Babelomurex macrocephalus, Oliverio, 2008

Oliverio, Marco, 2008, Coralliophilinae (Neogastropoda: Muricidae) from the southwest Pacific, Mémoires du Muséum national d'Histoire naturelle 196, pp. 481-586 : 542

Babelomurex macrocephalus n. sp.

Figs 93, 94, 181

TYPE MATERIAL. — Holotype (dd) MNHN 20232 and 2 paratypes (dd) MNHN 20233-20234 .

TYPE LOCALITY. — New Caledonia proper, 22°46’S, 167°20’E, 300 m [MUSORSTOM 4: stn DW 227] .

MATERIAL EXAMINED. — Coral Sea. MUSORSTOM 5: stn 349, 167°20’E, 300 m, 1 dd (holotype MNHN 20232 , Figs 93, 181). Plateau des Chesterfield , 19°34’S, 158°34’E, 275 m, 1 dd (para- — BATHUS 2: stn DW 731, Passe de Kouaré, 22°49’S, 166°45’E, type MNHN 20233 ). 300-370 m, 1 dd (paratype MNHN 20234 , Fig. 94) .

New Caledonia proper. MUSORSTOM 4: stn DW 227, 22°46’S,

DISTRIBUTION. — Only known from the present material, from the Coral Sea and southern New Caledonia, 3 empty shells in 275-300 m.

DESCRIPTION. — Shell small for the genus, holotype height 8.6 mm, width 6 mm, rather thick, rhomboidal in shape.

Protoconch of 1.4 conical whorls, 720 Μm high, 690 Μm wide at base. First 0.5 whorls sculptured with pustules over the entire surface. Remaining 0.9 whorl sculptured at first only with pustules, then with 2 weakly developed spiral keels, a series of subsutural threads and a series of similar threads over each keel; threads tending to fuse, giving rise to sinuouse collabral riblets.

Teleoconch of 4 whorls in holotype, last whorl about 70% of total height. Spire high, conical, with concave sides, angled at periphery. Suture not incised. Last whorl constricted at base. Aperture moderately large (2.8 mm high and 2 mm wide in holotype), rounded posteriorly and anteriorly. Outer lip internally ridged, angled at periphery, in most specimens continuous at the peripheral spines; inner lip almost straight, callous. Siphonal canal moderately long, open, straight; umbilicus open, narrow. Fasciole with scaly projections. Teleoconch axial sculpture of broad ribs: 9 ribs on last whorl, 8 ribs on preceding whorls. A row of blunt spines (each arising from an axial rib) at about 1/2 height of spire whorls. Spiral sculpture starting with 1 keel, bearing spiny nodules, on first 2 whorls (becoming adapical row of spines). An abapical, basal cord visible on last whorl, nodulose, without spine formation. Densely packed, minutely scabrous spiral cordlets in interspaces. Ground colour white, aperture bright white within.

REMARKS. — The new species, although based only on three, partly broken specimens, very similar to B. diadema in teleoconch characters, is immediately diagnosed by the protoconch shape and large size. All shells of B. diadema I have seen with an apex amenable to study - including the forms called B. gemmatus (Shikama, 1966) and B. macutanicus ( Kosuge, 1979) , have a different protoconch, with a narrower diameter at the base.

ETYMOLOGY. — The specific epithet ( macrocephalus , with a large head in Latin) refers to the diagnostic large protoconch.