Turbonilla willasseni, 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 : 247-249

Turbonilla willasseni sp. n.

Fig. 3

Etymology:This species is named in honour of Dr Endre Willassen, curator of invertebrates at the Bergen Museum, who is always supportive of our work.

Diagnosis: Tall, high spired with large protoconch, almost straight whorls, and, strong axial ribs crossed by microstriae.

Description: Shell small, slender, conical, white with rounded apex. Protoconch of type A-II, diameter 230 μm, semisubmerged. Whorls straight. Suture shallow. Axial ribs elevated, straight and orthocline. Axial ribs and interspaces equally broad. Ribs GLVDSSHDULQJ DW SHULSKHU\ RI XOWLPDWH ZKRUO. 0LFURVFXOSWXUH RI VXSHU¿FLDO VSLUDO VWULDH. Aperture oval, narrowing apically. Columellar tooth absent. No umbilicus.

Holotype: GABON: station G2, 00°19'N: 09°19'E, - 24 m ( ZMBN 86951 ). Length 1.51 mm, width 0.45 mm . Paratypes: Two from type locality in ZMBN (86952, 86953) . Two in NMSA ( L8457 / T2748 ) .

Distribution: Gabon and Congo, - 24– 162 m.

Comparison: Turbonilla fulgidula is similar to this species, but has a subsutural shelf and more prominent microsculpture than T. willasseni . The protoconch of T. willasseni is slightly larger than in T. fulgidula . A yet undescribed species also show some similarity to T. willasseni . However, this species has a larger, more protruding protoconch.

Figures

Fig.3. Turbonilla willaseni sp.n.: (A) holotype; (B) paratype, teleoconch, station G2, Gabon; (C) paratype, protoconch; (D) holotype, protoconch;(E) paratype, protoconch,station G2, Gabon;(F,G)holotype, details of sculpture.