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.     

Two new species of Metharpinia Schellenberg (Amphipoda: Phoxocephalidae) from the south-west Atlantic

Two new species, Metharpinia dentiurosoma and Metharpinia grandirama, belonging to the family Phoxocephalidae are described and illustrated from the Argentine Sea. Both taxa were collected dredging at different depths and the grain size of the sediment was determined for each sampling station. The new species share character states with Metharpinia Schellenberg, 1931 and Microphoxus Barnard, 1960, and their assignation to the first genus is discussed. Metharpinia dentiurosoma and Metharpinia grandirama are distinguished from the other known species of the genus by the dorsal hook on urosomite 3; in addition, the first species is characterized by its epimeron 3 and the second species by its uropod 2.