Triphora (Mastonia) coetiviensis Melvill, 1909

Albano, Paolo G., Bakker, Piet A. J. & Sabelli, Bruno, 2019, Annotated catalogue of the types of Triphoridae (Mollusca, Gastropoda) in the Natural History Museum of the United Kingdom, London, Zoosystematics and Evolution 95 (1), pp. 161-308 : 161

Triphora (Mastonia) coetiviensis Melvill, 1909

Figure 66

Triphora (Mastonia) coetiviensis Melvill 1909: 90, pl. 5, fig. 8.

Type locality.

"Coetivy I." ( Coëtivy Island, Seychelles).

Type material.

Lectotype: NHMUK 1910.3.17.1 (lectotype selection by inference of holotype by Trew (1987)) .

Original description.

T. testa mediocri, compacta, solidula, pupoidea, cinereo-brunnea, versus apicem attenuata; anfractibus ad 14, quorum apicales ipsi duo asperi, albo-vitrei, quatuor his proximis duobus ordinibus tuberculatis, caeteris tribus, ultimo quinque spiraliter instructis, tuberculis rotundis, nitidis, albo-cincreis; apertura fere rotunda, labro crenulato, tenui, brunneo tincto, canali breviter rostrato.

Long. 13, lat. 4 mm.

Loc. Coetivy I.

An ashy-brown little Triphora, evenly spirally tubercled throughout with shining small gemmae, of a compact growth, attenuate towards the apex, otherwise robust; on the upper whorls the spiral rows are alternately straw-coloured and grey, the lower whorls, however, are of a uniform dull grey, the orifice being tinged with brown, as is the shortly beaked canal. From figures and descriptions this species must be near T. funebris Jouss., from New Caledonia, and T. intermedia C.B. Ad., from the Antilles.

Translation of the Latin text.

Medium-sized shell, compact, rather solid, pupiform, brown-grey, narrowing towards its apex; up to 14 whorls, the two apical ones pointed, translucent white, the next four with two rows of tubercles, others with three rows and the last with five; bright, ash-white, round tubercles; aperture nearly rounded, crenulated brown thin lip, short bent anterior siphon.

Length 13 mm, width 4 mm.

Diagnosis.

Lectotype 10.5 mm high. Shell cyrtoconoid, with at least 12 teleoconch flat whorls that bear three spiral cords with tubercles at the intersection with arched axial ribs, a fourth suprasutural smooth cord is visible. The second spiral cord develops later but it is fully developed after one-third of shell height. Fine spiral threads and growth lines are present among the main elements of the sculpture. The peristome bears additional spiral cords and a shallow posterior sinus. Siphonal canal long; on the base, a fifth tuberculated spiral cord is present. Protoconch missing. Teleoconch colour brown, with pearly tubercles and lighter background on the first spiral cord and on the siphonal canal; very first whorls white.

Remarks.

Trew (1987) stated that this specimen is the holotype, but Melvill (1909) did not specify how many specimens he studied, nor we have found other evidence that the species was described on a single specimen.

Figures

Figure 66. Triphora coetiviensis Melvill, 1909, Coetivy Island, Seychelles. A-E, G-I Lectotype NHMUK 1910.3.17.1: front (A, B), side (C, D), back (E), aperture (G), peristome (H, I). F Original figures and labels. Scale bars: A-E: 2 mm; G-I: 1 mm.