Cornisepta aninga, Simone, Luiz Ricardo L. & Cunha, Carlo M., 2014

Simone, Luiz Ricardo L. & Cunha, Carlo M., 2014, Taxonomical study on the mollusks collected in Marion-Dufresne (MD 55) and other expeditions to SE Brazil: the Fissurellidae (Mollusca, Vetigastropoda), Zootaxa 3835 (4), pp. 437-468 : 441-442

Cornisepta aninga new species

Figures 17–27

Types. Holotype MNHN 25287. Paratypes: MNHN 25288, 32 shells, MZSP 102942, 10 shells, MNRJ 25962, 5 shells, all from type locality. Brazil. Espírito Santo; continental slope of Abrolhos (MD55; Bouchet, Leal & Métivier col., 27/v/1987); off Regência, 19°40’S 37°48’W, 790–940 m, MNHN 25289, 1 shell (sta. CB77); off Itaúnas, 19°00’S 37°49’W, 950–1050 m, MNHN 25290, 1 shell (sta. DC72), 18°59’S 37°48’W, 607–620 m, MNHN 25291, 1 shell (sta. DC73).

Type locality. Brazil. Espírito Santo; continental slope of Abrolhos, off Itaúnas, 18°59’S 37°50’W, 295 m (MD55 sta. DC75; Bouchet, Leal & Métivier col., 27/v/1987).

Diagnosis. Shell slightly curved posteriorly. Height 90–93% of length. Sculptured by pustules aligned in chevrons in lateral view, ca. 30 pustules per row (close to aperture).

Description. Shell size ca. 3.0 mm; highly conical, slightly arched posteriorly ( Figs 19, 20, 23–25, 27 ); height 90–93% of length. White, translucent. Protoconch not present. Foramen terminal, apical, almost circular, width ca. 90% of length; turned towards dorsal; ca. 1.5% of aperture area; edges rather irregular ( Figs 21, 23, 26 ). Shell broadens gradually towards aperture, aperture elliptical; apical angle ca. 40°, total shell angle ca. 40°. Outer sculpture consists of small pustules (Figs 17, 19–21, 23–24, 26–27), arranged in chevrons (concavity ventral), angle of ca. 25° in relation to vertical axis; this pattern somewhat more regular towards apex, pustules increasing in number with growth; each pustule volcano-shaped, surrounded by smooth area as wide as pustule in row of each chevron ( Fig. 26 ), up to 10 times as wide between rows of chevrons (Fig. 17); intersection of anterior and posterior halves of chevrons, in lateral surface, sometimes intercalated. Aperture planar ( Figs 19–20, 27 ), sometimes slightly concave ( Figs 23–25 ), elliptical, width 72% of length; edges somewhat irregular. Inner surface smooth, glossy (Figs 18, 22). Septum ca. 60% of shell height; 3 times higher than wide, ventral edge slightly concave, ca. 60% of aperture width; gradually narrowing up to posterior edge of foramen.

Measurements. Holotype: 3.2 by 2.8; paratypes MZSP 102942, #1: 2.8 by 2.2 (Figs 17–18); #2: 3.0 by 2.5, #3: 2.8 by 2.5.

Distribution. Continental slope off Espírito Santo, Brazil.

Habitat. Sandy mud bottoms, 295–1050 m (dead specimens).

Material examined. Types.

Etymology. The specific epithet is derived from the Tupy native language aninga , meaning bristle hair, an allusion to the outer surface of the shell resembling gooseflesh. Noun in apposition.

Figures

FIGURES 19 – 27: Cornisepta aninga n. sp. types. Fig. 19: holotype MNHN 25287, right view (L 3.2 mm). Fig. 20: same, left view. Fig. 21: same, dorsal view. Fig. 22: same, ventral view. Fig. 23: paratype MNHN 25288 # 1, young specimen left view (L 2.7 mm). Fig. 24: same station, # 2, young specimen (L 2.4 mm). Fig. 25: same station, # 3, very young specimen, right view (L 1.5 mm). Fig. 26: paratype MZSP 102942, SEM, dorsal-slightly left view (L 2.1 mm). Fig. 27: same, right view. FIGURES 28 – 30: Cranopsis hycavis n. sp. holotype MNHN 25292 (L 1.9 mm). Fig. 28: dorsal view. Fig. 29: right view. Fig. 30: ventral view. FIGURES 31 – 36: Cranopsis nymphalis n. sp. holotype MNHH 25293 (L 7.2 mm). Fig. 31: detail of anterior region, dorsal view (lateral side = 4 mm). Fig. 32: whole dorsal view. Fig. 33: right view. Fig. 34: ventral view. Fig. 35: detail of apex, right view (right side = 3 mm). Fig. 36: same left view (left side = 1 mm).