Acanthodaphne basicincta, Morassi & Bonfitto, 2010

Morassi, M. & Bonfitto, A., 2010, New raphitomine gastropods (Gastropoda: Conidae: Raphitominae) from the South-West Pacific, Zootaxa 2526, pp. 54-68 : 62-63

Acanthodaphne basicincta new species

Figures 2. J–P

Type material: Holotype MNHN 22306 . Paratypes: 3 MNHN 22307 , 1 MZB 45714, 1 ZRC 2979.

Type locality: Solomon Islands, 09°32.6’S 160°37.3’E, 283–305m [SALOMON 1 Stn CP 1786] .

Material examined: only known from the type material.

Description: Shell biconic (b/l 0.47–0.53; a/l 0.42–0.48), small but stout. Teleoconch consisting of 5.8 whorls, which are sharply angulated at one-quarter of whorl height on earlier spire whorls, at about one-third on later ones. Last whorl strongly excavated with a short neck. Whorls separated by a weakly impressed, strongly undulating suture margined by a prominent subsutural fold. Sutural ramp wide, strongly concave. Axial sculpture consisting of short, prominent, opisthocline ribs, separated by interspaces much wider than them, extending from lower suture to shoulder angle where they are abruptly truncated and form sharp tubercles. Axial ribs rapidly vanishing on last whorl below periphery. There are 11–13 axial ribs on penultimate whorl, 13–16 on last whorl. Subsutural fold bearing a row of tubercles more numerous than axial ribs. Sutural ramp sculptured by fine collabral threads sinuous in conformity with the anal sinus. Spiral sculpture consisting of narrow, flattened cords. Earlier spire whorls with one peripheral cord forming peripheral angulation, joined on penultimate whorl by a weaker cord anteriorly; interstice between these two cords sculptured by 1–2 very low threads. Last whorl with a third cord just below suture and a fourth prominent peribasal cord bearing tubercles; interstices between spiral cords sculptured by 2–4 threads. Remaining part of base sculptured by 2–3 widely-spaced low cords, lacking intermediaries; 8–10 threads on the neck. Under SEM, entire whorl surface is seen to be covered by dense rows of granules (fig. 2L). Aperture oblanceolate. Columella concave above, strongly twisted to left below forming a short, relatively narrow siphonal canal. Labial callus relatively thick over columella, wide, sculptured by microscopic rows of prickly nodules in its interior part. Parietal region rendered angular by the peribasal cord. Outer lip thin with a moderately deep, reversed L-shaped anal sinus; its deepest point below middle of sutural ramp. Protoconch conical of 3.25 whorls; protoconch I covered with minute, dense spiral threads rendered granulose where crossed by even finer axial threads; protoconch II subsequent part sculptured by opisthocyrt axial riblets extending from suture to suture decussate by oblique threads on lower half of each whorl. Protoconch diameter: 0.57–0.67 mm. Color white, protoconch yellowish-beige.

Dimensions: Holotype 7.2 x 3.4 mm, aperture height 3.4 mm; largest Paratype: 7.7 x 3.9 mm, aperture height 3.6 mm; smallest Paratype: 6.6 x 3.5 mm, aperture height 3.1 mm.

Remarks: Acanthodaphne basicincta is readily distinguished from other members of the genus Acanthodaphne in having a prominent peribasal cord and a twisted columella.

Etymology: basicincta refers to the prominent peribasal cord of this species.