Hirtomurex marshalli, Oliverio, 2008

Oliverio, Marco, 2008, Coralliophilinae (Neogastropoda: Muricidae) from the southwest Pacific, Mémoires du Muséum national d'Histoire naturelle 196, pp. 481-586 : 551-552

Hirtomurex marshalli n. sp.

Figs 108, 109

TYPE MATERIAL. — Holotype (dd) MNHN 20235 and 3 paratypes (dd) MNHN 20236-20238 .

TYPE LOCALITY. — Norfolk Ridge , 24°55’ S, 168°22’ E, 513 m [SMIB 3: stn DW 3] .

MATERIAL EXAMINED. — Norfolk Ridge. SMIB 3: stn DW 3, stn DW 1684, Banc Éponge, 24°55’S, 168°22’E, 508-541 m, 24°55’ S, 168°22’ E, 513 m, 1 dd (holotype MNHN 20235 , 1 dd (paratype MNHN 20238 , Fig. 109); stn DW 1694, Banc Fig. 108) . — NORFOLK 1: stn DW 1651, Banc N, 23°27’S, Introuvable, 24°40’S, 168°39’E, 575-589 m, 1 dd (paratype 167°50’E, 276-350 m, 1 dd (paratype MNHN 20236 , broken); MNHN 20237 ) .

DISTRIBUTION. — Known only from the area of the type locality, Norfolk Ridge, southwest Pacific , empty shells in 350-575 m.

DESCRIPTION. — Shell of medium size for the genus, 22 mm high, 12 mm wide, fusiform with angled shoulder, thick. Protoconch eroded in available material.

Teleoconch of 7+ whorls (tips missing in holotype and all paratypes). Spire high, conical, with flat sides, suture incised. Last whorl about 1/2 total height, angled at shoulder, curved at periphery, sharply constricted at base. Aperture long, oval, yet tapering anteriorly. Outer lip broken in holotype, crenulated on exterior, smooth internally, varicose (in the paratypes). Inner lip arcuate posteriorly, straight anteriorly, callous. Siphonal canal (damaged in holotype) long, broadly open; umbilical area narrow, with strongly twisted, imbricate fasciole, umbilical chink narrow and short.

Teleoconch spiral sculpture of regularly alternating major cords and minor cordlets. A total of 14 cords and 14 cordlets on last teleoconch whorl; 6 cords and 4 cordlets visible above aperture. Third cord evident on second visible teleconch whorl, first and second becoming evident soon after. Both cords and cordlets covered by imbricate scaly spines. Third cord consistently stronger giving a keeled appearance to spire. Axial sculpture of 10 sharply elevated ribs, fading out over base. Orientation of ribs (in the same specimen) not constant, varying from slightly prosocline to orthocline, occasionally opisthocline. Some also slightly sinuous. Weak microsculpture of irregular scaly growth lines over entire teleoconch.

Shell ground colour ivory-white, inside of aperture bright ivory-white.

REMARKS. — Hirtomurex marshalli is similar to smooth forms of the Babelomurex indicus complex in shape and sculpture, but has a rather more rounded shell shape and a less angled periphery, and lacks sharp scaly projections on the axial costae.

ETYMOLOGY. — The new species is dedicated to Bruce Marshall (NMNZ) for his deep knowledge of the South Pacific fauna and his contribution to our understanding of molluscan biodiversity.