Colpospira curialis (Hedley, 1907)
Description: Protoconch 2 whorls, teleoconch 11 whorls in mature shells. Whorls slightly concave or straight in outline, suture impressed. Whorls spirally ribbed; latter whorls sculptured with 1, 2 or 3 spiral ribs, usually at least lower rib nodulose. Axial sculpture of growth lines conforming to shape of outer lip sinus. Base with a rib below periphery, and a few weak riblets below. Inner lip flared outwards at base, outer lip thin with deep sinus, lip usually broken. Colour uniformly white. Operculum unknown.
Size: Up to 10 mm in length.
Distribution: Endemic to Australia: Cairns, Queensland, southwards to eastern Victoria.
Habitat: Known from 176-1550 m, most commonly from below 500 m. Moderately common.
Comparison: This is a small, very deep water species, readily identified by the nodulose ribs on the shell.
Synonymy: Turritella joannae Hedley, 1923 is a synonym
Remarks: The most common form of this species has three spiral ribs on each whorl, with the lowest one nodulose (Fig. 1), but forms also occur with only one or two ribs (Fig. 2). This is a very deep water species, originally collected by the Challenger expedition, with specimens only becoming available in quantity in the last 30 years. When Garrard discussed it in 1972 he had only eight specimens, but the Australian Museum now holds 45 lots totaling hundreds of specimens.
Fig. 1: Off Sydney, 750 m (C.371167).
Fig. 2: Off Sydney, 393 m (C.371168).
Copyright Des Beechey 2006