Colpospira accisa (Watson, 1881)
Description: Protoconch of 2 whorls, teleoconch 16 whorls in adult shell. Whorls overall straight-sided, suture incised. Whorls spirally ribbed; latter whorls with 3 strong, primary ribs, the upper usually broad and low, the lower narrow and high; interspaces between ribs with about 6 threads; upper and lower ribs themselves sometimes bear threads, but absent from central rib. Axial sculpture of growth lines conforming to shape of outer lip sinus. Inner lip of aperture reflected outwards at base; outer lip thin, with deep sinus, lip usually broken. Base with 10 or more weak spiral threads. Colour uniformly cream or fawn. Operculum circular, corneous.
Size: Up to 39 mm in length, but usually less than 25 mm.
Distribution: Endemic to Australia; Sydney, NSW, southwards to Eyre Peninsula, SA.
Habitat: Known from 37-300 m. Uncommon.
Comparison: The 3 strong spiral ribs with fine threads between distinguish this from species of similar size.
Fig. 1: Off Twofold Bay, NSW, in 73 m (C.077376).
Copyright Des Beechey 2006