Turbonilla hoeisaeteri, Lygre & Kongsrud & Schander, 2011

Lygre, Frøydis, Kongsrud, Jon Anders & Schander, Christoffer, 2011, Four new species of Turbonilla (Gastropoda, Pyramidellimorpha, Turbonillidae) from the Gulf of Guinea, West Africa, African Invertebrates 52 (2), pp. 243-243 : 249-252

Turbonilla hoeisaeteri sp. n.

Fig. 5

Etymology: This species is named in honour of our friend Tore Høisaeter, University of Bergen. Tore is a good friend and has made many important contributions to our knowledge of gastropods in the Atlantic.

Diagnosis: Tall, high spired with large protoconch, clearly convex whorls, and, strong axial ribs with well developed striae present in the interspaces.

Description: Shell very small, slender, conical, white and shiny with rounded apex. A diffuse coloured band in the lower half of the whorls can be seen in some specimens.

Protoconch of type A-I, diameter 305 μm. Whorls convex. Suture marked but not deep, undulating. Axial ribs elevated, thin, straight but curving left apically, prosocline. Ribs not equidistant; interspaces much broader than ribs. Axial ribs disappearing at periphery of ultimate whorl. Spiral sculpture of rectangular grooves, not equal or HTXLGLVWDQW. 9HU\ ¿ QH YHUWLFDO PLFURVWULDH SUHVHQW RQ EDQGV EHWZHHQ JURRYHV. 1 DUURZ spiral grooves present on base. Aperture oval, apically narrowed. Columellar tooth absent. No umbilicus .

Holotype: GABON: station G16, 03°49'S: 10°37'E, - 69 m ( ZMBN 86959 ). Length 2.08 mm, width 0.54 mm . Paratypes: Four from type locality in ZMBN (86960–86963) . Three in NMSA ( L8459 / T2750 ) .

Distribution: Nigeria and Gabon, - 24– 69 m.

Comparison: This species is similar to T. parsysti Peñas & Rolán, 2002 from West African waters, but is smaller and more slender. The whorls are more convex and not turreted. The axial ribs are not as prosocline apically in the whorls as they are in T. parsysti . The aperture is smaller and more oval.

Figures

Fig. 5. Turbonilla hoeisaeteri sp. n.: (A) holotype; (B, C) paratypes, teleoconchs, station G2, Gabon; (D) holotype, protoconch; (E) holotype, details of sculpture.