Abstract
The twenty species of Scleractinia (all azooxanthellate) known to occur off Argentina and the Falkland Islands (the Atlantic component of the cold temperate Magellan Province) are discussed, 15 of which are documented by new records. Five new species are described: Caryophyllia kellerae, C. coronula, Solenosmilia australis, Flabellum cinctutum, and Javania cristata. Five geographic and nine bathymetric range extensions are also documented. A brief history of species discovery in this region is given, and a key to the species is provided.