Common Name

None

Status

Regarded as a valid species.

Type Locality

Off Darwin, Northern Australia

Distribution

North Australia

Maximum Reported Size

55 mm

Description

Medium-sized, moderately light to moderately solid. Last whorl usually narrowly conoid-cylindrical to narrowly ovate; outline slightly convex at upper two-thirds, tapering towards base. Shoulder subangulate to rounded. Spire of moderate height; outline almost straight or slightly domed with an elevated apex. Larval shell of 2.0-2.25 whorls, maximum diameter 0.9 mm. First 4-6 postnuclear whorls tuberculate; later whorls distinctly stepped. Teleoconch sutural ramps flat to slightly convex, with 2 increasing to 4-6 spiral grooves. Last whorl with several widely spaced spiral ribs toward base, more closely spaced at base.

Ground colour bluish grey to dark violet-brown. Last whorl encircled with a variable number of darker brown bands, usually leaving intervening ground-colour bands near centre and below shoulder. Median area bearing dark brown markings varying in size and number. Overlying variably spaced solid, dotted or dashed brown spiral lines from base to shoulder. Larval whorls light brown. First postnuclear sutural ramps pale brown to pale violet; following ramps bluish grey, with brown radial blotches. Aperture white or violet behind a translucent marginal zone.

Shell Morphometry

L	40-55 mm
RW	0.08-0.16 g/mm (L 40-52 mm)
RD	0.45-0.51
PMD	0.73-0.85
RSH	0.14-0.19

Habitat & Habits

Reported from about 8-12 m under rocks.

Discussion

The species differs from C. viola in the following characters: C. viola has a smaller shell with its last whorl colour pattern dominated by reddish violet instead of dull brownish tones, a smaller number of tuberculate spire whorls (first 0.5-3.5), a greater number (about 3) variably red or pale yellow larval whorls, and less pronounced spiral sculpture on the late sutural ramps.

References

• Acta Conchyliorum (3): p. 8, pl. 1, figs 1-12.