BOUCHET, Fedosov & Puillandre & Herrmann & Kantor & Oliverio & Dgebuadze & Modica & Bouchet, 2018

KANTOR & BOUCHET SP. NOV.

( FIGS 17I, 18I, K)

Type data: Holotype: MNHN IM-2013-40665, Papua New Guinea, BIOPAPUA Stn CP 3692, SE of Manus I., 02°10′S, 147°19′E, 408–448 m, lv, 25.2 mm ( Fig. 18I, K) GoogleMaps . Paratype: BIOPAPUA Stn CP 3629, Gulf of Huon, South of Lae , 06°57′S, 147°08′E, 240–269 m, dd, 26.15 mm GoogleMaps .

Other material examined: BIOPAPUA Stn DW3735, 08°15′S, 150°34′E, 450–500 m, 21.4 mm; Stn data lost,

28.5 mm; Stn DW3771, 05°34′S, 151°33′E, 295–422 m, 9.2 mm.

Description: Shell medium sized (holotype 25.2 mm), fusiform, heavily sculptured, with rather high spire and elongated aperture. Protoconch pointed, cyrtoconoid, of three or more glossy, convex whorls (usually strongly corroded or missing). Teleoconch of six or more slightly convex whorls, suture distinctly canaliculated. Subsutural shelf well developed, rather narrow, slightly inclined towards axis, bordered by projecting margin of adapical spiral cord. Early teleoconch whorls corroded, third and subsequent teleoconch whorls with five very strong, elevated, gemmate spiral cords separated by deep interspaces. Spiral cords subequal, adapical and abapical cords slightly weaker than intermediate ones, microsculpture of fine growth lines in interspaces between spiral cords; abapical cord of previous whorl partly superposed by adapical cord of succeeding whorl. Gemmules on spiral cords axially aligned, connected by low and weak axial riblets in interspaces between spiral cords. Spiral cords become distinctly beaded on penultimate and last adult whorls, forming rows of closely set, rounded, glossy granules. Five spiral cords on adapical portion of last adult whorl succeeded by six cords on shell base and five cords on siphonal canal, of which last three oblique, weaker than preceding, irregularly gemmate. Siphonal canal delineated from shell base by slightly widened interspace with low wavy spiral thread. Siphonal canal rather long and stout, slightly recurved.

Aperture elongate, its outer lip gently convex throughout its height, wavy, reflecting arrangement of spiral cords. Inside of outer lip with eight strong lirae. Inner lip strongly calloused, reflected, retaining weak reticulate sculpture adapically, with three strong oblique columellar folds at mid-height.

Shell uniformly white or pale.

Radula of holotype 0.76–0.8 mm long, 0.19– 0.20 mm wide, composed of about 65 transverse rows of uniform, delicate, multicuspidate teeth. Rachidian about 60 µm wide, with 17 cusps, of which two marginals very weak, and the others subequal, long and pointed. Laterals about 50 µm wide, with slightly convex anterior margin, bearing 14–15 pointed, rather long cusps.

Distribution: Papua New Guinea, North of main island, 269– 450 m.

Etymology: The species is named after another giant in malacology, Winston Ponder of the AMS, whose early work, including his studies on mitriform families, set a milestone in our understanding of neogastropod evolution.

Remarks: The identification of Fusidomiporta ponderi sp. nov. is uneasy, mainly because of its striking resemblance to (still undescribed) species of Profundimitra gen. nov., represented in our analysis by specimens IM-2007-35618 and IM-2007-35711 (both mislaid). The single live-taken specimen of F. ponderi sp. nov. seems to have a proportionally slightly lower spire and a somewhat stepped appearance of spire whorls, with more elevated spiral cords. At the same time, the distinctive and heavy sculpture pattern makes it quite recognizable from among most Mitridae . In shell proportions and whorl outline, F. ponderi sp. nov. is very close to F. suturata ; however, the latter has lower and wider spiral cords with narrower grooves between them. Some deep-water species of Gemmulimitra gen. nov. have a somewhat similar, beaded sculpture, which however is nowhere as strong as in F. ponderi sp. nov. Besides, Gemmulimitra boucheti has a proportionally broader shell with more convex whorls compared to F. ponderi sp. nov. On the contrary, G. neocaledonica sp. nov. has a rather biconical shell with subcylindrical whorls and a rather reticulate sculpture pattern. However, at this moment, many of the deep-water mitrids are still represented in our data set by too few specimens to assess their intraspecific variation and elaborate robust species delimitation criteria.

GEMMULIMITRA NEOCALEDONICA FEDOSOV ,