Triphora interpres Melvill, 1918

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 interpres Melvill, 1918

Figure 69

Triphora interpres Melvill 1918: 150, pl. 5, fig. 23.

Type locality.

"Persian Gulf, Mussandam, 55 fms" (Musandam, Oman).

Type material.

Syntypes: NHMUK 1921.1.28.26, 1 specimen, Musandam, Oman. Syntypes: NMW 1955.158.208, 4 specimens, Musandam, Oman (fide Trew 1987; not seen) .

Original description.

T. testa elegantula attenuato-fusiformi, gracili, cinerea; anfractibus ad 20, quorum 5 apicales, apice ipso pallide fusco, laevi, his proximis pulchre cancellatis, ochraceo-fuscis, caeteris leniter et anguste ad suturas impressis, lateribus fere rectis, tribus spiralium gemmularum ordinibus arcte et regulariter praeditis, ordine medio minorum, superficie hic illic castaneo-tessellato, ultimo circa basin bilirato; apertura parva, semicirculari, canali conspicuo, brevi, recurvo.

Long. 11, lat. 2.25 mm. (sp. max.).

Hab. Persian Gulf, Mussandam, 55 fathoms.

A rare species, very gracefully attenuate, many (20 or more) whorled, the apical being five in number, ochreous-brown and finely cancellate in young specimens, but soon getting worn, the remainder slightly impressed suturally, with three spiral bands of gemmuled nodules, those on either side of the sutures being the largest and most pronounced, the median row smaller; the body-whorl has but three gemmuled rows in all the examples we have examined, the fourth row, at the periphery, being a simple ridge. The colour is ashy-white, flecked with pale chestnut dashed over the whorls at certain intervals. Mouth small proportionately, semicircular; peristome thin, canal short, recurved.

Translation of the Latin text.

Graceful light fusiform shell, slender, ash-grey; up to 20 whorls, of which 5 belong to the apex which is pale brown, smooth; the next whorls are finely cancellate and ochraceous brown; the others nearly straight, impressed at the sutures, with three spiral cords of regular gemmulated nodules, the middle one smaller; surface with brown spots, last whorl with two cords around the base; small semicircular aperture, remarkable, short bent anterior siphonal canal.

The largest specimen is 11 mm high, 2.25 mm wide.

Diagnosis.

The studied syntype is 4 mm high. Shell conical, with nine teleoconch flat whorls with two main spiral cords with tubercles at the intersection with slightly prosocline axial ribs. A third fine thread appears around half teleoconch height between the two main cords and becomes a fully developed tuberculated cord only on the last whorl. A very fine smooth suprasutural cord is also visible and becomes a fully developed tuberculated cord on the last whorl too. The peristome is regrown after breakage in the syntype but the posterior sinus appears shallow. The siphonal canal is short. The base bears a fifth smooth cord. The protoconch is incomplete in the syntype but clearly multispiral. The last three whorls bear two main spiral keels and axial riblets. The teleoconch has a white background with orange-brown blotches. Siphonal canal and protoconch brown.

Remarks.

There is a major discrepancy in size between this syntype (4 mm) and what stated in the original description (11 mm). Only the study of other syntypes will clarify the real identity of this taxon, because there are several species with this colour pattern which can be easily mixed together.

Figures

Figure 69. Triphora interpres Melvill, 1918, Musandam, Oman. A-F, H Syntype NHMUK 1921.1.28.26: front (A, B), side (C, D), back (E), protoconch (F), aperture (H). G Original figure. I Original label. Scale bars: A-E: 0.5 mm; F: 0.1 mm; H: 0.3 mm.