Mastonia aegle 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 : 61

Mastonia aegle Jousseaume, 1884

( Fig. 36 )

Mastonia aegle Jousseaume, 1884: 256 , pl. 4, fig. 12.

ORIGINAL LOCALITIES. — New Caledonia, La Réunion.

TYPE MATERIAL. — Syntypes. New Caledonia • MNHN-IM-2000-738; 7 specimens • MNHN-IM-2000-740; 6 specimens • MNHN-IM-2000-1496; 2 specimens. La Réunion • MNHN-IM-2000-741; 1 specimen .

ORIGINAL DESCRIPTION. — Testa elongato-turrita, antice perparum tumida, solida, cinereo-flava, tuberculis nitentibus ornata; anfractibus 15, irregulariter (primi laevigati, sequentes tuberculis biseriatim dispositis ac suturam impressam obtegentibus, cincti) crescentibus; ultimo antice attenuato, costulis quinque moniliformibus, armato; apertura subquadrato-rotundata, lateraliter fissa; canali brevi, recurvo, superne oblique uni-costulato, munita. — Long. 4,5-6,5; lat. 1,6-1,1 millim. [Latin diagnosis followed by a discussion in French]

TRANSLATION OF THE LATIN TEXT. — Turreted-elongated shell, anteriorly slightly swollen, solid, ashen-brown, adorned by bright tubercles; 15 whorls, irregularly growing (first whorls smooth, subsequent ones characterised by two series of tubercles which cover the impressed suture); last whorl anteriorly attenuated and with five moniliform ribs; squarish-rounded aperture, laterally fissured; short siphon, curved, above and obliquely with one rib. — Length 4.5-6.5; diameter 1.6- 1.1 mm.

DIAGNOSIS. — Shell conical with flat sides. Illustrated syntypes 4.8 mm (MNHN-IM-2000-738) and 5.1 mm (MNHN-IM-2000-740) high. Teleoconch of 10.5-11 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 with additional cords below the second and third spiral cord. Base with three additional spiral cords of which the first developing thin tubercles and the other two smooth. Protoconch incomplete in the syntypes but of at least 3 whorls with one strong spiral keel and axial riblets. Teleoconch with whitish tubercles on a brown background. Protoconch brown.

Figures

FIG. 36. — Mastonia aegle Jousseaume, 1884, New Caledonia: A, original figure in Jousseaume (1884); B-K, syntype, MNHN-IM-2000-738: front (B, C), side (D, E), back (F), peristome (G, H), protoconch (I, J), microsculpture (K); L-N, original labels MNHN-IM-2000-738; O-Q, syntype, MNHN-IM-2000-740: front (O), side (P), back (Q); R, S, original labels MNHN-IM-2000-740. Scale bars: B-F, O-Q, 1 mm; G, H, 0.4 mm; I-K, 0.2 mm.