Triphoris perlatus Issel, 1869

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 : 59

Triphoris perlatus Issel, 1869

( Fig. 35 )

Triphoris perlatus Issel, 1869: 152 , based on the illustration by Savigny 1817: Coquilles, pl. 4, fig. 4.

TYPE LOCALITY. — Red Sea.

TYPE MATERIAL. — Syntypes. Red Sea • MNHN-IM-2000-1582; 1 specimen; no locality • MSNG: 1 specimen; “spiagge emerse del Mar Rosso ” [raised Red Sea beaches] .

ORIGINAL DESCRIPTION. — Testa elongato-fusiformi, acuminata, nitida, albida; anfractibus 12-13 planis, angustis, lentissime crescentibus, duplice ordine margaritarum ornatis; ultimo anfractu brevi ad peripheriam subangulato, ad basim transversim costato; apertura ovato-angusta, obliqua, canali brevissimo terminata. — Altit. millim. 4-5; lat. 11/2-11/3.

[Latin diagnosis followed by a discussion in Italian]

TRANSLATION OF THE LATIN TEXT. — Elongated-fusiform shell, acute, bright, white; from 12 to 13 flat whorls, narrow, very slowly growing, adorned by a double series of granules; last whorl is short and slightly angled at the periphery, costulate at the base; oval and narrow aperture, oblique, ending with a very short siphon. — Length 4-5 mm; diameter 1 1/2-1 1/3

DIAGNOSIS. — MNHN syntype 4.7 mm high, but missing the apex. Shell cyrtoconoid with c. 9 (MNHN syntype) to c. 13 (Savigny’s figure) flat whorls, with two main spiral cords with tubercles at the intersection with slightly prosocline axial ribs and a third cord developing in between in the lower half of the shell, initially as a fine smooth cord and with well-developed tubercles only on the last whorl. Peristome missing in the MNHN syntype. Base with three, apparently tubercled, additional cords. MSNG specimen with multispiral protoconch. MNHN syntype generally whitishgreyish, but colour unreliable due to the state of the specimen; still an orange stripe is visible between the main cords, suggesting a dichromatic colour pattern.

REMARKS. — Issel’s original description is based on the specimen illustrated by Savigny (1817) (see also Bouchet & Danrigal (1982)). The resolution of this figure is very low and the diagnostic characters are not present in sufficient detail. The MNHN syntype is in terrible condition, lacking the apex, part of the last whorl, and being very worn. Still, it matches Savigny’s illustration well. The MSNG syntype is in better condition. Its label clearly states that the specimen comes from raised beaches and is thus a fossil specimen.

Figures

FIG. 35. — Triphoris perlatus Issel 1869, unknown locality: A, original figure in Savigny (1817); B-E, syntype, MNHN-IM-2000-1582; front (B, C), side (D), back (E). Scale bar: B-E, 1 mm.