Mastonia tricolor Jousseaume, 1884

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 : 99

Mastonia tricolor Jousseaume, 1884

( Fig. 67 )

Mastonia tricolor Jousseaume, 1884: 258 , pl. 4, fig. 13.

TYPE LOCALITY. — New Caledonia.

TYPE MATERIAL. — Syntype. New Caledonia • MNHN-IM-2000-1397; 1 specimen; from type locality.

ORIGINAL DESCRIPTION. — Testa elongato-turrita, solida, nitidiuscula, flavescente ac zonula alba alteraque atro-rufescente cincta; anfractibus 14-15 planiusculis, sat regulariter crescentibus (primi rufuli, laevigati, caeteri tuberculis triseriatim dispositis, cincti; tuberculorum series prima alba, secunda et tertia aequales, luteae), sutura sat profunda, discretis; ultimo costis quinque moniliformibus, ornato; apertura subovali, lateraliter fissa, canali, nigro, brevi, recurvo, superne unicostato, armata. — Long. 6, lat. l.5 millim.

[Latin diagnosis followed by a discussion in French]

TRANSLATION OF THE LATIN TEXT. — Turreted-elongated shell, solid, slightly bright, yellow on one side of the white bands and dark red on the other side; from 14 to 15 slightly flattened whorls, quite regularly growing (first whorls are reddish, smooth and with three series of tubercles; the first series of tubercles is white, the second and third series are equal, yellow), separated by a quite deep suture; last whorl adorned by five tubercled spiral cords; subovate aperture, laterally fissured, with a short, brown, curved siphon which bears a single rib above. — Length 6, diameter 1.5 mm.

DIAGNOSIS. — Shell conical with flat sides. Syntype 6.0 mm high. Teleoconch of c. 11 whorls. Three spiral cords present, the second appearing on the ninth whorl. A fourth suprasutural cord visible. First and third cords with tubercles at the intersection with rather prosocline axial ribs. Second cord initially as a fine thread, but later developing thin tubercles. Peristome with additional cords below the second and third spiral cords. Base with three additional tubercled spiral cords. Teleoconch yellowish with the first spiral cord white and brown suprasutural cord. Siphonal canal brown.

REMARK. — The original description suggests the existence of other syntypes (e.g. in the Museum of Bordeaux) whose presence and status we have not ascertained.

Figures

FIG. 67. — Mastonia tricolor Jousseaume, 1884, New Caledonia: A, original figure in Jousseaume (1884); B-K, syntype, MNHN-IM-2000-1397; front (B, C), side (D, E), back (F), apex (G, H), microsculpture (I), peristome (J, K); L, M, original labels. Scale bars: B-F, 1 mm; G, H, 0.1 mm; I, 0.2 mm; J, K, 0.4 mm.