Acmaea mitra

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

Taxonomy
Acmaea mitra was placed in the family Acmaeidae for many years, but based on molecular phylogeny evidence by Nakano & Ozawa (2007) Acmaeidae was synonymized with Lottiidae. However, this synonymy was subsequently found incorrect, having been the result of contaminated samples, and Acmaea mitra and a related species, Niveotectura pallida form a well-supported clade outside of the Lottiidae, and Acmaeidae was re-established.

Acmaea mitra is the type of the genus Acmaea

Description
The length of the shell varies between 12 mm and 38 mm.

Distribution
This species occurs in the Pacific Ocean between Alaska and Baja California, Mexico.