Trifora fuscescens E.A. Smith, 1904

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

Trifora fuscescens E.A. Smith, 1904

Figure 86

Trifora fuscescens E.A. Smith 1904: 37, pl. 3, fig. 6.

Type locality.

"Port Alfred, Cape Colony" (Cape of Good Hope, South Africa).

Type material.

Syntypes: NHMUK 1903.12.19.1087-1092: 6 specimens, Port Alfred, South Africa .

Original description.

Testa parva, gracilis, fuscescens, quadricingulata, cingulo supremo aliis majori, planiusculo, caeteris subaequalibus rotundatis; anfractus circiter 18, fere plani, ultimus cingulis septenis prope aperturam lineis incrementi sectis et subgranosis cinctus; apertura parva, rotunde quadrata, antice brevissime oblique canaliculata; labrum tenue, postice ad suturam sinuatum, in medio subpatulum, ad marginem leviter crenulatum.

Longit. 11.5 millim., diam. 2.25.

Some of the specimens named T. cingulatus, A. Ad., by Mr. Sowerby (Marine Shells of S. Africa, p. 36), belong to the present species. None of them agree with Adams’ species, which was described from the Red Sea, and has strong longitudinal sculpture between the spirals.

Translation of the Latin text.

Small shell, slender, brownish, with four spiral cords; the uppermost row larger than the others, almost flat, the others rather similarly rounded; about 18 whorls, nearly flat, the last with seven weakly granulated cords crossed by growth lines near the aperture; small subquadrate aperture, anteriorly with a very short oblique sinus; thin lip, posteriorly indented near the suture, in the middle lightly flared, with faint marginal crenulations.

Height 11.5 mm, diameter 2.25 mm.

Diagnosis.

Syntype NHMUK 1903.12.19.1087 (Fig. 86A-E ) 9.1 mm high. Very slender shell, slightly cyrtoconoid. Teleoconch of 14 flat whorls bearing four thick flat spiral cords made up of coalescent tubercles. A fifth thin smooth cord is visible between the second and the third on the last few whorls but never attains full size. A thin smooth cord is also visible suprasuturally. Base with three additional cords similar in appearance to those on the whorls. Peristome with a deep posterior sinus. Siphonal canal short. Protoconch paucispiral with a large smooth first whorl followed by two whorls with three smooth spiral cords. Transition with teleoconch poorly marked. Teleoconch orange to brown; protoconch white.

Figures

Figure 86. Trifora fuscescens E. A. Smith, 1904, Port Alfred, South Africa. A-E, K, L Syntype NHMUK 1903.12.19.1087: front (A, B), side (C, D), back (E), protoconch (K, L). H-J, M Syntype NHMUK 1903.12.19.1088: front (H), side (I), back (J), protoconch (M). F. Original figure. G Original label. Scale bars: A-E, H-J: 1 mm; K-M: 0.2 mm.