Acamptodaphne solomonensis, Morassi & Bonfitto, 2010

Morassi, M. & Bonfitto, A., 2010, New raphitomine gastropods (Gastropoda: Conidae: Raphitominae) from the South-West Pacific, Zootaxa 2526, pp. 54-68 : 57-59

Acamptodaphne solomonensis new species

Figures 1. G–O

Type material: Holotype MNHN 22301 . Paratypes: 1 MNHN 22302 , 1 MZB 45712, 1 ZRC 2978.

Type locality: Solomon Islands, 08°21.4’S 160°41.8’E .

Material examined: Solomon Islands: 08°21.4’S 160°41.8’E, 194–286 m [N/O “ Alis ” SALOMON 1 Stn DW 1768] (holotype, 1 paratype at MNHN and 1 paratype at MZB) ; 08°20.4’S 160°40.6’E, 290–303m, [N/ O Alis SALOMON 1 Stn DW 1769] (1 juv. paratype at ZRC) .

Description: Shell fusiform-biconic (b/l 0.44–0.47; a/l 0.49–0.53). Teleoconch consisting of 4.5–5.2 whorls sharply angulated at one-third of whorl height on earlier whorls; angulation slightly weaker and near middle on last two spire whorls. Last whorl strongly excavated with a relatively long neck. Whorls separated by a deep, narrowly channelled suture. Sutural ramp wide, shallowly concave. Axial sculpture consisting of short, prominent, opisthocline ribs, with wider interspaces, extending from lower suture to peripheral angle where they are abruptly truncated and form prominent tubercles. Penultimate whorl with 16–19 ribs; axial ribs weaker and restricted to periphery on last whorl, becoming obsolete on latter part of the whorl. Spiral sculpture commencing as a subsutural thread and a prominent cord, forming the peripheral angulation, joined on second whorl by a weaker cord anteriorly. On subsequent whorls, suture is margined by two threads forming a weak subsutural fold, while additional 1–2 spiral cords develop below the peripheral cord; interstices between cords with 1–3 spiral threads on last two whorls. Sutural ramp lacking spirals on first whorl, bearing 6–8 threads on later whorls. Base sculptured by 26–27 spiral elements consisting of cords and threads of variable strength. Whorls covered by dense, rough collabral growth lines particularly evident on sutural ramp where are weakly frilled and sinuous in conformity with the anal sinus in outer lip; growth lines forming small, axially elongate tubercles on subsutural fold and small nodules at points of intersections with spiral cords. Under SEM, entire shell surface is seen to be covered by spiral rows of microscopic granules. Aperture lanceolate. Columella nearly straight above, distinctly curved to left below. Labial callus thin, sculptured by microscopic rows of prickly nodules in its interior part (fig. 2L). Siphonal canal relatively long (for genus), oblique and relatively wide. Anal sinus moderately deep, broadly reversed L-shaped, with its apex below middle of sutural ramp. Protoconch domed of 1.5–1.8 whorls covered with minute, dense spiral threads rendered granulose where crossed by even finer axial threads; last whorl with a few close, arcuate, axial plicules near termination. Protoconch breadth: 0.43–0.56 mm. Teleoconch white, protoconch pale buff.

Dimensions: Holotype 8.2 x 3.6 mm, aperture height 4.0 mm; largest paratype: 7.2 x 3.2 mm, aperture height 3.8 mm; smallest paratype: 5 x 2,6 mm, aperture height 2,8 mm.

Remarks: This species is readily distinguished from its congeners in having a fusiform-biconic rather than biconic shell, with a strongly concave left side of the base, and a paucispiral protoconch (figs. 1N–O). Etymology: solomonensis refers to the fact that this species is described from Solomon Islands.