Triphoris triliratus Deshayes, 1863

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 : 27

Triphoris triliratus Deshayes, 1863

( Fig. 11 )

Triphoris triliratus Deshayes, 1863: 102 , pl. 11, figs 27, 28.

TYPE LOCALITY. — La Réunion.

TYPE MATERIAL. — Syntypes (but see Remarks). Reunion Island • MNHN-IM-2000-1576; 1 specimen; from type locality • MNHN-IM-2000-1577; 3 specimens; from type locality • MNHN-IM-2000-1578; 1 specimen; from type locality.

ADDITIONAL MATERIAL. — ReunionIsland • MNHN-IM-2012-36197; 1 specimen; La Réunion (coll. M. Jay) .

ORIGINAL DESCRIPTION. — T. testa elongato-turrita , omnino castaneofusca, apice acuminata; anfractibus tredecimis, transversim aequaliter triliratis, liris simplicibus, interstitiis minutissime punctulatis, ultimo anfractu brevi, ad peripheriam angulato, basi plano; apertura minima , subquadrata, canali brevi terminata.

[Latin diagnosis followed by a discussion in French]

TRANSLATION OF THE LATIN TEXT. — Elongated and turreted shell, completely dark brown, acute apex; thirteen whorls, with three equal and simple spiral rows, the interspaces bear very small cavities, short last whorl, angulated at the periphery, flattened at the base; small squarish aperture, ending with a short siphon.

DIAGNOSIS. — Shell cyrtoconoid with flat sides. Syntypes 3.2- 5.0 mm high. Teleoconch of 8-10 whorls. Three spiral cords present, the second appearing on the second whorl. First and third cords smooth, the second developing flat tubercles. Microsculpture of numerous fine spiral threads in spiral interspaces. Peristome with an additional cord below the second cord. Posterior sinus shallow. Base with two additional smooth spiral cords. Protoconch missing in the syntypes. Teleoconch whorls with brown flammulae on a white background. The first thread is darker. Protoconch brown.

REMARKS. — The specimens marked as syntypes belong to different species. Lot MNHN-IM-2000-1576 ( Fig. 11 B-I) contains the specimen best matching the original description and figure but lacks the uniform brown colour cited in the original description (“ omnino castaneofusca ”). Lot MNHN-IM-2000-1577 contains three specimens belonging to two species different from T. triliratus : two are fragments that have the second spiral cord just as a fine thread ( Fig. 11K, L ), the third is probably a Viriolopsis B. A. Marshall, 1983 ( Fig. 11M ). Lot MNHN-IM-2000-1578 contains a damaged specimen which is probably T. intergranosa Hervier, 1898 ( Fig. 11N ). This situation would require the designation of a lectotype. However, we still do not know the intraspecific variability of this species-group and thus if the syntype MNHN-IM-2000-1576 can really belong to T. triliratus as described. Therefore, we prefer to avoid any designation until the group is better understood.

Figures

FIG. 11. — Triphoris triliratus Deshayes,1863, La Réunion: A, original figure in Deshayes (1863); B-I, syntype, MNHN-IM-2000-1576; front (B, C), side (D, E), back (F), peristome (G, H), teleoconch microsculpture (I); J, original label lots MNHN-IM-2000-1576 to 1578;K, L, Viriola sp., MNHN-IM-2000-1577, La Réunion;M, Viriolopsis (?) sp.MNHN-IM-2000-1577, La Réunion;N, Viriola integranosa Hervier,1898,MNHN-IM-2000-1578, La Réunion;O, original label MNHN-IM-2000-1576; P, original label MNHN-IM-2000-1577; Q, original label MNHN-IM-2000-1578. Scale bars: B-F, M, 0.5 mm; G-I, K, 0.4 mm; L, N, 1 mm.