Mareleptopoma vaubani, Renard & Bouchet, 2003

Renard, Jacques Le & Bouchet, Philippe, 2003, New species and genera of the family Pickworthiidae (Mollusca, Caenogastropoda), Zoosystema 25 (4), pp. 569-591 : 580-581

Mareleptopoma vaubani n. sp.

( Fig. 7 )

TYPE MATERIAL. — Holotype (dd) in MNHN.

TYPE LOCALITY. — New Caledonia, off Nouméa, Vauban, 1979, stn 40, 22°30’S, 166°24’E, 250- 350 m. ETYMOLOGY. — The species is named after RV Vauban, on board of which the holotype was collected. MATERIAL EXAMINED. — A total of 3 specimens (3 lots).

Japan. Horseshoe Cliffs, 1 km WNW Onna Village, Okinawa, 26°29.6’N, 127°50.5’E, 60 m, gravel, 1979, leg. Bolland, 1 dd ( LACM 79-76.4).

Philippines. Panglao I., Bohol, 18 m, 1 dd ( UHM).

New Caledonia. New Caledonia, off Nouméa, Vauban, stn 40, 22°30’S, 166°24’E, 250-350 m, 1979, leg. Warén, 1 dd (holotype, MNHN).

DISTRIBUTION. — Pacific Ocean: Okinawa, Philippines, New Caledonia.

DESCRIPTION

Holotype ( Fig. 7 ). Shell very small, turbinate, consisting of six whorls. Protoconch ( Fig. 7C )

consisting of three whorls, styliform; protoconch I consisting of one smooth whorl; two protoconch II whorls bearing five or six granular spiral cords of unequal strength. Deep sinusigera notch, lined by reflected lip adpressed to whorl above. Protoconch axis slightly tilted on teleoconch axis. Teleoconch whorls angular, growing rapidly in diameter, separated by deep suture. Sculpture on spire consisting of two spiral cords of equal strength; one at upper third of whorls, separated from suture by broad, sloping ramp; the other very close to abapical suture. Axial sculpture consisting of raised narrow ribs, straight, orthocline, numbering 15 per whorl. Intersections of axial and spiral sculptures forming reticulations with depressed centers edged by spiny projections. Base of body whorl convex, with four smooth equidistant cords of equal strength. Periumbilical cord lining deep, rather narrow umbilicus. Axial sculpture hardly extending on base, with many incremental lines becoming more distinct, extending into umbilicus. Beside this first order sculpture, microsculpture of regular spiral lamellae. Aperture only slightly oblique, rounded, large (slightly narrowed by interior labral thickening). Peristome foliated, thickened into very narrow varix, with undulating profile in lateral view, with polygonal rounded outline in apertural view (due to termination of spiral cords of body whorl). Sculpture remaining strong behind peristome, with four rows of square reticulations.

Dimensions

H = 0.95 mm, D = 0.96 mm.

REMARKS

Mareleptopoma vaubani n. sp. shares characters with M. karpatensis and M. spinosa (Hedley, 1902) . With M. karpatensis , it shares the same outline, general shape, sculpture of the protoconch, teleoconch sculpture forming reticulations with spiny intersections, very convex base, and lamellar microsculpture. It differs however by its broader umbilicus, stouter shape and stronger sculpture. It closely resembles M. spinosa by its size, depressed appearance, and spiny sculpture. It can be distinguished from the latter by the basal disk with cords, by the peristome and axial ribs being almost straight in lateral view, and by the broad sutural ramp without a sutural cord. Mareleptopoma vaubani n. sp. can also be recognized by its first teleoconch whorl with two keels instead of one, by a spiral keel not overhanging the suture and by its flange-like labral rim. The protoconch of M. vaubani n. sp. has less convex whorls and stronger sculpture than that of M. spinosa .

Figures

FIG. 7. — Mareleptopoma vaubani n. sp., holotype, off Nouméa, New Caledonia, 250-350 m (MNHN), H = 0.95 mm; A, B, apertural and side views; C, protoconch. Scale bar: C, 50 µm.