This is the albino form of the southern population of M. carbonaria and although somewhat more slender than typical badia, it is intermediate in width ratio between badia and carbonaria. This form has been recorded as a white variety of M. badia by Pritchard & Gatliff (1899) and Macpherson & Gabriel (1962) from Port Fairy, Victoria. We have seen further specimens from Port McDonnell and Middleton, South Australia. The form is white, inside and out, when the brown periostracum is removed, but in some intermediate specimens the sutural half of the body whorl has a broad brown band.