Obesula borbonica Jousseaume, 1898

Albano, Paolo G., Franco, Davide Di, Azzarone, Michele, J., Piet A., Bakker & Sabelli, Bruno, 2023, Review of the types of Indo-Pacific Triphoridae (Mollusca, Gastropoda) in the Muséum national d’Histoire naturelle, Paris, Zoosystema 45 (2), pp. 13-106 : 66

Obesula borbonica Jousseaume, 1898

( Fig. 40 )

Obesula borbonica Jousseaume, 1898: 75 , not illustrated.

ORIGINAL LOCALITIES. — Red Sea, La Réunion.

TYPE MATERIAL. — Syntypes. La Réunion • MNHN-IM-2000-0728; 2 specimens.

ORIGINAL DESCRIPTION. — Testa solida, ovata, ventricosa, apice acuminata, nigro et albo sparsim marmorata; anfr. 13, primi 4 fulvi, sequentes 2 albi, alteri nigricantes, seriebus tuberculorum duobus ornati, tuberculi, aequalis opposita nitentes, series antica saepe albida, postica fulvonigra, sutura profunda canaliculata separati, anticus attenuatus, costis granulosis 5 ad peristomum 6 rugatus; apertura navicularis, lateraliter fissa; canalis brevis, recurvus. Long. 3mm; diam. 1mm 3.

[Latin diagnosis followed by a discussion in French]

TRANSLATION OF THE LATIN TEXT. — Solid shell, ovate, broad, with an acute apex, marbled with brown and white; 13 whorls separated by a deep canaliculated suture, first four whorls are brown, subsequent two are white, the other whorls are blackish, adorned by two series of equal and bright tubercles, the anterior series is often white, the posterior one is brown-blackish, the anterior (last) whorl is attenuated and characterised by five granulated spiral cords which become six near the aperture; boat-shaped aperture, laterally fissured; short siphon, curved. Length 3 mm; diameter 1.3 mm.

DIAGNOSIS. — Shell pupoid. Syntypes 1.9 and 2.9 mm high. Teleoconch of 6.5 whorls. Two spiral cords present, the first more prominent. Spiral cords with tubercles at the intersections with rather orthocline axial ribs. Spiral microsculpture of weakly granulate fine threads in the interspaces between the spiral cords. Peristome with an additional cord below the first spiral cord. Base with three additional cords of which the first tubercled and the other two smooth. Protoconch almost missing in the syntypes but most likely multispiral; the visible last whorl with two keels and axial riblets. First two teleoconch whorls white, others with pearly tubercles on a brown background. Protoconch brown.

Figures

FIG. 40. — Obesula borbonica Jousseaume, 1898, La Réunion: A-I, syntype 1, MNHN-IM-0728; front (A, B), side (C, D), back (E), apex (F, G), peristome (H), microsculpture (I); L, syntype 2, MNHN-IM-2000-0728, front; M-O, original labels. Scale bars: A-E, H, L, 0.5 mm; I, 0.2 mm; F, G, 0.1 mm.