Mastonia funebris 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 : 72

Mastonia funebris Jousseaume, 1884

( Figs 46 ; 47 )

Mastonia funebris Jousseaume, 1884: 262 , pl. 4, fig. 15.

TYPE LOCALITY. — New Caledonia.

TYPE MATERIAL. — Lectotype. New Caledonia • MNHN-IM-2000-29261; here designated.

Paralectotypes. New Caledonia • MNHN-IM-2000-490; 6 specimens; from type locality • Triphoridae sp., MNHN-IM-2000-29262; 1 specimen .

ORIGINAL DESCRIPTION. — Testa elongato-turrita, solida, zonula nigra altera que alba cincta, antice perparum tumida; anfractibus 15 regulariter crescentibus (primi laevigati, albi, sequentes tuberculis biseriatim dispositis, ornati [tuberculorum series prima nigra, postica alba], sutura vix distincta discretis; ultimo costis moniliformibus quinque munito, quarum 4 nigris et altera alba; apertura subovata, dilatata, intus lineis albis et nigris picta, lateraliter fîssa, canali brevi, recurvo nigroque munita. — Long. 4-6, lat. 1.2-1.5 millim.

[Latin diagnosis followed by a discussion in French]

TRANSLATION OF THE LATIN TEXT. — Turreted-elongated shell, solid, characterised by white and brown small bands, anteriorly very little swollen; 15 regularly growing whorls (the first whorls are smooth, white, subsequent whorls are adorned by two series of tubercles [the first series of tubercles is brown, the following one is white], separated by a barely distinct suture; last whorl with five tubercled spiral cords, four cords are brown and the other one is white; subovate aperture, expanded, internally coloured with white and brown lines, laterally fissured, with a short, curved and brownish siphon. — Length 4-6, diameter 1.2-1.5 mm.

DIAGNOSIS. — Shell conical with flat sides. Syntype 3.7 mm high. Teleoconch of 10 whorls. Three spiral cords present, the second appearing on the eighth 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 thin tubercles. Spiral microsculpture of barely visible fine threads. Peristome without additional spiral cords. Posterior sinus shallow. Base with two additional spiral cords of which the first with tubercles, the second smooth. Multispiral protoconch of 4.5 whorls with two spiral keels and equally strong axial riblets. Nucleus with hemispheric granules. Teleoconch brown, with the first spiral cord white. Protoconch brown.

REMARKS. — Mastonia funebris is characterized by the colour pattern of a white first spiral cord on a brown background (“ le rang antérieur est d’un noir plus ou moins foncé, le postérieur d’un blanc de porcelaine ”). One specimen of the type series ( Fig. 47 ) does not fit this description as it has a brown background again, but with a slightly darker first spiral cord. Additionally, its protoconch bears a single spiral keel on its lower whorls, whereas M. funebris bears two. Therefore, to stabilize the nomenclature, we designate here the lectotype of M. funebris ( Fig. 46 ).

Figures

FIG. 46. — Mastonia funebris Jousseaume, 1884, New Caledonia: A, original figure in Jousseaume (1884); B-L, lectotype, MNHN-IM-2000-29261; front (B, C), side (D, E), back (F), protoconch (G, H), peristome (I, J), microsculpture (K), first protoconch whorl (L); M-R, original labels.Scale bars:B-F, 0.5 mm; G-J, 0.2 mm; K, 0.1 mm; L, 0.05 mm.

FIG. 47. — Triphoridae indet. (not Mastonia funebris Jousseaume, 1884), New Caledonia, MNHN-IM-2000-29262; front (A, B), side (C, D), back (E), protoconch (F, G), microsculpture (H), first protoconch whorl (I). Scale bars: A-E, 0.5 mm; F-H, 0.2 mm; I, 0.05 mm.