Cranopsis cearensis, 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 : 445-446

Cranopsis cearensis new species

Figures 48–55

Types. Holotype MZSP 106894. Paratypes: MNHN 25299, 1 shell, MNRJ 30824, 2 shells, MZSP 93940, 18 fragmentary shells; MZSP 90280, 19 fragments, MZSP 100415, 2 shells, all from type locality.

Type locality. Brazil. Ceará, off Fortaleza, Canopus bank, 2°12’43”S 38°18’52”W, 250 m (Coltro col., viii/ 2005).

Diagnosis. Apex slightly high, located preceding posterior third. Height ca. 40% of length; width ca. 80% of length. Sculptured by ca. 60 rounded radial ribs, relatively narrow, profile rounded, extending beyond shell edges; bearing transverse low scales extending on relatively wide interspaces between ribs forming comarginal sculpture. Foramen slightly deviated to right, flanked by low edges; located more posteriorly, separated from anterior edge.

Description. Shell size up to 15 mm; low; height ca. 40% length. Pure white. Protoconch of one convex whorl; situated on right; smooth, glossy; 270 µm. Foramen cuneiform (pointed anteriorly), width 16% of length; located at about 25% of shell length posterior to anterior edge; width 4% of shell width, length 38% of shell length; edges irregular ( Figs 48, 50 ). Groove anterior to foramen narrow, flanked by pair of ribs as wide as radial ribs ( Figs 48, 50 ); shifted to right by ca. 10° relative to longitudinal axis of shell. Beak curved ventrally, between middle and dorsal thirds of shell height; located between middle and posterior thirds of shell length (in dorsal view) ( Figs 48, 52 ); teleoconch of one whorl; profile highly curved ventrally, as arc with center located in middle level of ventral surface, just on aperture level) ( Figs 49, 51 ). Sculpture regular, of ca. 60 narrow, rounded, radial ribs ( Figs 48, 49, 51, 52 ); about twice as tall as wide; lower secondary ribs between primary ribs, gradually increasing in width towards margin; interspaces between ribs as wide as ribs; transverse, semilunar, low scales arranged along ribs at regular intervals of 1/2–1/3 of ribs width; scales forming series of rectangular pits (ca. twice as wide as long); interspaces between successive scales with series of 10–12 striae in each pit, parallel to scales ( Figs 54, 55 ); ca. 40 scales along ribs close to median line. Selenizone as wide as foramen; edges slightly higher than radial ribs, with sharp edges; lunules regular distributed, well-spaced ( Figs 48–52 ). Aperture planar ( Fig. 49 ), outline elliptical, width ca. 80% of length; edges undulating due to radial sculpture ( Figs 50, 53 ). Inner surface smooth, glossy. Septum well-developed, 16% of shell height; 3 times longer than wide; ventral edge slightly concave, 19% of aperture width; forming concavity protecting posterior edge of foramen ( Figs 50, 53 ).

Measurements (in mm). Holotype: 13.0 by 5.2; MZSP 93940, #1: 6.2 by 2.8.

Distribution. Known only from type locality.

Habitat. Sandy bottoms with gravel, 250 m (dead specimens).

Material examined. Types.

Etymology. The specific epithet is derived from the locality where the species was collected, in the littoral off Ceará.

Figures

FIGURES 48 – 55: Cranopsis cearensis n. sp. types. Fig. 48: Holotype MZSP 106894, dorsal view (L 13.0 mm). Fig. 49: same, right view. Fig. 50: same, ventral view. Fig. 51: paratype MZSP 93940 in SEM, left view (L 6.2 mm). Fig. 52: same, dorsal view. Fig. 53: same station, other specimen, ventral view (L 9.3 mm). Fig. 54: detail of Fig. 51 in middle region, scale = 100 µm. Fig. 55: same, higher magnification, scale = 30 µm. FIGURES 56 – 60: Cranopsis apostrema n. sp. holotype MNHN 25300 (L 4.8 mm). Fig. 56: dorsal view. Fig. 57: right view. Fig. 58: ventral view. Fig. 59: left view. Fig. 60: detail of apical region, right view (right side = 2.5 mm).