Onchidiids are slug-like mollusks that live in the high intertidal. They lack a shell and have tuberculate mantles. Unlike Opisthobranchs, they are relatives of the land slugs, belonging to the class Pulmonata. They may be distinguished from dorid nudibranchs by their eyes which are on the tips of their cephalic tentacles. They feed on micro-algae. The only Hawaiian species:

Peronia platei CP: Hekili Point, Maui; Nov. 19, 2007

For more information see:   The marine pulmonate addendum on this site   Marine pulmonates on the Sea Slug Forum