Shell: Size relatively large for genus (height up to 11.8 mm, width up to 13.0 mm), slightly wider than high, conical; height 0.9x width, 2.6-3.2x aperture height; periphery weakly angular to almost rounded. Protoconch paucispiral, diameter approx. 330 µm, rounded, with 5 thin, equally spaced spiral threads; terminal lip straight, without varix. Teleoconch of up to 6.2 whorls; first two whorls convex, subsequent whorls almost straight; shoulder oblique with angulate rim, except on last whorl where shoulder horizontal; whorls with up to 20 spiral cords; cords thin and nearly smooth on first two whorls, thicker and beaded on subsequent whorls, beads of adapical cords stronger. Suture canaliculate on early whorls, not so on later whorls. First whorl sculptured by 6 thin, more or less equally spaced, cords; cords arising immediately after protoconch; PI and P2 slightly stronger than other cords; PI forming rim of shoulder; close-set axial threads between cords. On second whorl, axial threads hard to distinguish and evanescing at end of whorl; P6 at suture. Prosocline subsutural axial folds develop at start of third whorl, rendering PI and P2 subgranular; PI and P2 the strongest with secondary cord S2 arising and rapidly reaching strength of P3; P5 thickening after middle of whorl, smooth and forming a weak suprasutural carina. On fourth whorl all adapical cords beaded, abapical cords subgranular; S4 and SI arising; PI stronger than other cords; P5 almost as strong as PI, forming prominent carina above suture; shoulder more or less horizontal, suture not canaliculate; axial folds weaker, but still visible. On fifth whorl, P6 emerging from suture; tertiary cords arising by intercalation between PI and SI and/or between S4 and P5. On last whorl, numerous additional tertiary cords arising, resulting in a total of up to 20 cords; carina on P5 weaker than on penultimate whorl. Aperture subcircular; peristome incomplete; outer and inner lips thin; columella vertical, concave, the middle portion slightly reflected and overlapping umbilicus; a small flange at columella base. Base moderately convex, with 15-18 spiral cords; periumbilical region with approx. 30 axial pleats, rendering 5-8 most inner cords beaded; cord at umbilical rim 1.5-2.Ox wider than penultimate cord and strongly beaded with coarse, pointed beads; outer basal cords thin, smooth, becoming weakly beaded in central part of base, intervals between cords 1.5-2.0x width of cords. Umbilicus deep, relatively narrow (diameter ca. 9-13% of shell width), with angulate rim; internal wall almost straight, with 6-8 strong, subgranular to beaded spiral cords; cord closest to rim coarsely beaded; intervals between cords approx. 0.5-1 .Ox width of cords. Colour: Teleoconch whorls nacreous, pinkish to orange; base white to grey; protoconch white, holotype MNHN IM-2009-17850 H=11.5 W=12.7.

The shell of Arxellia boucheti is distinctive on account of its large size, numerous spiral cords and rounded periphery. The external anatomy is almost identical to that illustrated by Waren (1993) for Solariella obscura and S. varicosa, and is also close to that of Spectamen (Herbert 1987). In the molecular analysis of Williams et al (2013), this species forms a clade with A. tracheia and A. helicoides.

Type locality. Southern New Caledonia, Norfolk Ridge, NORFOLK 2, stn DW2057, 24°40'S, 168°39'E,
555-565 m.
Distribution. Southern New Caledonia and Norfolk Ridge, 402-666 m, living at 402-650 m.