Colpospira quadrata (Donald, 1900)
Description: Protoconch 2 whorls, teleoconch 14 whorls in adult shells. Early whorls convex, latter whorls concave; suture impressed. Whorls spirally ribbed; latter whorls with 2 strong spiral ribs, one at upper quarter, one at lower quarter, concave between. Whole surface above, between and below major ribs with about 20 fine spiral threads. Axial sculpture of growth lines conforming to shape of outer lip sinus. Inner lip of aperture reflected outwards at base; outer lip thin, with a deep sinus, lip usually broken Base convex with flat threads. Colour cream or fawn, sometimes with axial brown streaks and major ribs white with brown splashes. Operculum circular, corneous.
Size: Up to 22 mm in length.
Distribution: Endemic to Australia; Sydney, NSW, southwards to SA, including Tasmania.
Habitat: Known from 9-200 m. Moderately common.
Comparison: Three species in the NSW fauna are of similar size with brown and white markings - C. sinuata, C. guillaumei, C. quadrara. C. sinuata has only fine spiral threads and the whorls are weakly convex or straight sided. C. guillaumei has broad, low ribs at top and bottom of whorls but is smooth between. C. quadrata also has ribs at top and bottom of whorls but has spiral threads between.
Remarks: This species occurs in quite shallow water, and it could be expected to occur as beach shells, but the Australian Museum collection has no beach collected specimens.
Fig. 1: Off Twofold Bay, NSW, in 91 m (C.358215).
Copyright Des Beechey 2006