Wikipedia
Lernaeodiscidae
The Lernaeodiscidae are a family of parasitic barnacles belonging to the bizarre and highly apomorphic superorder Rhizocephala, and therein to the less diverse of the two orders, the Kentrogonida. The Lernaeodiscidae are one of the smallish families of Rhizocephala, though the only one among the Kentrogonida (which otherwise contain the two larger rhizocephalan families). The family contains three genera: Lernaeodiscus Müller, 1862, Septodiscus Van Baal, 1937 and Triangulus Smith, 1906.