The mysterious Facetotecta are barnacle relatives represented by a single genus, Hansenocaris. These animals were first described at the end of the nineteenth century, but the adult forms have still not been identified. It is believed they are probably parasites of some sort. (Brusca and Brusca 2003) For more background on this intriguing group, see Høeg and Kolbasov (2002a,b) and Pérez-Losada et al. (2002, 2009).