Navanax inermis, common name the California aglaja, is a species of predatory sea slug, a marine opisthobranch gastropod mollusk in the family Aglajidae and the order Cephalaspidea, the headshield slugs and bubble snails. It has been suggested that this species should be moved to the genus Aglaja, but the name Navanax is still used in many of the popular works on mollusks. Navanax is not a nudibranch, even though it somewhat resembles one; it belongs to a more ancient lineage of opisthobranchs called the cephalaspideans or head shield slugs and snails.