Abalone vary in size from 20 mm (0.8 in) (Haliotis pulcherrima) to 200 mm (8 in) while Haliotis rufescens is the largest of the genus at 12 in (30 cm).The shell of abalones is convex, rounded to oval in shape, and may be highly arched or very flattened.The shell of the majority of species has a small, flat spire and two to three whorls.The last whorl, known as the body whorl, is auriform