Leucosyrinx bolognai, comb. nov.

Leucosyrinx bolognai (Bozzetti, 2001) comb. nov. Figs 20E, 22A–E Comitas bolognai Bozzetti, 2001: 18, unnumbered figure. Type material Holotype MADAGASCAR • Tuléar; MNHN-IM-2000-2819. Material examined (sequenced) MADAGASCAR • 1 lv; Baie Mahajamba; 14°48′ S, 47°00′ E; depth 620–637 m; MIRIKY, stn CP3249; MNHN-IM-2009-16895 • 2 lv; off Majunga; 15°22′ S, 46°00′ E; depth 493–662 m; MIRIKY, stn CP3250; MNHN-IM-2009-16896, MNHN-IM-2009-16899. Non-sequenced material MADAGASCAR • 1 dd; 22°18′ S, 43°02′ E; depth 640–660 m; VAUBAN, stn CH112; MNHN-IM-2016-4822. MOZAMBIQUE CHANNEL • 1 dd; 19°35′ S, 36°46′ E; depth 518–524 m; MAINBAZA, stn CC3153; MNHN-IM-2016-4628. NE MADAGASCAR • 6 dd; 15°22′ S, 46°00′ E; depth 493–750 m; MIRIKY, stn CP3250 • 4 dd; 14°47′ S, 46°58′ E; depth 512–680 m; • 1 dd; 14°47′ S, 46°58′ E; depth 512–680 m; MIRIKY, stn CP3285; MNHN-IM-2016-4615. SW MADAGASCAR • 3 dd; 22°25′ S, 43°05′ E; depth 530 m; Campagne crevettière 1986, stn 56; MNHN-IM-2016-4622, MNHN-IM-2016-4644 • 4 dd; 22°26′ S, 43°06′ E; depth 460 m; Campagne crevettière 1986, stn 57; MNHN-IM-2016-4640, MNHN-IM-2016-4636 • 1 dd; 22°26′ S, 43°06′ E; depth 475 m; Campagne crevettière 1986, stn 60; MNHN-IM-2016-4627 • 1 dd; 22°14′ S, 43°05′ E; depth 530 m; Campagne crevettière 1986, stn 62; MNHN-IM-2016-4635 • 1 dd; 22°27′ S, 43°05′ E; depth 530 m; Campagne crevettière 1986, stn 63; MNHN-IM-2016-4629 • 1 dd; 22°26′ S, 43°03′ E; depth 520 m; Campagne crevettière 1986, stn 65; MNHN-IM-2016-4634 • 1 dd; 22°11′ S, 43°03′ E; depth 540 m; Campagne crevettière 1986, stn 72; MNHN-IM-2016-4637 • 3 dd; 22°26′ S, 43°03′ E; depth 530 m; Campagne crevettière 1986, stn 74; MNHN-IM-2016-4639 • 1 dd; 22°13′ S, 43°03′ E; depth 560 m; Campagne crevettière 1986, stn 75; MNHN-IM-2016-4617 • 4 dd; 22°22′ S, 43°03′ E; depth 530 m; Campagne crevettière 1986, stn 76; MNHN-IM-2016-4635 • 1 dd; 22°10′ S, 43°03′ E; depth 525 m; stn79; MNHN-M-2016-4633 • 2 dd; 22°23′ S, 43°03′ E; depth 525 m; Campagne crevettière 1986, stn 81; MNHN-IM-2016-4641 • 1 dd; 22°11′ S, 43°03′ E; depth 520 m; Campagne crevettière 1986, stn 82; MNHN-IM-2016-4625 • 1 dd; 22°21′ S, 43°04′ E; depth 535 m; Campagne crevettière 1986, stn 84; MNHN-IM-2016-4621 • 1 dd; 22°18′ S, 43°02′ E; depth 590 m; Campagne crevettière 1986, stn 126; MNHN-IM-2016-4619 • 1 dd; 22°27′ S, 43°07′ E; depth 350 m; Chalutier “Mascareignes III”, stn 3; MNHN-IM-2016-4642 • 1 dd; 22°17′ S, 43°04′ E; depth 425–450 m; Chalutier “Mascareignes III”, stn 8; MNHN-IM-2016-4632 • 1 dd; 22°24′ S, 43°05′ E; depth 400–425 m; Chalutier “Mascareignes III”, stn 12; MNHN-IM-2016-4620 • 1 dd; 22°18′ S, 43°05′ E; depth 425 m; Chalutier “Mascareignes III”, stn 13; MNHN-IM-2016-4618 • 1 dd; 22°18′ S, 43°05′ E; depth 450– 475 m; Chalutier “Mascareignes III”, stn 37; MNHN-IM-2016-4631 • 1 dd; 22°24′ S, 43°06′ E; depth 400–500 m; Chalutier “Mascareignes III”, stn 38; MNHN-IM-2016-4630 • 1 dd; 22°25′ S, 43°05′ E; depth 530 m; Chalutier “Mascareignes III”, stn CH70; MNHN-IM-2016-4626. Description SHELL. Very large, reaching 90 mm (82.9 mm in holotype), broadly fusiform, strong, with medium high spire, light orange or beige. Small, bulbous, paucispiral protoconch of about 1.75 conex microshagreened whorls, same color as teleoconch. Protoconch–teleoconch transition clearly markied by thickened growth line and appearance of shoulder keel. Teleoconch whorls obtusely angular on shoulder in smaller specimens and on upper teleoconch whorls of holotype. Subsutural ramp distinctly concave on all whorls. Distinct impressed suture. 14–16 on last whorl strong, slightly oblique axial folds present on and below shoulder. Folds can reach lower suture on teleoconch whorls and can extend to shell base. Intervals between folds similar or exceding folds’ width. Moderately well-developed spiral sculpture of varying width and irregularly spaced very low, rounded cords, over entire shell except subsutural ramp. On ramp cords either lacking or very weak and hardly discernible. Intervals between cords from narrower than cords’ width to twice as broad. Shell base moderately convex, gradually narrowing at passing into medium-long broad and straight canal, slightly inclined leftwards. Rather broad, elongate-oval to irregularly shaped aperture, poorly differentiated from canal. Well-developed white or light yellowish columellar and parietal callus. Columellar and parietal callus is well-developed. Shallow subsutural, arcuate, anal sinus extends across subsutural ramp, confluent with large forward extension of outer lip. RADULA (Fig. 20E; examined in MNHN-IM-2009-16895). Marginal teeth duplex, ~300 µm in length (2.4% AL without canal). Major limb medium broad lanceolate in dorsal view, weakly curved. Accessory limb about half of tooth width, ~0.75 of total tooth length, inserted into distinct deep socket on dorsal side of major limb. DNA diagnosis (based on 3 cox 1 sequences) ‘C’ in site 289, ‘C’ in site 487, ‘G’ in site 556. Remarks This is the largest known species of Leucosyrinx, reaching up to 90 mm in length. Our largest sequenced specimen, with a shell length 69.4 mm, is comparable in size with the holotype. Our specimens closely resemble the holotype, particularly the largest one (MNHN-IM-2009-16896). The smaller sequenced specimens also show a strong similarity to the holotype when comparing corresponding whorls. The type locality is given in broad terms, without specifying a depth range. Here, we confirm the occurrence of this species off northwestern Madagascar at depths of 493–620 meters. The reclassification of this species from the genus Comitas to Leucosyrinx, supported by both molecular, conchological (shape and position of the anal sinus), and anatomical (radula) data, underscores the challenges in conchological differentiation between Comitas and Leucosyrinx. Distribution Madagascar, 350– 640 m.