Cranopsis alaris, 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 : 448-449

Cranopsis alaris new species

Figures 66–75

Types. Holotype MNHN 25305. Paratypes: MNHN 25306, 3 shells, MZSP 105512, 2 shells; all from type locality. Espírito Santo, continental slope of Abrolhos (MD55; Bouchet, Leal & Métivier col.); off Conceição da Barra, 19°08’S 37°34’W, 3450 m, MNHN 25307, 1 young shell (sta. DS66, 25 /v/1987). Rio de Janeiro; off Arraial do Cabo, continental slope, 23°41’S 42°06’W, 430–450 m, MNHN 25308, 1 shell (sta. CB104, 01 /vi/1987).

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

Diagnosis. Apex curved dorsally, performing wide arc, located in dorsal half. Height ca. 85% of length; width ca. 70% of length. Sculpted by ca. 48 radial cords, with transverse folds, interspaces minute. Foramen flanked by tall edges; located dorsally.

Description. Shell size ca. 3.5 mm; tall, bluntly conical, widely curved; height ca. 85% of length. Pure white. Protoconch of 1.5 rounded whorls (Figs 67, 71–73); situated on right; smooth, glossy; ca. 200 µm (Fig. 72). Foramen cuneiform (pointed anteriorly), width ca. 30% of length; located dorsally, preceding anterior slope; ca. 10% of shell width and ca. 20% of shell length; edges irregular (Figs 66, 70, 74), elevated ca. 10% total shell height, with distinct rounded profile (Figs 67, 68, 71, 73). Groove anterior to fissure narrow; flanked by cords of similar size as neighbor cords; length ca. 70% of shell height. Shell profile high, rounded, beak curved dorsally, forming wide arc (almost scalariform), located posteriorly, exceeding posterior end of aperture by ca. 15% of shell length (in dorsal view) (Figs 66, 70), dorsal to middle shell height; teleoconch of 1.25 whorls, total angle ca. 50° (Figs 67, 68, 71, 73). Sculpture of 48 broad primary radial cords (Figs 66–68, 70–71, 73–74), with wide folds, with longer axis parallel to aperture; cords gradually increasing in width towards aperture, width of cords ca. 5% of apertural length; in ventral third 4–5 intermediary cords gradually appearing (Figs 67, 68, 71, 73); each fold slightly elevated, pustule-like, ca. 4 times longer than wide, separated from neighbor folds in line by space ca. 1/4 of its width; interspaces ca. 1/10 cords width; ca. 60 pustules along cords close to median line. Selenizone short, shallow, narrower than foramen; edges simple, low; lunules dense (Figs 66, 70, 74). Aperture planar (Fig. 71, 73) to slightly convex (Figs 67–68), outline elliptical, width 71% of length; edges slightly denticulated by radial sculpture. Inner surface smooth, glossy (Figs 69, 75). Septum ca. 60% shell height; ca. 3 times higher than wide; ventral edge slightly concave, ca. 35% of aperture width; gradually narrowing up to posterior edge of fissure (Figs 69, 75).

Measurements (in mm). Holotype: 3.3 by 2.3; Paratype MZSP 105512 #1: 2.7 by 2.1 (Figs 70–71).

Distribution. Continental slope off Ceará to Rio de Janeiro, Brazil.

Habitat. Sandy-mud bottoms, 250–450 m, with a single eroded young shell collected in 3450 m (dead specimens).

Material examined. Types.

Etymology. The specific epithet is derived from the Latin, alaris , alarius, meaning bearing wings; an allusion to projected edges of the fissure of the shell.