Family Propeamussiidae Abbott, 1954 (5 species)

Remarks: Propeamussium lucidum (Jeffreys in Wyville–Thomson, 1873) was refereed from Pernambuco (Brazil) by Smith (1885), and recently Allen (2008) recorded it as a dominant in samples from Brazil. However, Morton & Thurston (1989) suggested that "all the material attributed to P. lucidum by Smith (1885) (...) must be excluded from this species". Cyclopecten thalassinus (Dall, 1886) and Parvamussium cancellatum (E. A. Smith, 1885) are recorded from Brazil (Mikkelsen & Bieler 2007; CTFB 2024), as well as P. marmoratum (Dall, 1881) (CTFB 2024), but these occurrences need a double-check.