A new species of Diplophryxus Richardson, 1904 is described from shallow waters of Chile infesting Alpheus inca Wicksten & Méndez G., 1981. This is the ninth species described in the genus. Diplophryxus richardsonae Chopra, 1930 from India does not belong in the genus and a new genus, Micropodiphryxus, is erected for it. Diplophryxus is now known to have a circumglobal distribution in temperate and tropical latitudes infesting host shrimp in Alpheidae, Palaemonidae, and Gnathophyllidae, whereas the new genus is known only from the Andaman Islands and Kerala, India, from hosts in Crangonidae. A key to species of both genera is provided along with a summary of all records from the literature.