Obesula pantherina 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 : 86-90

Obesula pantherina Jousseaume, 1898

( Fig. 59 )

Obesula pantherina Jousseaume, 1898: 76 , not illustrated.

TYPE LOCALITY. — Djibouti.

ADDITIONAL ORIGINAL LOCALITIES. — Aden, Perim Island (Bab al-Mandab Strait, Yemen).

TYPE MATERIAL. — Lectotype. Djibouti • MNHN-IM-2000-29266; here designated.

Paralectotypes. Djibouti • MNHN-IM-2000-1596; 2 paralectotypes; Djibouti .

Yemen • Mastonia maenades Jousseaume, 1898 ; MNHN-IM-2000-1597; 3 paralectotypes; Perim Island , Bab al-Mandab Strait .

ORIGINAL DESCRIPTION. — Testa parva , solida, ovata, ventricosa, apice attenuata, acuminata, alba maculis ferrugineis aut fulvo-nigris irregulariter tincta; anfr. circiter 12 seriebus tuberculorum duobus ornati, intertitiones cancellatae, sutura profunda, distinctissima separati, ultimus antice attenuatus costis, quatuor moniliformibus rugatus; apertura pyriformis, lateraliter fissa, canalis brevis. Long. 2mm 2; diam. 1mm. [Latin diagnosis followed by a discussion in French]

TRANSLATION OF THE LATIN TEXT. — Small shell, solid, ovate, broad, slender apex, acute, irregularly coloured with white, rustcoloured or dark brown spots; about 12 whorls adorned by two series of tubercles, with cancellate interspaces, separated by a deep and very distinct suture, anteriorly reduced last whorl with four tubercled spiral cords; pyriform aperture, laterally fissured, short siphon. Length 2.2 mm; diameter 1 mm.

DIAGNOSIS. — Shell cyrtoconoid. Lectotype 2.4 mm high.Teleoconch of 6.5 whorls. Three spiral cords present, the second appearing on the sixth whorl. First and third cords with tubercles at the intersection with rather prosocline axial ribs. Second cord initially as a fine thread, but later developing tubercles. Base with three additional tubercled spiral cords. Second spiral cord on the base smaller. Multispiral protoconch of 5 whorls with two spiral keels and equally strong axial riblets. Nucleus eroded in the lectotype but apparently with a reticulated sculpture. First teleoconch whorl white, the following ones white with orange-brown blotches. Base brown. Protoconch most likely light brown but faded in the lectotype.

REMARKS. — The type series contained two lots and two species. Obesula pantherina is characterized by its acuminate shape (“ acuminata ”), with four distinct tubercled spiral cords on the last whorl (“ quatuor moniliformibus rugatus ”). However, lot MNHN-IM-2000-1597 contained three shells of which only one in good condition ( Fig. 58 I-L), characterized by a more oval shape and only three distinct spiral cords on the last whorl. Additionally, this specimen has a spiral microsculpture and a colour pattern that readily distinguishes it from O. pantherina . To stabilize nomenclature, we here designate the lectotype of O. pantherina ( Fig. 58 A-H).

Figures

FIG. 59. — A-H, Obesula pantherina Jousseaume, 1898, lectotype, MNHN-IM-2000-29266, Djibouti: front (A, B), side (C, D), back (E), protoconch (F, G), microsculpture (H); I-L, Mastonia maenades Jousseaume, 1898, Perim Island, Bab al-Mandab Strait, Yemen, paralectotype, MNHN-IM-2000-1597; front (I, J), back (K), microsculpture (L); M, original label lot MNHN-IM-2000-29266. Scale bars: A-E, I-K, 0.5 mm; F-H, L, 0.1 mm.

FIG. 58. — Mastonia obesula Jousseaume, 1884, New Caledonia: A, original figure in Jousseaume (1884); B-H, J, K, M, lectotype, MNHN-IM-2000-29265: front (B, C), side (D, E), back (F), peristome (G, H), apex (J, K), microsculpture (M); I, Triphoridae indet., MNHN-IM-2000-1614; front; L, N, O, original labels. Scale bars: B-F, I, 0.5 mm; G, H, M, 0.2 mm; J, K, 0.1 mm.