Epitonium jousseaumei (de Boury, 1886)
Description: Shell average width for genus; whorls disconnected, joined only by axial ribs. Whorls rounded, with about 14 axial ribs. Ribs high, shouldered, (giving the impression that the whorls themselves are shouldered), strongly rolled back except on shoulder, peaked at shoulder, aligned from whorl to whorl, ending in a coarse rib edging umbilicus. Interspaces with spiral threads. Aperture oval, outer lip with normal rib externally. Umbilicus open as a narrow slit. Colour white. Operculum unknown.
Size: Up to 13 mm in length.
Distribution: Australia, New Caledonia and Japan. In Australia, Port Douglas southwards to Gladstone, Queensland, plus a few specimens, probably fossil, from Sydney Harbour, NSW. In Japan, off Simoda Izu Peninsula, in about 60 m (Nakayama, 2003).
Habitat: Mainly known from empty beach shells, plus a few down to 82 m. Uncommon.
Comparison: See "Identification of the NSW species of Epitonium" in the introduction to this family.
Synonymy: Mazescala heloris Iredale, 1936 is based on a specimen of this species, probably fossil, dredged from Sydney Harbour (NEW SYNONYM).
Fig. 1: HOLOTYPE of Mazescala heloris. Sydney Harbour, dredge Triton (C.060642)
Fig. 2: HOLOTYPE of Mazescala heloris. Detail of sculpture
Copyright Des Beechey 2008