Epitonium bellicosum Hedley, 1907
Description: Shell slender for genus; whorls disconnected, joined only by axial ribs. Whorls rounded, with 14-20 axial ribs. Ribs high, thin, ragged on top, rolled back on top quarter of whorl, aligned from whorl to whorl, sometimes peaked above middle of whorls. Interspaces smooth or with faint spiral grooves. Aperture oval, outer lip with normal rib externally. Umbilicus closed or open as a narrow slit. Colour white. Operculum corneous.
Size: Up to 15 mm in length.
Distribution: Endemic to Australia; Sydney, NSW, southwards to Bass Strait.
Habitat: Known from 110-1463 m. Uncommon.
Comparison: See "Identification of the NSW species of Epitonium" in the introduction to this family.
Synonymy: Mazescala thrasys Iredale, 1936 is a synonym (Fig. 2) (NEW SYNONYM).
Remarks: The holotype of this species is a slightly wider shell than most of the specimens available. Hedley's figure of the holotype (Fig. 1) is further exaggerated in width, and it is probably this distortion that led Iredale to describe the slender shells as a new species. The holotype of E. bellicosum is held by the Australian Museum, registered number C.026629, and that specimen agrees well with Hedley's illustration, but the paratypes are typical narrow shells. Kaicher (1980, card 2293) figured another type specimen from the BMNH type collection, registered number 1907.9.10.20, but she did not indicate the type status of the specimen.
Fig. 1: HOLOTYPE of Epitonium bellicosum. 35 miles east of Sydney, 800 fathoms (1463 m) (C.026629). Figure from Hedley (1907).
Fig. 2: Holotype of Mazescala thrasys. Off Green Cape, NSW, 70 fathoms (128 m) (C.060641)
Fig. 3: Holotype of Mazescala thrasys. Detail of sculpture.
Copyright Des Beechey 2008