Moderately small to large, moderately light to solid. 30-93 mm. Specimens from shallow-water habitats in W. Australia smaller but relatively heavier than deeper subtidal specimens from eastern localities. Last whorl ventricosely conical to ovate, sometimes conoid-cylindrical or pyriform; outline slightly to strongly convex, rarely sigmoid; left side often variably concave above base. Shoulder angulate, occasionally subangulate. Spire low to high, outline straight to concave; spire height of form carmeli usually outside the range of all other variants (mean RSH 0.28). Larval shell "hooked", of 2-2.5 whorls, maximum diameter about 1.3 mm; surface with irregularly arranged minute granules (at high magnification; Kohn, 1993). First 2-5 postnuclear whorls tuberculate; in form carmeli, first 6-8 postnuclear whorls tuberculate. Teleoconch sutural ramps flat and steep to horizontal, with 2-3 increasing to 7-10 spiral grooves. Last whorl variable in surface sculpture: Often closely spaced and uniformly broad spiral ribs extending from base to shoulder; occasionally a few more widely spaced and stronger ribs at base. In largely smooth specimens, spiral ribs weak and restricted to base, followed adapically by spiral threads up to shoulder. In some populations (throughout entire range), distinctly sculptured shells intergrade with fairly smooth ones; some variants are more constant in surface sculpture, e.g., the relatively smooth form peronianus. Ground colour white, cream, pale blue, pink, or light violet; usually several of these colours merge on the same shell. Pattern of last whorl variable, consisting of 2-3 spiral bands, variably sized blotches, flames, axial streaks and lines. Pattern elements orange or brown to reddish and blackish brown. Immaculate white or pink shells intergrade with shells largely overlaid with solid dark brown, except for a central ground-colour band with brown reticulation. Additional spiral rows of orangish, reddish or blackish brown dashes vary considerably in number and arrangement; dark dashes may alternate regularly with ground-colour dashes within the rows. Colour pattern typically relatively sombre (dark brown markings on a bluish ground) in northwestern populations and often exhibiting bright, light colours (orange, pink, light violet) in populations from Southern Australia. Larval whorls white, cream, orange or brown (for development, see Kohn, 1993). Postnuclear sutural ramps variably maculated with brown radial streaks and blotches; immaculate spires intergrade with heavily blotched ones. Aperture mainly pale blue or violet variably suffused with brown, also dark brown or orange, pink or rarely white. Periostracum light brown, thin, translucent, smooth.
Animal white, mottled with pinkish grey; dorsum of foot, rostrum and siphon edged with light pink (Whitehead, pers. comm., 1988). Siphon, foot and mantle dull white or pale grey, sparsely flecked with bright white (Rottnest Id., W. Australia; Kohn, pers. observ.). Bergh (1895) reports the animal to be brown or violet, with the rostrum and siphon brighter and the sole of the foot grey (Port Jackson, NSW). Radular teeth with an adapical barb opposite a second barb; serration rather weak and terminating in a cusp; base with a distinct spur (Bergh, 1895; Peile, 1939, as C. novaehollandiae; Cotton, 1945).

C. anemone may be similar to C. cocceus, C. ardisiaceus, and C. clarus. For comparison with C. clarus, see the Discussion of that species. C. cocceus is generally smaller and tends to have a broader last whorl (RD 0.60-0.71); its shoulder is rounded to indistinct, its spire outline convex rather than straight, and its postnuclear whorls are not tuberculate. C. ardisiaceus differs in its usually broader last whorl (RD 0.65-0.73) that is distinctly smoother and has a contrasting brown anterior end. The periostracum is smooth in C. anemone but bears tufted spiral ridges in C. ardisiaceus. Diversity of suitable habitats and benthic development with reduced vagility apparently have led to a high intraspecific variability and the description of variants as different nominal taxa. Rather the variants appear to be individual forms, local forms or ecological variants of somewhat wider range. We consider the following nominal taxa to be such forms: - C. atractus (nom. nov. for C. fusiformis) (Pl. 59, Fig. 20): The holotype is a relatively high-spired, faded pale brown shell lacking any pattern. With regard to the presence of tuberculate early postnuclear whorls and the absence of a carinate shoulder, we assign it to C. anemone rather than to C. clarus. Form atractus