| Diagnosis |
Shell rather thick and large (attaining 25 cm in length), subcircular in outline, with a short and ill-defined posterior ear which is not drawn out into a wing-like process. Anterior margin markedly protruding beyond the tip of anterior ear. Outer surface of valves, when not worn, with densely set, flattened, imbricating concentric scales and moderately long, parallel-sided and flattened spines with tapering or rounded ends; spines lying relatively flat on surface of valves, arranged in radial rows and often strongly projecting on shell margins. hinge completely devoid of teeth. Colour: outside of shell greyish brown or green to nearly black in ground colour, with radial stripes of white or yellowish markings corresponding to the basal portion of old flattened spines. Internal nacreous area silvery, with a darker smoky hue and a hint of red and green iridescence on border. Non-nacreous area very dark. |
