Cranopsis enigmatica, 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 : 444-445

Cranopsis enigmatica new species

Figures 42–47

Types. Holotype MNHN 25297 (Figs 42–44). Paratypes: MNHN 25298, 1 shell, MZSP 102941, 1 shell (Figs 45–47); all from type locality.

Type localit y. Brazil. Espírito Santo; off Regência, continental slope of Abrolhos, 19°40’S 37°48’W, 790–940 m (MD55, sta. CB77; Bouchet, Leal & Métivier col, 27/v/1987).

Diagnosis. Apex curved backwards, located in dorsal region in profile. Height ca. 80% of length; width 74% of length. Sculptured by ca. 50 radial cords, with triangular pustules. Foramen flanked by elevated, projected edges; located totally turned towards dorsal.

Description. Shell size approximately 2.8 mm; slender, bluntly conical; height ca. 80% of length. White, translucent. Protoconch of one rounded whorl (Fig. 43); situated on right, smooth, glossy; diameter ca. 110 µm. Foramen elliptical (slightly tapering anteriorly), width 27% of length; located dorsally, preceding anterior slope; width of foramen 9% of shell width; length of foramen 26% of shell length; edges irregular (Figs 42, 46). Groove anterior to foramen very narrow; flanked by pair of cords twice as wide as neighboring radial primary cords (Fig. 42). Beak curved ventrally, located preceding posterior 1/5 of shell length (in dorsal view); teleoconch of 1.3 whorls, overall angle ca. 65° (Figs 43, 45). Sculpture of ca. 50 narrow radial cords (Figs 42, 43, 45–47), composed of aligned, small, narrowly triangular pustules (Fig. 47); primary cords gradually increasing in size, being stronger close to aperture; secondary cords gradually appearing in adapertural half, being slightly narrower, lower; pustules slightly elevated, triangular, with base wider, scale-like, narrowly touching neighbor pustules in line; interspaces between cords ca. 1.5 times their width; ca. 45 pustules along median threads. Selenizone well-marked, narrower than foramen; edges slightly higher than radial cords, continuation from those of foramen, with sharp edges; lunules well-spaced (Fig. 46). Aperture planar (Figs 43, 45), outline elliptical, width 74% of length; edges simple. Inner surface smooth, glossy (Fig. 44). Septum ca. 60% of shell height; twice as high as wide; ventral edge straight, 48% of aperture width; gradually narrowing to posterior edge of fissure.

Measurements. Holotype 2.8 by 2.0 mm; Paratype MZSP 102941 (SEM) 2.3 by 1.6 mm.

Distribution. Known only from type locality.

Habitat. Sandy mud bottoms, 790–940 m (dead specimens).

Material examined. Types.

Etymology. The specific epithet is derived from the Greek word aenigma, meaning enigmatic, something obscure; an allusion to the similarity of the species with other congeners, being its differentiation an enigma.