is very similar to form carmeli. - C. carmeli: This variant (Pl. 59, Figs. 14, 15) has sometimes been considered a valid species. More often, it is erroneously referred to as C. anemone f. compressus (Wilson & Gillett, 1971 ; Walls, [1979]; Lauer & Richard, 1989), but this has been corrected by Kendrick & Ryland (1981) and Coomans et al. (1985a). Specimens described as C. carmeli have biconic shells (RD 0.57-0.75) with a spire of moderate height to high. They differ from other forms of C. anemone in spire height (mean 0.28 vs. 0.14), larger number of tuberculate postnuclear whorls (6-8), and yellowish brown aperture. Only extreme variants of C. carmeli have RD outside the range of other C. anemone variants (0.53-0.68); the mean values, however, are the same. We consider the differences from C. anemone insufficient to justify separation at species level. The form described as C. carmeli occurs from the Bass Strait (Victoria/Tasmania) westward to Ceduna (S. Australia). - C. compressus: A local form from the Houtman Abrolhos (see Kendrick & Ryland, 1981) (Pl. 59, Fig. 18). - C. maculosus: A shape and colour pattern variant occurring in various parts of the species range. - C. novaehollandiae: Considered a subspecies of C. anemone from northern W. Australia by Coomans et al. (1980) and Richard (1990). Coomans et al. cited C. a. novaehollandiae only as "with a low spire". However, the shells from the northwestern populations and the typical form of C. anemone cannot be separated by spire height (RSH 0.09-0.20 vs 0.10-0.23), nor by shape, sculpture and colour pattern. Therefore we favour the taxonomic status of a form rather than that of a geographical subspecies (Pl. 59, Fig. 19). - C. peronianus: Probably an ecological variant, growing larger, usually with a lower spire and generally brighter in colour than other forms of C. anemone (Pl. 59, Figs. 11-13). It ranges from southern W. Australia eastward to Tasmania and Sydney, New South Wales. Walls ([1979]), da Motta (1986), and Richard (1990) considered C. peronianus a valid species, but its shell morphometry characters are entirely within the range of C. anemone, and there are no constant differences in colour, number of larval whorls, or sculpture of spire and last whorl. - C. remo: A colour form ("splashed with bright orange"; Cotton, 1945) (Pl. 59, Fig. 16) from South Australia and Victoria (Cotton: Port Macdonnell to Western Port). - C. saundersi: A shape and colour pattern variant very similar to C. maculosus. - C. singletoni: A variant with a white shell (Pl. 59, Fig. 17). - C. comptus, C. flindersi, C. roseotinctus, and C. rossiteri are based on subadult specimens. C. rossiteri (holotype: L 14.5 mm) may be a juvenile of C. anemone or of C. papilliferus.

Queensland southward and westward to W. Australia, northward to King Sound; N. coast of Tasmania.
Intertidal and subtidal to about 40 m; on reefs, rock platforms, sand bottoms or rock rubble, often sheltering beneath stones, rock or boulders and among algae or eel-grass. In N. W. Australia, C. anemone is reported from the intertidal zone to 6 m, and in S.W. Australia, to approximately 30 m. Some variants from S. Australia are found even deeper: Form peronianus in 10-20 m, and form carmeli to 40 m. However, intertidal populations also occur in the southern part of the species range. Preserved material from Victoria (AMS) shows that C. anemone preys on polychaetes (also Kohn & Almasi, 1993). Egg capsules variable in size and shape: Dimensions range from 7-11 x 4-8 mm or 9-12 x 7 mm to 16-19 x 9-12 mm (Mornington Peninsula, Victoria; Jervis Bay, New South Wales), and capsule sacs are circular to rectangular in outline. Spawning takes place in sheltered sites, under rocks or stones in 1-5 m in typical form of C. anemone. Capsules are deposited in often irregular clusters and affixed to the substrate by confluent basal plates. Substrate may be hard (stone, shells) or capsules of the same spawn; some capsules may be affixed to others at various sites and in a variable orientation. Huish (1978) reports a mean number of 65 eggs per capsule and a mean egg diameter of 590 µm indicating a totally benthic development (acc. Perron & Kohn, 1985). Smith, Black & Shepherd (1935) report "large communal egg masses" with individually attached capsules of 8 x 3 mm each containing 15-60 eggs about 300-500 µm in diameter. In spite of this egg size, the hatchling is reported to be a crawling stage. At Rottnest Id., capsules contain 16-22 ovoid eggs each; egg diameter is 756-830 x 671-744 µm, and the hatchling is a veliconcha of about 1.6 mm (Kohn 1993).