Clithon (Pictoneritina) barbei, Symonds, Malcolm Francis & Pacaud, Jean-Michel, 2010

Symonds, Malcolm Francis & Pacaud, Jean-Michel, 2010, New species of Neritidae (Neritimorpha) from the Ypresian and Bartonian of the Paris and Basse-Loire Basins, France, Zootaxa 2606, pp. 55-68 : 59-60

Clithon (Pictoneritina) barbei sp. nov.

( Fig. 3 a–c)

Type material. Holotype NHM PI TG 26448 (M. Symonds coll., Fig. 3 a–c). One paratype NHM PI TG 26449 (M. Symonds coll.), one paratype MNHN A33473 (Ledon coll.). All from type locality. Stratum typicum. Early Eocene, Ypresian (Sparnacian), “Sands of Pourcy”.

Locus typicus. Pourcy, Marne, France. 49˚09ˏ43˝ N 3˚54ˏ21˝ E.

Derivatio nominis. Named after Gérard Barbe of Champillon, Marne, France, a palaeontologist, who is familiar with the fossils of Pourcy, and who assisted the senior author with the collection of material from there, in which the types of this taxon were found.

Diagnosis. A small semiglobose Pictoneritina ; spire depressed, septum with poorly defined teeth, colour pattern of three dark spiral bands on light background.

Description. Shell small for subgenus, consisting of about 2.25 whorls, semiglobose with spire depressed. Protoconch small, approximately 0.2 mm wide, smooth, almost spherical. Teleoconch about 2.25 whorls, evenly convex, increasing rapidly in size; surface glossy, smooth. Suture sharp, well defined. Colour pattern of 3 dark spiral bands on light background, highest immediately below suture, varying in width but usually narrower than spaces between them. Aperture oblique, semicircular. Septum convex, smooth. Septum edge slightly concave in centre; teeth consist of one rather broad, rounded, indistinct tooth at about one third of distance from adapical end of septum, 1 to 3 denticulations abapical to it, also indistinct. Outer lip evenly rounded, thin, smooth within. Apertural tooth low, curved ridge below abapical end of septum.

Size. Holotype: height 3.2 mm, width 3.2 mm.

Remarks. Clithon (P.) barbei is similar in size and shape to Clithon (P.) nucleus Deshayes, 1825 from the Cuisian of Cuise-la-Motte, Oise, France, although in that species the spire is usually wholly or partially covered by the following whorl. The colour pattern in C. (P.) nucleus consists of dark, wavy, transverse lines on a light background, in some specimens the transverse lines are interrupted by two or three pale spiral bands, while C. (P.) barbei has a colour pattern of 3 dark spiral bands on a light background.

Range and distribution. Only known from type locality.

Figures

FIGURES 1 – 4. 1. Tomostoma angusta sp. nov., holotype, a. apertural, b. abapertural, c-d. side views. Length 5.2 mm, width 2.8 mm. Bartonian, Le Quoniam, Haravilliers, Val d’Oise, France. MNHN A 31487 (J-M Pacaud leg.). 2. Nerita gouetensis sp. nov., holotype, a. apertural, b. abapertural, c. apical views. Height 4 mm, width 4 mm. Bartonian, Bois- Gouët, Saffré, Loire-Atlantique, France. MNHN A 31489 (J-M Pacaud leg.). 3. Clithon barbei sp. nov., holotype, a. apertural, b. abapertural, c. apical views. Height 3.2 mm, width 3.2 mm. Ypresian, Pourcy, Marne, France. NHM PI TG 26448 (M. F. Symonds coll.). 4. Neritodryas guillioui sp. nov., holotype, a. apertural, b. abapertural, c. apical views. Height 15 mm, width 16 mm. Ypresian, Pourcy, Marne, France. MNHN A 31490 (Faullummel coll.).