Taxonomic review of _Parathyone_ Deichmann, 1957

The genus Parathyone is composed of two Caribbean species, Parathyone surinamensis and Parathyone suspecta, initially described in the genus Thyone and later transferred to the genus Ocnus. In this context, the Brazilian species Parathyone braziliensis (Verril, 1868) is circumscribed, a species widely distributed throughout the Brazilian coast, but little known taxonomically, so that its taxonomic identity and its generic position need revision. The nominal species Phyllophorus palmae is, according to some authors, a species synonymous with Parathyone surinamensis. However, the occurrence of P. surinamensis in Brazil is uncertain, since it was mentioned only in conference abstracts, with no more detailed systematic background. Parathyone suspecta and P. braziliensis share many morphological similarities, which, due to the precarious morphological characterization of both, makes their distinction very difficult. With this, several authors have questioned the validity of these species.