Common Name

"Austral Cone"

Status

Regarded as a valid species.

Type Locality

Not mentioned, designated (Coomans, Moolenbeek & Wils) Taiwan

Distribution

C. a. australis: Japan to Philippines and Vietnam; India and W. Thailand, probably also Fiji

Maximum Reported Size

107 mm

Description

C. a. australis moderately large to large, moderately solid to solid. Last whorl narrowly conoid-cylindrical to ventricosely conical, to conical in subadults; outline variably convex adapically, less so to straight below. Shoulder subangulate to sometimes angulate. Spire of moderate height, outline slightly concave to slightly sigmoid. Larval shell of about 3.25 whorls, maximum diameter 0.8-0.9 mm. First 2-7 postnuclear whorls tuberculate. Teleoconch sutural ramps flat to slightly concave, with 0 increasing to 3-8 spiral grooves. Last whorl usually encircled with variably spaced, variably granulose ribs sometimes grouped in pairs or replaced by ribbons; intervening grooves narrow to wide and axially striate.

C. a. australis: Ground colour white, often suffused with pale yellow or brown. Last whorl with brown spirally or axially aligned dots or flecks, axial streaks, flames and dashes. Pattern elements merging into 3 interrupted to solid brown spiral bands, below shoulder and above and belowcentre. Larval whorls white. First 1.5-3 postnuclear sutural ramps immaculate. Following sutural ramps with brown radial blotches and streaks. Aperture white, sometimes violet deep within. Aperture white.

Periostracum brownish olive, thin, slightly translucent, smooth. Periostracum dark brown.

Radular teeth with an adapical barb opposite a blade; serration twice as long as blade, ending in a cusp at centre of shaft; central waist and basal spur present (Rolán, pers. comm., 1993).

Shell Morphometry

L	64-107 mm
RW	0.20-0.53 g/mm
RD	0.44-0.52
PMD	0.76-0.85
RSH	0.14-0.21

Habitat & Habits

C a. australis in 35-240 m. sandy mud bottom.

Discussion

C. ateralbus can be separated from C. venulatus because of its normally black last whorl and spire, with white dots, angulated shoulder and purplish aperture instead of pure white, and also from C. trochulus which has a lavender shell, straight sides, convex and purplish spire, and aperture of a darker color.

C. alabasteroides and C. cebuganus are based on subadult specimens of C. a. australis and are synonyms. C. duplicatus matches deep subtidal shells from the Philippines (in shape and sculpture (Röckel, 1987b). We therefore consider it an ecological form of C. a. australis, characterized by strong, paired ribs on the last whorl, weak spiral colour bands, predominant short axial lines and dashes, and a rather straight last whorl outline.

References

• Enum. Syst. Conch: p. 39, no. 487, not figured.