77).

TYPE LOCALITY. — Brazil, Espírito Santo, off Itaúnas, continental slope of Abrolhos, 18°59’S, 37°48’W, 607- 620 m depth ( MD 55, stn DC 73).

DISTRIBUTION. — Only known from the type locality.

ETYMOLOGY. — The specific epithet is derived from the Latin “lacrima”, meaning tear, an allusion to the general form of the shell.

DIAGNOSIS. — Shell length c. 7 mm, strongly biconic; width c. 60% of length. Periphery very thick, forming callus. Inner lip with c. 13 well-spaced teeth, protruded mostly inside.

DESCRIPTION

Shell: outline biconic, thick, strongly involute; length 7.5 mm. Colour pure white, weakly glossy. Width c. 60% of length; wider region located between 3�5 and 4�5 of shell length ( Fig. 3M, O ). Height c. 80% of width. Superior angulation c. 80°; inferior angulation c. 60°; left side more weakly rounded than right side. Periphery marked by strong callus, comprising c. ⅓ of shell height ( Fig. 3N ). Aperture narrow, comprising c. 80% of shell length and c. 12% of shell width; uniform width along its length, weakly arched, somewhat parallel to left shell edge. Outer lip thick, with c. 32% of shell width, thicker in middle, gradually narrowing towards both canals; c. 13 small, rounded teeth more protruded inside ( Fig. 3O ), with weak radial fold in inner region of ventral surface, corresponding to each tooth; teeth uniformly sized from each other, and with interval equivalent to each tooth; teeth slightly closer with each other anteriorly. Inner lip simple, lacking teeth; weak callus at base of anal siphon, somewhat protruded ventrally ( Fig. 3N ). Canals with thick edges; anal canal weakly more pointed than incurrent canal ( Fig. 3O ).

MEASUREMENTS (in mm). — Holotype: 7.5 × 4.8.

HABITAT. — Sandy-mud bottoms, 607-940 m depth.

REMARKS

Pseudosimnia lacrima n. sp. is somewhat similar in shape to Primovula concinna (Adams & Reeve, 1848) from eastern Africa ( Cate 1973), but differs in lacking developed transverse striae, by a wider shell region in the middle (instead of upper third), a wider aperture and teeth protruding inside the aperture. It differs from Pseudosimnia carnea (Poiret, 1789) , from the Mediterranean, in having thicker walls, fewer labial teeth and a more rounded siphonal canal. It differs from P. perilla Cate, 1973 in being wider and shorter, in having fewer teeth in the outer lip, and by possessing a closed anterior canal. In the same region, only two deep-water ovulids occur, P. vanhyningi (Smith, 1940) and Spiculata bijuri Cate, 1976 ( Simone 2007) ; P. lacrima n. sp. differs from the former in being much smaller, in having wider anterior and posterior ends, and by having canals broader and less protruded; from the latter P. lacrima n. sp. differs in being shorter, in having much blunter anterior and posterior ends, thicker walls, callus less protruded and the teeth in inner lip.

Family TRIVIIDAE Troschel, 1863

Figures

FIG. 3. — Cypraeoideans: A, Erosaria acicularis (Gmelin, 1791), MNHN (1), apertural view (L 23.1 mm); B, same, dorsal view; C, Luria cinerea (Gmelin, 1791), MNHN, stn DC73 (1), apertural view (L 17.0 mm); D, same, dorsal view; E, stn DC75 (1), young specimen, apertural view (L 7.4 mm); F, same, dorsal view; G; Lamellaria sp., MNHN (stn DC73), apertural view (L 3.7 mm); H, same, dorsal view; I, Pedicularia tibia Simone, 2005, MNHN (stn DC73), apertural view (L 3.8 mm); J, same, left view; K, same, right view; L, same, dorsal view; M, Pseudosimnia lacrima n. sp., holotype MNHN 25217, dorsal view (L 7.5 mm); N, same, right view; O, same, apertural view; P, Cleotrivia antillarum (Schilder, 1922), MNHN (stn DC73), apertural view (L 4.5 mm); Q, same, right view; R, same, dorsal view; S, same, MZSP 104031, apertural view (L 4.1 mm); T, same, dorsal view.