Two new phoxocephalids (Crustacea: Amphipoda: Phoxocephalidae) from the south-west Atlantic

A new genus and species, Parafoxiphalus longicarpus, and a new species, Metharpinia protuberantis belonging to the family Phoxocephalidae, are described from the Argentine Sea. Both taxa were collected from sandy substrata in the intertidal and subtidal regions. Parafoxiphalus longicarpus is related to Foxiphalus Barnard, 1979 and they share many characters, most of them in plesiomorphic condition. Metharpinia protuberantis is an intermediate species between Metharpinia Schellenberg, 1931 and Microphoxus Barnard, 1960, and its assignation to the first genus is discussed.