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Mitrella lincolnensis (Reeve, 1859) Description: Shell average width for genus, whorls straight sided or slightly rounded, spire straight, aperture about 1/3 of shell length. Protoconch of 2-2¼ smooth whorls. Spiral sculpture restricted to cords on base; axial sculpture absent. Aperture narrow. Outer lip sinuous in profile, with shallow sinus; lip much thickened externally; thickened internally, with 5-9 denticles decreasing in size from the uppermost. Columella callus sharp-edged in mature shells; axial ridge along edge, sometimes bearing about 5 small denticles. Siphonal canal very short. Colour of white spots on golden, fawn or tan background; spots small or large, randomly arranged, or in axial or spiral rows; spots may join together into white axial flames; sometimes a spiral tan band below suture. Brown in aperture around outer lip denticles, or whole aperture brown. Periostracum smooth. Size: Up to 13 mm in length. Distribution: Endemic to Australia; Port Stephens, NSW, around southern Australia to Abrolhos, WA. Habitat: Lives in sand among sea grass intertidally and in the shallow subtidal, in bays and estuaries. Common. Comparison: This species is similar in size to M. tayloriana, but differs in colour pattern, and also by having flat whorls, a narrow aperture, brown within the aperture, and lip denticles that decrease in size from the uppermost. In shell shape it is like M. menkeana, but is smaller and the colour and aperture features distinguish it. M. leucostoma is similar in size, but has rounded whorls and different colour patterns. Synonymy: No synonyms. Remarks: The aperture is completely brown, or there may be brown only between the denticles on the outer lip. The brown colour fades, so old shells are white or grey in the aperture. Fig. 1: Port Jackson, Sydney, NSW (C.302250) Fig. 2: Variation |
