RECORDS OF INTERTIDAL AMPHIPODS FROM THE SOUTHWEST ATLANTIC, WITH THEDESCRIPTION OF A NEW SPECIES OF ELASMOPUS

One new species and 3 well-known species are reported from marine warm temperate waters in Argentina. Elasmopus marplatensis, new species, i s described and fully illustrated, and its relationships with other sp ecies of the genus are discussed. Corophium insidiosum Crawford is a n ew record for the area and is partially illustrated. The presence of M elita palmata (Montagu) and Ampithoe valida Smith is confirmed and bot h are figured in part. In addition, biogeographical considerations for the Southern Ocean are discussed.