Otitoma hadra, Morassi & Nappo & Bonfitto, 2017

Morassi, Mauro, Nappo, Andrea & Bonfitto, Antonio, 2017, New species of the genus Otitoma Jousseaume, 1898 (Pseudomelatomidae, Conoidea) from the Western Pacific Ocean, European Journal of Taxonomy 304, pp. 1-30 : 16-17

Otitoma hadra sp. nov.

urn:lsid:zoobank.org:act:D699962E-3975-4973-A6AB-047323F41C8B

Fig. 4 P–U

Etymology

The specific epithet refers to the Greek ‘ hadros ’ (thick), alluding to the small but very thick shell.

Type material

Holotype

NEW CALEDONIA: BATHUS 4, Stn DW 882, N of New Caledonia , 22°02 ′ S, 165°56 ′ E, 250–350 m ( MNHN IM-2000-32603 ).

Paratype

NEW CALEDONIA: same data as holotype ( MNHN IM- 2000-32604).

Description

Shell somewhat biconic (b/l 0.41–0.48; a/l 0.56–0.57). Teleoconch of 3–3¼ weakly and evenly convex whorls, with a slight shoulder at mid-whorl height. Suture shallow, bordered by a weakly prominent sub-sutural fold followed by a shallowly concave sutural ramp. Axial sculpture of opisthocline ribs, subequal to or narrower than intercostal spaces, abruptly ending at level of abapical side of sutural ramp ( Fig. 4S). 14–16 axial ribs on penultimate and 18–19 ribs on last whorl. First teleoconch whorl with 3 spiral cords between the sutural ramp, sutures of following whorl increasing to 4–5 on penultimate and last whorl. Spiral cords closely-spaced, not plicate where crossing axial ribs. Sutural ramp with 1 spiral cord increasing to 2 cords on later two whorls. Last whorl with 19–22 main spiral cords and 1 occasional secondary cord in interspaces on base and rostrum. Interspaces between cords lacking secondary sculpture. Aperture rather narrow, ovate, constricted at entrance to siphonal canal. Siphonal canal short, relatively wide. Inner lip covered with a thick callus. Outer lip edge sharp, preceded by a strong, wide varix. Stromboid notch weak. Anal sinus relatively broad and moderately deep, a C-shaped notch, its entrance weakly constricted. Protoconch domed, of up to 1½ smooth whorls, diameter 1.04– 1.09 mm. Protoconch white, teleoconch yellowish-white flecked with orange-yellow on sutural ramp and along some axial ribs on last whorl.

Dimensions

Holotype: 5.1 × 2.1 mm, aperture height 2.85 mm. Paratype: 4.7 × 2.25 mm, aperture height 2.7 mm.

Remarks

Otitoma hadra sp. nov. is readily distinguished from its described congeners by its rather small, thick shell (about 5 mm in maximum length), with a relatively large protoconch and well developed sculpture (both spiral and axial).