"Pleurotomella (Anomalotomella) rossi n.sp. (Figs 424, 425, 429)
MATERIAL EXAMINED: NZOI Stn A470; Eltanin Stn 1995; USNM 638845, 72°16'40"S, 170°18'00"E, 133 m (juvenile).
DISTRIBUTION: Known only from the Ross Sea in 133-377 m.
DESCRIPTION: Shell small, broadly biconic, creamy white. Whorls gently convex with a slightly concave sutural ramp, last whorl greatly inflated. Whorls 5 ½ including a protoconch of 2 ½ fairly bulbous whorls. Protoconch clearly marked off from teleoconch by an oblique varix. Under normal powers protoconch apparently sculptured with very fine spiral threads crossed by fine axial riblets. Under SEM (Fig. 425) spiral sculpture seen to be of irregular raised blotches more or less arranged in lines, with axial riblets equally irregular. Penultimate whorl with five fine spiral cords on the ramp, followed by a zone dominated by the axial sculpture following the line of the sinus. Margin of sinus sculptured by five very fine, closely spaced spiral threads. A further 10 more widely spaced spiral cords extend across the rest of the whorl. The same sculptural elements extend on to last whorl with additional fine, closely spaced spiral cords developed across the rest of the whorl, base and canal. The sinus is deep, situated on the ramp, essentially as in P. (A.) anomalapex Powell. Axial sculpture of fine riblets strongest on the shoulder where they trace the outline of the sinus, then bending very sharply forwards, curving broadly across the periphery, and on the last whorl sweeping backwards over the base and canal as little more than regular growth lines. Aperture narrowly ovate, drawn out into a moderately long, open canal. Columella almost straight, parietal lip excavated into surface of the last whorl.
MEASUREMENTS: height 11.9 mm, diameter 6.0 mm (holotype), height 6.8 mm, diameter 4.1 mm (paratype).
HOLOTYPE: from NZOI Stn A470 in NZ Oceanographic Institute (H.550).
PARATYPES: from NZOI Stn A470 in NZ Oceanographic Institute (one, P.756) and National Museum of New Zealand (one, MF.56622).
REMARKS: The nearest relative of this new species would appear to be P. (A.) frigida Thiele, from which it differs in the very much finer spiral sculpture and the much more swollen last whorl."
(Dell, 1990: 243)
Pleurotomella rossi is a species of sea snail, a marine gastropod mollusk in the family Raphitomidae.[1]
The length of the shell attains 11.9 mm.
This species occurs in the Ross Sea, Antarctica and off Visokoi Island, SE of island, South Sandwich Islands, South Atlantic Ocean at a depth between 93 mm and 121 m.
Pleurotomella rossi is a species of sea snail, a marine gastropod mollusk in the family Raphitomidae.
