Acmaea achates

Acmaea achates is a species of sea snail or true limpet, a marine gastropod mollusc in the family Acmaeidae, one of the families of true limpets.

Description
The ovate shell is rather thin. It is convexly depressed, radiately densely striated with the striae here and there finely corded. The shell is intense black, irregularly variegated with lightning-marked white rays. The interior is bluish, with a broad black variegated border.

Distribution
This marine species occurs off India.